Note: For comparison, the original series of Laitinen is at the bottom.
aSome studies with different patient numbers from the same institutions have overlapping samples. bSome patients had Parkinson-plus syndromes and others had combined pallidotomy and thalamotomy. °Marglnally significant result.
dOne patient developed anarthrla and two patients required re-operation as they had no benefit from the first pallidotomy. eOne death two weeks postoperatively secondary to Ipsllateral Intracerebral hemorrhage. 'One patient required re-operation as had no benefit from the first. 9Flgure calculated from a graph In manuscript
Abbreviations: n, number of patients; MES, macroelectrode stimulation at target site; MER, mlcroelectrode recording at target site; MT, finger movement time between two adjacent targets; Goetz, the Goetz dyskinesia rating scale; A%, % change; A+T+R, combined score for akinesia, tremor, and rigidity reported; +R, combined score with rigidity reported; v/VAS, video and visual assessment scale; PLM, electronic recording of posturolocomotlon manual test; PPT, Purdue pegboard test; (B), assumed bilateral as no distinction made between contralateral and Ipsllateral scores.
another developed abulia, and a third developed mental automatisms. Scott et al. (30) described hypophonia, increased salivation, and reduced verbal fluency, following bilateral simultaneous pallidotomy. An open-labeled trial of bilateral simultaneous pallidotomy compared with unilateral pallidotomy plus DBS had to be halted early, as all three patients with bilateral lesions developed deterioration in speech, swallowing, salivation, depression, apathy, freezing, and falling (72). In another series, staged bilateral pallidotomy was associated with a deficit in speech in four patients: one patient had a decline in memory and there were three cases of cerebral infarction (73). These results are similar to the study of De Bie et al. (74) who showed that seven out of 13 patients developed dysarthria and one suffered a severe delayed infarction. Further, a reduced response to levodopa has been documented in a small number of patients undergoing bilateral staged pallidotomy (73).
These results are in contrast to the milder side effects reported in one series of 14 patients who underwent staged bilateral pallidotomy, in whom no overall effect on speech or cognitive function was detected six months postoperatively, but five had mild hypophonia, two had transient confusion, two had deterioration of gait, and one had deterioration of a pre-existing dysarthria postoperatively (75). A larger series of 53 bilaterally operated patients, combined from U.K. and Australian centers, has also been presented with full follow-up of a subgroup of 17 patients for 12 months (76). Major deterioration in speech (defined as a two-point decline on the UPDRS subset score) occurred in 8% of bilaterally operated patients compared with 4% of unilaterally operated patients, although the study was not specifically designed to compare the two procedures. Similarly, postoperative major deterioration in salivation occurred in 13% and 10% of bilaterally and unilaterally operated patients, respectively. Gait freezing while on and handwriting each deteriorated with a frequency of 11% in the bilaterally operated group, and medically unresponsive eyelid opening apraxia occurred in 6%. Dysphagia was not reported. The authors suggest that these relatively low rates of complications may be attributable to the placement of a smaller lesion (100 mm3) in the medial pallidum contributing to the lesser affected hemibody compared with the medial pallidum corresponding to the worse-affected hemibody (150 mm3). Complications were only defined according to their occurrence on the UPDRS rather than by using specific questions designed to assess their presence and severity. Additionally, precise lesion locations and cognitive results were omitted. The question of safety and timing of bilateral pallidotomy, therefore, currently remains controversial and this procedure has not been undertaken by many groups. It is likely to continue to fall out of favor, especially where bilateral DBS is available as an alternative.
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