title: Pallidotomy for hemiballismus: efficacy and characteristics of neuronal activity.
abstract: A patient with unremitting, medically intractable hemiballismus underwent a pallidotomy that abolished his involuntary movements. Firing rates of cells in the internal segment of the globus pallidus (GPi) recorded during this procedure were significantly lower than those observed during pallidotomy for Parkinson's disease, either "on" or "off" medication. Firing patterns in hemiballismus were characterized by low-frequency modulation of the firing rate. These results are consistent with the hyperkinetic model, which suggests that hemiballismus results from decreased inhibition of the pallidal relay nucleus of the thalamus by the GPi. The efficacy of surgery in the case of hemiballismus demonstrates that pallidotomy can be an effective treatment for this condition and suggests that patterned neuronal activity in the GPi is important in the mechanism of hyperkinetic disorders.
authors.affiliation: Department of Neurology, Johns Hopkins University, Baltimore, MD 21287-7713, USA.
authors.forename: J I
authors.initials: JI
authors.lastname: Suarez
authors.forename: L V
authors.initials: LV
authors.lastname: Metman
authors.forename: S G
authors.initials: SG
authors.lastname: Reich
authors.forename: P M
authors.initials: PM
authors.lastname: Dougherty
authors.forename: M
authors.initials: M
authors.lastname: Hallett
authors.forename: F A
authors.initials: FA
authors.lastname: Lenz
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage; D001058:Apomorphine / Q000008:administration & dosage; D004594:Electrophysiology; D005917:Globus Pallidus / Q000166:cytology / Q000601:surgery*; D006801:Humans; D008297:Male; D009069:Movement Disorders / Q000601:surgery*; D009474:Neurons / Q000502:physiology*; D010300:Parkinson Disease / Q000188:drug therapy / Q000601:surgery
chemical_list: D000978:Antiparkinson Agents; D001058:Apomorphine