Alternating hemiplegia of childhood

Alternating hemiplegia of childhood (AHC) is a rare neurodevelopmental disorder characterized by recurrent episodes of hemiplegia (paralysis affecting one side of the body) that can alternate between sides or sometimes affect both sides simultaneously (quadriplegia). The condition primarily affects the nervous system and typically presents before 18 months of age. Episodes of hemiplegia may last from minutes to days and are often triggered by environmental stressors such as temperature changes, emotional stress, bathing, or physical exertion. A hallmark feature of AHC is that hemiplegic episodes resolve with sleep, although symptoms may briefly recur upon awakening. Beyond the characteristic hemiplegic episodes, individuals with AHC commonly experience abnormal eye movements (episodic nystagmus or monocular nystagmus), dystonic episodes, epileptic seizures, progressive cognitive impairment, and developmental delay. Choreoathetosis, ataxia, and autonomic disturbances (such as changes in skin color and body temperature) are also frequently observed. The majority of cases (approximately 75-80%) are caused by de novo heterozygous mutations in the ATP1A3 gene, which encodes the alpha-3 subunit of the sodium-potassium ATPase pump, critical for neuronal function. Less commonly, mutations in the ATP1A2 gene have been identified. There is currently no cure for AHC. Treatment is primarily symptomatic and supportive. Flunarizine, a calcium channel blocker, is the most widely used medication and may help reduce the frequency and severity of hemiplegic episodes in some patients, though its efficacy varies. Avoidance of known triggers is an important management strategy. Antiepileptic drugs may be used to manage seizures. Multidisciplinary care involving neurology, physical therapy, occupational therapy, and speech therapy is essential to optimize developmental outcomes and quality of life.

Common questions about Alternating hemiplegia of childhood