A brief history of pallidotomy.

A large number of surgical procedures involving the globus pallidus and ansa lenticularis were performed from 1939 to the late 1950s for alleviation of rigidity and tremor, two of the main symptoms of Parkinson's disease. Several groups reported beneficial effects using a wide array of techniques and targets within the pallidum and its projections. Over time, pallidal targets lying in the ventral and posterior portions of the internal pallidum were considered to be the most effective. Based on anatomic studies, surgical misadventures, and empirical observations, there was an abrupt shift regarding the favored target to treat parkinsonian tremor to the thalamus, and most neurosurgeons abandoned pallidotomy in the 1960s. With the advent of L-dopa and the realization of its striking clinical benefits in the mid 1960s, within 5 to 10 years, virtually all surgery for Parkinson's disease ceased. We are now witnessing a rediscovery of pallidotomy as patients with Parkinson's disease are experiencing the shortcomings of medical therapy. In this article, we examine the evolution of pallidotomy and discuss the reasons for the renewed interest in this procedure.