b. Clinical findings include: bilateral spastic paresis, with pyramidal signs below the lesion; bilateral loss of pain and temperature below the lesion; bilateral Horner syndrome; bilateral flaccid paralysis; and loss of voluntary bladder and bowel control.
6. Vitamin BI2 neuropathy a. Vitamin B,2 neuropathy results in damage to the dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts, usually due to pernicious (megaloblastic) anemia.
b. Clinical findings include: bilateral loss of tactile discrimination, vibration sensation, and proprioception; bilateral spastic paresis with pyramidal signs; and bilateral arm and leg dystaxia.
7. Syringomyelia a. Syringomelia is central cavitation of the cervical spinal cord whose etiology is unknown.
b. It results in damage to the ventral white commissure (involving the decussating lateral spinothalamic axons) and to the ventral gray horns.
c. Clinical findings include: bilateral loss of pain and temperature, and flaccid paralysis of the intrinsic muscles of the hand.
B. Spinal cord injury (SCI)
1. Complete SCI, or transection of the spinal cord, results in loss of sensation and motor function below the lesion. There are two types.
a. Paraplegia, or paralysis of the lower limbs, results if the transection occurs anywhere between the cervical and lumbar enlargements of the spinal cord.
b. Quadriplegia, or paralysis of all four limbs, occurs if the transection occurs above C3. If the phrenic nerve is compromised, death may occur rapidly as a result of respiratory failure.
2. Incomplete SCI can be ameliorated somewhat by rapid surgical intervention. Three situations may lead to incomplete SCI: concussive blow, anterior spinal artery occlusion, or penetrating blow (e.g., Brown-Sequard syndrome).
3. Complications of SCI include: hypotension in the acute setting, ileus (bowel obstruction because of lack of motility), renal stones, pyelonephritis, renal failure, and deep venous thrombosis. Methylprednisolone may be beneficial if administered within 8 hours of injury.
C. Tumors of the spinal cord
1. Intramedullary tumors (within the spinal cord)
a. Ependymoma is the most common intramedullary tumor (60%). These tumors may occur in the cervical region, near the obliterated central canal where tumor cells align around pathologic tubular cavities (syrinx). They also may occur in the lumbosacral region associated with the conus medullaris.
b. Astrocytoma usually occurs in the cervical and thoracic regions of the spinal cord.
2. Intradural tumors (within the meninges)
a. Meningioma usually occurs in the thoracic region of the spinal cord, predominantly in women.
b. Schwannomas arise from Schwann cells associated with a spinal nerve and present as a dumbbell-shaped tumor that protrudes through the intervertebral foramen. Multiple schwannomas may occur in association with neurofibromatosis type 2.
c. Neurofibroma has a clinical presentation that is nearly identical to that of a schwannoma (see VI C 2 b).
3. Extradural tumors (outside the meninges)
b. Chordomas arise from remnants of the embryonic notochord. They usually occur in the sacral or clival region.
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A Beginner's Guide to Healthy Pregnancy. If you suspect, or know, that you are pregnant, we ho pe you have already visited your doctor. Presuming that you have confirmed your suspicions and that this is your first child, or that you wish to take better care of yourself d uring pregnancy than you did during your other pregnancies; you have come to the right place.