title: Unilateral lesions of the globus pallidus: report of four patients presenting with focal or segmental dystonia.
abstract: OBJECTIVE
  To interpret clinical features after unilateral lesions of the globus pallidus on the basis of physiology of the basal ganglia.
  
  
  METHODS
  Four patients with unilateral lesions in the globus pallidus (GP) were clinically examined and the literature on patients with pallidal lesions was reviewed.
  
  
  RESULTS
  Three patients presented with contralateral dystonia largely confined to one arm in one case and one leg in two cases. One patient had predominant contralateral hemiparkinsonism manifested mainly as micrographia and mild dystonia in one arm. The cause of the lesions was unknown in two patients. In the other two symptoms had developed after head trauma and after anoxia. All lesions involved the internal segment of the GP. Two patients, including the patient with hemiparkinsonism, had additional involvement of the external segment of the GP. In the literature reports on 26 patients with bilateral lesions restricted to the GP only two with unilateral lesions were found. The patients with bilateral pallidal lesions manifested with dystonia, parkinsonism, or abulia. One of the patients with unilateral GP lesions had contralateral hemidystonia, the other contralateral arm tremor.
  
  
  CONCLUSIONS
  These cases emphasise the importance of the GP, particularly its internal segment, in the pathophysiology of dystonia.
authors.affiliation: University Department of Clinical Neurology, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
authors.forename: A
authors.initials: A
authors.lastname: Münchau
authors.forename: D
authors.initials: D
authors.lastname: Mathen
authors.forename: T
authors.initials: T
authors.lastname: Cox
authors.forename: N P
authors.initials: NP
authors.lastname: Quinn
authors.forename: C D
authors.initials: CD
authors.lastname: Marsden
authors.forename: K P
authors.initials: KP
authors.lastname: Bhatia
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D002675:Child, Preschool; D020821:Dystonic Disorders / Q000473:pathology*; D005917:Globus Pallidus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male