Parkinson's Disease Research Today is a free monthly online journal that collates and summarizes the latest research about Parkinson's Disease, including details on symptoms, treatment, genetics, medication.

High-frequency stimulation in Parkinson's disease: more or less?

Garcia L, D'Alessandro G, Bioulac B, Hammond C

Laboratoire de neurophysiologie (Centre National de la Recherche Scientifique UMR 5543), Université de Bordeaux 2,146 rue Léo Saignat, 33076 Bordeaux Cedex, France.

Deep-brain stimulation at high frequency is now considered the most effective neurosurgical therapy for movement disorders. An electrode is chronically implanted in a particular area of the brain and, when continuously stimulated, it significantly alleviates motor symptoms. In Parkinson's disease, common target nuclei of high-frequency stimulation (HFS) are ventral thalamic nuclei and basal ganglia nuclei, such as the internal segment of the pallidum and the subthalamic nucleus (STN), with a preference for the STN in recent years. Two fundamental mechanisms have been proposed to underlie the beneficial effects of HFS: silencing or excitation of STN neurons. Relying on recent experimental data, we suggest that both are instrumental: HFS switches off a pathological disrupted activity in the STN (a 'less' mechanism) and imposes a new type of discharge in the upper gamma-band frequency that is endowed with beneficial effects (a 'more' mechanism). The intrinsic capacity of basal ganglia and particular STN neurons to generate oscillations and shift rapidly from a physiological to a pathogenic pattern is pivotal in the operation of these circuits in health and disease.

Published 5 April 2005 in Trends Neurosci, 28(4): 209-16.
Full-text of this article is available online (may require subscription).

© 2004-2008 Parkinson's Disease Research Today. All Rights Reserved.