Prolonged conduction block with axonal degeneration. An electrophysiological study.

Serial electrophysiological studies were performed in a case of 'tourniquet paralysis' of the upper limb after the application of an Esmarch bandage above the elbow. Three months after onset of paralysis, nerve conduction was reduced to a quarter of normal between elbow and and axilla along the few fibres still conducting through the lesion, but was normal distal to the block. Seven months after nerve damage, EMG showed evidence of reinnervation after Wallerian degeneration, and half the nerve fibres had recovered from the conduction block. Thirteen months after nerve injury clinical examination and nerve conduction were normal, but EMG still showed evidence of partial denervation.