Conduction block as an early sign of reversible injury in ischemic monomelic neuropathy

We report three patients with reversible motor conduction block in the forearm associated with ischemic monomelic neuropathy (IMN), which occurred in two patients following placement of brachial artery-cephalic vein shunts for hemodialysis. In the third patient, IMN resulted from spontaneous, probably embolic, brachial artery occlusion. Conduction block was observed shortly after the onset of symptoms, and preferentially involved the median nerve. Slowing of conduction velocity was seen in the same nerve segments. Electrophysiologic resolution, correlating with clinical improvement following treatment, occurred promptly in one patient and over several weeks in the others. Recognition of conduction block is important in the evaluation of IMN, and indicates the need for prompt treatment of likely reversible nerve injury.