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Biomedical subjects

P Brunet

Publications and source records attributed to P Brunet.

At least 109 records · Page 6Linked to original sources

Postradiation segmental myoclonus selectively inhibited by REM sleep (sleep-wake myoclonus).

A 46-year-old male patient was irradiated following left orchiectomy for seminoma. Three months after radiation, segmental myoclonus appeared involving all skeletal muscle groups up to the level of D10, the area of radiation. Urodynamic testing showed the presence of segmental myoclonus in the urethral sphincter. An around-the-clock 'continuous segmental myoclonus' during sleep and wakefulness with a frequency of 1 c/s and an amplitude of 400 microV selectively inhibited by REM sleep was not found in the literature. This continuous segmental myoclonus caused by a radiation myelopathy at D10-D11 was followed up for 2 years. It was partially controlled by carbamazepine.

Carbamazepine↗

[The peripheral nervous system and HIV infection. 13 cases].

Disorders of the peripheral nervous system occur at all stages of HIV infection. From 13 patients referred for a peripheral neuropathy, 9 were known to be HIV seropositive and 4 were found to be seropositive. All were Caucasian males aged 27 to 58. Ten were homosexual, 2 were drug-addicts. Patients fell into several groups: the first group was made of 5 patients, 4 asymptomatic and 1 AIDS-related-complex (ARC), with an inflammatory demyelinating polyneuropathy, acute in 1 case and subacute in 4; the CSF showed pleiocytosis in all cases. Motor conduction nerve velocities were markedly reduced and motor distal latencies prolonged. Three patients recovered spontaneously, 1 responded to corticosteroids, 1 to plasmapheresis. In the second group, 4 patients, 1 asymptomatic and 3 ARC, had a distal symmetrical polyneuropathy; CSF was normal in 2 cases. Electrophysiological studies and nerve biopsies indicated a mixed axonal-demyelinating polyneuropathy. Three patients recovered spontaneously, 1 is unchanged. Among both groups, an infiltration of mononuclear cells was found on nerve biopsies in 4 cases. The third group was made of 3 patients with AIDS who presented with a painful sensory polyneuropathy involving the distal lower limbs. Electrophysiological and pathological study of the nerve indicated axonal degeneration. No cell infiltration was found. The last patient with AIDS had a progressive meningoradiculopathy. These 4 patients died within 6 months after the onset of the neuropathy. These findings are close to those previously reported, and confirm the wide spectrum of disorders of the peripheral nervous system associated to HIV infection.

Acquired Immunodeficiency Syndrome↗

[Human acquired immunodeficiency virus infection of the nervous system].

Neurological manifestations of HIV infection are recognised at different phases of the evolution of the disease. During the late stages opportunistic neuro-meningeal infections and tumors develop as a result of the immuno-suppression. There exist, however, various manifestations which evolve independently of the immune state, and seem to be directly related to the virus itself. One can distinguish central neuro-meningeal syndromes and peripheral syndromes at the onset, or at later stages. Their prognostic implications are uncertain, but often severe, for example in the case of the subacute dementias which, in this setting, may lead to death in several months. There are also other manifestations which may be self limited or slowly evolving in the central and peripheral nervous systems. The neuropathological changes are known for the dementias as mentioned above, though the characteristics lesions due to HIV infection per se remain controversial. The presence of the virus in the nervous system has been established by in situ hybridization techniques, immunohistochemistry and culture. Studies on CSF have also allowed virological (cultures) and immunological studies to be carried out. The physiopathological mechanisms for the apparent neurological effects of this virus remain hypothetical. A better understanding of these mechanisms should lead to a rationalisation of therapeutic strategies, in a disorder which would seem to be an early and persisting viral infection of the nervous system.

Acquired Immunodeficiency Syndrome↗

Isolation of HIV in a seronegative demented patient without symptoms of immune deficiency.

A 60-year-old male patient, originating from West Africa, developed acute and regressive neurologic symptoms associated with aphasia, apraxia, acalculia, behavioral impairments, and an epileptic phase. Eighteen months after the onset of the disease, the patient was almost normal. All along the clinical course, biological abnormality patterns were minor. We noted only a mild neutropenia in the blood. We also observed a weak lymphocytosis and elevated protein content in the cerebrospinal fluid. Electroencephalogram examination revealed slow waves which disappeared after remission. A weak ventricular dilatation was detected on CT scan. Neither vascular, nor tumoral, nor a classical infectious origin could be identified. While the patient was seronegative to HIV, a HIV-like virus was isolated twice from his peripheral blood lymphocytes during the disease. Eighteen months later, the patient remained seronegative. He developed neither AIDS nor immunodeficiency. The subtype of HIV has been isolated and characterized, and its neurotropism is being investigated.

Antibodies, Monoclonal↗

[Neuromuscular forms of hyperparathyroidism. Apropos of 2 cases].

The authors report two cases of hyperparathyroidism presenting mainly with muscular weakness. In the first case, a 74 year old woman had become completely bed-ridden and muscular recovery was obtained in 18 months. In the second case, a 24 year old sportsman had to stop all competition. Hypercalcaemia was suspected after finding radiological muscular calcification; the patient was able to start his sporting activities again two months after excision of the adenoma. After a review of the literature the authors discuss the principal physiopathogenic mechanisms; a direct action of parathormone is the probable cause but this has not been proved. Muscular forms of hyperparathyroidism are rare but this "pseudo-myopathic" presentation justifies the systematic exclusion of hyperparathyroidism in all cases of unexplained muscle weakness.

Adolescent↗

Interaction of bradykinin and des-Arg9-bradykinin with isolated pig coronary arteries: mechanical and electrophysiological events.

This paper describes the effect of bradykinin (BK) and des-Arg9-BK on the isometric tension and smooth muscle membrane potential of transverse strips of pig coronary artery. BK causes a relaxation of contracted muscle. This effect is particularly evident in muscle which has previously been contracted by acetylcholine. The relaxation is accompanied by a transient hyperpolarization of the vascular smooth muscle. Des-Arg9-BK, in contrast, causes a contraction of the muscle which is not accompanied by a significant change of transmembrane potential. The relaxing action of BK depends on the presence of the endothelium. In a "cascade" experiment, evidence is presented that a relaxing factor is released by the endothelium in response to BK. Thus the perfusate from a BK-stimulated intact artery can cause the relaxation of a pre-contracted de-endothelialized artery. We conclude that the endothelium has B2-receptors which cause the release of a humoral factor which hyperpolarizes and relaxes the muscle. The contracting action of des-Arg9-BK does not depend on the endothelium and appears to be mediated through B1-receptors directly on smooth muscle by pharmacomechanical coupling.

Animals↗

Kinetics of methotrexate and its metabolites in red blood cells.

It has been suggested that the intra-erythrocyte levels of methotrexate (MTX) and its polyglutamized derivatives could offer a method for evaluating intracellular MTX accumulation and its metabolism in children with acute lymphoblastic leukemia. We were interested in measuring the intra-erythrocyte levels of MTX in patients with solid tumors receiving high-dose MTX treatment. After a first incorporation stage occurring during infusion, MTX concentrations subsequently increased 9-12 days after the treatment as polyglutamized derivatives. Thirty days after the infusion, MTX and its polyglutamates were still measurable in erythrocytes. The percentage of polyglutamization varied on an individual basis, but two groups of patients could be separated according to their ability to form polyglutamates. We also noted the presence of 7-hydroxy-methotrexate (7-OH-MTX) appearing 48 hours after the beginning of the infusion which was still present in 17/20 samples 30 days after the treatment.

Adult↗

[Amyloidosis and orthostatic hypotension. Physiopathology, therapeutic attempts. Apropos of 5 cases].

Three cases of primary amyloidosis and 2 cases of familial amyloidosis complicated by asympathicotonic orthostatic hypotension are reported. Blood pressure measurements on a tilting table, plasma renin activity and plasma aldosterone or catecholamine concentrations enabled localisation of the lesion of the baroreceptor reflex in some cases. When the pre- and post-synaptic efferent sympathetic pathway was intact, treatment associating Tyramine and Tranylcypromine may provide these bedridden patients some autonomy of movement. When this pathway is affected by the disease the association of Indomethacin, Dihydroergotamine and 9-alpha-fluorohydrocortisone may be tried.

Adult↗

Infarcts of both inferior parietal lobules with impairment of visually guided eye movements, peripheral visual inattention and optic ataxia.

Clinicopathological correlations are reported in a case with bilateral isolated infarcts in the posterior part of the parietal lobes, due to nonbacterial thrombotic endocarditis accompanying pancreatic adenocarcinoma. The initial left-sided infarct induced right visual neglect, impairment of right-beating optokinetic nystagmus (OKN), optic ataxia, Gerstmann's syndrome and apraxia. After the right-sided infarct, which occurred six weeks later, bilateral visuo-oculomotor disturbances were observed, including peripheral visual inattention, disorder of visually guided saccades, severe impairment of foveal smooth pursuit and OKN slow phase. The lesion on the left involved the upper part of the angular gyrus and a part of the adjacent superior parietal lobule (SPL). That on the right involved the supramarginal gyrus and extended posteriorly into the superoanterior extremity of the angular gyrus, into both margins of the adjacent intraparietal sulcus and into a small part of the SPL. As the oculomotor deficits and the peripheral visual inattention were bilateral after the second infarct, they probably resulted from the lesion of homologous areas in both cerebral hemispheres. The zone damaged in common included a small part of the SPL, the superoanterior extremity of the angular gyrus, and the adjacent intraparietal sulcus and a small portion of the subcortical white matter. This restricted cerebral zone could therefore, in man, be implicated both in the control of all visually guided eye movements and in visual attention. It is further suggested that two corticofugal pathways are implicated in visually guided saccades, the first arising from the frontal eye fields and projecting directly onto the premotor structures in the brainstem, the second arising from the posterior parietal cortex (probably mainly the intraparietal sulcus adjacent to the angular gyrus) and including a relay in the superior colliculus before reaching the premotor structures. Lastly, the findings support the hypothesis that optic ataxia results from interruption of direct and/or crossed occipitofrontal pathways coursing in the deep white matter of the parietal lobe.

Ataxia↗

[Marfan's disease and familial neuropathy with sausage-shaped swelling. A case of fortuitous association].

A 25-year-old patient and his sister had Marfan's syndrome and recurrent pressure neuropathy. Marfan's syndrome was inherited from their father while the neuropathy was inherited from their mother. Thus, the association of both disorders in the same patient was fortuitous. However it is suggested that the ligamentous hyperlaxity related to Marfan's syndrome may favour the occurrence of the neuropathy due to pressure.

Adult↗

Familial disorder of the central and peripheral nervous systems with particular cytoplasmic lamellated inclusions in peripheral nerves, muscle satellite cells, and blood capillaries.

Four siblings of a family of 11 were afflicted with a predominant parkinsonian syndrome, pyramidal signs, intellectual deterioration, and peripheral neuropathy. Symptoms were noticed first when they were aged 8 years; the condition was slowly progressive. All presented similar clinical features of varying severity. Nerve and muscle biopsies of two patients exhibited inclusions of concentric lamellae 2 nm thick with a periodicity of 3.6 nm, in the cytoplasm of perineurial and Schwann cells, endothelial cells and pericytes of blood capillaries, and muscle satellite cells. These inclusions differ in their location and morphological features from other inclusions that have been described in nerve and muscle biopsies of many disorders. The features of these inclusions suggest that they may represent a storage deposit whose nature could not be determined. They may be a distinguishing morphological feature of a multisystem disorder which to our knowledge has not been identified previously.

Adult↗

[Electro-clinical semiology of subintrant temporal lobe seizures].

The authors recorded 10 to 67 TLS (mean 29) in 10 patients (5 M, 5 F; 9 to 41 years, mean 23) during 'acute' (4-6 hours) stereo-EEG exploration. At the onset of seizures, we observed: subjective manifestations (often epigastric), autonomic symptoms, and oro-alimentary 'automatisms'. Affective, unpleasant, manifestations occurred in only 2 patients. The discharges may only affect the Ammon's horn, but they never involve only the amygdala. There is a strong relationship between the duration of the discharge, the number of cerebral structures (temporal and, later, extratemporal) involved in the discharge, and the clinical symptomatology. Somatomotor lateralized manifestations, and gestural 'automatisms' only occur when the discharges spread to extratemporal cerebral structures. The secondary generalizations are very rare and are also linked to a large extratemporal spread of the discharge.

Adolescent↗

Correlation between stereo-EEG, CT-scan and stereotactic biopsy data in epileptic patients with low-grade gliomas.

Stereo-EEG activity, which was recorded precisely from the same location as stereotactic biopsies, was studied on 11 patients with low-grade glioma and severe partial epilepsy. The volume of the lesions varied from 6 to 72 cm3 (mean 23 cm3). A very depressed activity was recorded in all the 25 specimens of solid tumor and in more than half of infiltrated white matter. The background activity was still conserved in all 'normal' fragments, while it is never found in solid tumor; sometimes it could be found in the infiltrating tumors of white or gray matter. High voltage theta and delta activity was recorded in neither 'normal' nor solid tumors. We emphasize the importance of considering the stage of evolution when we evaluate the significance of the stereo-EEG activity.

Adolescent↗