Deep brain stimulation in Parkinson's disease: opposite effects of stimulation in the pallidum.
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Antiparkinson Agents↗
Biomedical subjects
C Marsault
Publications and source records attributed to C Marsault.
Glossopharyngeal neuralgia associated with a vascular loop demonstrated by magnetic resonance imaging.
We report two cases of glossopharyngeal neuralgia associated with a vascular loop of the postero-inferior cerebellar artery, diagnosed by magnetic resonance imaging. Reviewing the literature, we found this to be the first report of a magnetic resonance-validated vascular abnormality related to such a condition. One patient was cured by surgical decompression, confirming the role of the abnormal vessel in the pain. As with trigeminal neuralgia, a possible vascular aetiology should be considered in glossopharyngeal neuralgia.
Cerebellum↗
Computerized tomographic angiography scan following carotid endarterectomy.
The purpose of this study was to evaluate the role of computed tomographic angiography (CTA) for postoperative assessment of carotid endarterectomy (CE). Twenty carotid endarterectomies were performed and controlled by using (1) intraoperative angiography, (2) postoperative duplex scanning and CTA with multiprojection volume reconstruction (MPVR). Intraoperative angiographic controls were deemed satisfactory for all patients. In 12 patients, the postoperative morphological aspect was satisfactory with CTA and duplex scanning. In the eight remaining patients, CTA and/or duplex scanning revealed 12 abnormalities: 3 were equally visualized on CTA and duplex scanning, 6 only on CTA and 3 only on duplex scanning. CTA is a rapid and noninvasive technique allowing the surgeon to get informative and comparative data. It might be an interesting alternative to postoperative angiography.
Aged↗
Magnetic resonance imaging of cerebral central sulci: a study of monozygotic twins.
The cerebral central sulci, seat of the sensorimotor cortex, vary anatomically in form, length and depth among individuals and present a left/right asymmetry. The purpose of this work was to measure central sulcus's lengths, at the surface and in-depth, in each hemisphere of monozygotic twins in order to evaluate the influence of environmental factors on the morphometry and asymmetry of this structure. A measurement technique on MR images of the brains using 3 D software was developed. Two operators applied this technique to measure central sulcus lengths at the surface of the brain and in-depth in each hemisphere. Besides the fact that the technique developed gave high Intraclass Correlation Coefficients (ICC) for the surface lengths (mean value 0.94), and slightly less high for the in-depth length (mean value 0.87), we found a weak (from 0.57 to 0.73 for raw data) but significant ICC between homologous sulci in pairs of twins. In addition, the ICC for asymmetry indices were not significant. Hence, if central sulcus morphometry is in part genetically influenced, these results show that nongenetic factors are nonetheless important in their development.
Adult↗
Diffusion-weighted magnetic resonance imaging in a case of cerebral venous thrombosis.
BACKGROUND: Diffusion-weighted imaging (DWI) is the most sensitive MR sequence in acute arterial ischemic stroke but has not yet been evaluated in venous cerebral ischemia. We describe a patient with DWI performed at the acute phase of a venous ischemic stroke. CASE DESCRIPTION: A rapid cerebral MRI including DWI and fast fluid-attenuated inversion recovery (FLAIR) sequences was performed at the acute phase of a venous stroke confirmed by conventional angiography. DWI showed a slight decrease in apparent diffusion coefficient values 3 hours after onset (0.53+/-0.07x10(-3) mm2/s) and was normal 48 hours later (0.064+/-0.15x10(-3) mm2/s). Fast FLAIR sequences showed large left frontoparietal hyperintensities. The lack of a clear decrease in apparent diffusion coefficient values associated with marked FLAIR abnormalities may suggest prominent or early associated vasogenic edema. Physiopathological differences between arterial and venous ischemia may explain the different type of DWI FLAIR abnormalities during the acute phase as well as the better recovery of neurological deficit in venous stroke than in arterial ischemic stroke. CONCLUSIONS: In the context of an acute stroke, the contrast between marked FLAIR and subtle DWI abnormalities on MRI may reflect the venous mechanism of cerebral ischemia.
Brain↗
[What is your diagnosis? Hypertrophic olivary degeneration].
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Adult↗
Loss of digitations of the hippocampal head on high-resolution fast spin-echo MR: a sign of mesial temporal sclerosis.
PURPOSE: The purpose of our study was to determine the significance of the loss of visualization of digitations in the hippocampal head on high-resolution fast spin-echo MR images in the diagnosis of mesial temporal sclerosis (MTS). METHODS: MR examinations of 193 patients with intractable epilepsy were evaluated retrospectively for atrophy and/or T2 signal changes of the hippocampi. On the basis of these two criteria, MTS was diagnosed in 63 hippocampi. Twenty-four patients had surgery, and MTS was confirmed in all cases. A control group included 60 hippocampi in patients with frontal seizures but no MR-detectable abnormalities. In a second step, visibility of digitations in the hippocampal head was evaluated in the two groups of subjects. RESULTS: In the group of 63 hippocampi in which MTS was diagnosed, digitations were not visible in 51 cases, poorly visible in eight, and sharply visible in four. Twenty-two of 24 hippocampi in which MTS was confirmed histologically had no MR-visible digitations. In the control group, digitations were sharply visible in 55 cases and poorly visible in five. Statistical analysis showed a significant difference in the visualization of digitations between hippocampi with MTS and those in the control group. CONCLUSION: With a sensitivity of 92% and a specificity of 100%, the finding of complete loss of digitations in the hippocampal head may be used as a major diagnostic criterion to establish the MR diagnosis of MTS. This morphologic sign may also be useful in the diagnosis of bilateral MTS or to validate the MR diagnosis of MTS when there is no obvious atrophy or changes in signal intensity.
Adolescent↗
Are the brains of monozygotic twins similar? A three-dimensional MR study.
PURPOSE: The role of genetic mechanisms and the influence of environmental events in human brain development have been difficult to evaluate. The purpose of this study was to compare the cerebral cortical morphology and midline structures of monozygotic twin pairs using MR imaging. METHODS: Six observers, blinded to twin pairings, evaluated the 3-D renderings of the cortical surface and midline structures from MR images of seven monozygotic twin pairs. A morphometric analysis of the corpus callosum and of the distance between the anterior and posterior commissures was also performed. RESULTS: Despite surprising anatomic differences, the brains of the twin pairs were similar enough to enable the observers to distinguish twin pairs from unrelated subjects. Five of six observers correctly identified the brains of all seven twin pairs; the remaining observer failed to make a correct match in only one of seven pairs. Three of six observers identified the midline sagittal images of the related twins in all seven pairs, and the other three identified the related midline sagittal images in five of seven pairs. The results were statistically significant. CONCLUSION: Although the observed differences in morphologic characteristics between twins necessarily reflect nongenetic influences, the cortical patterns and midline structures of monozygotic twins probably are genetically similar.
Adult↗
[Dementia and memory: morphologic imagery with MRI].
Modern imaging techniques, and notably magnetic resonance imaging (MRI) enable an increasingly precise exploration of primary degenerative dementias. The main contribution of imaging is to demonstrate lesion localizations which confirm the degenerative nature of the observed disorders, contributing to an understanding of the correlation between clinical signs and causal lesions. The development of techniques quantifying cerebral volume which can be applied to an analysis of small structures such as the hippocampus coupled with a better understanding of primary degenerative dementias allow more specific study of the atrophy than could be obtained with a global assessment of ventricular dilatation. More recently, the development of MRI methods studying brain perfusion open the way for noninvasive exploration of perfusion anomalies in these patients.
Dementia↗
MRI of pituitary adenomas in acromegaly.
Adenomas causing acromegaly represent at least a quarter of pituitary adenomas. We studied 12 patients presenting with active acromegaly due to a pituitary adenoma with a 1.5 T superconductive MRI unit. All had T1-weighted sagittal and coronal sections before and after Gd-DTPA; six had coronal T2-weighted images. Surgical correlation was obtained in seven patients. Histologically, there were eight growth hormone (GH)-secreting and three mixed [GH and prolactin (PRL) secreting] adenomas, and one secreting GH, PRL and follicle-stimulating hormone. Macroadenomas (10) were more frequent than microadenomas (2). No correlation was found between serum GH and tumour size. There were nine adenomas in the lateral part of the pituitary gland; seven showed lateral or infrasellar invasion. Homogeneous, isointense signal on T1- and T2-weighted images was observed in six cases. Heterogeneous adenomas had cystic or necrotic components.
Acromegaly↗
Temporal lobe epilepsy with varying severity: MRI study of 222 patients.
MRI was performed in 222 consecutive adult patients with temporal lobe epilepsy of varying severity from January 1991 to May 1993. The diagnosis of hippocampal sclerosis was established visually by three independent observers. The accuracy of visual assessment of hippocampal asymmetry was compared with volumetric measurements. Neuropathological correlations were obtained in 63 patients with refractory seizures. Temporal lobe abnormalities were observed in 180 patients (81%) as follows: hippocampal sclerosis in 122 (55%); developmental abnormalities in 16 (7.2%); tumours in 15 (6.8%); scars in 11 (5%); cavernous angiomas in 10 (4.5%); miscellaneous lesions in 6. MRI was normal or showed unrelated changes in 42 patients (19%). Visual assessment correctly lateralised hippocampal sclerosis in 79 of the 84 patients measured (94%). Temporal lobectomy confirmed the MRI data (side and aetiology) in all 63 operated patients. Patients with normal MRI had an older age of seizure onset and were more often drug-responsive than patients with hippocampal sclerosis. MRI showed temporal lobe abnormalities in 81% of epileptic patients with varying severity with good neuropathological correlation. Patients with normal MRI had a less severe form of the disease.
Adolescent↗
Three-dimensional computed tomographic angiography in detection of cerebral aneurysms in acute subarachnoid hemorrhage.
OBJECTIVE: Three-dimensional computed tomographic angiography (CTA) is a recently developed imaging modality. We demonstrate the value of this noninvasive method in replacing digital subtraction angiography (DSA) in the detection of aneurysms of the circle of Willis in patients with subarachnoid hemorrhage admitted to our institution. METHODS: A helical acquisition was performed for computed tomographic scans obtained for 120 patients with a 1 mm per second table speed and a 1-mm collimation, 1:1 pitch. Axial source images were transferred on a console Advantage Windows workstation (General Electric, Milwaukee, WI) and CTA was obtained using maximum intensity projection reconstruction. All patients had undergone DSA of the circle of Willis (80 patients preoperatively and 40 postoperatively). RESULTS: A total of 129 aneurysms were detected in 107 patients. Three-dimensional CTA disclosed nothing abnormal in 13 patients. Ninety-two patients sustained one aneurysm, 10 patients sustained two, 3 patients sustained three, and 2 patients sustained four. All results were confirmed by DSA. In two cases, aneurysms of the middle cerebral artery were defected by CTA but not by DSA. When using angiographic views, the aneurysm was always masked by a branch of the middle cerebral artery. CONCLUSION: The sensitivity of three-dimensional CTA is comparable with that of DSA, and its specificity is 100%. Because CTA is simple, quick, noninvasive, and reliable, we think that it can eventually replace DSA.
Adult↗
Pallidal stimulation for Parkinson's disease. Two targets?
There has been renewed interest in functional surgery as treatment for Parkinson's disease (PD). Although pallidotomy and chronic pallidal stimulation are highly effective in suppressing levodopa-induced dyskinesia (LID), both methods also seem to be effective in reducing parkinsonian disability. However, the simultaneous improvement of LID and motor signs is hard to explain with the classic model of basal ganglia circuitry. Taking advantage of the fact that deep brain stimulation is reversible and that implanted electrodes contain four discrete stimulation sites, we investigated the effect of stimulation on different sites of the globus pallidus (GP) in five PD patients. Stimulation in the dorsal GP (upper contact) significantly improved gait, akinesia, and rigidity and could induce dyskinesia when patients were in the "off" state. In contrast, stimulation in the posteroventral GP (lower contact) significantly worsened gait and akinesia, although the reduction in rigidity remained. For patients in the "on" state, stimulation in the posteroventral GP dramatically reduced LID but, as in the "off" state, worsened gait and akinesia, thus canceling out the antiparkinsonian effect of levodopa. Our results indicate that stimulation had a striking different effect on parkinsonism and dyskinesia when applied at two different loci of the GP and that stimulation applied in the posteroventral GP produced opposite effects on rigidity and on akinesia. We conclude that parkinsonian signs and LID are a reflection of at least two different anatomofunctional systems within the GP and that this functional organization of the GP needs to be considered when determining the optimal target for surgical treatment of PD.
Adult↗
[Is magnetic resonance the first indication in neurologic imaging?].
Various methods of neuroradiologie examination are described, with an emphasis on recent developments, in particular in CT scan (angioscan, spiral acquisition) and MRI. CT scan, which is the most accessible method, can answer most questions in intracerebral emergencies (trauma, vascular accidents, intracerebral hypertension ...). Outside the emergency setting, morphological study of the brain by MRI is much superior to that provided by CT scan and should be the first-line examination for investigation of suspected tumour, wite matter lesion.... This is even more evident in exploration of lesions of the posterior cranial fossa. In addition, introduction in the near future of functional MRI should lead to better knowledge of the relationship between cerebral lesions and functional zones. Ultrasonography remains a noninvasive and effective technique to seek lesions of the arteries supplying the brain. For spinal cord disorders, MRI is by far the examination of choice, except when contraindicated by the presence of cardiac pacemaker, metallic foreign bodies in the patient.
Brain Diseases↗
[Surgery of brain tumors].
Treatment of brain tumors represents a very important chapter of neurological surgery. In fact, surgery is of primary importance in the management of benign or potentially anaplastic brain tumors. It not only provides histological diagnosis but radical surgical removal, when feasible, is the goal standard treatment of a very large group of these lesions. Surgery is directed specifically against tumoral processes which are widely different and heterogeneous anatomically and histologically. Some of them are benign and their treatment is essentially relaying on surgery. Others are anaplastic or malignant and surgery has to be associated with other treatment modalities [radiotherapy and (or) chemotherapy] but remains crucial for the histological assessment of the lesion even obtained from stereotactical biopsy specimens. Whenever possible surgical resection must be proposed because it improves the patient's clinical and functional state and allows a better efficacy of complementary treatments when indicated. These factors correlates with the quality and length of the postoperative radiological and clinical remission.
Adult↗
Striatopallidal and thalamic dystonia. A magnetic resonance imaging anatomoclinical study.
OBJECTIVE: To determine which brain structures are involved in symptomatic unilateral dystonia caused by localized cerebral infarction. DESIGN: Three-dimensional T1-weighted magnetic resonance imaging sequence and stereotactic analysis were used to analyze the topography of the lesions. Stereotactic localization of thalamic lesions was conducted according to the atlas of Hassler with a Voxtool software (Advantage Windows Workstation, General Electric, Milwaukee, Wis) workstation system. PATIENTS: Eight patients with hemidystonia, segmental dystonia, or focal dystonia were selected from among 51 consecutive patients (between January 1988 and May 1993) with symptomatic unilateral dystonia. RESULTS: Patients had dystonic spasms (n=4) or myoclonic dystonia (n=4). Lesions associated with dystonic spasms were located in the striatopallidal complex, and those with myoclonic dystonia were in the thalamus contralateral to the dystonia. Lesions of the striatopallidal complex involved the putamen posterior to the anterior commissure in all patients and extended variably into the dorsolateral part of the caudate nucleus, the posterior limb of the internal capsule, or the lateral segment of the globus pallidus. These lesions were centered in the "sensorimotor" part of the striatopallidal complex, with a trend toward a somatotopical distribution. Lesions of the thalamus were located in the ventral intermediate and ventral caudal nuclei, while the ventral oral anterior and posterior nuclei (which receive pallidal efferents) were largely spared. CONCLUSIONS: These results suggest that striatopallidal and thalamic dystonia may have different pathophysiologic bases.
Adolescent↗
Long-term MR follow-up of cerebral lesions in neuro-Behçet's disease.
To study the long-term evolution of cerebral lesions in neuro-Behçet's disease, MRI was carried out on 12 patients, with follow-up from 1.5 to 6 years (mean 3.5 years). On the first MRI, 66 lesions in all were found; each patient had 1-10 lesions (mean 5.5). There were 30 (46%) lesions in the brain stem, 18 (27%) in the basal ganglia region and 18 (27%) in the periventricular white matter. Of these 22 (33%) were small, 31 (47%) medium-size and 13 (20%) large lesions. On the last MRI, 60 lesions were found: each patient had 1-10 lesions (mean 5). At this time 31 lesions (52%) were in the brain stem, 13 (22%) in the basal ganglia region and 16 (26%) in the periventricular white matter. There were 41 (68%) small, 13 (22%) medium-size and 6 (10%) large lesions. About 40% of the lesions disappeared, 35% reduced in size and 25% remained unchanged. No lesion had enlarged. Of the 60 final lesions 20 (34%) were not observed on the first study. Small new lesions were found in 5 of 12 patients (42%), and were asymptomatic. Medium-size or large new lesions were found in 2 patients (17%) who had stopped steroid treatment and had a neurological relapse. Enlargement of the ventricular system or worsening of initial cerebral atrophy was observed in 9 of 12 patients. Appearance of small lesions and worsening of cerebral atrophy on long-term follow-up suggest the possibility of subclinical progression of cerebral vasculitis and should be considered in the prognosis of neuro-Behçet's disease.
Adolescent↗
[Iridium 192 brachytherapy of supra-tentorial high grade glioma recurring in irradiated areas: technique and preliminary results of the Pitié-Salpêtrière hospital group].
UNLABELLED: Our aim was to analyse feasibility and preliminary results obtained with iridium 192 re-irradiation of recurrent high grade gliomas. MATERIAL AND METHODS: a technique for implanting rigid plastic tubes afterloaded with iridium 192 wires was developed that utilised a stereotactic Leksell frame. Nineteen glioblastomas and one anaplastic glioma (12 males and 8 females: age: 20-69 years, median: 50) were implanted between January 1993 and December 1994. Previous treatments included surgery (18/20). 55-60 Gy external beam radiotherapy (20/20), and chemotherapy (16/20); interval between initial treatment and retreatment with iridium 192 was 6 to 39 months (median: 10). Maximum diameter of the tumour at the moment of implantation was 2.1-10.1 cm (median: 6.4 cm) and tumour volume 2.122 cm3 (median: 22 cm3). All tumours were supra-tentorial (right hemisphere: 9; left hemisphere: 11). Karnofsky index was 60-100 (median: 80). Implantation was carried out under local anaesthesia; tumour contours were visualised using either a CT-scan (16/20) or a MRI (4/20). Dosimetry was carried out using two orthogonal films and CT-scan images. Total dose on the reference isodose was 40-60 Gy (60 Gy: 9; 50 Gy: 7; 40 Gy: 4); dose-rate was 0.24-0.73 Gy/h (median: 0.38). RESULTS: probability of overall survival is 90% at 6 months, 55% at one year, and 26% at two years. Median survival is 56 weeks. Eleven patients died from local failure, and three from leptomeningeal metastasis. Six patients are alive, 15-30 months after the implantation. Two were reoperated for brain necrosis. Three patients showed evidence of bacterial meningitis, and three others of skin necrosis. CONCLUSION: according to this preliminary analysis, results obtained after reirradiation of high grade gliomas with iridium 192 are encouraging. More patients and longer follow-up are needed to draw definitive conclusions.
Adult↗