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Biomedical subjects

S Métral

Publications and source records attributed to S Métral.

15 recordsLinked to original sources
PubMed2001

[Type B botulism: a family outbreak].

CASE REPORTS: Three cases of an outbreak of familial foodborne botulism are reported. The food incriminated could not be identified despite a careful investigation into the food history of the patients. The outcome was good following endotracheal ventilation and botulism antitoxin trivalent therapy. CONCLUSION: In France, foodborne botulism is an uncommon public health disease, and with a good prognosis when the diagnosis is promptly performed. The value of emergency electromyographic findings is emphasized, particularly when the repetitive stimulation of the motor nerve shows a presynaptic block of neuromuscular transmission. Management depends on the symptomatology, and trivalent antitoxin therapy is the only specific treatment.

Adult↗
PubMed2000

[Electrophysiological diagnosis of neurogenic thoracic outlet syndrome].

The neurogenic thoracic outlet syndrome includes the symptoms caused by the compression of the brachial plexus at some point between the interscalene triangle and the inferior border of the axilla. Five patients diagnosed as having neurogenic thoracic outlet syndrome were examined. We determinated clinical and electrophysiological features which lead to thoracic outlet syndrome diagnosis. The clinical features included paresthesia and pain along the inner part of the arm, forearm and hand. Diminished sensation was rare. Muscle weakness was usual and muscle atrophy was associated in severe cases. The association with a lower cervical rib was useful. Electrodiagnostic studies always showed abnormalities. Electromyographic studies showed a reduced recruitment pattern of motor unit activation in intrinsic hand muscles. The medial antebrachial cutaneous nerve action potential amplitude was low. Nerve conduction studies also showed loss of amplitude of the ulnar sensory and median motor responses.

Adult↗
PubMed1995

[Electrophysiologic tests and benzodiazepine hypnosis].

The effects of a pure benzodiazepine antagonist (Flumazenil) on the responses R1 and R2 of the blink reflex, psychomotor tests, and Event Related Potentials (ERP), in six healthy volunteers sedated with Midazolam have been compared. Measurements were made during each of four successive phases. Phase 0 corresponded to control recordings. Midazolam was administered rapidly during phase 1 and slowly during phase 2. Phase 3 corresponded to spontaneous waking once the administration of Midazolam had been stopped. Flumazenil was administered during phase 2. As the subjects fell asleep, R1 and R2 were the last parameters to disappear. Under the influence of Flumazenil, R1 was the first to reappear, while R2 did not recur until complete waking, and the other tests were unpracticable. During phase 3, R1 reappeared before R2 once more, the psychomotor test responses and ERP returning only later. The modifications of both R1 and R2 of the blink reflex are a good criterion of the presence of BZD in a toxic coma and a good test to indicate the depth of a coma or a sedation with BZD, whilst ERP, since they require the cooperation of the patient, are a test of vigilance and not of awakening.

Anti-Anxiety Agents↗
PubMed1990

In vitro model of far-field stationary potentials: boundary effects on propagated potentials.

Far-field stationary potentials have been said to result from several factors such as changes in the anatomical orientation of the direction of a propagating nerve action potential (AP) or local modifications of the impedance in the external volume conductor by changes in its geometry or resistivity. In the case of an impedance variation due to the presence of boundaries in the geometry of the medium, the findings reported in this paper showed that it is possible to record simultaneously AP and stationary potentials which we have called boundary potentials (BPs). The BP amplitude depended on the number of active axons at the boundary, on the distance between the boundary and one of the recording electrodes, and on the local impedance variation. Its polarity depended only on the direction of the AP propagation relative to the sign of the local impedance modification, the recording electrodes being in the same relative positions with respect to the direction of the propagating impulse. Finally, the recording of a BP remained possible whatever the relative position of the boundary and of the recording electrodes. These findings are in accordance with some clinical observations not yet explained.

Action Potentials↗
PubMed1989

[Lepromatous leprosy: clinical and electrophysiological arguments in favor of axonal multi-neuritis].

UNLABELLED: This work was undertaken because there were only few reports on neurological aspects on lepromatous leprosy. We studied 30 patients suffering from lepromatous leprosy who, at their first visit to the Institute had never been treated. The clinical examination included a quantitative evaluation of the neurological status following the method developed by Pearson. Motor and sensory nerve conduction velocities were measured: values of conduction velocity and distal amplitude were analysed and compared to those of a group of 22 healthy subjects. IN CONCLUSION: (a) There is a high frequency of clinical and especially electrophysiological neurological impairment. This impairment can be extremely precocious and may happen shortly after the first cutaneous signs. (b) Nervous impairment is diffuse, bilateral but not homogeneous. These are characteristics of mononeuritis multiplex. Impairement is predominantly sensitive and tactile sensibility is more involved than thermo-algic sensation. (c) The radial superficial nerve is the most frequently involved clinically and electrophysiologically. (d) The electrophysiological results, showing a normal or slightly reduced conduction velocity and a low amplitude of evoked potentiel are in favour of a predominantly axonal damage.

Axons↗
PubMed1985

Peripheral nerve involvement in children with chronic cholestasis and vitamin E deficiency. A clinical, electrophysiological and morphological study.

Seven children with early onset cholestasis who developed signs of peripheral neuropathy were investigated before and after one and a half to three years of treatment by vitamin E. This neuropathy appeared to be due to neuronoaxonal degeneration, but unusual Schwann cell inclusions were also observed. Although the treatment stabilized or improved the condition of all patients, no striking changes were noted neither in the EMG nor in the second nerve biopsy of a patient treated for three years. As the pathological process concerned it is probably both a developmental disorder and a degenerative phenomenon, substitutive vitamin E treatment should be proposed very early in life.

Adolescent↗
PubMed1978

[Prospective etiologic survey on apparently primary nonobstructive myocardiopathies in adults. 57 cases, excluding ischemic cardiopathies].

A prospective study into the aetiology of presumed primary non-obstructive cardiomyopathy was carried out in 57 patients who had no lesions of the trunk of the coronary artery; one case of haemochromatosis and one of amyloidosis were found. Excluding these two cases of cardiomyopathy which were in fact secondary, most of the others were associated with manifestations or with complications of myocardial diseases (two pulmonary emboli and one case of jaundice) or pathology associated with it. Investigation into possible infection, biochemical abnormalities and dietary indiscretion (alcohol, colza oil), were unfruitful. Electromyographic changes of the "myositic" type were very common. The bicycle ergometry test was often interrupted through fatiguing of the peripheral muscles. These findings suggest that the muscular abnormalities may not be limited to the heart. The cost of an enquiry of this type has been investigated.

Adolescent↗
PubMed1975

Free erythrocyte protoporphyrin level and nerve conduction velocity in end-stage renal disease.

Increased free erythrocyte protoporphyrin concentrations and depressed motor nerve conduction velocities (MNCV) were observed in 45 patients on maintenance haemodialysis. Neither of these findings could be correlated with age, duration or frequency of dialysis, or the degree of uraemia present. A strong negative correlation (r=--0-53; P less than 0-001), however, existed between the free erythrocyte protoporphyrin level and the MNCV, which suggested either (a) a direct effect of iron status on nerve function, or (b) a toxic factor in "uraemia" that depresses both nerve conduction and haemsynthetase activity.

Adult↗
PubMedDate not supplied

[Negative schizophrenic symptomatology and the P 300 potential].

We studied the latency and amplitude of the P 300 wave of event-related potentials (P 3) in 19 hospitalised schizophrenic patients. We used an odd ball paradigm procedure in acoustic stimulation. We found a negative correlation between the amplitude of P 3 and negative schizophrenic symptomatology, measured by the negative BPRS score and the SANS score. However, no link would appear to exist in our study between positive symptomatology and P 3 amplitude. The correlation with the negative BPRS score is found in both evaluations, at the beginning and at the end of the period of hospitalisation. P 3 latency would appear to be independent of either positive or negative schizophrenic symptomatology. It would thus appear to us that the negative symptomatology, rather than the positive, could be at the origin of marked changes in P 3, observable fro relatively simple experimental but parameters such as reaction time or error scores remain to be specified, even if they appear to intervene infrequently. The use of event-related potentials would thus appear pertinent in clinical research and could help in the homogenisation of schizophrenic populations studied.

Adolescent↗