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Biomedical subjects

B Lechevalier

Publications and source records attributed to B Lechevalier.

At least 73 records · Page 4Linked to original sources

[Crying provoked by sound stimuli in a case of probable dementia of Alzheimer's type].

A case of pathological crying elicited only by non-verbal auditory stimulations in a woman with probable dementia of the Alzheimer type is reported. As neuropsychological data available in this case have suggested a greater involvement of left than right temporal cortex, the authors propose that the crying phenomenon could have been explained by a similar inter-hemispheric asymmetry in pathological involvement of the limbic structures.

Acoustic Stimulation↗

[A case of aphasia with speech disorders by infarction of the left caudate nucleus and putamen].

An infarction involving the left putamen, caudate nucleus and the anterior limb of the internal capsule, resulted in aphasia with semantic paraphasias, verbal incoherence and verbal memory impairment. Cerebral blood flow (CBF) studies with 133Xe inhalation at 20 days post onset showed, on one hand, a bilateral lowering of cortical blood flow and on the other hand a left frontal-parietal hypoperfusion area. Spontaneous recovery occurred within 2 months. While the mean CBF became normal at 14 months post onset, a relative hypoperfusion area persisted on the anterior left hemispheric cortex. On the basis of these findings and current CBF and metabolic studies carried out in patients with subcortical lesions, the authors discuss the role of cortical and subcortical structures in subcortical aphasic syndromes. The importance of reciprocal connections between cortex, striatum and thalamus is stressed.

Aphasia↗

[Hemodynamic study of obstructive lesions of the internal carotid artery: value of coupled measurement of regional cerebral blood flow and volume].

A study of 130 patients having presented either a transient ischemic attack or a completed stroke, or admitted for an asymptomatic carotid stenosis, allowed the following investigations: CT-scan, doppler, angiography, measurement of the regional cerebral blood flow (rCBF) by the study of 133Xe clearance (Novocerebrograph (R)), and measurement of the regional cerebral blood volume (rCBV) made by gamma emission tomography after autotransfusion of 99m Tc-labeled erythrocytes with an Elscint Apex 415 ECT (R) camera. Our aim was to look in which case a rCBF and/or a rCBV interhemispheric asymmetry was observed, by comparing the previous hemodynamic parameters with clinical, CT-scan and angiographic data. Although a rCBF and/or a rCBV asymmetry appeared more often among patients presenting with infarction than among those of the asymptomatic category, this does not seem specific for any clinical grade. The same statement applies to the comparison between hemodynamic parameters and CT data. The arterial lesions were classified in 4 groups: no stenosis (12 cases), uni or bilateral moderate carotid stenosis (40 cases), unilateral severe carotid stenosis or occlusion (65 cases), bilateral carotid severe stenosis or occlusion (13 cases). We observed a rCBF asymmetry among some patients in the 4 groups, although this was more frequent among the two latter groups. Nevertheless no case of a rCBV asymmetry was observed in the 2 first groups. Such an asymmetry was present in 31 percent of the patients belonging to the two latter groups. In patients of the third group the asymmetry was always due to a relative increase of rCBV beyond the carotid lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial Occlusive Diseases↗

Spiramycin has no effect on serum theophylline in asthmatic patients.

Fifteen asthmatic patients receiving a sustained-release theophylline preparation were also treated with spiramycin for at least 5 days. The macrolide antibiotic had no significant effect on the steady-state theophylline concentration, unlike erythromycin and troleandomycin, which belong to the same class of antibiotics. The latter two drugs have different chemical structures and decrease theophylline clearance. Accordingly, spiramycin comedication does not require special serum level drug monitoring or adjustment of the dose of theophylline.

Adult↗

Hemodynamic study of internal carotid artery stenosis and occlusion: value of combined isotopic measurements of regional cerebral blood flow and blood volume.

The assessment of the intracranial hemodynamic consequences of obstructive lesions of the carotid artery by measuring resting rCBF is inadequate because cerebral blood flow may remain constant in spite of significant drops in the intraluminal pressure due to autoregulation. Moreover, flow may be permanently decreased following cerebral infarction, even if the arterial anatomical conditions have resumed their normal state because of the decreased metabolic demand of an infarcted area. Measurement of the regional cerebral blood volume (rCBV) helps with the hemodynamic assessment of these conditions, since there is a linear and inverse relationship between intraarterial pressure and intracranial blood volume. In 24 patients exhibiting various carotid and ischemic brain lesions we studied both rCBF and rCBV. The latter is a comparative measure between hemispheres obtained by single photon emission tomography after autotransfusion of 99m Technetium labeled erythrocytes. There was no correlation between rCBF and clinical status, CT scan or arterial lesions. There was no correlation between rCBV and clinical status or CT scan. There was, however, an interesting correlation between rCBV and the severity of the arterial lesion. The rCBV was symmetrical in all patients with normal or moderately stenotic carotid arteries before and after operation. In some patients with severe unilateral stenosis or occlusion, there was a significant relative increase of rCBV in the hemisphere downstream from the lesion, which disappeared after surgery (endarterectomy or extra-intracranial bypass). In some patients with severe and bilateral carotid lesions, we noted an asymmetry in rCBV that disappeared after a unilateral operation. Other patients with similar lesions develop asymmetry only after an operation that resulted in a relative increase in rCBV in the hemisphere supplied by the non-operated artery. In conclusion analysis of these results suggests that in this series of patients, rCBV modifications were the consequence of cerebral autoregulation distal to the arterial lesions and provided satisfactory assessment of hemodynamic improvement after surgical repair.

Adult↗

[Neuropathies and monoclonal dysglobulinemias].

Nine patients with peripheral neuropathy and monoclonal gammapathy are presented (4 multiple myeloma, 5 Waldenström's macroglobulinemia). Two patients had tremor and ataxia. All patients had delayed nerve conduction and increased cerebrospinal fluid protein. Symptoms of neuropathy preceded detection of serum protein abnormalities in seven cases. Nerve fiber lesions involved myelin and axons. Biphasic myelopathy with uniform separation of myelin lamellae was observed in one case of Waldenström's disease. Amyloid stains were negative. Treatment was successful in one of four patients. 185 cases of peripheral neuropathy with monoclonal gammapathy are reviewed. Pathogenic role of microvascular changes, amyloid depositions, antimyelin antibody is discussed. The role of anti MAG antibody remains unresolved. Nerve damage due to another cause is possible. The paraprotein and the neuropathy may not be directly related but both caused by the underlying condition.

Aged↗

[Charcot-Marie-Tooth disease and glomerular nephropathy].

Anatomoclinical profile and follow-up of a glomerular nephropathy in a prepubertal girl with Charcot-Marie-Tooth disease is reported; striking common pattern features with the few cases previously published of such an association strongly suggest that renal involvement is possible in sensorineural neuropathies and may be one major factor in the overall prognosis of the disease.

Charcot-Marie-Tooth Disease↗

[Recurrent herpes with neuralgia and zones of cutaneous hypoesthesia].

A 52-year old man presented with recurrent Herpes simplex of the thigh and buttock of 30 years duration. The skin eruption was preceded by pain and sciatica. Surgical excision of the skin area involved modified the site of recurrence. During an attack, the patient developed severe pain and hypoaesthesia in the left half of his chest. The skin lesions were unmodified, and a type 2 Herpes simplex virus was isolated from a vesicle. A clinical examination performed 5 weeks later showed reduced sensitivity to pin prick in the previously painful D5 to D12 territory. Three points are of interest in this case: the site of recurrence moved after surgical excision, pain extended over a wide area and, most of all, persistent hypoaesthesia occurred during a recurrence.

Dermatologic Surgical Procedures↗

[Neuropathies caused by thalidomide].

Symptoms and signs in four patients with thalidomide-induced neuropathy developing during treatment of discoid lupus were limited for long period to distal paresthesiae with altered sensory conduction velocities. Semi-thin biopsy specimens of the distal sural nerve showed depopulation of myelinized fibers, mainly affecting those of large caliber, and signs of axonal degeneration. Study of dissociated fibers showed a high proportion of E fibers. Morphometry confirmed the axonal lesion. Ultrastructural examination demonstrated anomalies of axons of amyelinic fibers (vacuoles, lamellar figures) and of Schwann cells (stacked cytoplasmic prolongations), together with numerous collagen pockets, all non-specific lesions. The disease course was slow, with disappearance of sensory symptoms in a few weeks in 3 of the 4 cases and normal clinical findings in one of the four patients one year after cessation of treatment. Definite correlations between the dose administered and the severity of the neuropathy could not be established. The still poorly understood mechanism of action is discussed.

Acute Disease↗

[Peripheral nerves in a case of lead neuropathy].

A patient developed lead neuropathy with an asymmetrical distal weakness of the four limbs and sensory signs. Tap water contained high amounts of lead and biopsy confirmed the intoxication. The electromyogram was altered from the onset of the disorder and was still abnormal one year after treatment with EDTA, which however brought frank improvement. Biopsies were taken from nerves of the upper and lower limbs. Examination of teased nerve fibers showed the predominance of fibers of small diameter and segmental demyelinization with signs of remyelination in the lower limbs. Semi-thin sections demonstrated depopulation of large myelinated fibers, regeneration clusters and Schwann cells with globular nuclei. Electron microscopy showed myelin sheath alterations and neuritic lesions, some hyperactive Schwann cells. Main alterations were seen in basal membranes of Schwann cells of unmyelinated fibers and endoneuronal capillaries. Such alterations to our knowledge have never been reported in human peripheral lead neuropathy, but have been described after experimental intoxication. These findings together with recent experimental studies allow a discussion about the site of entry of lead into the nerve and about its site of action on the various constituents of the peripheral nerve.

Adult↗

[Case of cortical deafness sparing the music area].

A 33-year-old woman had developed cortical deafness with profound initial deafness lasting for eleven months after pneumococcal meningitis ten years previously. CT scan demonstrated bilateral temporal lobe lesions, predominantly on the left side where it extended into the adjacent parietal and frontal lobes. Audiometry suggested integrity of the internal ear and brain stem. Early auditory evoked potentials were present, while potentials of moderate latency and delayed potentials were abolished. Neuropsychological investigations demonstrated total absence of spoken language, contrasting with conservation of written language, though with agrammatism and an impossibility of identifying non-verbal noises, spoken language, and music. The patient could not identify rhythms, pitch, melodies or the different types of music. The musical quality of sound stimuli and musical pleasure were, however spared as shown by recognition of tape recorded sound stimuli with written denomination and designation of images in multiple choice tests. The relations between auditory agnosia, "pure" verbal deafness and cortical deafness are discussed. Reported cases are reviewed and an attempt is made to demonstrate the existence of several levels in the integration of musical stimuli, the most elementary of which could be the perception of the musical quality of sounds, as was the case in the present patient.

Adult↗

[Granular cell tumor of a cerebral hemisphere: value of gliofibrillary protein acid assay].

A patient with a left parieto-occipital tumor presented generalized convulsions, and aphasia with alexia and agraphia. Diagnosis was confirmed by CT scan. Partial excision only was possible and was followed by radiotherapy. Histology showed the tumor to be composed of moderate and large sized cells with a granular PAS+ cytoplasm. Protoplasmic astrocytes were numerous at the periphery. Electron microscopy demonstrated typical features of Abrikossof's granular cell tumor: heterogeneous granulations constituted mainly of secondary lysosomes, autophagic vacuoles, multivesicular bodies, and rare angular bodies. The granular cells were interspersed with astrocytes, the feet of which were implanted on the capillary basal membrane. Immunoperoxidases assay of gliofibrillary protein acid demonstrated high levels in the intercellular prolongations, considered here to be astrocytic, but weak concentrations in the granular cells. This suggests uptake by the latter cells of adjacent astrocytic gliofibrillary protein acid, especially as the action of an anti-albumin serum on the tumor demonstrated that the granular cells can take up extracellular proteins by a passive mechanism. These findings stand against an astrocytic origin of the tumor. Comparison with other granular cell tumors, particularly pituicytomas, provides evidence of morphological unity, but cerebral granular cell tumors are rich in astrocytes, whereas these are absent in pituicytomas. The oncogenic unity of these tumors has not been established.

Brain Neoplasms↗