Pallidotomy for Parkinson’s Disease

Abstract

Pallidotomy is a longstanding surgical procedure that was rediscovered in the 1990s and, with the development of modern imaging and electrophysiological techniques, has become an effective treatment for Parkinson’s disease (PD). Pallidotomy was performed in the 1950s by Fenelon, Guiot, Cooper, Spiegel, Wycis, Talairach, Riechert, Narabayashi, and Leksell (1) in attempts to palliate the symptoms of PD. At that time, the focus was primarily on tremor, which is often the least disabling but most noticeable symptom of PD. The work of Hassler, Riechert, and Mundinger popularized the ventral lateral region of the thalamus and led to abandonment of the pallidum as the surgical target of choice for tremor alleviation for PD (2) With the introduction of L-dopa therapy in the 1960s (3), surgical approaches for the treatment of PD were performed infrequently. Despite advances in medical treatment, however, patients often developed severe disabling medication-induced dyskinesias and motor fluctuations. The reintroduction of Leksell’s posteroventral pallidotomy by Laitinen in 1992 (4) generated a new interest in this procedure among neurologists and neurosurgeons. Not only were the primary motor symptoms improved but medication-induced dyskinesias were also reduced. Patients in the modern era of surgery for PD differ from the pre-L-dopa era in several ways. First, contemporary patients are generally very advanced in the course of their disease. Second, today’s patients are all on antiparkinsonian medications and frequently suffer from drug-induced side effects in the form of motor fluctuations and drug-induced dyskinesia. Third, there are no longer large numbers of postencephalitic parkinsonian patients. Finally, many forms of parkinsonism other than idiopathic PD have been identified. Today, the standard to which new surgical therapies are compared is the posteroventral pallidotomy.