Unilateral pallidotomy in PD - A controlled study of cognitive and behavioral effects

Objective: To investigate whether unilateral pallidotomy affects cognitive and behavioral functioning. Methods: At baseline and after 6 months we asse ssed neuropsychological functioning in 35 patients with advanced PD. After baseline examination, patients were randomized to pallidotomy within 1 mont h (6 left-sided, 13 right-sided) or to pallidotomy after follow-up assessme nt 6 months later (n = 16; control group). We performed neuropsychological tests of language, visuospatial function, memory, attention, and executive functions. Self ratings and proxy ratings of memory problems and dysexecuti ve symptoms were also collected. Results: No significant differences over t ime were found between pallidotomy and control groups, with the exception o f a decrease of verbal fluency in the left-sided pallidotomy group. Conclus ions: Unilateral pallidotomy is relatively safe with respect to cognition a nd behavior. Left-sided pallidotomy may lead to minor deterioration in verb al fluency. The sample size of this study is too small, however, to rule ou t the possibility of infrequent but clinically important side effects.