Residual function in motor cortex contralateral to amputated hand

Objective: To investigate residual function of the motor cortex correspondi ng to the hand of the amputated arm (MCamp). Methods: Focal transcranial ma gnetic stimulation (TMS of MCamp was performed in 10 patients 22 to 52 year s after arm amputation to inhibit tonic muscle contraction in the intact ha nd ipsilateral to cortex stimulation. Results: In all patients, onset laten cy, degree, and duration of this inhibition were normal. Conclusion: The pr esence of motor inhibition in the residual hand of amputees originating fro m the hand motor representation of MG(amp) indicates residual cortical moto r representation of the lost hand irrespective of whether the effect is med iated by commissural or ipsilateral corticospinal connections.