Leigh syndrome is a subacute necrotizing encephalomyelopathy of infancy or early childhood. The clinical presentation can be highly variable. The classical presentations are central hypotonia, developmental regression or arrest, ataxia, ophthalmoplegia, and abnormal respiratory pattern. Diagnosis is usually confirmed by radiologic evidence of focal, bilateral and usually symmetric lesions of the both gray and white matter in the brain and the spinal cord. We experienced 2 cases of Leigh syndrome in a brother and sister.The first case, 4 year-old boy, was misdiagnosed as a cerebral palsy initially, but after acute infection, he revealed developmental regression and abnormal movement. His disease was confirmed by typical magnetic resonance imaging findings. The second case, 1 year-old girl with nystagmus, showed bilateral symmetric high signal intensity in globus pallidus on T2WI. We reported these cases with a brief review of the related literature. (J Korean Acad Rehab Med 2006; 30: 406-408)
