Deafness Ebooks Catalog

Hearing Aids Inside Out

Hearing Aids Inside Out

Have you recently experienced hearing loss? Most probably you need hearing aids, but don't know much about them. To learn everything you need to know about hearing aids, read the eBook, Hearing Aids Inside Out. The book comprises 113 pages of excellent content utterly free of technical jargon, written in simple language, and in a flowing style that can easily be read and understood by all.

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Improve Your Hearing Naturally

What You'll Find Inside Improve Your Hearing Naturally: What Supplements Vitamins and Herbs You Need To Be Taking Right Now To Stop Hearing Loss, Restore Your Hearing and Open Up Those Muffled Ears . In Fact If You Missing These Nutrients In Your Diet Your Hearing Will Continue To Decline. How To Unblock And Clean Out Years Of Built Up Toxins From Your Ears and Ear Canals Instantly Improving Your Hearing! No More Muffled Hearing, How Would You Like To Hear Out Of Both Ears Equally? - Most People Are Completely Shocked When They See What Comes Out Of Their Ear Canals. Learn The Best Natural Home Remedies For Ear Infections, Ear Blockage, Ear Aches, Ringing In The Ears (Tinnitus) And Other Ear Problems - Plus How To Properly Clean Your Ears, Safely With No Risk Of Damage. Discover What Common Drugs Every Home Has In Their Medicine Cabinet You May Be Taking That Can Permanently Damage Your Hearing - Doctors Don't Tell You This And You Need To STOP Immediately

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Prevalence of hearing impairment

Hearing impairment is undoubtedly a common disease. Around 1.06 per 1000 children are born with a significant, permanent hearing impairment (40 dB or greater increase in threshold in their better hearing ear), and by the age of nine years, this number has risen to around 1.65 per 1000 (Fortnum et al., 2001). The prevalence of hearing impairment continues to increase with each decade of life, until 40 of the 71-80 years age group and 80 of the 80+ age group have a hearing loss of 35 dB or more (Davis, 1989 Davis and Moorjani, 2002). In total, approximately 20 of all adults over 18 in the UK suffer some form of hearing impairment (25 dB or greater hearing loss in at least one ear), and the proportions for other countries are very similar (Davis and Moorjani, 2002). The increase at various impairment levels is illustrated in Figure 33.1. However, thresholds are a crude reflection of the impairment, because it is not just the amplitude but the clarity of hearing that is affected. Our...

Mechanisms of hearing impairment

Figure 33.1 Prevalence of hearing loss (HL) with age, for different severities in decibels (db). Figure 33.1 Prevalence of hearing loss (HL) with age, for different severities in decibels (db). It is frequently stated that age-related hearing loss is due to degeneration of the sensory hair cells in the organ of Corti of the cochlea. However, there is no evidence for this contention from animal studies. Rather, it appears that hair cell degeneration is a correlate or a consequence of some primary dysfunction, either of hair cells or of some other part of the auditory system. Figure 33.3 Typical audiograms of 70-80 years old, sensory type. Hearing loss (HL) is shown in decibels (db). Figure 33.3 Typical audiograms of 70-80 years old, sensory type. Hearing loss (HL) is shown in decibels (db). These sensory hair cells seem to be particularly sensitive to any disturbance of their homeostasis, resulting in their degeneration. However, findings in animal models suggest that hearing...

Environmental causes of deafness

It is well established that exposure to certain environmental factors will lead to hearing loss (e.g. Fransen et al., 2003). Excessive noise exposure is the most obvious cause of hearing loss. However, infections such as prenatal rubella or meningitis can lead to deafness. Certain drugs also have ototoxic effects, including aminoglyco-side antibiotics, cisplatin and diuretic agents. In some cases it is clear that one of these factors is the immediate cause of deafness, such as hearing impairment that develops over the few days after exposure to an ototoxic drug or after meningitis, but often it is not so obvious. For example, although many studies of noise exposure in animals have shown the deleterious effects of noise on auditory function, such experiments are impossible in humans so we are left trying to piece together a history of noise exposure long after the event. The National Study of Hearing in the UK found a small but significant effect of relatively high reported noise...

Role of genetics in deafness in the population

Many reports of clinical populations of children with permanent hearing impairment have been published, usually suggesting between a third and a half of children have a genetic etiology (e.g. Fortnum et al., 2002 Morzaria et al., 2004). However, the criteria for ascribing a genetic aetiology often are not clear many authors assume a genetic causation in the absence of any other clear cause, while others report syndromic deafness as a separate category even when it is highly likely to be due to a single gene mutation. Other reports of the role of single gene mutations in hearing impairment use a selected clinical population as the denominator. Examples of this are the reports of the frequent involvement of mutations of the GJB2 gene in deafness (in some Mediterranean populations up to 50 ) the clinical populations reported often include only those with a definitive family history suggesting autosomal recessive inheritance of severe or profound deafness, excluding the sporadic cases...

Modifiers of deafness genes

Several modifier genes have been localised that modify the phenotype of carriers of known deafness genes. In humans, a dominant modifier has been reported to suppress deafness in people homozygous for the DFNB26 recessive deafness locus (Riazuddin et al., 2000). Two modifiers have been proposed to influence the hearing loss observed in carriers of the A1555G mitochondrial mutation associated with progressive hearing loss, a locus on chromosome 8 near D8S277 and a locus on chromosome 6 near the TFB1M gene (Bykhovskaya et al., 2000 2004). In the mouse, three modifiers of deafness genes have been identified. The first is moth1, which has a major effect upon the hearing of tubby mutant homozygotes (tub tub), and has been identified as a variant of the Mtap1 gene. A second is mdfw, modifier of deaf waddler, which largely determines whether heterozygous carriers of a deaf waddler mutation (+ Atp2b2dfw2J) show progressive hearing loss or not. This modifier is most likely to be a synonymous...

A model for human hearing impairment

Age-related hearing loss is an extremely common human disease, so what have we learnt so far that might suggest the causes Does the common disease common variant model look the most likely model If we look firstly at childhood deafness, despite the large number of genes that have been identified, most families with a deaf child still have no molecular diagnosis. The gene most commonly involved in severe or profound childhood deafness is GJB2, encoding the connexin 26 molecule, a component of gap junctions thought to be important for homeostatic control within the cochlear duct. Mutations in this gene account for between 25 and 50 of cases of known recessive congenital severe or profound deafness, and about 10 of sporadic cases. There are still a large number of cases with severe or less severe hearing impairment for which no gene is known. Many of the genes known to be involved in deafness affect only a handful of families. These observations suggest that childhood deafness is...

Systemic Lupus Erythematosus

Manifestations of SLE occur through a variety of pathogenetic mechanisms. Lesional skin biopsies can demonstrate inflammation and degeneration of the dermo-epidermal junction. Granular deposits of immunoglobulins and complement components can be seen, often in a band-like pattern, under immunofluorescent microscopy. Frank vasculitis can affect small blood vessels as well. Whether otorhinolaryngeal manifestations such as autoimmune hearing loss seen in association with SLE result primarily from autoantibody-mediated events, or vasculitis, or a combination of inflammatory and immune events, is largely unknown. Some neurologic manifestations of SLE have been associated with antiphospholipid antibodies, giving rise to the possibility that pathogenesis could be linked to thrombosis.

Animal Models for AIED

Animal models have definitively demonstrated that the immune response of the inner ear can lead to reversible or permanent damage to the delicate inner ear structures. One of the first animal models for AIED was developed by Beickert who immunized guinea pigs with homologous inner ear tissue. Although the guinea pigs developed cochlear lesions, hearing loss was not demonstrated and antibodies to inner ear antigens were not identified (24). Yoo developed an animal model for AIED based on type II collagen. Rats were immunized with bovine type I and type II collagen. Rats immunized with type I collagen or with denatured collagen had no change in hearing, whereas rats immunized with type II collagen had hearing loss based on auditory brainstem recordings. High levels of antibodies to type II collagen were identified. Upon sacrifice, histologic findings were of cochlear nerve degeneration and perineural vasculitis (25). Harris developed an animal model of AIED when he immunized guinea pigs...

Complicationsprognosis

The prognosis for patients with AIED is quite variable. Part of this variability can be explained by the diverse nature of the disorder. Autoimmune injury in general can be from direct antibody injury toward specific epitopes, from immune complex deposits, or from cellmediated attacks by T cells. Depending on the cause of the autoimmune process and the speed with which it is treated, the damage to the cochlea and vestibule can be reversible or permanent. Cogan's syndrome, for example, carries a poor prognosis leading to bilateral profound hearing loss in greater than 60 of cases, even with aggressive treatment (see Complications of AIED include deafness as well as oscillopsia. Cochlear implants are an excellent choice for rehabilitation of patients with AIED who have progressed to unaidable profound bilateral hearing loss. As the autoimmune process damages the inner ear, cochlear nerve function remains intact, allowing for excellent results upon cochlear implantation. There have been...

Complications And Prognosis

Rarely, patients with chronic IK may develop progressive corneal opacification, which decreases visual acuity. Such patients may require corneal transplantation. Cataracts may also occur and require extraction. Serious posterior segment eye disease can lead to decreased visual acuity. The hearing decline is the major debilitating complication of CS. Progression to deafness is frequent and occurs in approximately 25 to 50 of patients. Many patients have benefited from a cochlear implant, which has dramatically improved their quality of life. Vestibular symptoms usually improve with time, but as many as 20 of patients may have persistent oscillopsia.

Head and Neck Manifestations

Tuberculous otitis media is rare and usually represents hematogenous spread. Roughly one-half of the cases have no other evidence of present or past TB. The classic clinical picture is painless otorrhea with multiple tympanic perforations, exuberant granulation tissue, early severe hearing loss, and mastoid bone necrosis (see Chapter 25 for further discussion of otorrhea). The finding of multiple tympanic membrane perforations is most likely TB, possibly pathognomonic. Nonetheless, the diagnosis is difficult, even when tissue is available. Tuberculous otitis may be complicated by facial nerve paralysis, which is discussed in detail in Chapter 29. Response to drug therapy is excellent, and surgery usually is not required.

Wegeners Granulomatosis

Wegener's granulomatosis is an idiopathic vasculitis of small arteries, arterioles, and capillaries primarily affecting the upper aerodigestive tract, lungs, and kidneys. Typical presentation is in middle-aged patients with a slight male predominance. Otologic manifestations are common and range from 19 to 45 of cases (103). They include conductive hearing loss, sensorineural hearing loss, otalgia, otorrhea, and serous otitis media. Neurologic involvement is frequent with nearly half of patients demonstrating either peripheral or central neuropathy (104). Cranial nerve involvement was reported in 6.5 of patients (105). When the ear is affected by the disorder, facial nerve involvement has been estimated at 5 (103,106). Injury to the facial nerve may be from destructive granulomatous lesions involving the skull base, necrotizing vasculitis, or compressive effect due to granuloma in the middle ear (107). Pathologically, the disorder is characterized by noncaseating granulomas with...

Clinical Manifestations

Start Shingles Behind Ear

Of the facial nerves, the ophthalmic division of the trigeminal nerve is most frequently affected in herpes zoster (Fig. 11), and this event can cause optic keratitis, a potential cause of blindness. The most visible sign of motor nerve involvement is facial paralysis as seen in Ramsay Hunt syndrome, a condition which is more properly described as herpes zoster cephalicus (Fig. 7). Patients affected with this condition also have palatal and laryngeal paralysis and hearing loss. Acute facial paralysis with pain and hearing loss is pathognomonic of herpes zoster infection. The diverse manifestations of VZV activation

Jugular foramen syndrome

Primary lesions of the jugular foramen include glomus jugulare tumors, schwannomas, and meningiomas. Metastatic lesions to the jugular foramen are more common than primary neoplasms (36,38-42). Glomus jugulare tumors are the most common primary neoplasms of the jugular foramen. These are vascular tumors arising from neuroectodermally derived paraganglia present at the jugular fossa, the inferior tympanic canaliculus, the promontory, and within the vagus nerve. Paraganglia are very similar histologically and embryologically to the adrenal medulla. They, along with their derivative glomus tumors (jugulare and tympanicum), are typically supplied by the inferior tympanic branch of the ascending pharyngeal artery (43) however, the blood supply to glomus tumors may be very extensive, originating from the external carotid, the internal carotid, and the vertebral arteries (44). These tumors are more common in females (6 1 female-to-male ratio) and usually present in middle age. Functional...

Scleroderma

Sensorineural hearing loss has been reported to occur, but has not been found to correlate with other disease manifestations (20,21). Virtually the entire gastrointestinal tract can be affected in scleroderma. Swallowing dysfunction due to oropharyngeal involvement can occur (22) and increase the risk of aspiration. Esophageal dysmotility and nonobstructive dysphagia are seen in the majority of patients, making symptoms of gastroesophageal reflux very common.

Summary

Systemic rheumatic disease may present with a variety of manifestations in the head and neck regions. Especially important among these are the dermatologic findings of SLE, DM, and scleroderma. Rashes characteristic of these disorders may also arise later in the course of the diseases. Some of the more frequently reported manifestations to be aware of are autoimmune hearing loss, especially in SLE esophageal dysmotility in scleroderma oropharyngeal and esophageal involvement in DM PM and keratoconjunctivitis sicca and cervical spine involvement in RA.

Definition

AIED can be defined as a fluctuating or rapidly progressing sensorineural hearing loss that is responsive to immunosuppressive therapy. Vestibular dysfunction may or may not be present. In some cases, a concurrent systemic autoimmune disorder exists at the time of diagnosis. Therefore, AIED can exist in isolation as an organ-specific disease (primary AIED) or can occur as a nonspecific injury as part of a systemic autoimmune disease (secondary AIED). Currently, there is no diagnostic laboratory test or imaging modality available to confirm the diagnosis with certainty.

Complications

About one in eight patients with herpes zoster infection has at least one complication of this condition. Major complications include postherpetic neuralgia, uveitis, motor deficits, skin infection, and systemic involvement (with manifestations such as meningoencephalitis, pneumonia, deafness, or dissemination). Postherpetic neuralgia occurs most frequently in patients older than 50 years of age and can be prolonged and intractable despite early antiviral therapy. The pain is often excruciating and does not respond well to conventional methods of pain control. Granulomatous vasculitis has recently been added to the list of complications (25).

Fibrous dysplasia

Temporal bone involvement is uncommon. The most common presentations are hearing loss (80 ), mass (26-50 ), draining ear (14-30 ), otalgia (7-10 ), and trismus (2.3-10 ) (1). A conductive hearing loss or canal cholesteatoma may result from collapse of the external auditory canal, if it is extensively involved. The otic capsule and or internal auditory canal are rarely involved. This involvement is associated with sensorineural hearing loss, which may be profound (5). Facial nerve involvement is not unusual (5-10 ).

Genetic Diseases

Congenital hearing loss is common, and about one-half of cases are thought to be genetic. Genetic hearing loss is typically classified as syndromic or nonsyndromic. When hearing loss consistently coexists with other pathologic findings, it is considered part of a syndrome when it exists in isolation, it is nonsyndromic. As our focus is on systemic diseases, nonsyndromic hearing loss, which accounts for two-thirds of hereditary hearing loss, will not be discussed extensively. Mutations in the GJB2 gene coding for connexin 26 are now thought to account for over half of the cases of nonsyndromic genetic hearing loss (1). Nearly 100 mutations have been identified, some being quite specific to individual ethnic groups. Hearing loss tends to be moderate to severe, symmetric, and nonprogressive. There are no associated temporal bone malformations, and patients tend to do well after cochlear implantation. There are more than 400 syndromes associated with sensorineural hearing loss. It is...

Medications

Many treatments have been advocated for sudden sensorineural hearing loss, which is presumed to be of viral (or rarely vascular) origin. The diagnosis of autoimmune inner-ear disease is still predicated by a documented response to corticosteroid administration (20). Treatment strategies have varied between reports, but, in general, a dose of prednisone, 40 to 60 mg in the adult for two weeks, is an appropriate therapeutic trial. Substantial improvement on this dosage regimen would then warrant a slow taper of steroids over several months with close observation for recurrence. Even prompt administration of these There are several circumstances that warrant special mention. Patients with M ni re's disease and certain forms of genetic hearing loss may manifest spontaneous fluctuations in hearing. In these situations, the administration of steroids at the onset of the hearing loss may result in a false impression that the subsequent spontaneous improvement in hearing was actually the...

Prosthetics

Hearing-aid amplification remains the mainstay of rehabilitation for patients with sensorineural hearing loss. Unfortunately, hearings aids are amplifiers, not clarifiers, and, as such, leave patients less than satisfied. Cochlear implants have revolutionized the management of patients with severe sensorineural hearing loss or deafness. They are the only prosthesis that successfully replaces sensory function. Many objective studies have proven their value in the treatment of pediatric patients' prelingual and postlingual severe-to-profound sensorineural hearing loss, and in adults with postlingual sensorineural hearing loss. Implant devices and surgical techniques have been refined since their introduction and surgical complications are rare. This remains a rapidly expanding and exciting field as software and hardware become more sophisticated and indications for use of these devices broaden.

Osteopetroses

One subtype of osteopetroses, termed sclerosteosis, has a proclivity for facial nerve involvement. It is characterized by syndactyly, conductive hearing loss, and sclerosis, and almost always has progressive recurrent facial nerve palsy (123). Attacks of facial paralysis commonly begin in childhood, are recurrent, and often alternate sides of the face. Total nerve degeneration is the rule and recovery with significant synkinesis at three to five months is the usual outcome (124).

Infection Viral

Cytomegalovirus (CMV) is a double-stranded DNA virus in the herpesvirus family. CMV presents similarly to EBV and patients are commonly misdiagnosed with mononucleosis when acutely infected. CMV is transmitted by direct contact of mucosal surfaces, blood transfusion or organ transplant, maternal breast milk consumption, and rarely by aerosolized viral particles. Symptoms predominantly include fever, lymphadenopathy, and less commonly pharyngitis. Ulceration of the pharynx or esophagus may be present in severe cases, especially in immunocompromised patients with human immunodeficiency virus (HIV). CMV infection during pregnancy may result in fetal hearing loss, visual impairment, and diminished mental and or motor capabilities.

Migraine Syndrome

Migraine Aura Fortification

Migraine is a syndrome characterized by periodic headaches. Often, however, patients experience other symptoms, including hearing loss, tinnitus, and dizziness and in some cases, these can be the only symptoms. Migraine is nearly always familial and occurs in complex patterns and settings. The association of migraine and dizziness dates back to the nineteenth century when Liveing noted their connection in his book On Megrin Sick Headaches and Some Allied Health Disorders. Overall, episodic vertigo occurs in about one-quarter of patients with migraine headaches approximately the same frequency as that of the classical migraine visual aura. In addition, patients with migraine frequently report sensitivity to motion, with bouts of carsickness in childhood and motion sickness as adults. Auditory symptoms are generally considered less common than vestibular symptoms with migraine, but phonophobia occurs in more than two-thirds of patients, usually in association with headache. Tinnitus is...

Syphilis

Other head and neck manifestations of infection include sensorineural hearing loss in otosyphilis chancres of the oral cavity in primary syphilis and pharynx in secondary syphilis laryngeal chancres mucous patches or gummata encompassing the full spectrum of stages associated with syphilitic infection and numerous effects of congenital syphilis such as palatal defects, saddle nose deformities, and congenital deafness.

Tuberculosis

The treatment of facial palsy in active tubercular otitis media or mastoiditis is controversial. Singh published a review of 43 patients to assess the role of surgery in tuberculous mastoiditis. Of the patients, 17 had facial paralysis in this study. He found that 92 of patients treated with antituberculosis medical therapy without surgery had recovery of the facial nerve, with only 80 of patients undergoing surgery (cortical mastoidectomy and removal of sequestrum) obtaining recovery. In the surgical patients, facial nerve decompression was not performed as a part of the operation. These results may reflect more severe cases being selected into the surgical group. The authors concluded that the only role for surgery is incision and drainage of a postauricular abscess or removal of sequestrum, if present and chemotherapeutic management is the treatment of choice for tubercular mastoiditis (22). Harbert in 1964 had a similar conclusion and felt that surgical intervention was...

Congenital Syphilis

Children who survive the early disease manifestations will then enter a latent phase. Late symptoms may present years to decades later. Skeletal defects from the osteo-chondritis and periostitis are quite notable, with characteristic facies consisting of a high arched palate, protruding mandible, frontal bossing, and saddle-nose deformity. Other structural defects include palatal and nasal septum perforations, anterior bowing of the lower extremities known as saber shins, and bilateral knee effusions termed Clutton's joints. Hutchinson's triad consists of eighth nerve deafness, interstitial keratitis, and peg-shaped, centrally notched, widely spaced central incisors known as Hutchinson's teeth. Congenital otosyphilis is usually more severe than that seen with acquired syphilis. It typically presents with sudden onset, profound, bilateral hearing loss with rare vestibular symptoms. Untreated, congenital syphilis frequently progresses to neurosyphilis with sequelae similar to the...

Infectious Diseases

Hearing loss is an uncommon presenting symptom of a systemic infectious disease but may develop during the course of several viral and bacterial infections. Pathogens may infect the inner ear and auditory pathways in utero, resulting in congenital syndromes that often include deafness, or infection may be acquired after birth. As the fluids of the inner ear are not easily accessible for sampling, the implication of viral pathogens as the causes of sensorineural hearing loss has often depended on circumstantial evidence, including an associated viral illness for example, an upper respiratory infection or demonstration of seroconversion during the time of hearing loss. Cytomegalovirus. Cytomegalovirus (CMV) is a large, double-stranded DNA virus belonging to the herpesvirus family. Its name is derived from the typical appearance of infected tissues, containing massively enlarged cytomegalic inclusion cells. CMV is the most common congenital infection in the world. Of babies born in the...

Examination screening specific to children

Note Formal audiological evaluation should be carried out at any time if there is clinical suspicion or parental concern. No simple screening test is very reliable for sensorineural or conductive deafness. Testes. Screen at birth, and 6-8 weeks, 6-9 months and 3 years for absence or maldescent. Those who have been treated for maldescent have a higher risk of neoplastic development in adolescence. Dental assessment fluoride. Advise daily fluoride drops or tablets, if water supply is not fluoridated. Children's teeth should be checked regularly, particularly if a school dental service is not available. Advice should be given on sugar consumption, especially night-time bottles, and tooth cleaning with fluoride toothpaste to prevent plaque.

Physical characteristics

Digits on fore- and hindlimbs fused to a mitten-like structure from which only the 3.2-3.9 in (8-10 cm) long claws protrude. These allow branches to be gripped without expending muscular force. The number of digits on the forelimb distinguish Bradypus from Choloepus sloths. They would be better named, three- and two-fingered sloths, since both have three digits on the hindlimbs. There are eight or nine neck vertebrae (most species of mammal, even giraffes, have seven). This allows the head to be turned with a considerable range, an important advantage for an animal with otherwise rather limited flexibility. The testes are internal. There are no incisors or canine teeth and the simple, peg-like incisors lack enamel. Sloths have poor hearing, but fairly good eyesight and smell.

Hyperhomocysteinaemia

Together with vitamins B12 and B6, folic acid has been shown to reduce high plasma levels of homocysteine. Of the three, folate appears to have the strongest activity (Voutilainen et al 2001). Although elevated homocysteine has been implicated as a risk factor in cardiovascular disease (including atherosclerosis and coronary artery disease), cerebrovascular disease, peripheral vascular disease and venous thromboembolism (Clarke et al 1991, den Heijer 1996, Malinow et al 1989, Selhub 1995), exudative age-related macular degeneration, noise-related hearing loss, cognitive dysfunction, and adverse pregnancy outcomes (Gok et al 2004, Nowak et al 2005), cognitive dysfunction, and adverse pregnancy outcomes (Bjorke Monsen & Ueland 2003), clinical trials are currently underway to determine the clinical relevance of this association.

Clinical Presentation

Disease at any site in the pharynx can present with dysphagia (difficulty swallowing), dysphonia (change in voice quality), otalgia (earache), cranial nerve palsies or cervical lymphadenopathy. In the nasopharynx, tumours may evoke deafness, otitis media, epistaxis (nose bleeds), nasal obstruction or palsy of cranial nerves (especially II-VI, IX, X, XII) while those in the oropharynx usually present with sore throat or dysphagia. Hypopharyngeal masses may cause dysphagia or signs of laryngeal involvement, such as hoarseness or a whistling sound during inspiration (stridor).

Segmental Duplications And 22q112 Rearrangement Disorders

Both intrachromosomal and interchromosomal unequal crossover events were found to be responsible for the 3-Mb deletion (Fig. 2) (26,38,39). This was determined by performing haplotype analysis with microsatellite markers, of three generations, the patient, parents, and grandparents. For interchromosomal events, which are more predominant (Baumer et al. 38 Siatta et al. 39 ), there should be individuals with the reciprocal duplication, dup(22)(q11.2q11.2). An analogous mechanism has been described for chromosome 17p11.2 for Smith-Magenis syndrome (SMS) (40). Indeed, interchromosomal unequal recombination events between two misaligned chromosomes 22 during meiosis resulted in a reciprocal duplication, dup(22)(q11.2)(11.2), (Fig. 2) (11,12,26). Unrelated dup(22)(q11.211.2) patients had been ascertained based on suspicion that they had VCFS DGS. Dup(22)(q11.2q11.2) disorder is associated with some clinical findings occurring in VCFS DGS, but also with other features which are distinct...

General Neurological Evaluation

A detailed neurological examination in a child is beyond the expertise of most ophthalmologists, but a few areas are of particular concern. Helpful neuro-ophthalmic localizing information can be learned by assessing the trigeminal nerve (facial sensation), facial nerve (muscles of facial expression), and the auditory nerve (hearing). As an example, an abduction deficit plus ipsilateral facial weakness is most likely caused by a lesion in the brainstem (pons). An abduction weakness plus ipsilateral hearing loss and facial pain is most likely the result of inflammation of the petrous bone (Gradenigo's syndrome). Testing motor function and sensation in the upper and lower extremities, although less helpful from an ophthalmic standpoint, should also be attempted. Such information can be useful in guiding further neurological and neuroradiologic investigation. Only by considering the ocular abnormality within the context of the entire neurological system can appropriate therapy be...

Incidence And Prevalence

Public school data on MR prevalence are not entirely reliable since intelligence tests are not administered universally and procedures for referral practices for testing and placement of children into special education vary among schools and by states, although they are all within guidelines from the U.S. Department of Education. Reports from the U.S. Department of Education include the number of children, aged 5-21, enrolled in special education programs and there are two and sometimes three programs for children with MR Educable Mental Deficiency (EMD), Trainable Mental Deficiency (TMD), and Severe Mental Deficiency (SMD). In addition, some children with multiple disabling conditions are placed in other special education programs, i.e., multiply disabled, speech and language, orthopedic, or vision or hearing impairment, and are only counted in the one program with the highest level of reimbursement to the district, leading to an undercount of MR. Federal guidelines for placement of...

Neoplastic Conditions

Endocrine Neoplasia syndrome 10 recur 10 malignant. Slowly growing painless mass may evoke neural symptoms such as hoarseness, conductive deafness or an intracranial mass effect. Characteristic histology of discrete cell nests (Zellballen) of polygonal endocrine chief cells and spindle-shaped neural sustentacular cells. Neither nuclear pleomorphism nor the presence of mitotic figures signify malignancy rather markedly infiltrative growth pattern and or metastasis required. The intimate relationship to adjacent vital structures makes wide excision impossible with recurrence likely.

Combination Ia Chemotherapy Of Recurrent Gliomas

IA chemotherapy approaches utilizing multiple IA agents or the combination of an IA agent with an oral or intravenous drug have also been extensively reported in the literature (see Table 17.4). The majority of regimens have focused on the use of IA carmustine in combination with other drugs. The initial experience was reported by West and colleagues, when they utilized a regimen of IA carmustine (100 mg m2) plus PCV for nine patients with recurrent malignant gliomas 46 . The objective response rate was 22 per cent, with a median survival of 20 weeks. Neurotoxicity was similar to that reported above for IA carmustine. Another report combined IA carmustine (100-125 mg m2), IA cisplatin (60 mg m2), and IA teniposide (VM-26 150-175 mg m2) in a series of 19 patients 68 . The response rate was 68 per cent, with another 6 per cent stabilizing while on treatment. However, the overall median TTP was only 15 weeks. The regimen was limited by retinal toxicity (19 per cent), hearing loss (5 per...

End Organ Targets and Receptors

Children with primary IGF-1 deficiency have the same phenotype as those with GH gene deletions. A boy with severe prenatal and postnatal growth failure has been described with a homozygous partial IGF-1 gene deletion (137). His growth failure was associated with bilateral sensorineural deafness, delayed motor development, and behavioral difficulties (hyperactivity and short attention span). He did not have a significant delay in bone age or hypoglycemia. An IGFBP-3 level was normal. This case suggests that IGF-1 has a role not only in GH action, but also in CNS development and function.

Toxicity Of Ia Chemotherapy

Hearing loss is a common form of toxicity in patients after IA cisplatin chemotherapy 4-7 . The deficit is often bilateral, but can be unilateral in some patients. In most studies, the incidence of symptomatic hearing loss is 5-15 per cent. However, the incidence is much higher (45-62 per cent) when serial audiometric testing is utilized 42 . Audiological testing usually demonstrates a bilateral, irreversible, dose-related loss in the 4000- to 8000-Hz frequency range. The affected frequencies are higher than what is required for conversational speech, so that most patients do not notice the deficit.

Clinical Bbbd Technique

Abnormal signal on cervical MRI has occurred in several patients treated with carboplatin-based chemotherapy with BBBD 22 . This toxicity requires immediate treatment with dexamethasone and very close observation of the patient. Carboplatin also causes high-frequency hearing loss when administered intra-arterially with BBBD 23 . This toxicity can be substantially decreased with delayed high-dose sodium thiosulfate (STS), a thiol chemo-protectant 24,25 . Additional side effects which are known to occur secondary to the chemotherapy drugs, such as nausea, fatigue, and myelosuppres-sion, occur in patients in the BBBD program. Of note, the above side effects and toxicities can often be avoided if standard BBBD patient care guidelines developed by the BBB Consortium are closely followed.

Preclinical Studies Of Thiol Chemoprotection

Chemotherapy dose intensive strategies for the treatment of malignant brain tumors necessitate minimizing CNS and systemic toxicities. Carboplatin has shown efficacy in malignant brain tumors 23 . However, carboplatin causes myelosuppression including severe thrombocytopenia, often requiring platelet transfusions and dose reductions of subsequent carboplatin treatments. In addition, when administered in conjunction with BBBD, carboplatin causes irreversible hearing loss in a large proportion of subjects 24,25 .

Clinical Evidence for Deficiencies of TCell Mediated Immunity in the Neonate

In contrast, infection in utero can have dramatic, damaging effects on an otherwise healthy fetus (Brown and Abernathy, 1998 Gandhi and Khanna, 2004). Although the majority of infected infants are asymptomatic, 5-10 will suffer severe neurologic damage including microcephaly, seizures, deafness, and retardation. Additional infants will appear asymptomatic at birth but will progress to have significant hearing loss. Infection acquired after birth is usually asymptomatic, but interestingly both congenital infection and post-natal infection through the pre-school years result in prolonged shedding of the virus, while in adults such continuous shedding after primary CMV infection is limited to approximately 6 months after acquisition. This indicates an inability of the neonatal and infant immune system to control the virus compared to the immunocompetent adult (Stagno, 1983).

The Pneumococcal Cell Surface

This family of pneumococcal surface proteins are anchored to the cell wall by covalent linkage to peptidoglycan via a carboxy-terminal motif, LPXTG. This motif is recognized by a sortase enzyme, which links the threonine residue of the motif to the cell wall. Analysis of the pneumococal genome sequence (Tettelin et al., 2001) reveals a family of these proteins including hyaluronidase and neur-aminidase enzymes. Hyaluronidase breaks down the hyaluronic acid component of mammalian connective tissue and extracellular matrix and is secreted by 99 of clinical isolates of pneumococcus (Humphrey, 1948). Deletion of the hyaluronidase gene alone does not affect virulence in a mouse model of infection but deletion of hyaluronidase in a pneumolysin-negative background reduces the virulence of the pneumolysin-negative mutant (Berry and Paton, 2000). Neuramindase cleaves N-acetylneuraminic acid from glycolipids, lipoproteins and oligosaccharides on cell surfaces and in body fluids (Camara et al.,...

Ion Channelrelated Diseases

Are defects in cardiac K+ channels that occur in only 1 in 15,000 individuals and result in cardiac arrhythmia and sudden death. However, understanding long-QT may lead to improved therapeutic strategies for ventricular arrhythmia, a more common cause of sudden death 25 . Other diseases associated with channel defects include deafness and hyperinsulinemia 26 (K+), cystic fibrosis 27 and myopathies 28 (CP), hereditary hypertension 29 and periodic paralysis 30 (Na+), and malignant hyperthermia 31 (Ca++) and congenital myasthenic syndrome (nAChR) 32 . It is likely that the number of ion channels as drug targets will continue to grow as channel function and dysfunction are better understood.

Clinical Considerations

Alport syndrome (hereditary nephritis) is a genetic defect involving the absence of type IV collagen. It results in renal failure and deafness because type IV collagen is an integral component of both the glomerular basal lamina and the tectorial membrane of the inner ear.

Treacher Collins Syndrome

It so happens that it was in the same year that Mendel's research came to light, in 1900, that E. Treacher Collins described the essential features of the syndrome which is today known by his name. Treacher Collins Syndrome has clinical manifestations that include abnormalities of the ears with hearing loss, anomalies of the facial bones and cleft palate. The 'Identification of the complete coding sequence and genomic organization of the Treacher Collins Syndrome gene' has recently been reported by a team based at the University of Manchester (Dixon et al., 1997). In their article, the authors report isolating the complete nucleotide sequence of the TCS gene, referred to as TCOF1, and the derived amino acid sequence of its predicted protein product, known as Treacle. They explain that in their research they turned to the use of a number of bioinformatics programs

Rocky Mountain Spotted Fever Rmsf

RMSF is an acute febrile systemic tick illness with significant mortality caused by the organism Rickettsia rickettsii. The infection is most commonly seen in the southeast United States. The incubation period is between 2 and 14 days. The symptoms are nonspecific, with fever, severe headache, myalgias, prostration, and nausea vomiting. The characteristic maculopapular rash usually appears on the fourth febrile day on the wrists, ankles, palms, soles, and forearms. A vasculitis may develop that can cause hypotension, edema, and petechiae. Specific organ involvement includes cardiac (car-diomegaly, myocarditis, EKG changes), pulmonary involvement (interstitial pneumonitis), and neurologic (mild headache to lethargy, seizures, coma, transient deafness, tremor, rigidity, paralysis, ataxia, aphasia, blindness). The initial diagnosis is often made clinically. Confirmation is obtained by serology, skin biopsy, or direct isolation and identification of the organism. Treatment is with...

Lessons from other monogenic syndromes

Tissues and systems) which can result in T2D. One of the most instructive of these syndromes (although not strictly a monogenic condition) is that associated with a mutation at position 3243 in the mitochondrial genome, within the gene encoding the non-nuclear form of tRNA (leucine). Depending on the tissue load of the abnormal mitochondrial sequence in any given individual, this mutation can result in either MELAS (a neurological syndrome characterized by Myalgic Encephalopathy, Lactic Acidosis and Stroke-like episodes) or Maternally-Inherited Diabetes and Deafness (MIDD) (Kadowaki et al., 1994). The molecular mechanism here is thought to be one of disrupted mitochondrial metabolism, resulting in reduced oxidative phosphorylation, and ATP depletion. In the beta-cell this compromises glucose-stimulated insulin secretion.

Special Considerations For Aging Colonies

Aging results in the progressive decline of the cardiovascular system, characterized in part by an increase in wall thickness of the ventricles. Aged rodents experience ventricular hypertrophy associated with an excess accumulation of collagen.47 Systemic mitochondrial dysfunction will frequently compromise muscle and cardiac function. Therefore, it is useful to evaluate mitochondrial physiology and cardiac function. Many neurological deficits associated with aging are subtle and not grossly observable, especially learning and memory deficits. The Morris water task is presently the most frequently used paradigm to evaluate learning and memory abilities in genetically engineered mice.22 Aged C57BL 6 mice show impairments in performance on this task.48 Additional neurological assessments for locomotor function include open field activity and rotarod procedures.49 Hearing is another neurosensory mechanism that exhibits an age-associated decline. The auditory-evoked brainstem response...

Evolution Of The Ear And Hearing

Some but not all of these systems involve similar hair cell mechanosensory mechanisms. The near ubiquity of the sensory hair cell in vertebrate ears and the lateral line suggests that it arose early in the evolution of hearing, pressure, or vibration detection. Specialization in form and function, however, suggests that the hair cell has adapted to the specific needs of a variety of vertebrates (Fay and Popper 2000). If precedent (and the results of mouse deafness studies) is a guide, different genetic mechanisms will be found even among animals having very similar physical phenotypes.

Methodological Issues

In reviewing the preceding literature, a number of methodological procedures suggest themselves for future research on aging and auditory scene analysis. First, and somewhat obvious, it is essential that participants be screened for hearing impairment in both ears. In particular, the integrity of the cochlea should be assessed in a more comprehensive way than just measuring pure tone thresholds in an effort to dissociate nonthreshold-changing peripheral deficits from true central deficits in auditory processing. One test that could provide some information is a distortion-product otoacoustic emission (OAE). Although outer hair cells must be functioning to some degree in order to measure normal thresholds, OAEs are a more sensitive measure of outer hair cell health than pure-tone audiometry and may prove useful in assessing cochlear damage in general. Another potentially useful test would be fine-scale audiometry, which consists of obtaining thresholds with a greater degree of...

Pagets disease of bone

Paget's disease of bone (PDB) is one of the most common chronic skeletal diseases affecting up to 3 of many White populations over the age of 60 years. Its ethnic and geographic distribution is variable, with a high prevalence in Whites from the United Kingdom, Australia, North America and Western Europe. PDB is characterized by focal areas of increased bone resorption and formation, leading to deformity and or enlargement. The axial skeleton (pelvis, lumbar and thoracic spine, and sacrum) is most frequently involved, followed by the femur, skull, and tibia. The newly formed bone in pagetic lesions is disorganized, frequently resulting in bowing and increased fracture. Bony overgrowth in the skull may lead to nerve entrapment, headache, and deafness.

Familial expansile osteolysis

Familial expansile osteolysis (FEO) is characterized by focal regions of increased bone remodeling resembling those seen in adult PDB. There is increased activity of osteoclasts and osteoblasts leading to expansion, deformity and increased risk of fracture. Although PDB and FEO have histologic and phenotypic similarities, they are sufficiently different to be considered separate diseases. FEO begins in the second decade, tends to be more severe, and the bone lesions are predominantly peripheral. Pain is prominent with increased medullary expansion leading to deformity and increased risk of fracture. Many affected individuals have early onset deafness and loss of dentition. FEO has been mapped to the TNFRSF11A gene which encodes RANK, where two different tandem duplications in exon 1 encoding the signal peptide have beeen found in several families (Hughes et al., 2000). Signal peptide cleavage is defective, leading to intracel-lular accumulation of RANK and increased

Craniometaphyseal dysplasia

Craniometaphyseal dysplasia (CMD) is characterized by metaphyseal dysplasia with sclerosis and hyperostosis of cranial bones. CMD is usually autosomal dominant, although autosomal recessive inheritance has been reported. The long bones have broadened metaphyses and develop an ''Erlenmeyer flask'' appearance. Hyperostosis of calvarial and facial bones leads to nasal obstruction, compression of the cranial nerves, and hypertelorism. Much of the disability associated with CMD is due to facial nerve palsy and hearing loss secondary to nerve compression. Linkage between autosomal dominant CMD and chromosome 5p15.2-p14.1 has been established in three kindreds (Chandler et al., 2001 Nurnberg et al., 1997). Studies of the positional candidate gene, ANKH, have revealed several missense mutations, deletions and insertions (Nurnberg et al., 2001 Reichenberger et al., 2001). ANKH encodes a transmembrane protein (ANKH) expressed in osteoblasts that transports inorganic pyrophosphate (PPi) (Figure...

Clinical Features and Natural History

Elevated CSF protein deafness vestibular dysfunction cerebellar ataxia descending myopathy of face and limbs mild corticospinal tract signs subnormal intelligence demyelinating polyradiculopathy slowed electroencephalogram decreased ventilatory drive sudden death spongiform degeneration of cerebrum and brainstem

Physical Psychological And Socioeconomic Sequelae

The main difficulties faced by former child soldiers and those trying to help them are limited healthcare access and social stigma. Local hospitals do not have the equipment or the medications to provide adequate treatment, and as a result many child soldiers go without medical attention for long periods of time. Common combat-related injuries include hearing loss, blindness, and limb amputations, usually from landmines or grenades. Prostheses are in high demand because so many amputees are still growing and need frequent replacements. Sexually transmitted diseases (STDs), malaria, skin and respiratory diseases, malnutrition, bone deformation from carrying heavy loads, as well as drug and alcohol addiction are widespread.

Effects on Medium Term Outcomes

Dispose to recurrent AOM, cause hearing impairment and may result in surgical interventions such as tympanostomy tube placement. However, in the Cochrane review, antibiotics had no statistically significant effect in reducing persistent effusion as measured by tympanometry 1-3 months after the acute infection (Figure 19.3). However audiometry was only performed in two studies, neither of which found significant differences between groups. The Cochrane review found no effect on perforation in the two studies which had assessed this outcome.

Scope Of Ethical Issues Addressed In This Chapter

G, a 79-year-old widowed, white woman, has been admitted to the short-stay unit of a comprehensive geriatric health care center after discharge from the hospital for hip replacement. She has been discharged to the short-stay unit as part of a contract arrangement between the hospital and the geriatric health care center. Her care plan includes postsurgical follow-up, physical therapy, and planning for the future. Her medical problems include mild heart failure and moderate visual impairment, secondary to macular degeneration. She also has moderate right-side hearing loss. Her poor eyesight contributed to the fall that resulted in her broken hip. This fall occurred at home, where Mrs. G lives alone. She has lived in this home for 50 years and alone in this home since her husband died 10 years ago. She has three children, her oldest, a son, and two daughters, all of whom are married with children of their own. She is closest to her youngest child, who is 49 and has three teenage...

Genetic Heterogeneity

For example, nearly 200 forms of hereditary deafness are known, each due to impaired actions of a different gene. The eleven types of clotting disorders reflect the many protein factors and enzymes that control this process. Any of several genes may also cause cleft palate, albinism, diabetes insipidus, colon cancer, and breast cancer.

Specific language impairment SLI

SLI is estimated to affect 2-7 of pre-primary school children and is diagnosed if significant language deficits are present despite adequate educational opportunity and normal nonverbal intelligence (Law etal., 1998). Alternative diagnoses of medical and developmental disorders such as deafness and autism must be excluded before a diagnosis of SLI is given. Features such as the orofacial dyspraxia found in the KE family would exclude a diagnosis of SLI. A continuum of language impairment exists, depending on the level of articulation and verbal expression, the ability to produce speech sounds, and verbal comprehension of others. SLI has been classified into subtypes, but it is possible that the variability seen in the phenotype reflects severity of impairment and the developmental stage of the child rather than an expression of specific deficits. Early evidence from a longitudinal study of language-impaired twins found that the majority (65.9 ) of individuals diagnosed with early...

Cochlear Physiological Potentials

Willott and coworkers were the first to systematically investigate changes in tonotopic or cochleotopic organizations of brainstem auditory nuclei as the high-frequency hearing loss characteristic of presbycusis progresses in mice (Willott et al., 1985, 1988a, b Willott, 1986, 1991). Tonotopic or cochleotopic organization refers to the fact that the major cell groups, or nuclei, of the brainstem auditory system have frequency organizations that originate in the cochlear spiral, where high frequency nerve cells are in one location, then middle frequency, then low frequency nerve cells in another, much like the keys on a piano. Tonotopically organized nerve cell pathways connect the cochlea to the cochlear nucleus, the first major nucleus of the central auditory system, and these pathways continue in an organized manner up through the auditory cortex, with sound information being processed at each step along the way. In aging, when the basal portions of the cochlea lose a significant...

With Many Different Genetic Abnormalities Conclusion From Animal Models

Congenital neuromuscular disorders of the gut are commonly encountered during the neonatal period. These conditions include, in addition to Hirschsprung's disease (long and short segment varieties), the allied disorders, hypoganglionosis, neuronal intestinal dysplasias (hyper-ganglionosis), ganglion cell immaturity, and dysgangli-onoses. There are also additional defects such as hyper-trophic pyloric stenosis, volvulus, and intussusception, that may also involve abnormalities of the development of the ENS. Hirschsprung's disease is quite common and occurs in up to 1 in 5,000 live births 267 . In some patients, Hirschsprung's disease has been shown to be associated with loss-of-function mutations in the RET pro-tooncogene 267-271 . Only a small minority of patients with Hirschsprung's disease can be accounted for by RET mutations 267-269 . Both long and short segment Hirschsprung's disease can occur in patients with identical Ret abnormalities and patients may also exhibit other...

Genes and environment

Some cases of hearing impairment result primarily from a single gene mutation inherited in a Mendelian fashion, and other cases are the consequence of a known environmental insult such as meningitis or cisplatin administration. However, in many (maybe most) cases, both the genome of an individual and the environment interact to lead to deafness. For example, not all cases of meningitis lead to hearing loss, and people working in the same noisy environment do not all develop the same degree of hearing impairment, and the genetic susceptibility of the individuals probably accounts for these differences. We already know one mutation, A1555G in the mitochondrial genome, which makes carriers especially sensitive to aminoglycoside-induced hearing loss. This same mutation is associated with age-related progressive hearing loss in some families, irrespective of exposure to any drug. Gene variants that make carriers more susceptible to noise-induced deafness are difficult to find in humans,...

Secondary Malignancies

Audiometry assessment of a patient after cisplatin-based chemotherapy, demonstrating bilateral hearing impairment, most notably at higher frequencies. O right ear X left ear. Figure 28-5. Audiometry assessment of a patient after cisplatin-based chemotherapy, demonstrating bilateral hearing impairment, most notably at higher frequencies. O right ear X left ear.

Body Proportions At Different Ages

Development Fetus Month Month

The virus that causes rubella (German measles) is a powerful teratogen. Australian physicians first noted its effects in 1941, and a rubella epidemic in the United States in the early 1960s caused 20,000 birth defects and 30,000 stillbirths. Exposure in the first trimester leads to cataracts, deafness, and heart defects, and later exposure causes learning disabilities, speech and hearing problems, and type I diabetes mellitus. Widespread vaccination has slashed the incidence of this congenital rubella syndrome, and today it occurs only where people are not vaccinated.

Procedure Bhearing Tests

Rinnes And Weber Test

This test is done to assess possible conduction deafness by comparing bone and air conduction. To conduct this test, follow these steps b. Place the end of the fork's handle against the subject's mastoid process behind one ear. Have the prongs of the fork pointed downward and away from the ear, and be sure nothing is touching them. (See fig. 33.5a.) The sound sensation is that of bone conduction. If no sound is experienced, nerve deafness exists. If hearing is normal, the sound (from air conduction) will be heard again if there is conductive impairment, the sound will not be heard. Conductive impairment involves outer or middle ear defects. Hearing aids can improve hearing for conductive deafness because bone conduction transmits the sound into the inner ear. Surgery could possibly correct this type of defect. 4. Weber test. This test is used to distinguish possible conduction or sensory deafness. To conduct this test, follow these steps deafness exists, the sound will be...

Clinical Correlations

The organ of Corti may be damaged by exposure to rubella virus, especially during weeks 7 and 8 of development. C. Atresia of the external auditory meatus results from failure of the meatal plug to canalize this results in conduction deafness and is usually associated with first arch syndrome. D. Congenital cholesteatoma (epidermoid cyst) is a frequent cause of conduction deafness. This cyst is a benign tumor that is found in the middle ear cavity it is thought to develop from epidermoid thickenings of endodermal lining cells.

Examine the cranial nerves

Perform Rinne's test (512 Hz vibrating tuning fork placed on mastoid process and its loudness compared with sound several centimetres from the external auditory meatus. Normally air conduction AC is better than bone conduction BC . BC > AC suggests conductive deafness. Impaired hearing and AC > BC suggests sensorineural deafness.) Perform Weber's test (512Hz vibrating tuning fork placed in middle of forehead and the patient asked which side the sound localizes to. Normally it is heard centrally in conductive deafness it is localized to the poor ear and in sensorineural deafness it is localized to the good ear).

Auditory Nerve Pathways

Equilibrium Pathway Ear

The cochlear branches of the vestibulocochlear nerves enter the auditory nerve pathways that extend into the medulla oblongata and proceed through the midbrain to the thalamus. From there they pass into the auditory cortices of the temporal lobes of the cerebrum, where they are interpreted. On the way, some of these fibers cross over, so that impulses arising from each ear are interpreted on both sides of the brain. Consequently, damage to a temporal lobe on one side of the brain is not necessarily accompanied by complete hearing loss in the ear on that side (fig. 12.17). Table 12.4 summarizes the pathway of vibrations through the parts of the middle and inner ears. Clinical Application 12.4 examines types of hearing loss. On the decibel scale, a whisper has an intensity of about 40 dB, normal conversation measures 60-70 dB, and heavy traffic produces about 80 dB. A sound of 120 dB, such as that commonly produced by the amplified sound at a rock concert, produces discomfort, and a...

Van Buchems disease and sclerosteosis

Van Buchem's disease and sclerosteosis have very similar phenotypes with large increases in the amount of bone tissue (Janssens and Van Hul, 2002). Van Buchem's disease usually begins during puberty, with osteosclerosis of the skull, mandible, clavicles, ribs, and long bone diaphyses. In scle-rosteosis mainly the skull and mandible are affected, although osteosclerosis and hyperostosis can be more generalized. In both disorders optic atrophy and deafness can occur secondary to bone encroachment on nerves. Facial paralysis is common in sclerosteosis, and may be present at birth or develop shortly thereafter. Sclerosteosis tends to be more severe, and excess height and weight (gigantism) and syndactyly are found in most patients. In a cohort of South Africans followed over a 38-year period, almost half died during the course of the survey (mean age of 33 years), usually from increased intracranial pressure (Hamersma et al., 2003). The gene(s) responsible for van Buchem's disease and...

Challenge Questions

Several families have been described that exhibit vision problems, muscle weakness, and deafness. This disorder is inherited as an autosomal dominant trait and the disease-causing gene has been mapped to chromosome 10 in the nucleus. Analysis of the mtDNA from affected persons in these families reveals that large numbers of their mitochondrial genomes possess deletions of varying length. Different members of the same family and even different mitochondria from the same person possess deletions of different sizes so the underlying defect appears to be a tendency for the mtDNA of affected persons to have deletions. Propose an explanation for how a mutation in a nuclear gene might lead to deletions in mtDNA.

Medicolegal Forms With Legal Analysis P-47

Related Terms Familial amyloidosis (multiple forms, including familial Mediterranean fever and familial amyloid nephropathy with urticaria and deafness hereditary cerebral angiopathies) idiopathic or primary amyloidosis (AL protein) (1) localized or isolated amyloidosis (amyloid in islets of Langerhans and insulinoma congophil cerebral angiopathy * isolated atrial amyloid medullary carcinoma of thyroid) reactive or secondary amyloidosis (AA protein) systemic senile amyloidosis.

Radiation Oncology Nurse

Radiation therapy provides an important role in the management of HGG. Nursing care provided by the radiation oncology nurse begins at the initial consult visit and continues into the early post-radiation phase. Patients and families must be educated regarding treatment schedules and expected effects and side effects. Options available to patients include conventional regional radiation, whole brain radiation, stereotactic radiosurgery such as gamma knife or photon beam, brachytherapy, and hyperthermia (31). It is often difficult to assess if symptoms are being caused by the radiation therapy itself, tumor growth, or other concurrent therapies. Acute symptoms occur within the first few weeks to months and are usually self-limiting. These include nausea but rarely vomiting, anorexia, impaired taste, fatigue, increased seizures, increased neurologic deficits, skin changes, hair loss, and impaired wound healing. Some patients whose radiation fields lie near the ear can experience hearing...

Case 2

A 43-year-old woman was reported who was referred for evaluation because of minor facial anomalies, myopathy, sterility, short stature, hearing loss, downward slant of palpebral fissures, bilateral ptosis, severe micro retrognathia, high arched palate, and scoliosis (Chen et al., 1999). Cytogenetic analyses showed the presence of one i(1p) and one i(1q) without normal chromosome 1 homologues. Fluorescence in situ hybridization analysis showed hybridization to only two chromosomes, consistent with the G-banded interpretation of i(1p) and i(1q). Molecular investigations using markers for chromosome 1 showed inheritance of only one set of paternal alleles and absence of any maternal alleles in the patient. The authors concluded that the adverse phenotype of the patient may be due to

Policy Matters

Some individuals worry, for example, that ''artificially'' extending human lives would cheapen our existence, whereas others point out that the modern medical enterprise has already drastically increased lifespans with no ill effects on society. Other subjects that the site has explored include the paucity of older people included in clinical trials the wisdom of using human growth hormone to combat symptoms of aging despite data suggesting that the substance curtails lifespan and how we might improve our flu-combating measures. It has discussed nanotech-nology, hormone replacement therapy, guidelines for keeping bones strong, and chronic pain, as well as age-related voice changes and hearing loss. SAGE Crossroads ponders such topics in News and Views articles as well as through Webcasts in which experts debate and discuss such matters.

Analyzing Pedigrees

An important technique used by geneticists to study human inheritance is the pedigree. A pedigree is a pictorial representation of a family history, essentially a family tree that outlines the inheritance of one or more characteristics. The symbols commonly used in pedigrees are summarized in i Figure 6.2. The pedigree shown in I Figure 6.3a illustrates a family with Waardenburg syndrome, an autosomal dominant type of deafness that may be accompanied by fair skin, a white forelock, and visual problems ( FIGURE 6.3b). Males in a pedigree are represented by squares, females by circles. A horizontal line drawn between two symbols representing a man and a woman indicates a mating children are connected to their parents by vertical lines extending below the parents. Persons who exhibit the trait of interest are represented by filled circles and squares in the pedigree of Figure 6.3a, the filled symbols represent members of the family who have Waardenburg syndrome. Unaffected persons are...

Lassa Fever

Meningitis, cerebellar syndrome, pericarditis, uveitis and orchitis. A characteristic feature of Lassa fever, unrelated to the severity of the acute illness, is a unilateral or bilateral sensorineural deafness that occurs in one third of patients, typically during early convalescence, and which is permanent in up to a third of those affected by this complication.

Ginkgo biloba

Controlled studies suggest that administration of Ginkgo biloba (GB) extract has limited effectiveness in improving memory and cognition, either in elderly subjects with dementia or healthy subjects. GB administration does seem to reverse sudden hearing loss in patients with mild cases of this disorder. Additionally, GB administration may blunt the rise in blood pressure in response to stress and may blunt the glycemic response after an oral glucose tolerance test. Despite the lack of evidence of effects on coagulation in vivo, a number of case reports of excessive bleeding in patients taking GB have been reported. Finally, GB does not appear to be prone to causing drug interactions, except for agents metabolized by cytochrome P450 2C19 (in which case, induction is observed).

Effects of neglect

Ods, the child's development will not follow the normal Z and usual pattern. Common physical and psychological gl reactions to neglect include stunted growth, chronic med- ct ical problems, inadequate bone and muscle growth, and lack of neurological development that negatively affects normal brain functioning and information processing. Processing problems may often make it difficult for children to understand directions, may negatively impact the child's ability to understand social relationships, or may make completion of some academic tasks impossible without assistance or intervention from others. Lack of adequate medical care may result in long-term health problems or impairments such as hearing loss from untreated ear infections.

CDK46D cyclins

Neither p18INK4C- nor p19INK4D-null mice develop tumors and neither are susceptible to tumor formation upon carcinogen treatment 41,42 . However, p19INK4D-null mice exhibit progressive hearing loss while widespread hyperplasia and organomegaly are observed in mice lacking p18INK4C 42,43 . Closer examination of the p18INK4C-null mice identified slow-growing intermediate lobe pituitary tumors later in life. The hyperproliferative effects of p18INK4C loss could be canceled in p18INK4C CDK4 mutant mice and suggests that p18INK4C is functionally dependent on CDK4 43 .

Delusional Disorders

Delusions sometimes form part of the symptom picture in schizophrenia, particularly in younger patients, but delusions without schizophrenia are more common. The frequency of delusional disorders tends to increase with age, being exceeded only by dementia and depression in older adults. The delusions of older patients are often accompanied by a chronic hearing loss, which makes it difficult for them to understand what other people are saying and invites suspiciousness, and by cognitive disturbances, as in Alzheimer's disease. Older loners who have lived most of their lives in relative isolation from other people are more likely to be delusional than individuals with normal social interactions (Berger & Zarit, 1978).

Coloring

One of the first signs of domestication is variability of color. The individuals all have white spots or all white or all black. It is interesting that white coloring is usually connected with lower performance (there are few white racing horses and even fewer winners) or with different defects (white noble cats have a high incidence of deafness).

Clinical Overview

Physical manifestations of WBS usually include involvement of the cardiovascular system, most often as a narrowing of the ascending aorta (SVAS) although a generalized arteriopathy can lead to vascular stenoses in other vessels, and hypertension is common in later life. Stellate irides, flat nasal bridge, short, up-turned nose with anteverted nostrils, long philtrum, full lips and lower cheeks, and a small chin are the recognizable facial features. Other symptoms include hernias, visual impairment, hypersensitivity to sound, chronic otitis media, malocclusion, small or missing teeth, renal anomalies, constipation, vomiting, growth deficiency, infantile hypercalcemia, musculoskeletal abnormalities, and a hoarse voice (11,12). As WBS individuals grow older they may also present with premature graying of the hair, diabetes and impaired glucose tolerance, decreased bone mineral density, sensorineural hearing loss, and a high frequency of psychiatric symptoms (13).

Clinical Features

Lassa Fever does not have a pronounced hemorrhagic component (17 ), and neurological impairment is rare except for sensorineural deafness (the most common cause of deafness in West Africa). On the other hand, Bolivian Hemorrhagic Fever has neurological impairment as a prominent feature (headache, tremor, encephalitis).

Down Syndrome

Adults with DS show a variety of age-related changes in physical and functional capacities suggestive of premature or accelerated aging (Martin, 1978), including changes in skin tone, hypogonadism, increased frequency of cataracts, increased frequency of hearing loss, hypothyroidism, seizures,

Long Term Toxicity

There are relatively few data on the long-term toxicity of high-dose chemotherapy for brain tumors. Furthermore it is difficult to differentiate the consequences of high-dose chemotherapy from those of the other components of therapy or from the brain tumors themselves. However, hearing loss has been reported in about half of children who received carboplatin-containing conditioning regimens 36 . Neurological and intellectual functions in children who received high-dose chemotherapy but not

Late syphilis

Late syphilis should be excluded in any patient with aortic incompetence or dilatation of the ascending arch of the aorta. Syphilis should be excluded as the cause of dementia, personality change, multifocal neurological disorders, nerve deafness, pupillary abnormalities, retinal disease or uveitis.

Prenatal infections

Rubella, if contracted by a woman during the first trimester of pregnancy, can cause LD, deafness, cataract and cardiac lesions in the child. Such cases are preventable by vaccination of girls who have not developed natural immunity to rubella in childhood. Congenital syphilis, now rare, causes LD, deafness, keratitis, and malformed teeth, and general paralysis of the insane (GPI) develops in adolescence. Serological tests may be negative. It can be prevented by screening pregnant women and giving antisyphilitic treatment if required.

Auditory Assessment

Exposure to an augmented acoustic environment (AAE) can be used to assess the amount of hearing loss evident in transgenic mice as compared to control mice. In AAE, mice are exposed beginning at approximately four weeks of age to a 70 dB SPL broadband noise. Exposure should be for at least 12 h per night and should continue for no less than 30 days sequentially. After AAE exposure, auditory performance is measured using one or more of several tests.32

Deletion 17p

Features include digital anomalies such as broad short hands, hearing loss, deep voice, and cardiac and genital anomalies. Ophthalmic features include up- or downward slanting of the palpebral fissures, strabismus, Brushfield spots of the iris, synophrys, and colobomatous microphthalmia.207-260,328,339

Inv Dup22

A proportion of CES chromosomes have one or two copies of the DGS VCFS region in additional to four copies of the CES region. Duplications of the DGS VCFS region have been associated recently with variable symptoms including learning disabilities, cognitive and behavioral abnormalities, palate defects, hearing loss, heart defects, growth deficiency, developmental and motor delays, and urogenital anomalies (56). This likely represents only a spectrum of the microduplication 22q11.2 syndrome, because the patients were ascertained during testing specific for the DGS VCFS deletion. In any case, one would assume that the addition of extra copies of the DGS VCFS region would worsen the phenotype of CES, but this has not been observed. However, because only 10 CES patients have been characterized in this way (9), this lack of correlation is likely to be because of the extreme variability of the overall syndrome masking more subtle changes brought on by additional copies of the DGS VCFS

Deletion 18q

Narrow or atretic canal and hearing loss. Cardiac and genitourinary malformations are common. The fingers taper markedly with a high frequency of whorl patterns, and simian creases may be evident. Toes have abnormal placement with the third toe placed above the second and fourth. Dimples may be evident on knuckles, knees, elbows, and shoulders. Ophthalmic abnormalities include epicanthus, hypertelorism, downward slanting of the palpebral fissures, nystagmus, strabismus, corneal abnormalities, cataracts, blue sclerae, dys-plastic or atrophic optic nerve heads, and colobomatous

Postnatal Infections

Hemophilus influenzae type b (HiB), an invasive bacterium that can cause meningitis, was one of the most significant infectious causes of MR, deafness, and death in the United States from 1980 to the mid-1990s. The peak incidence, 150 100,000 per year, was in 1986 among children 6-7 months of age. Since 1991 the conjugate vaccine has been available for

Treatments

There are no treatments available, only two main types of prosthesis. First is the hearing aid, which amplifies incoming sounds and can be adjusted to amplify certain frequencies more than others to match the pattern of hearing loss of an individual, and to match the limited dynamic range of the damaged ear to avoid painfully loud sounds being delivered. However, there is much to be learnt about how we use the temporal and frequency cues in speech and other sounds in order to improve programming of hearing aids to facilitate use of these cues. The threshold for provision of a hearing aid is often considered to be around 25 dB hearing level, although many people are not fitted with an aid until their hearing is much worse than this (Davis and Moorjani, 2002). Second is the cochlear implant, which involves surgery to place an extended array of electrodes within the cochlear duct and a subcutaneous receiver for detecting the coded stimulation and transmitting to the electrode array. This...

Neurotoxicity

The ototoxicity associated with cisplatin is high-frequency hearing loss and is related to the cumulative dose and rate of infusion.32,33 It occurs in 20 to 40 of patients.15 Older age, serum creatinine level > 1.5 mg dL, cumulative doses of cisplatin, and preexisting hearing impairment are predictive for oto-toxicity (Figure 28-5). Although there may be some improvement over months to years, recovery to normal hearing is rare if a clinical or symptomatic hearing deficit is noted by a patient. When higher single doses of cisplatin are used, up to 60 of patients may exhibit occult audiometric changes.14

Pagets disease

This disorganized remodelling of particular areas of bone can present with abnormal shape and enlargement of bones such as the tibia or the skull. This can produce pain, deformity or be recognized as a cause of a raised alkaline phosphat-ase. Rarely, it produces cranial nerve palsies and, for example, deafness. Very rarely (if ever) Paget's disease is a cause of high output cardiac failure or it can undergo sar-comatous change. It may have a prevalence of > 3 in people over 55 years of age, but the vast majority of people with the disease are asymptomatic.

Acknowledgements

Supported by the Wellcome Trust, MRC, Defeating Deafness and EC. Bitner-Glindzicz, M. (2002). Hereditary deafness and phenotyping in humans. Br Med Bull., 63, 73-94. Bykhovskaya, Y. et al. (2000). Candidate locus for a nuclear modifier gene for maternally inherited deafness. Am J Hum Genet., 66, 1905-10. Bykhovskaya, Y. et al. (2004). Human mitochondrial transcription factor B1 as a modifier gene for hearing loss associated with the mitochondrial A1555G mutation. Mol Genet Metab., 82, 27-32. Coling, D.E. etal. (2003). Effect of SOD1 overexpression on age- and noise-related hearing loss. Free Radic Biol Med., 34, 873-80. Davis, A. C. (1989). The prevalence of hearing impairment and reported hearing disability among adults in Great Britain. Int J Epidemiol., 18, 911-17. Fechter, L. D. (2004). Promotion of noise-induced hearing loss by chemical contaminants. J Toxicol Environ Health A., 67, 727-40. Fortnum, H. M. et al. (2001). Prevalence of permanent childhood hearing impairment in the...

Trichina worm

Trichinosis is a zoonotic infection associated with the colonization of worms in muscles. It is often found in humans because of the consumption of uncooked or insufficiently cooked pork products (though other animals are also potential sources). Trichinella is the third most common worm that infects humans. They cause nausea, dysentery, puffy eyes, and colic. They also cause pain and more severe problems such as edema, cardiac and pulmonary problems, deafness, delirium, muscle pain, muted reflexes, nervous disorders, and pneumonia. Their natural hosts are flesh-eating animals, especially humans, pigs, rats, and other mammals. Humans are considered accidental hosts because, under normal conditions, the parasite ends its cycle that is, no other animals eat humans in order to transfer their larvae to other hosts. But concern for trichinosis is not as great today with improved pork production practices. Still, an estimated 5-6 million human infections are present at any one time in North...

Auditory Tests

Conduction deafness (left ear) Conduction deafness (right ear) Nerve deafness (left ear) Nerve deafness (right ear) Conduction deafness middle ear deafness (e.g otosclerosis, otitis media) nerve deafness - sensorineural deafness (e.g., presbycusis AC air conduction BC bone conduction. Conduction deafness middle ear deafness (e.g otosclerosis, otitis media) nerve deafness - sensorineural deafness (e.g., presbycusis AC air conduction BC bone conduction. a. A patient who has unilateral conduction deafness hears the vibration more loudly in the affected ear. b. A patient who has unilateral partial nerve deafness hears the vibration more loudly in the normal ear. a. A patient who has unilateral conduction deafness does not hear the vibration in the air after bone conduction is gone. b. A patient who has unilateral partial nerve deafness hears the vibration in the air after bone conduction is gone.