Myoencephalopathies with abnormal mitochondria: a review.

Myoencephalopathies with abnormal mitochondria comprise a heterogeneous group of diseases and syndromes with a large diversity of clinical signs. Thus, their identification and classification pose many difficulties. The underlying biochemical disorders of energy metabolism evoke non-specific structural alterations of the mitochondria in skeletal muscle and brain, but also in other organs. In this paper the morphologic and biochemical background of confirmed cases is reviewed and the position of these cases within the concept of mitochondriopathy is discussed.