Trains of transcranial direct current stimulation antagonize motor cortex hypoexcitability induced by acute hemicerebellectomy.
OBJECTIVE
The cerebellum is a key modulator of motor cortex activity, allowing both the maintenance and fine-tuning of motor cortex discharges. One elemental defect associated with acute cerebellar lesions is decreased excitability of the contralateral motor cortex, which is assumed to participate in deficits in skilled movements and considered a major defect in motor cortex properties. In the present study, the authors assessed the effect of trains of anodal transcranial direct current stimulation (tDCS), which elicits polarity-dependent shifts in resting membrane potentials.


METHODS
Transcranial DCS countered the defect in motor cortex excitability contralaterally to the hemicerebellar ablation.


RESULTS
The depression of both the H-reflex and F wave remained unchanged with tDCS, and cutaneomuscular reflexes remained unaffected. Transcranial DCS antagonized motor cortex hypoexcitability induced by high-frequency stimulation of interpositus nucleus.


CONCLUSIONS
The authors' results show that tDCS has the potential to modulate motor cortex excitability after acute cerebellar dysfunction. By putting the motor cortex at the appropriate level of excitability, tDCS might allow the motor cortex to become more reactive to the procedures of training or learning.
Ben Taib
Nordeyn Oulad
NO
Service de Neurochirurgie, Hôpital Erasme-ULB, Brussels, Belgium.
Manto
Mario
M
D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D002531:Cerebellum / Q000503:physiopathology* / Q000601:surgery*; D004558:Electric Stimulation; D055724:Electrophysiological Phenomena / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D023421:Models, Animal; D009044:Motor Cortex / Q000502:physiology*; D019635:Neurosurgical Procedures / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar