Biomedical subjects
Publications and source records attributed to J Verroust.
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The place of lumbar sympathectomy in the treatment of occlusive arterial disease of the lower limbs remains controversial. An adequate assessment of sympathetic nerve function in the practice of sympathectomy may reduce unsatisfactory results of this procedure. We report a series of 25 lumbar sympatholyses indicated for claudication, rest pain or distal arterial ulcer, and attempted by means of phenol injection in sympathetic ganglia under tomographic guidance. Sympathetic skin response (SSR) recording, an electrophysiological test of sympathetic activity, was performed before and after phenol injection, and its results were compared to the clinical outcome. SSR was abolished in the treated limb after phenol injection in only 64% of the cases. The post-injection abolition of SSR was correlated with the clinical improvement rate: 11% when SSR was still present, but 75% when SSR was abolished. In this latter case, the pre-injection values of SSR amplitudes could predict the clinical benefit of sympatholysis. It is necessary to assess the sympathetic activity in a limb before and after doing sympatholysis. Preoperatively, this activity may be diminished or already abolished in patients suffering from neuropathy involving the autonomic nervous system, limiting the indication of sympathectomy. Postoperatively, if sympathetic activity is still present in the treated limb, it implies that the sympathectomy is not completed, and it supports the indication of a new sympatholysis attempt. These observations show the usefulness of SSR recording in the practice of phenol sympatholysis, this test being simple and specific of sympathetic nerve function.
Electromyographic interference patterns during a gradual increase in force were studied by means of the turns-amplitude analysis in a series of HIV-infected patients with and without clinical, biological and histological signs of myopathy. Different parameters were evaluated to determine their sensitivity for the diagnosis of the myopathies that occur in this context. The studied parameters were the number of turns (NT), the mean amplitude of the turns (MA) and the ratio NT/MA (RTA). For each parameter, we compared the interest of mean values, calculated at moderate contraction, to that of peak values. In addition, the shape of the cloud of MA plotted versus NT data points was analyzed. The sensitivity of the turns-amplitude analysis was 95% for the diagnosis of myopathy when NT, MA and RTA were taken together into account, versus 80% in the cloud studies. Peak values were the most sensitive criteria, but mean values abnormalities were observed in some cases of zidovudine myopathy, indicating a potential usefulness of this quantitative EMG method in the differential diagnosis among myopathies in HIV-infected patients.
BACKGROUND AND DESIGN: We retrospectively studied 12 patients with dermatomyositis (DM) with at least one laboratory criterion of muscle involvement but without muscle weakness. We reported their outcome without systemic corticosteroid treatment and searched for distinctive baseline data and associated neoplasia among a group of 29 patients with classic DM. RESULTS: After a mean follow-up of 5.3 years, complete or partial skin improvement occurred in nine patients with DM without muscle weakness, and muscle enzyme levels were normalized in all. When compared with the classic DM group, no statistical differences were found for associated neoplasia or for any baseline data studied except, as expected, for muscle parameters. CONCLUSIONS: The lack of distinctive baseline data between DM without muscle weakness and classic DM suggests that there is a continuum from amyopathic to classic DM. However, DM without muscle weakness is a clinical entity with respect to favorable long-term prognosis. Unless frank muscle weakness develops, treatment with systemic corticosteroids can be avoided.
A methodology which accounts for uncertainty or imprecision in experimental observations and both norm and pathology definitions is developed on the basis of a distance measure between fuzzy numbers. These fuzzy numbers may represent, respectively, the measurements, norm, and pathology. The distance measure, called normalized fuzzy pathology index (NFPI), evaluates the difference of distance between observed experimental values for a given patient and norm on the one hand, and pathology on the other hand. The NFPI characterizes patient state as a continuous index; however, to conform to medical usage, categories of values are defined. Each of these categories corresponds to a linguistic variable. The case study used to illustrate the methodology is the electrodiagnosis of peripheral polyneuropathy in diabetic patients. Here, four initial linguistic categories are defined by a physician, namely: normal state, borderline state, clear-cut, and severe pathology. The NFPI is calculated in three cases that provide a sensitivity analysis on measurement fuzziness and distance function weighting. The model is calibrated using 203 cases and validated using 291 different cases. The results correspond very closely to the physician's diagnosis. The loss of information in discretizing the continuous state of patients is discussed. Transferring this fuzzy approach to other cases where the concept of distance is relevant offers no difficulty.
BACKGROUND AND DESIGN: Thalidomide therapy was shown to be effective in numerous dermatologic diseases. As reliable methods of contraception are now available, neurotoxicity has become the most important side effect limiting the use of thalidomide. The incidence of this neuropathy and its relationship to thalidomide doses are still matters of debate. In a retrospective study, we reviewed the files of 42 patients who had received thalidomide between 1987 and 1992 for various dermatologic diseases. The incidence and the conditions of occurrence of the neuropathy were analyzed. RESULTS: Evidence of a thalidomide-induced neuropathy was present in nine patients (21%), who had both clinical and electrophysiologic typical abnormalities. Twelve other patients (28%), however, presented with isolated clinical or electrophysiologic signs. Thus, the diagnosis of thalidomide neuropathy could not be affirmed. The occurrence of the neuropathy did not appear to be related to the daily dose nor to the duration of treatment. The highest risk of developing a thalidomide neuropathy was found in female and elderly patients. Two monozygotic twin sisters, who received thalidomide for Behçet's disease, both developed a neuropathy. CONCLUSIONS: These data suggest that the incidence of thalidomide neuropathy may be between 21% and 50%. Individual susceptibilities with possible genetic predisposition seem to be more important than daily dose and duration of thalidomide therapy.
A young woman suffering from sleeping sickness was treated with melarsoprol. Thirty-eight days after the first administration of this organo-arsenic compound, myalgias, distal paresthesias and rapidly progressive weakness developed in all four limbs. Electrophysiological studies were misleading for Guillain-Barré syndrome. Neuropathological data included massive distal wallerian degeneration in peripheral nerves and abnormalities in dorsal ganglia and spinal cord where vacuolation of anterior horn cells and axonal neurofilamentous masses were observed. Very high concentrations of arsenic were found in the spinal cord, contrasting with undetectable levels in peripheral nerves. Our findings are consistent with an arsenic neuronopathy manifested by initial proximal demyelination and delayed distal axonal damage. Renal and hepatic dysfunctions, which were implicated in the toxic arsenic accumulation, should be systematically detected before administration of melarsoprol. The diagnosis of Guillain-Barré syndrome must be considered with caution in patients treated with this compound.
To specify the factors related to taste function in Type 1 diabetes mellitus, 50 diabetic out-patients and 50 control subjects paired for age and sex were screened for taste disorders. None of them consumed significant amounts of alcohol, smoked, or had disease or took drugs capable of altering taste. Taste was studied with electrogustometry, retinopathy was detected by fluorescein angiography, nephropathy by measurement of albuminuria and microalbuminuria, peripheral neuropathy by electroneurography and electromyography, and autonomic neuropathy by cardiovascular function tests. The electrogustometric threshold was, on average, significantly higher in the diabetic group (133 +/- 30 microA) than in the control group (29 +/- 9 microA; p less than 0.001). Electric hypogeusia (electrogustometric threshold greater than 100 microA) was found among 54% of the diabetic patients vs 2% of the control subjects (p less than 0.001). In the diabetic group, the electrogustometric threshold was associated with complications of diabetes, especially with peripheral neuropathy (210 +/- 24 vs 90 +/- 22 microA; p less than 0.001) and microalbuminuria (185 +/- 25 vs 86 +/- 21 microA; p less than 0.01). It was correlated with age (r = 0.37; p less than 0.01) and duration of diabetes (r = 0.52; p less than 0.001) but not with HbA1c (r = -0.04). Using multivariate analysis, duration of diabetes and peripheral neuropathy had the strongest association with taste impairment. These results support previous findings, suggesting that taste impairment is a degenerative complication of diabetes mellitus.
The somatosensory evoked potentials from median nerve were studied in a group of 127 normal adults aged from 19 to 79. The latencies of elbow, Erb's, cervical N11 and N13 as well as cortical N20 and P25 potentials were analyzed as a function of height and age. Two central conduction times, N20-N11 and N20-N13, were equally studied. The corresponding regression formulae were calculated and can be used to predict normative values of these parameters over a wide range of height and age. Standard error estimates are given for all parameters.
The aim of this paper is to study the neuromuscular excitability of a group of marathon runners and to see how it can be modified right after the marathon. Spontaneously appearing multiplets in EMG signal under ischaemia served as a test of the neuromuscular hyperexcitability. The percentage of positive tests is much higher than in the control population; as a rule, the effect of the marathon is to diminish the neuromuscular hyperexcitability. The concentrations of Ca, Mg and P in the plasma as well as the globular concentration of Mg have been determined several times, both before and after the marathon; no correlation has been found with the neuromuscular hyperexcitability.
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Asterixis was observed in 20 cases of focal brain lesions. Metabolic or toxic factors were excluded. An electromyogram study of asterixis was carried out in nine cases to establish the diagnosis. The site of the focal lesion was either parietal or mesencephalic and was always contralateral to the asterixis. "Focal asterixis" could result from a dysfunction of the sensorimotor integration in the parietal lobe and the midbrain.
This article concerns the electromyographical study of a synthetic curare derived from Azobis Arylimidazo (1-2a) Pyridinium (AH/8165) with a simultaneous recording of the spontaneous diaphragmatic activity and "testing" of the neuro-muscular transmission at the level of a peripheral muscle. This study shows that AH/8165 is a powerful non-depolirizing curarimimetic drug that quickly induces a neuro-muscular block at the level of the diaphragm and the peripheric muscles that can be reversed by anticholinesterasic drugs. Its reaction time is short (about 1 mn). There are importante individual variations in the duration of the neuromuscular blockage. Towards the end of the experience, tetanizing stimulations reveal a muscular fatigability in all the cases. No ill side-effects could be observed upon the cardiovascular system or any side-effects ascribable to a histaminergic mechanism.
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