Benign nocturnal alternating hemiplegia of childhood is a rare neurologic disease characterized by recurrent attacks of nocturnal screaming or crying followed or accompanied by unilateral or sometimes bilateral hemiplegia. Disorder is not associated with neurological or developmental impairments but may be associated with mild behavioral abnormalities. The disease is benign familial nocturnal alternating hemiplegia of childhood (MONDO_0016209, a Monarch Disease Ontology identifier). Also known as: benign familial nocturnal alternating hemiplegia in childhood.