Neuropsychological outcome following pallidotomy and thalamotomy for Parkinson's disease

Cognitive and emotional outcomes were assessed after unilateral posteroventral pallidotomy (PVP) and ventral intermediate nucleus thalamotomy (Vim-Th) in patients suffering from idiopathic Parkinson's disease (PD). PVP was performed on 12 PD patients (8 men and 4 women, mean age 56.4 years, 6 left lesions and 6 right lesions) and Vim-Th was performed on 13 PD patients (5 men and 8 women, mean age 63.2 years, 6 left lesions and 7 right lesions). In both the PVP group and the Vim-Th group, the Hoehn and Yahr staging scores (p < 0.01) and the Unified Parkinson's Disease Rating Scale activities of daily living and motor scores (p < 0.001) improved significantly. No significant changes in cognitive function were observed 4 weeks after unilateral PVP or Vim-Th. PVP produced a significant decline in Hasegawa's Dementia Scale-Revised scores in immediate postoperative assessments (p < 0.05), which resolved 4 weeks after surgery. While the Minnesota Multiphasic Personality Inventory depression and social introversion scores improved significantly in the Vim-Th group (p < 0.01 and p < 0.05, respectively), the hypochondriasis and hypomania scores improved significantly in the PVP group (p < 0.01 and p < 0.05, respectively). We conclude that PVP and Vim-Th influence postoperative emotional status rather than postoperative cognitive status.