Isolated dysphagia as initial sign of anti-IgLON5 syndrome

OBJECTIVE: To report on dysphagia as initial sign in a case of anti-IgLON5 syndrome and provide an overview of the current literature. METHODS: The diagnostic workup included cerebral MRI, fiber optic endoscopic evaluation of swallowing (FEES) with the FEES tensilon test, a videofluoroscopic swallowing study, evoked potentials and peripheral nerve conduction studies, polysomnography, lumbar puncture, and screening for neural autoantibodies. A systematic review of all published cases of IgLON5 syndrome is provided. RESULTS: We report a case of anti-IgLON5 syndrome presenting with slowly progressive neurogenic dysphagia. FEES revealed severe neurogenic dysphagia and bilateral palsy of the vocal cords. Autoantibody screening was positive for IgLON5 IgG (+++, 1:1,000) serum levels but no other known neural autoantibody. Polysomnography was highly suggestive of non-REM parasomnia. Symptoms were partially responsive to immunotherapy. CONCLUSIONS: Slowly progressive neurogenic dysphagia may occur as initial sign of anti-IgLON5 syndrome highlighting another clinical presentation of this rare disease.