Monocular nystagmus in a patient with

Abstract

Monocular nystagmus is a rare condition that occurs in limited number of disorders, such as spasmus nutans, multiple sclerosis, and alternating hemiplegia of childhood (AHC).1 AHC is a neurodevelopmental disorder characterized by intermittent hemiplegic episodes with variable neurologic features.2 We present a 1-year-old infant with episodes of alternating hemiplegia and tetraplegia. He had onset at 7 months of life with monocular nystagmus (video). Neurologic examination was also notable for choreic and dystonic movements. Genetic sequencing confirmed mutation 2443G>A (p.Glu815Lys) in the ATP1A3 gene. Treatment with flunarizine has led to improvement with decreasing frequency and duration of episodes.