Focal conduction block in n-hexane polyneuropathy.

A 19-year-old man with an asymptomatic history of recreational gasoline vapor inhalation presented with subacute progressive quadriparesis. For 2 weeks, he had intensely inhaled Coleman fuel oil vapor, which contains n-hexane. Nerve conduction studies including near-nerve needle stimulation showed focal conduction block in the bilateral median and ulnar nerves. Sural nerve biopsy was consistent with giant axonal neuropathy. Conduction block as seen in this case has not heretofore been described in n-hexane polyneuropathy.