CHRONIC PROGRESSIVE EXTERNAL OPHTHALMOPLEGIA AND MUSCULARDYSTROPHY

Mitochondrial cytopathy. A multisystem disorder with ragged red fibres on muscle biopsy

Thirteen children with abnormal mitochondria in muscle tissue, and a progressive neurological disorder that affected the cerebrum, cerebellum, extrapyramidal system, vestibular system, retina, upper motor neuron, lower motor neuron, and musculature, are reported. Other signs and symptoms were short stature, diabetes mellitus, cardiopathy, hypoplastic anaemia, glomerulopathy, and renal tubular dysfunction. These symptoms may occur singly or in various combinations and the manifestation may differ even within the same family. The most common clinical picture was that of "ophthalmoplegia plus'. Occurrence in relatives varied from isolated symptoms to the complete syndrome with "ragged red fibres' and is not inconsistent with an autosomal dominant mode of inheritance with variable expressivity. Theories for the pathophysiological basis of this syndrome are discussed and the literature reviewed.

Oculopharyngeal myopathy with distal and cardiomyopathy

Two patients are described with distinctive clinical features including an insidious onset, slow progression, bilateral ptosis, weakness of facial muscles, dysphagia, muscle atrophy, and weakness with a distal distribution in the extremities, and cardiomopathy with conduction system disorders. Electromyographic studies and muscle biopsy showed features highly suggestive of a myopathic disorder. One case is considered to be sporadic. The other seems to be a familial disorder, because of the presence of a mild atrioventricular block and right incomplete bundle branch block in the patient's son and the presence of eyelid ptosis in his sister. This may be a variant of oculopharyngeal myopathy with distal and cardiomyopathy. It will be necessary to perform long-term follow-up studies in these families.

Progressive external ophthalmoplegia. Evidence for a generalised mitochondrial disease with a defect in pyruvate metabolism

Muscle biopsies from four patients with chronic progressive external ophthalmoplegia and pigmentary retinopathy with symptoms and signs from other organs were studied by means of light and electron microscopy. Examination revealed a marked proliferation of abnormal mitochondria with a degeneration of both muscle and nerve tissue. Blood levels of lactate and pyruvate were measured and abnormal values of these metabolites were found in the three patients with the most pronounced ultrastructural changes. On the basis of these findings it is suggested that there is a biochemical defect in pyruvate-lactate metabolism which could be responsible for the marked proliferation of the abnormal mitochondria.

Congenital oculoskeletal myopathy with abnormal muscle and liver mitochondria

We report a 22-year-old very thin man, who showed various symptoms and signs of oculoskeletal muscle weakness, episodes of myalgia, prolonged diarrhea, severe myopia, perceptive deafness, electrocardiographic and electroencephalographic abnormalities, and endocrinological abnormality. The onset was at about 3 months of age and a positive family history was strongly suggested. The light-microscopic, histochemical and electron-microscopic findings showed abnormal mitochondria not only in the skeletal muscle, but also in liver cells. From the clinical as well as morphological points of view, this case was suspected to be one of congenital oculoskeletal myopathy probably due to an unidentified systemic metabolic disorder.

Chronic progressive external ophthalmoplegia, pigmentary retinopathy, and heart block (Kearns-Sayre syndrome). Report of a case

Chronic progressive external ophthalmoplegia associated with a pigmentary retinopathy and heart block was described by Kearns & Sayre in 1958. They suggested that the triad represented a syndrome. The cases recorded since then are reviewed and summarised, and several common features are noted. Little attention has previously been paid to the retinopathy. A similar case is presented, and the pigment changes, retinal function, annd fluorescein angiography are examined. There is no clinical evidence for the diagnosis of classical retinitis pigmentosa. The prognosis and aetiology of the condition are discussed.