COGNITIVE AND PERCEPTUAL FUNCTIONS AND LESION LOCATION IN BASAL GANGLIA SURGERY.

The article cites that subcortical involvement, specifically basal ganglia surgery performed to relieve Parkinsonian tremor and rigidity, has sometimes been held responsible for psychological changes. Tests were administered individually to the 22 Parkinsonian subjects, 1 to 3 days before surgery, during the immediate postoperative period, and in follow-up examinations. The median time interval between pre- and post-operative tests was 7.5 days, range 5 to 13 days. The median time interval between pre-operative and follow-up tests was 101 days, range 84 to 127. Ratios derived from intracerebral landmarks were used as indices for lesion parameters to decrease the effects of marked anatomic variation among individual brains.