"Dropped head syndrome" caused by Lambert-Eaton myasthenic syndrome.

A 67-year-old man was admitted with a 2-year history of dropped head. Neurological examination revealed ptosis, dysarthria, neck weakness, hyporeflexia of all limbs, and autonomic failure. Electrophysiologic study showed a 400% increment response to high-rate repetitive nerve stimulation. Serum anti-P/Q-voltage-gated calcium channel antibody was positive, confirming the diagnosis of Lambert-Eaton myasthenic syndrome (LEMS). His symptoms and electrophysiological abnormalities improved with oral prednisolone following plasmapheresis. This is the first report of LEMS as a cause of dropped head syndrome.