[Ptosis and asthenia manifesting a mitochondrial myopathy].

We report a case of mitochondrial myopathy discovered in a 55-year old woman who was being investigated for the cause of her asthenia. Physical examination showed ptosis of the upper eyelid and proximal muscle deficit. Histological examination of a muscle biopsy disclosed rare fibres with mitochondrial aggregates. Biochemical exploration of muscle tissue revealed a double enzyme deficit involving complexes I and IV of the respiratory chain. Clinical improvement was obtained after the patient was put on coenzyme Q10. We conclude that a diagnosis of mitochondrial myopathy must be considered in patients, including middle-aged adults, presenting with muscular asthenia.