Ventroposterolateral pallidotomy was used in the surgical treatment of
259 patients suffering from intractable Parkinson's disease. Pallidot
omy was equally effective against tremor, rigor, bradykinesia, and the
L-dopa-induced dyskinesias. The effect of surgery seemed to be long-l
asting, and side effects were rare. The author believes that the benef
icial effect of pallidotomy is based on interruption of striopallidal
and pallidosubthalamic pathways.