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V Dousset

Publications and source records attributed to V Dousset.

At least 55 records · Page 3Linked to original sources
PubMed1998

Early structural changes in acute MS lesions assessed by serial magnetization transfer studies.

BACKGROUND: Whether acute MS lesions are primarily inflammatory or demyelinative is unresolved. Our study examined acute MS lesions longitudinally by quantitative magnetization transfer (MT), an MRI technique that identifies tissue integrity and destruction. METHODS: Four MS patients were studied by serial MRI including MT, conventional T2-weighted images, and postgadolinium T1-weighted images for 9 to 12 months. In 15 new lesions, the MT ratio (MTR) was calculated retrospectively. RESULTS: In 13 lesions, a marked decrease in the MTR was present early during the first 2 months after the onset of the lesion and was followed by a variable increase. In two other lesions, the MTR progressively declined. CONCLUSIONS: These results suggest that major early structural changes compatible with demyelination and followed by remyelination and gliosis, or by continuous demyelination, occur in new MS lesions. The various MTR profiles provide in vivo confirmation of the current knowledge of the progression in MS lesions. Furthermore, MTR may be used to monitor in vivo drug efficacy in new MS lesions.

Adult↗
PubMed1998

Periganglionic foraminal steroid injections performed under CT control.

PURPOSE: The purpose of our study was to evaluate the efficacy of direct intraforaminal steroid injections into the periganglionic space in the treatment of radicular pain. METHODS: Periganglionic infiltrations were performed in 41 patients with acute or chronic radicular pain. Neuroradiologic imaging in all patients showed foraminal stenosis due to degenerative disorders or herniated disk. All injections were performed under CT control. RESULTS: Seventy percent of patients had significant pain reduction, with the greatest success (90% of patients) in those whose foraminal stenosis was due to degenerative disorders; 45% of patients with foraminal herniated disks had pain relief. CONCLUSION: Intraforaminal steroid injection is useful in the treatment of radicular pain, particularly in cases of foraminal degenerative stenosis.

Adult↗
PubMed1998

[Study of cortical atrophy with magnetic resonance imaging in corticobasal degeneration].

Corticobasal degeneration (C.B.D.) is a neurodegenerative disorder characterized mainly by an asymmetrical a kineto-rigid syndrome associated with fronto-parietal cortical signs, particularly apraxia. Conventional imaging even magnetic resonance imaging (M.R.I.) has often been considered as poorly contributive for the diagnosis of C.B.D. We retrospectively studied routinely performed M.R.I. scans of 15 patients presenting a clinical and metabolic (P.E.T/S.P.E.C.T.) syndrome characteristic of probable C.B.D. M.R.I. scans were assessed by 3 investigators, not aware of the clinically most affected side, taking into account M.R.I. technical parameters. We quantified, on each side, the cortical atrophy (frontal, parietal and temporal) and the white matter changes, by using the semi-quantified method of Victoroff et al. (1994). Abnormalities were considered if observed by at least 2 of the 3 investigators. Abnormalities were then correlated with the side initially and most severely affected. The most contributive findings were the asymmetric parietal atrophy (clinically correlated in 93 p. 100 of cases), asymmetric frontal atrophy (clinically correlated in 60 p. 100) and asymmetric dilatation of the lateral ventricles (clinically correlated in 60 p. 100). 80 p. 100 of affected subjects displayed at least 2 of these M.R.I. abnormalities. These results are in accordance with the metabolic and pathologic features of C.B.D. This study demonstrates that M.R.I. evaluation of the cortical atrophy asymmetry may contribute to the diagnosis of C.B.D.

Age of Onset↗
PubMed1998

[Fulminant orthochromatic leukodystrophy in an adult].

A 27-year-old man from Marocco developed a progressive dementia leading within a year to a mutic akinetic state. The course of the disease was also marked by epileptic seizures. MRI revealed diffuse white matter involvement. A frontal white matter brain biopsy was consistent with the diagnosis of orthochromatic leucodystrophy, i.e: presence of sudanophilic lipids and pigmented cells associated with myelin loss. Adult forms of orthochromatic leucodystrophy are very rare. Our case was characterized by a fulminant course.

Adult↗
PubMed1998

[Propriospinal myoclonus induced by relaxation and drowsiness].

Propriospinal myoclonus is a subtype of spinal myoclonus characterized by axial flexion or extension jerks, arrhythmic and prolonged muscle bursts with a pattern of activation consistent with a slow conduction within the propriospinal pathways. We describe a new idiopathic case of flexion propriospinal myoclonus occurring upon relaxation and drowsiness. This syndrome is to be added to the spectrum of movement disorders occurring during drowsiness.

Anticonvulsants↗
PubMed1997

Magnetization transfer imaging in vivo of the rat brain at 4.7 T: interpretation using a binary spin-bath model with a superLorentzian lineshape.

Proton magnetization transfer contrast (MTC) imaging, using continuous wave off-resonance irradiation, was performed on the rat brain in vivo at 4.7 Tesla. The observed MTC was studied in three different brain regions: the corpus callosum, the basal ganglia, and the temporal lobe. By systematically varying the offset frequency and the amplitude of the RF irradiation, the observed signal intensities for each region of interest were modeled using a system including free water and a pool of protons with restricted motions (R. M. Henkelman, X. Huang, Q. Xiang, G. J. Stanisz, SD Swanson, M. J. Bronskill, Magn. Res. Med. 29, 759 (1993)). Most of the relaxation parameters of both proton pools remained fairly constant for the three regions of interest, with a T2 value of about 9 micros for the immobilized protons, whereas the rate of exchange increased significantly from the temporal lobe to the corpus callosum. The optimal acquisition parameters for the improved MTC under steady-state saturation were found to be 2-10 kHz offset frequency and 500-800 Hz RF irradiation amplitude. Conversely, an irradiation amplitude of 3 kHz at an offset frequency of 12 kHz is required to minimize the direct effect of off-resonance irradiation. Such an approach could be extended to human brain imaging with the aim of characterizing tissue-specific disease.

Animals↗
PubMed1997

Improvement of post-gadolinium contrast with magnetization transfer.

Magnetization transfer (MT) provides post-gadolinium contrast improvement through decreasing the tissue signal. Our study had two aims: to analyse the effect of MT qualitatively and quantitatively in 13 patients, and to analyse in vitro the competition between two relaxation phenomena, dipole-dipole which is characteristic of MT and proton - electron which is characteristic of gadolinium. Contrast between lesion and white matter improved from 20.6 % before MT to 65.1 % after MT, enabling new lesions to be detected in two patients. The improvement was due mainly to the proton - electron effect of gadolinium rather than the dipole relaxation of MT. These results are in agreement with those in the literature. The existence of spontaneous high-signal induced by MT in the absence of gadolinium indicates that it is preferable to perform an MT sequence before and after administration of gadolinium.

Adolescent↗
PubMed1997

Cranial aneurysmal bone cysts presenting with raised intracranial pressure: report of two cases.

Aneurysmal bone cysts in the skull vault are reported in two patients 7 and 9 years old, who presented with vomiting and headaches caused by raised intracranial pressure. CT showed the cystic lesion in the diploë, with predominantly inward expansion. Fluid-fluid levels were seen on both CT and MRI; the latter also showed bleeding within the cyst. MR angiography showed compression of the superior sagittal sinus in the second case.

Bone Cysts, Aneurysmal↗
PubMed1997

Enzyme immunoassay for myelin basic protein in cerebrospinal fluid.

Myelin basic proteins (MBPs) are a set of proteins making up about 30% of the protein content of the central nervous system myelin. Four human isoforms have been identified. The most abundant is a highly conserved 18.5 kDa polypeptide. For this species, the amino acid sequence homologies between human and monkey or human and chick are 98.2% and 71.1%, respectively. As a consequence, there is a very good immunological cross-reactivity between the mammalian MBP. This protein has been extensively used to induce experimental allergic encephalomyelits (EAE) in numerous animals. The evolution of chronic EAE in animal is similar to that of multiple sclerosis (MS), a demyelinating human pathology, and chronic EAE is considered to be an animal model of MS. In demyelinating pathologies, MBP concentration in the cerebrospinal fluid (CSF) is considered to be a good marker of demyelination. MBP concentration, in biological fluids, is generally determined by radioimmunoassay (RIA). The RIA technique currently used is highly sensitive (0.1-2.5 ng/ml) but has the drawback of requiring the handling of radioactivity and frequent labelling of MBP. So we developed a new enzyme immunoassay (EIA) technique. Our technique has the same sensitivity as RIA, needs only small volumes of CSF (50 microliters) and the enzyme-labelled MBP tracer is stable for at least 12 months.

Alkaline Phosphatase↗
PubMed1997

Transitional progressive multiple sclerosis: a clinical and imaging study.

OBJECTIVE: To study the prevalence and the natural course of transitional progressive multiple sclerosis (TPMS). This clinical form is defined by a progressive course beginning many years after an isolated bout. METHODS: 214 consecutive outpatients with definite or probable multiple sclerosis were studied. The prevalence of TPMS was established. Patients with TPMS were compared with patients with other progressive forms of multiple sclerosis according to the clinical course. A prospective one year follow up study was performed in a subgroup of patients to compare progression of the disease using clinical indices and MRI. RESULTS: In this clinical population of 214 outpatients with multiple sclerosis, 55 had secondary progressive multiple sclerosis (SPMS), 38 primary progressive multiple sclerosis (PPMS), and 12 TPMS. Retrospective analysis of the clinical data of these patients shows that TPMS is very similar to SPMS at the beginning of the disease (age at onset, time before progression, clinical symptoms at onset, progression index). In addition a cohort of patients was prospectively followed up clinically and by MRI for one year. CONCLUSIONS: The results did not show any significant differences between the three forms during this follow up. However, all data showed a concordant trend suggesting that at this progressive stage, TPMS is closer to PPMS in terms of progression of disability and new MRI lesions.

Brain↗
PubMed1997

[Progressive multifocal leukoencephalopathy. Study of the demyelination by magnetization transfer].

PURPOSE: magnetization transfer imaging (MT) has been used to study the degree of demyelination in progressive multifocal leukoencephalopathy (PML). MATERIAL AND METHOD: two groups were studied: a group of 10 HIV + patients with clinical, MR features, biological and/or biopsy proven PML, and a group of 11 normal volunteers with matched age. MT ratio (MTR) were obtained from the center of the PML lesions and 11 areas of normal appearing white matter (NAWM) in the control group. RESULTS: the mean MTR of NAWM in the control group was 46.6% (SD = 2,3). PML lesions demonstrated a strong and significant (p = 0) decreased of the MTR with mean MTR value of 22.4% (SD = 2,3). CONCLUSION: MT characterized the demyelinating process in PML, and can be used to improve diagnosis. Furthermore, MT allowed a quantification of the degree of demyelination which can be helpful in other demyelinating process of CNS such as multiple sclerosis.

Adult↗
PubMed1997

Magnetization transfer study of HIV encephalitis and progressive multifocal leukoencephalopathy. Groupe d'Epidémiologie Clinique du SIDA en Aquitaine.

PURPOSE: To ascertain whether the use of magnetization transfer (MT) in MR imaging can characterize tissue destruction in human immunodeficiency virus (HIV)-positive patients with presumed progressive multifocal leukoencephalopathy (PML) or HIV encephalitis. METHODS: Brain MR studies that included MT were obtained in three groups: 11 healthy control subjects, 10 HIV-positive patients with clinical and radiologic findings of PML, and 13 HIV-positive patients with HIV encephalitis. MT ratios (MTRs) were calculated in PML and HIV encephalitis lesions and in normal-appearing white matter in the patients and control subjects. RESULTS: PML lesions revealed a dramatic decrease in MTR (22% +/- 2.3). HIV encephalitis lesions had statistically significantly higher MTR values (40% +/- 3.8) than PML lesions. The MTR of normal-appearing white matter was significantly higher in the control subjects (47% +/- 2.3) than in the PML group (46% +/- 3.3) or the HIV encephalitis group (44% +/- 2.6). CONCLUSION: MTR determinations suggest the possibility of distinguishing PML from HIV encephalitis and of indicating whether HIV encephalitis is involved in white matter that appears normal on conventional MR images.

Adult↗
PubMed1997

Magnetization transfer imaging in AIDS-related brain diseases.

MT makes it possible to characterize tissue destruction in several CNS diseases, including AIDS-related diseases such as PML or HIV encephalitis. MR may be helpful in establishing diagnosis, disease burden, prognosis, and therapeutic efficacy. MT may also contribute to the investigation of the natural history of the diseases. The other application is in improving contrast after the injection of gadolinium chelates. This contrast improvement can be achieved routinely on any device and may be a good alternative to other methods, such as increasing dose or delay.

AIDS Dementia Complex↗
PubMed1996

Asymptomatic cervical haemangioma treated by percutaneous vertebroplasty.

We report a 17-year-old asymptomatic patient with a partially collapsed seventh cervical vertebra due to a haemangioma revealed by conventional radiographs performed for army enrollment. Given radiological evidence of aggressiveness, percutaneous vertebroplasty by injection of methyl methacrylate cement was performed to prevent complications. CT a year later showed no progression of the lesion. The patient remains asymptomatic.

Adolescent↗
PubMed1996

Magnetisation transfer ratios of contrast-enhancing and nonenhancing lesions in multiple sclerosis.

Magnetisation transfer (MT) is a recently introduced technique for assessing the water content of tissues in vivo and its relationship to macromolecules or membranes. It has been suggested that MT could provide indirect evidence of the characteristics of multiple sclerosis (MS) lesions (oedema, demyelination, or gliosis). Our aims were to characterise brain MS lesions and to compare the magnetisation transfer ratio (MTR) values of lesions with different patterns of contrast enhancement. In patients with MS we measured the MTR of 65 gadolinium-enhancing and 292 nonenhancing lesions. Using the equation published by Dousset et al. we studied 29 patients with clinically definite MS and 10 healthy controls. Lesions had significantly lower MT than the normal-appearing white matter of the patients or the normal white matter of healthy controls. There was no difference in the MTR of enhancing and nonenhancing lesions. Enhancement was homogeneous in 45 and ring-like in 20 lesions; MTR values were lower in the latter. These findings are presumably related to the differences in pathological features of enhancing (different amounts of proteins and inflammatory cells, oedema and demyelination) and nonenhancing (gliosis, demyelination and axonal loss) lesions.

Adult↗
PubMed1996

[MRI and Listeria monocytogenes rhombencephalitis].

Rhombencephalitidis is a serious form of brainstem inflammation, difficult to diagnose on the basis of clinical and laboratory findings alone. We describe the MR appearance of 3 cases of Listeria monocytogenes rhombencephalitidis and correlate the findings with clinical information. MR imaging is crucial for early diagnosis of this illness: patchy signal hyperintensity throughout the medulla and cerebellar peduncles on T2 weighted images, always in association with a hypointense dot; numerous gadolinium-enhanced microabcesses in the rhombencephalon. MR imaging is very useful for follow-up examinations.

Brain Abscess↗