title: Does unilateral basal ganglia activity functionally influence the contralateral side? What we can learn from STN stimulation in patients with Parkinson's disease.
abstract: In humans, the control of voluntary movement, in which the corticobasal ganglia (BG) circuitry participates, is mainly lateralized. However, several studies have suggested that both the contralateral and ipsilateral BG systems are implicated during unilateral movement. Bilateral improvement of motor signs in patients with Parkinson's disease (PD) has been reported with unilateral lesion or high-frequency stimulation (HFS) of the internal part of the globus pallidus or the subthalamic nucleus (STN-HFS). To decipher the mechanisms of production of ipsilateral movements induced by the modulation of unilateral BG circuitry activity, we recorded left STN neuronal activity during right STN-HFS in PD patients operated for bilateral deep brain stimulation. Left STN single cells were recorded in the operating room during right STN-HFS while patients experienced, or did not experience, right stimulation-induced dyskinesias. Most of the left-side STN neurons (64%) associated with the presence of right dyskinesias were inhibited, with a significant decrease in burst and intraburst frequencies. In contrast, left STN neurons not associated with right dyskinesias were mainly activated (48%), with a predominant increase 4-5 ms after the stimulation pulse and a decrease in oscillatory activity. This suggests that unilateral neuronal STN modulation is associated with changes in the activity of the contralateral STN. The fact that one side of the BG system can influence the functioning of the other could explain the occurrence of bilateral dyskinesias and motor improvement observed in PD patients during unilateral STN-HFS, as a result of a bilateral disruption of the pathological activity in the corticosubcortical circuitry.
authors: 1Centre de Recherche de l’Institut du Cerveau et de la Moelle Épiniere, UMR-S975, Paris, France.
authors: Yohann
authors: Y
authors: Brun
authors: Carine
authors: C
authors: Karachi
authors: Sara
authors: S
authors: Fernandez-Vidal
authors: Nicolas
authors: N
authors: Jodoin
authors: David
authors: D
authors: Grabli
authors: Eric
authors: E
authors: Bardinet
authors: Luc
authors: L
authors: Mallet
authors: Yves
authors: Y
authors: Agid
authors: Jerome
authors: J
authors: Yelnik
authors: Marie-Laure
authors: ML
authors: Welter
mesh_terms: D000368:Aged; D058256:Brain Waves; D046690:Deep Brain Stimulation; D020820:Dyskinesias / Q000503:physiopathology; D005260:Female; D005917:Globus Pallidus / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000502:physiology; D010300:Parkinson Disease / Q000503:physiopathology* / Q000628:therapy; D020531:Subthalamic Nucleus / Q000503:physiopathology*