[Ischemic vascular accidents in the acute phase].
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to V Dousset.
Explore the source record for details and available documents.
In most cases, extensive cerebral venous thrombosis present themselves with a severe clinical outcome and poor prognosis. We present the case of a 59-years-old patient with a slight rather unrevealing symptoms but suffering from a cerebral thrombosis impacting on both superficial and deep venous system. The etiologic assessment revealed activated protein C resistance. Clinical evolution under systemic anticoagulation was prompt, with complete repermeabilization of the various venous structures.
PURPOSE: To evaluate the efficacy of foraminal steroid injections performed under CT guidance for the management of radicular pain. METHODS: Periganglionic infiltrations were performed in 160 patients with radicular pain refractory to medical treatment. Imaging showed either degenerative foraminal stenosis, herniated disk or postsurgical fibrosis. RESULTS: 102 patients (63.8%) had significant pain reduction. Pain relief was lasting in 68 (66.6%). CT showed the position of the needle tip, as well as the diffusion of the therapeutic compounds. CONCLUSION: We consider that CT-guided periganglionic steroid injections should be an integral part of the management strategy for radicular pain resistant to medical treatment.
Explore the source record for details and available documents.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Explore the source record for details and available documents.
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.
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.
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.
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.