Journal of Neurology Neurosurgery & Psychiatry

Ballantyne, John P.; Hansen, Stig

doi: 10.1136/jnnp.37.11.1187pmid: 4457614

An on-line computer method is described for the isolation of single motor unit potentials, evoked by stimulation of the anterior tibial nerve at the ankle, from the compound action potential recorded from surface electrodes over the extensor digitorum brevis muscle. The latencies, durations, amplitudes, and areas of the potentials were measured in a group of control subjects and patients with myasthenia gravis. In myasthenic patients there is a significant reduction in the durations of motor unit potentials and a significant increase in latencies while their amplitudes and areas remain unchanged. The results are consistent with the presence of a `terminal neuropathy' in myasthenia gravis.

Ballantyne, John P.; Hansen, Stig

doi: 10.1136/jnnp.37.11.1195pmid: 4457615

The results of the application of a computerized method for the estimation of motor unit numbers in the human extensor digitorum brevis are presented. In patients with Duchenne and limb-girdle and facioscapulohumeral muscular dystrophies, motor unit numbers are within the normal range, but are significantly reduced in myotonic muscular dystrophy.

Singh, Naunihal; Behse, Friedrich; Buchthal, Fritz

doi: 10.1136/jnnp.37.11.1202pmid: 4376162

The diagnostic yield of different electrophysiological criteria was examined to establish whether a peroneal palsy was due to compression of the nerve in the region of the capitulum fibulae. Slowing of sensory conduction along the segment of the nerve across the capitulum fibulae localized the lesion in 64% of 47 consecutive patients with a history indicating or suggesting compression of the nerve in the vicinity of the capitulum fibulae and there were no false positive findings in 18 patients whose peroneal palsy was not due to compression at the capitulum fibulae. In 20% of the patients with slowing along the segment across the capitulum, conduction velocity was normal when measured from the superior retinaculum to the popliteal fossa. Slowing along motor fibres (m. extensor digitorum brevis) localized the site of the lesion in one-third of the patients. Differences in amplitude and in split-up of the sensory responses recorded in the popliteal fossa as compared with those recorded distal to the capitulum fibulae were of limited diagnostic value because of many false positive findings among patients whose peroneal palsy was not due to compression of the nerve at the capitulum fibulae.

Brown, J. Colin; Johns, Richard J.

doi: 10.1136/jnnp.37.11.1214pmid: 4376163

Six patients with the physiological features of the myasthenic syndrome associated with carcinoma are presented. The clinical features encountered in this group, including age, mode of onset, and duration of symptom indicate that it may escape detection owing to its resemblance to other neuromuscular disorders. Conventional concentric needle electromyography may lead to the disorder being confused with a myopathy. The association with carcinoma is by no means constant. Clinical and physiological improvement with guanidine is described in each case.

Visser, B. W. Ongerboer De; Goor, C.

doi: 10.1136/jnnp.37.11.1225pmid: 4457616

Recorded jaw reflexes were studied in 51 normal subjects. In addition, the blink and jaw reflexes combined with masseteric electromyography were recorded in 17 unselected patients with facial pain. Six of these patients, including two without neurological anomalies, showed electrodiagnostic anomalies. The method proved valuable for differentiation between idiopathic and symptomatic trigeminal neuralgia.

Isaacs, Hyam; Heffron, J. J. A.

doi: 10.1136/jnnp.37.11.1231pmid: 4281819

Two cases suffering from the syndrome of `continuous muscle-fibre activity' have been followed-up for 14 years. These patients have gradually gone into remission and no longer require therapy. The results of recent histology, histochemistry, and electronmicroscopy, as well as sural nerve biopsy studies, are presented. The sarcoplasmic reticulum calcium binding activity and ATPase activity are normal.

Sulaiman, W. R.; Doyle, D.; Johnson, R. H.; Jennett, S.

doi: 10.1136/jnnp.37.11.1236pmid: 4376164

Apparently new information about a metabolic abnormality has been obtained by measuring biochemical and respiratory responses to controlled exercise in a patient with abnormal mitochondria in muscle fibres. A male patient (49 years old) presented with bilateral ptosis of 15 to 20 years' duration and weakness for one to two years. Biopsies from the deltoid and triceps muscles were subjected to histological, histochemical, and electron microscopical examination. Routine histology showed only minor changes; 2-5% of muscle fibres had pale borders in which there were aggregates of mitochondria and 1-5% of fibres showed atrophy. Histochemical examination showed increased activity of succinic dehydrogenase in mitochondria and lactate dehydrogenase in cytoplasm. Electron microscopy showed crystalline inclusions in many subsarcolemmal mitochondria. Metabolites were studied during and after exercise on an ergometer and revealed remarkable differences from normal. Blood lactate rose to 12·5 μmol/ml and pyruvate to 0·39 μmol/ml compared with up to 4·0 and 0·16 μmol/ml respectively in controls exercising to a comparable percentage of capacity. Concentrations of ketone-bodies and free fatty acids fell during and after exercise, while they rose in the controls. These observations imply a major mitochondrial defect which causes dramatic biochemical changes in fuel supply in blood during exercise. The changes suggest that fat metabolism was accelerated (in this patient) and was related to a block of carbohydrate utilization as fuel.

Herbison, G. J.; Jaweed, M. Mazher; Ditunno, J. F.

doi: 10.1136/jnnp.37.11.1247pmid: 4457617

There are no studies that define the optimum intensity or time to begin exercising reinnervating muscle. Through overwork of reinnervating muscle, accomplished by synergistic tenotomy, we developed a working hypothesis. This hypothesis was tested on a physiological model. In the present study, the sciatic nerve of five groups of rats was crushed. One group served as the control and the remaining animals were exercised by swimming with weights attached to their tails for one or two hours each day (early reinnervation group) or four weeks (late reinnervating group) after crush denervation. The evaluation of muscle weights, fibre types, and protein concentration indicate that intense swimming (two hours every day) does not enhance the repair of reinnervation muscle. An evaluation of total proteins suggests that a high workload may be hazardous in the early phase of reinnervation. This study tends to confirm the hypothesis that when there are too few contractile units, as presumably is the case in early reinnervation, exercise inhibits the reinnervation process.

Iivanainen, M.; Taskinen, E.

doi: 10.1136/jnnp.37.11.1252pmid: 4142044

The behaviour of the CSF cells during gas encephalography (GEG) with O2, N2O, and halothane is poorly known in cerebral developmental disorders. One hundred and fifty CSF samples taken during pneumoencephalography from 75 mentally retarded patients were examined cytologically by the millipore technique with Papanicolaou staining. The results were processed automatically. An approximately 25-fold increase in CSF cells (P<0·001), mainly meningeal, reticulohistiocytic, and monocytic types, was found to occur. The cortical gas filling rate had a positive correlation (P<0·001) with the increase of number of CSF cells. There were no significant differences between the cellular changes in different cerebral disorders. Thus, though the irritant effect of GEG gives a rich cell yield, diagnostic atypical cells in developmental disorders of the central nervous system probably rarely exfoliate into the lumbar CSF.

Barnard, R. O.; Triggs, Margaret

doi: 10.1136/jnnp.37.11.1259pmid: 4457618

A neuropathological study of 20 multiple sclerosis brains using celloidin-embedded slices was carried out to assess the extent of changes in the corpus callosum. Severe atrophy of the callosum was found in cases with marked hydrocephalus. Demyelination of the callosum varied in extent from slight involvement (with a few small plaques) to almost total myelin loss. A clinical history of mental deterioration was usual in the cases with severe callosal lesions, but no symptoms were recorded that indicated a specific disconnection syndrome. The ventricular enlargement noted in this series could not be explained either on the basis of obstruction to the flow of cerebrospinal fluid, or by the effects of shrinkage of the white matter.