Psychological Studies on the Effects of Chemosurgery of the Basal Ganglia in Parkinsonism

A Multidisciplinary Investigation of Neurosurgical Rehabilitation in Bilateral Parkinsonism*

“…Results of a series of standard follow‐up tests indicated that surgically‐induced bilateral lesions restricted to the globus pallidus or ventrolateral thalamus had no lasting effect on cognitive functioning. This finding corroborates the clinical findings reported previously by others (Gillingham et al, 1960; Gillingham, 1961; Hassler and Riechert, 1958; Krayenbuehl, Wyss and Yasargil, 1960; Krayenbuehl and Yasargil, 1961) and tends to complement our findings on the long‐range effects of unilateral basal‐ganglion surgery (Levita, Riklan and Cooper, 1964; Riklan et al, 1960). Thus, although the dysfunction is more clinically apparent, and although second‐side brain surgery involves a longer and more arduous immediate postoperative course in the hospital, a functional reorganization of “higher” integrative behavior occurs in due time.…”

Long-Term Effects on Verbally Expressed Cognition Following Left and Right Ventrolateral Thalamotomy

“…This test is comprised of two parts, both re quiring the subject to perform a continuous reading task under conflicting conditions, the degree of conflict being particularly strong in the second part (CWT-w; see under Methods). The differentiation obtained with the WPT was of about the same magnitude (p=0.01) as found by other exper imenters using similar instruments within this field of research [McF ie, 1960; Riklan et al, 1960;R iklan andLevita, 1964, 1970;Krayenbuhl et al, 1965]. The aim of the present investigation was to explore whether the differences previously found were still present after a much longer postoperative interval (median about 10 months).…”

Psychological aspects of diencephalotomy

“…can be attributed to deterioration associated with Parkinsonism. Riklan et al (1960) reported no significant change in Wechsler I.Q. scores in their unoperated Parkinson patients in a mean testretest of nine months.…”

“…There was a trend for a greater number of subjects oper- ated on the right brain to show impaired simple perception than those operated (Table V) on the left brain. COMMENT Riklan, Diller, Weiner, and Cooper (1960) reported significant impairment in the Wechsler verbal I.Q. in the 'immediate' (8 to 43 days) post-operative period.…”