Case Report of Lewis and Sumner Syndrome with Bilateral Vagus Nerves Paralysis for 16 Years.

This report describes a patient with dysphonia for 16 years in combination with asymmetric and progressive decrease in sense and power of both upper and lower extremities for the past 3 years. Electrophysiological study revealed asymmetric conduction block and abnormal sensory action potential in 4 limbs. The vagus nerves palsy and abnormal electrodiagnosis of the limbs led us to diagnose the disease as Lewis and Sumner syndrome, also called multifocal acquired demyelinating sensory and motor neuropathy diagnosis, which improved by corticosteroid consumption to some extent. This case is uncommon by its long time presentation and progression. To the best of the authors' knowledge, this is the first report of simultaneous bilateral vagus nerve palsy in combination with upper and lower limbs' demyelinating neuropathy. In conclusion, persistent dysphonia can be a part of the presentation of demyelinating neuropathy.