Lumping or splitting? "Ophthalmoplegia-plus" or Kearns-Sayre syndrome?

Mitochondrial myopathy and lactic acidaemia with myoclonic epilepsy, ataxia and hypothalamic infertility: a variant of Ramsay-Hunt syndrome?

A case of mitochondrial myopathy and lactic acidaemia with myoclonic epilepsy, cerebellar ataxia and high-tone hearing loss is presented. There was no ptosis or ophthalmoplegia. Endocrine investigations showed a defect in hypothalamic function which was a likely cause of infertility. The case is compared with previously reported examples of mitochondrial myopathy with myoclonic epilepsy, and contrasted with the Kearns-Sayre syndrome. It is concluded that mitochondrial myopathy, myoclonic epilepsy and ataxia may be distinguishing features of a specific familial disease, which on presentation may mimic the Ramsay-Hung syndrome.

Demyelinating radiculopathy in the Kearns-Sayre syndrome: a clinicopathological study

In the few previously autopsied patients with the Kearns-Sayre form of progressive ophthalmoplegia, the most prominent abnormalities have been in muscle, with less conspicuous changes in the central nervous system, primarily in the brainstem. Similar findings were present in the case reported here, but in addition there was severe demyelination in the initial few millimeters of the cranial and spinal motor roots distal to the glial-Schwann cell junction. Milder demyelination was observed in the dorsal spinal and afferent cranial nerve roots, including the eighth nerve, but deafness was due to virtually total destruction of the organ of Corti. Our observations suggest that a radiculopathy may be a feature in some cases of Kearns-Sayre syndrome.

Large mitochondria in a pituitary adenoma with hyperprolactinemia

A 27-year-old woman with amenorrhea following cessation of birth control pills was found to have a pituitary tumor which was secreting large amounts of prolactin. Many tumor cells had large mitochondria, the diameter of which ranged between 7 and 12 mu. Some tumor cells also displayed oncocytic transformation, and a few were definite oncocytes. The pathogenesis of mitochondrial swelling in pituitary tumors is discussed and the possible roles of prolonged intake of steroids and/or ischemia are suggested.

Familial mitochondrial myopathy with cataract

A 62-year-old female had severe progressive ophthalmoplegia associated with facial, pharyngeal and limb muscle involvement. When 40, she had undergone surgery for bilateral cataract present for about 20 years. Biopsies of skeletal muscles indicated myopathy; histochemistry and electron microscopy gave evidence of abnormal mitochondria in type I fibres. Bilateral cataract needing surgical treatment at 32 was the prominent symptom in her daughter, then with only mild facial weakness. Despite absence of ophthalmoplegia, similar pathological changes were observed in an inferior oblique muscle. The child of the former, a 10-year-old clinically healthy boy, had been surgically treated for a bilateral cataract at the age of 3. As indicated by a review of literature, cataract is not an exceptional occurrence in this particular type of ocular myopathy and therefore should be included within its multisystem associations. The same HLA haplotype (A2-B21) was found in the three patients.

Neuropathy and mitochondrial myopathy

It has been stated that peripheral neuropathy can be a feature of so-called ophthalmoplegia-plus syndrome, but to date only one case of hypertrophic neuropathy has been reported. This study is concerned with the clinical, electrophysiological, and pathological observations in a 37-year-old man with progressive external ophthalmoplegia and a ragged-red fiber myopathy associated with severe sensorimotor neuropathy. Histological and morphometric studies of the sural nerve revealed a marked loss of large myelinated fibers and an occasional degenerating axon. Residual fibers had disproportionately thin myelin sheaths in relation to axon calibers. In contrast to the muscle biopsy findings, no mitochondrial paracrystalline inclusions were observed in the nerve. However, the number of mitochondria per square micron of Schwann cell cytoplasm was elevated when compared with values obtained from normal subjects and a patient with a chronic neuropathy. These findings may indicate an alteration of mitochondrial function common to muscle fibers and Schwann cells which, in nerves, could lead to axon loss and abnormality of myelination.

Ophthalmoplegia plus. A multisystem disorder of unknown etiopathogenesis

Six cases of Ophthalmoplegia Plus (OP) have been studied: all the patients had palpebral ptosis, ophthalmoparesis and descending myopathy. Hypoacusis, cardiac conduction impairment, small stature, mental deficit and vestibulo-cerebellar dysfunction were present only in some cases. EMG showed a severe slowing of motor and sensory conduction velocity in one patient. Polyphasic and long duration MU action potentials, which are indicative of a neurogenic myopathy, were found in all cases. Every muscle biopsy showed many "ragged red fibers" which, in EM, appeared to contain abnormal mitochondria. According to the literature and our data, OP appears to be a multisystemic disorder with severe muscle mitochondrial abnormalities, but it is not certain whether it must be considered a syndrome with multiple etiological factors or a single nosological entity with different possibilities of clinical manifestations.

Autosomal dominant Kearns-Sayre syndrome

External ophthalmoplegia, retinal pigmentary degeneration, and heart block constitute the Kearns-Sayre syndrome. Skeletal muscle weakness, deafness, ataxia and endocrine disturbances also may occur. We examined 15 members in two generations of a family with autosomal dominant Kearns-Sayre syndrome. Seven had external ophthalmoplegia, six had electrocardiographic abnormalities, six had limb weakness nad six patients were normal. A deltoid muscle biopsy specimen from one patient contained typical "ragged-red fibers," abnormal lipid accumulation, and mitochondria increased in size and number, containing inclusions. The study demonstrated: (1) the marked variability in genetic expression; (2) the need to examine family members to discover asymptomatic patients and to establish an otherwise unrecognized hereditary pattern; and (3) the absence of specific and consistent biochemical abnormalities.

Hirano bodies in the axon of peripheral nerves in a case with progressive external ophthalmoplegia with multisystemic involvements

Inclusions, ultrastructurally identical with Hirano bodies which were previously believed to be limited to the central nervous system (CNS), were found both within peripheral myelinated nerve axons and within terminal axons of neuromuscular junctions in the ocular muscles of an autopsied woman who had suffered from progressive external ophthalmoplegia with multisystemic involvements. Electron micrographs showed the inclusions to consist of beaded filaments or lattice-like structures with filamentous elements continuing onto neurofilaments in the axon. The corelation of these new pathological findings in peripheral nerve axons and ophthalmoplegia is discussed.

Extraocular muscle biopsy in chronic progressive external ophthalmoplegia

A quantitatives assessment of the pathological changes in extraocular muscle is presented in 8 patients with chronic progressive external ophthalmoplegia (CPEO). Serial cross-sections of extraocular muscle were stained with a battery of histochemical and immunohistochemical techniques and compared with 36 normal extraocular muscles and 1 muscle from a patient who had longstanding third nerve plasy with anomalous reinnervation. Several of the patients had a striking increase in the number of ragged-red fibers in extraocular muscle, particularly if frequent ragged-red fibers also were found on limb muscle biopsy. One patients demonstrated extrajunctional acetylcholine receptor (AChR) in a small percentage of fibers, although this finding was not present in the reinnervated muscle. Numerous darkly staining central regions were noted in the ocular muscle fibers of a patient with Stephens syndrome (CPEO, peripheral neuropathy, and cerebellar disease) and in the reinnervated muscle. A patient with myotubular myopathy had single central nuclei in both limb and ocular muscle. All patients demonstrated in their extraocular muscles variation in both the size and distribution of each of the three histochemical fiber types. Extraocular muscle biopsy proved to be a safe, reliable technique. As a similar quantitative analysis is applied to the study of further patients, a better understanding of the pathogenesis of CPEO should be possible.

Progressive extrinsic ophthalmoplegia with peripheral neuropathy and storage of muscle glycogen

A case of progressive extrinsic ophthalmoplegia associated with peripheral neuropathy and hypertriglyceridemia type IV is described. Motor and sensory conduction velocities of the spinal nerves were severely decreased, while the EMG of the facial muscles was more suggested of a myopathic disorder. Electron microscopic study of biopsies of biceps and peroneus brevis muscles disclosed many ragged red fibers, mainly type I, which contained typical abnormal mitochondria. Other fibers, all type II, contained increased amounts of glycogen between myofibrils or beneath the sarcolemmal membrane, but the mitochondria were normal. These fibers were more abundant in the peroneus brevis than in the biceps muscle. Nerve biopsy revealed marked loss of myelinated fibers, but neither mitochondrial changes nor glycogen storages were evident in Schwann's cells. Biochemical investigations confirmed the increased amount of glycogen in both muscle biopsies and revealed a decrease of guanilcyclase. Phosphorylase, phosphorylase b kinase, adenilcyclase, and carnitine concentrations were all normal. The pathogenesis of this syndrome is discussed and the relationship between mitochondrial abnormalities and glycogen accumulation in muscle tissue are considered.

The early effects of ischemia upon skeletal muscle mitochondria

The effects of early ischemia were studied in the anterior tibial muscle of Sprague-Dawley rats after 2--24 hr of tourniquet compression at the thigh. Ragged-red fibers, moth-eaten fibers, cores and targets were seen in tissue examined by enzyme histochemistry and electron microscopy. Giant mitochondria, abnormalities of cristal arrangement, crystalloids, osmiophilic inclusion bodies and myeloid figures were dominant features of the mitochondrial reaction. The results of this experiment indicate that early ischemia induces a variety of changes described in other neuromuscular conditions such as dystrophy and the "mitochondrial myopathies". The pathogenesis of these changes and their relationship to human disease of muscle is discussed.

The significance of ragged-red fibres in neuromuscular disease

The pathological significance of ragged-red fibres is uncertain. We have studied ragged-red fibres in the muscle biopsies of 3 adults; one with polymyositis and two with progressive external ophthalmoplegia. All the ragged-red fibres were Type 1 fibres. In two patients the mean diameter of the ragged-red fibres was significantly smaller than the unaffected Type 1 fibres. Some of these fibres showed features of regeneration, and others of degeneration. In the patient with polymyositis the mitochondria were proliferated and contained osmiophilic dense bodies; in the other two patients paracrystalline mitochondrial inclusions were prominent. These findings suggest that ragged-red fibres do not represent a single pathological process.

Kearns-Sayre syndrome with hypoparathyroidism

The history, clinical findings, and postmortem examination of a patient with Kearns-Sayre syndrome are presented. In addition to the usuual symptoms, the patient also had hypoparathyroidism. There is increasing evidence that the syndrome is frequently associated with involvement ofthe endocrine system. Central nervous system involvement consists of a spongy encephalopathy.