Neuropsychological outcome after unilateral pallidotomy for the treatment of Parkinson's disease.

OBJECTIVE: To assess the long term cognitive outcome of unilateral posteroventral pallidotomy (PVP) and the overall efficacy of the surgery. METHODS: Forty two (29 left and 13 right PVP) patients with Parkinson's disease underwent neurological and neuropsychological testing before PVP and at 3 and 12 months after PVP. The neuropsychological testing battery emphasised measures of verbal learning and memory, visuospatial abilities, speed of information processing, executive functioning, and affective functioning. RESULTS: All patients demonstrated motor improvements after surgery during their off state, and 86% of patients also showed improvements in motor functioning in their on state. Repeated measures ANOVA showed significant improvements in confrontational naming, visuospatial organisation, and affective functioning 3 months and 12 months after surgery, with inconsistent improvements in executive functioning 12 months post-PVP. Patients demonstrated a transient impairment in verbal memory, with verbal learning performance returning to baseline 12 months post-PVP after a significant decline 3 months after PVP. When three patients with lesions extending outside of the PVP were excluded from the analysis, a decline in verbal fluency performance after PVP was not found to be significant. Differences due to side of lesion placement were not found on any of the cognitive measures. CONCLUSIONS: In the largest long term follow up study reported to date, the cognitive changes found up to a year after PVP are minimal compared with the robust improvements in motor function. The findings highlight the need to investigate the relation between the specific fibre tracts affected by the lesions and cognitive outcome.

Posteroventral medial pallidotomy in levodopa-unresponsive parkinsonism.

BACKGROUND: Parkinsonism in a 42-year-old patient, which was presumably related to peripheral trauma, did not respond to levodopa therapy. OBSERVATION: We treated the patient with microelectrode-guided unilateral posteroventral medial pallidotomy and followed up with magnetic resonance imaging and prospective clinical evaluation. Pallidotomy resulted in marked improvement of right-sided parkinsonian symptoms and functional disability at 4.5 months after surgery. Microelectrode recording during pallidotomy revealed discharge patterns that were similar to those seen in patients with Parkinson disease. Postoperative magnetic resonance imaging confirmed the location of the lesion in the posteroventral medial pallidum. CONCLUSIONS: Posteroventral pallidotomy usually has limited benefit in patients with degenerative atypical parkinsonism who do not respond to levodopa therapy. Nevertheless, pallidotomy can be an effective treatment for other levodopa-unresponsive parkinsonian disorders.

Alpha rhythm slowing during initiation of carbamazepine therapy: implications for future cognitive performance.

A prospective study comparing the immediate changes in occipital electroencephalographic (EEG) frequency following institution of carbamazepine therapy to long-term alterations of neuropsychological performance is reported. The patient group consisted of 16 previously untreated children in the 5-14-year age range who had recent onset partial seizures and were managed for at least 1 year with carbamazepine monotherapy. EEG changes following initiation of carbamazepine therapy, as compared to baseline, were determined by a computer-based quantitative method. Neuropsychological factors were assessed at baseline and after 1 year of therapy. While the alpha frequency decreased following institution of carbamazepine in most subjects, a greater decline (typically > 0.5 Hz) was observed in the subset who subsequently demonstrated decreased neuropsychological performance at 1 year. The major effects could be attributed to the Arithmetic and Picture Completion subtests of the Wechsler Intelligence Scale for Children-Revised (WISC-R). The findings suggest that quantitative EEG analysis may be useful for identifying individuals at increased risk for developing anticonvulsant-related long-term cognitive changes.

The effect of intrauterine malnutrition on the term infant. A 14-year progressive study.

The developmental outcome of 33 newborn infants with clinical intrauterine malnutrition at birth and 13 clinically well nourished infants from a middle to high socio-economic population have been followed from birth to 12-14 years of age. Psychometric studies revealed a lowering of the IQ score in malnourished infants compared to well nourished infants (104 +/- 15 compared to 121 +/- 13, p less than 0.05) and a need for special education (p less than 0.03). Forty-five percent of the malnourished infants' birth weights were above the 10th percentile on the Colorado Intrauterine Growth Grid. The Full Scale IQ of malnourished infants with BW greater and less than 10th percentile on the Colorado Intrauterine Growth Grid were comparable. Malnourished infants with birth weights greater than 10th percentile had lower IQ scores than well nourished infants (101 +/- 13 compared to 121 +/- 13, p less than 0.006). Thirty-nine percent of the infants with handicaps would have been missed if only infants with birth weights less than 10th percentile were considered high risk.