Ataxia, nystagmus and ophthalmoplegia is seen in-

Chronic progressive externalophthalmoplegia (CPEO), is a type of eye disorder characterized by slowly progressive inability to move the eyes and eyebrows. It is often the only feature of mitochondrial disease, in which case the term CPEO may be given as the diagnosis. It is characterized by Nystagmus Ataxia Ophthalmoplegia Ref khurana 6/e