Alternating hemiplegia of childhood (AHC) is a rare neurological disorder that usually affects children before 18 months of age. It is characterized by repeated episodes of weakness or paralysis that may affect one side of the body or both sides of the body at once, as well as intermittent abnormal eye movements, episodes of muscle stiffness or posturing (dystonia), and seizures. The symptoms can last for minutes to days and are relieved with sleep. AHC is caused by mutations in the ATP1A3 gene in the majority of those affected.

AHC is a highly variable and unpredictable disorder, and the specific symptoms and severity of the disorder can vary greatly from one person to another. Some individuals may experience mild symptoms, while others may have severe and frequent episodes that significantly impact their daily lives. Complications often include developmental delays, learning disabilities, gastrointestinal issues including constipation, behavioral issues, epilepsy, and sleep disorders. People with AHC also have a higher risk of developing heart problems later in life.

There is currently no cure for AHC, but there are many treatments that can make a big difference in patients’ lives. The cornerstone of care is the use of multidisciplinary approaches that can address a variety of needs. While more research is necessary to improve early diagnosis, understand the full range of symptoms, and develop more effective treatments, there is active research on new kinds of therapies that could potentially have major impacts on the symptoms.