Multifocal Conduction Blocks in Sarcoid Peripheral Neuropathy

Peripheral neuropathy is a rare manifestation of sarcoidosis, and previous studies have shown axonal degeneration as the main pathology. We herein report three patients with sarcoidosis who presented with multiple mononeuropathy as the initial manifestation. Nerve conduction studies showed prominent multifocal conduction blocks in the intermediate nerve trunk. In all three patients, corticosteroid treatment resulted in a dramatic clinical improvement associated with rapid resolution of conduction blocks. The sequential electrodiagnostic findings suggest that demyelinative or ischemic-functional conduction block is responsible for their neuropathy. To date, only three cases of acute conduction block neuropathy associated with sarcoidosis have been reported, but it may occur more frequently than expected.