Intracortical inhibition of the motor cortex is normal in chorea

• Published in: Journal of neurology, neurosurgery and psychiatry neurosurgery and psychiatry, 1999-06, Vol.66 (6), p.783-786
• Main Authors: Hanajima, Ritsuko, Ugawa, Yoshikazu, Terao, Yasuo, Furubayashi, Toshiaki, Machii, Katsuyuki, Shiio, Yasushi, Enomoto, Hiroyuki, Uesugi, Haruo, Mochizuki, Hitoshi, Kanazawa, Ichiro
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Analysis of Variance; Biological and medical sciences; chorea; Chorea - physiopathology; Electromyography; Female; Humans; Huntingtons disease; intracortical inhibition; magnetic stimulation; Magnetics; Male; Medical sciences; Metabolism; Middle Aged; motor cortex; Motor Cortex - physiopathology; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Parkinson's disease; Short Report; Studies; Variance analysis
• ISSN: 0022-3050; 1468-330X
• DOI: 10.1136/jnnp.66.6.783

Intracortical inhibition of the motor cortex was investigated using a paired pulse magnetic stimulation method in 14 patients with chorea caused by various aetiologies (six patients with Huntington’s disease, one with chorea acanthocytosis, a patient with systemic lupus erythematosus with a vascular lesion in the caudate, three with senile chorea and three with chorea of unknown aetiology). The time course and amount of inhibition was the same in the patients as in normal subjects, suggesting that the inhibitory mechanisms of the motor cortex studied with this method are intact in chorea. This is in striking contrast with the abnormal inhibition seen in patients with Parkinson’s disease or focal hand dystonia, or those with a lesion in the putamen or globus pallidus. It is concluded that the pathophysiological mechanisms responsible for chorea are different from those producing other involuntary movements.