J. A. Levy

Mitochondrial dysfunction in myasthenia gravis: report of a case

The case of an 11-year-old boy with external ophthalmoparesia, tetraparesia and bilateral eyelid ptosis is reported. He was 7-years-old when first symptoms appeared. Anticholinesterasic drugs were used. He was submitted to muscle biopsy. The results of histochemistry analysis showed storage of granulous material at the subsarcolemmal region of muscle fibers by SDH. Increase in the number of mitochondria with electron dense bodies was found at electron microscopy. Anticholinesterasic drugs administration was interrupted and consequently he got worse, and bouts of dyspnea occurred. Due to this worsening anticholinesterasic agents were reintroduced together with prednisone, and he improved. Due to clinical and histological expressions we think it is possible that morphological mitochondrial alterations may occur also in myasthenia gravis.

Mitochondrial myopathy with respiratory muscle involvement: a case report.

A case of a 10-year-old patient with a benign congenital myopathy, suddenly aggravated because of an accentuated deficit in respiratory muscles is reported. The institution of assisted respiration at night allowed the patient to return to her daily activities. Examination of muscular biopsy with ultra-microscope permitted the diagnosis of mitochondrial myopathy.

Non-epileptic myoclonus and mitochondrial encephalomyopathy

Two brothers presented to us with a progressive myoclonic syndrome with slight cerebellar symptoms. Neurological examination disclosed moderate cerebellar signs and pale optic discs; asymmetric, asynchronous and arrhythmic myoclonus, an arrthesthesic deficit and no muscular weakness. EEG background activity was moderately slow with no irritative discharges. CT was normal in both cases. Intermittent photic stimulation increased the frequency of the myoclonic jerks, which became bilateral and synchronous, progressing to a generalized tonic-clonic seizure. EPs and MRI in one case were normal. Anticonvulsant drugs were ineffective. The diagnosis of mitochondrial encephalomyopathy was based on the finding, in muscle specimens, of thickened basement membranes with myofibrillary degeneration and increased number of mitochondria peripherally distributed and with a dense granular matrix and some vacuoles. The clinical and EEG data suggest a subcortical origin for this type of myoclonic syndrome.

Cytogenetical and dermatoglyphic studies in patients affected by steenert's myotonic dystrophy

Cytogenetic and dermatoglyphic studies were performed in 10 patients affected by Steinerts myotonic dystrophy. No anomalies were found in karyotype and dermatoglyphs in these patients, except for an occasional chromosomal translocation.