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Biomedical subjects

A Donnet

Publications and source records attributed to A Donnet.

At least 55 records · Page 3Linked to original sources

A multiparametric data analysis showing the potential of localized proton MR spectroscopy of the brain in the metabolic characterization of neurological diseases.

We conducted an extended clinical evaluation of localized proton magnetic resonance spectroscopy (MRS) of the brain, performed on various brain diseases using short stimulated echo times. Pathologies studied were mainly multiple sclerosis, stroke, leukoaraiosis, AIDS-related leukoencephalopathies and glial tumors. Other miscellaneous pathologies were also studied. Magnetic resonance examination of the brain was conducted on a Siemens Magnetom SP63 (equipped with a 1.5 T magnet). Localized proton MRS was performed on a routine basis immediately after imaging, using the STEAM (stimulated echo acquisition mode) with a short echo time (20 ms) combined with a CHESS (chemical shift selective excitation) sequence. One or two VOI (8 ml) were examined. Data on 125 spectra were processed by principal component analysis (PCA) and conventional variance analysis. The following metabolite resonances were studied: inositol-glycine, taurine-scyllo-inositol, choline derivatives, phosphocreatine-creatine, aspartate, glutamine glutamate, N-acetylaspartate, acetate and lactate. PCA demonstrates that the different metabolic variables are independent. The analysis of groups of spectra clearly demonstrates that the metabolic profiles detected by localized MRS in various pathologies (i) differ significantly from controls, and (ii) allow a metabolic discrimination between groups of pathologies. Results of PCA are confirmed by variance analysis. Strokes are characterized by an increase in lactate concentration and leukoaraiosis by a decrease in inositol-glycine resonance. AIDS-related leukodystrophies are characterized by increases in lactate and choline concentrations. Reduction in N-acetylaspartate which is observed in most pathologies is not significant in the small lesions of white matter. Lactate has often been found in MS plaques, but no variation in the choline/phosphocreatine ratio was observed. GABA was tentatively assigned in the spectrum of a patient with epilepsy under sodium valproate treatment. This study illustrates the clinical feasibility of the technique, the value of a multiparametric data analysis in the definition of the pertinent variables characterizing the metabolic impairment, and the impact of localized proton MR spectroscopy of the brain in the assessment of cerebral suffering.

AIDS Dementia Complex↗

Pure left hemianacousia: clinical and neurophysiological study.

Hemianacousia is a pure sensory deficit revealed by an abnormality of dichotic listening test associated with an asymmetry of late auditory evoked potentials. We report a case of a patient with pure left hemianacousia. LAEPs, MLAEPs and P300 were recorded. Left hemisphere N90 wave amplitude was significantly reduced over the right hemisphere. CT scan revealed a right temporal hematoma which seemed to correspond to area 41.

Brain↗

[Neurological form of cryptococcosis. Apropos of 2 atypical cases in non HIV-infected patients].

Cryptococcal infection is the most common fungal infection of the central nervous system. More than 50% of the cases of cryptococcal infection are superimposed on an immunosuppressive or other general debilitating condition. Cerebral cryptococcosis usually presents as meningitis or meningoencephalitis, although cerebral granuloma has also been reported. Hydrocephalus is the most common neurosurgical complication of cerebral cryptococcosis. The majority of patients require only medical treatment with antifungal drugs. However, when complications ensue, surgical intervention is mandatory. We suggest that chronic meningitis be ruled out in all patients prior to the placement of shunts. In the two cases reported here treatment of cryptococcal meningitis was a combination of amphotericin B and flucytosine for six weeks. Fluconazole is a new alternative and at least as effective as amphotericin B.

Adolescent↗

Minocycline and benign intracranial hypertension.

A case is reported of a 16-year-old girl who developed benign intracranial hypertension, with severe bilateral papilledema after minocycline therapy. A lumboperitoneal bypass was carried out in view of the ophthalmologic signs and the pressure of cerebrospinal fluid.

Adolescent↗

Sleep electroencephalogram at the early stage of Creutzfeldt-Jakob disease.

We describe sleep EEG studies in three patients at the early stage of Creutzfeldt-Jakob disease. Little work has been devoted to the study of the sleep EEG in the course of the CJ disease: disorganized sleep architecture was noted, associated with a decrease in stage 4 and an almost complete disappearance of the REM stage. Our patients were considered to have normal stage 2; yet spindles and K complexes were rare at this stage. No evolution towards stage 4 was noted. The percentage of rapid eye movement sleep was significantly low in two cases and normal in one case. Sleep disturbances in the other dementing disorders are reported.

Aged↗

[Segmental dystonia and mitochondrial encephalomyopathy].

A 55 year-old male experienced a dystonia of the right upper limb followed by a ptosis with complete ophthalmoplegia and cataract. He developed a sensory neuropathy and personality changes. Ragged-red fibers were found on muscle biopsy. There was a major defect in complex III and IV activity.

Blepharoptosis↗

[Value and limits of the tilt-test in the etiological diagnosis of transient malaise].

This study was undertaken to assess the usefulness of the head-up tilt test in the diagnosis of vasovagal syncope and to evaluate the indications of this investigation. The test consists in a 30 minute period in the horizontal decubitus position followed by a 60 degrees head-up tilt position for 30 minutes. In the 26 subjects in whom the diagnosis of repeated vasovagal syncope had been made on the basis of typical prodromic symptoms after exclusion of all other causes, the test induced a vasodepressive or vagal reaction in 10 cases (38%) 20 +/- 4 minutes after tilting. In 8 patients in whom the test was performed within 48 hours of their syncopal episode, a similar malaise was induced in 7 cases. Twenty patients with repeated malaise without loss of consciousness had no symptoms during the test which was also negative in 10 normal control subjects. In a group of 27 subjects with unexplained syncope after clinical and paraclinical investigations, the test was accompanied by a malaise on five occasions (19%). Using this protocol, the tilt test had good specificity but moderate sensitivity in the diagnosis of vasovagal syncope. Its sensitivity increased when performed within 48 hours of syncope. It is of no value in the diagnosis of recurrent malaise without loss of consciousness.

Blood Pressure↗

[Transient Korsakoff's syndrome after intraventricular hemorrhage].

A 42 year-old man with intraventricular haemorrhage developed a transient Korsakoff's syndrome. A small arteriovenous malformation was identified on the inner side of the left parietal lobe. Cognitive disorders are very frequent after surgery on anterior communicating artery aneurysms, more rarely when the haemorrhage interest the axial anatomic loci implicating in the process of amnesic syndromes. This case illustrates well the possibility of transient Korsakoff's syndrome after pure intraventricular haemorrhage.

Adult↗

[Lacunar syndromes due to intracerebral hemorrhage].

Nine cases (seven men and two women, mean age 64.5 years) of classical lacunar syndromes due to intracerebral hemorrhage are reported. Three patients presented with pure motor hemiparesis (two putaminal hematomas with proportional weakness and one cortical hemorrhage with brachio-crural hemiparesis). Four patients presented with sensorimotor stroke due to thalamo-capsular hemorrhage. The last two patients had thalamic hemorrhage causing ataxic hemiparesis or dysarthria-clumsy hand syndrome. Four subjects had arterial hypertension, one was diabetic, and two were treated with anti-vitamin K. Abrupt onset was noted in all instances. Only one patient experienced moderate inaugural headaches. Good recovery occurred in all cases. Lacunar syndromes are a very uncommon presentation of intracerebral bleeding. Hemorrhages are yet the second etiology of such syndromes. Distinguishing hemorrhage from infarction is not clinically possible and needs early unenhanced CT scan.

Aged↗

Neuroleptic malignant syndrome induced by metoclopramide.

Neuroleptic malignant syndrome (NMS) associated with metoclopramide is rare. NMS probably results from neuroleptic-induced dopamine receptor blockade. We describe a case and have found only seven reports of metoclopramide-induced NMS in the literature.

Aged↗