Mehdi Mejdoubi

Carotid-Bulb Atypical Fibromuscular Dysplasia in Young Afro-Caribbean Patients With Stroke

Background and Purpose— An atypical form of fibromuscular dysplasia located in the internal carotid-bulb (CaFMD) is thought to be uncommon and is poorly described as a cause of ischemic stroke in the young. This study aimed to obtain a better description of CaFMD in Afro-Caribbean population, who could be particularly affected by it. Methods— This study included consecutive patients <55 years consulting at Fort-de-France University Hospital Stroke Center (Martinique, FWI) found to have CaFMD as the only cause after a comprehensive work-up. CaFMD was diagnosed when computed tomographic angiography showed a bulbar spur without calcification. Results— Twenty-five patients with stroke and CaFMD were identified. Computed tomographic angiography showed 2 CaFMD patterns: a thin (n=15) or thick (n=10) spur. Three patients initial computed tomographic angiography images showed a mural thrombus overlying the CaFMD. CaFMD was surgically removed from 7 of 25 and 20 of 25 patients who received antiplatelet therapy; after mean follow-up of 25.3±19.5 months, their respective recurrence rates were 0% and 30%. Conclusions— CaFMD could be a common condition in young Afro-Caribbeans with carotid-territory ischemic stroke. Recurrences were frequent under antiplatelet treatment, while surgical CaFMD removal seemed more effective.

Trends in Incidence and Early Outcomes in a Black Afro-Caribbean Population From 1999 to 2012 Etude Réalisée en Martinique et Centrée sur l’Incidence des Accidents vasculaires cérébraux II Study

Background and Purpose— Seldom studies are available on trends in stroke incidence in blacks. We aimed to evaluate whether stroke risk prevention policies modified first-ever stroke incidence and outcomes in the black Afro-Caribbean population of Martinique. Methods— Etude Réalisée en Martinique et Centrée sur l’Incidence des Accidents Vasculaires Cérébraux (ERMANCIA) I and II are 2 sequential prospective population-based epidemiological studies. There have assessed temporal trends in first-ever stroke incidence, risk factors, pathological types, and early outcomes in the black Afro-Caribbean population of Martinique comparing two 12-month periods (1998–1999 and 2011–2012). Crude and age-standardized incidence and 30-day outcomes for stroke in the 2 study periods were compared using Poisson regression. Results— We identified 580 and 544 first-ever strokes in the 2 studies. World age-standardized incidence rates decreased by 30.6% in overall (111 [95% confidence interval, 102–120] versus 77 [95% confidence interval, 70–84]). Rate decline was greater in women than in men (34% versus 26%) particularly in women aged 65 to 74 years (−69%) and 75 to 84 years (−43%). Frequencies of hypertension and diabetes mellitus were unchanged, whereas dyslipidemia, smoking, and atrial fibrillation significantly increased. Only ischemic stroke types showed significant rate reduction in overall and in women, incidence rate ratio (95% confidence intervals) of 0.69 (0.50–0.97) and 0.61 (0.42–0.88), respectively. The overall 30-day case-fatality ratio remained stable (19.3%/17.6%), whereas a better 30-day outcome was found (modified Rankin Score, ⩽2 in 47%/37.6%; P=0.03). Conclusions— Over 13 years, there has been a significant decrease (30.6%) in the age-specific first-ever stroke incidence in our Afro-Carribean population. Although prevention policies seem effective, we need to focus on new risk factors limitation and on male population adherence to prevention program.

Bilateral wallerian degeneration of the middle cerebellar peduncles due to unilateral pontine infarction: A morphologic and spectroscopic study

We report the case of a patient with bilateral and symmetrical T2 hyperintensities of the middle cerebellar peduncles. She had a history of left pontine infarction 8 months before. This was attributed to bilateral Wallerian degeneration. MR Spectroscopy showed decreased N-acetyl aspartate/Creatine (NAA/Cr) ratio in the cerebellar peduncles as well as in the whole cerebellum. We hypothesize that this could reflect neuronal degeneration following a stroke.

MRI characteristics of carotid bulb atypical fibromuscular dysplasia in black stroke patients

BACKGROUND AND PURPOSE In black stroke patients, a particular form of fibromuscular dysplasia (FMD), called atypical FMD (aFMD), is involved in stroke mechanism. The high rate of stroke recurrence under medical treatment leads to propose surgery in such patients. Regarding its location level on the carotid bulb, aFMD is often confused with atherosclerosis or free-floating thrombus. Nowadays, only histology can confirm the diagnosis. MRI of aFMD has never been assessed. MATERIALS AND METHODS The constitution of a black patients cohort with aFMD-related ischemic stroke is currently in progress in the French West Indies, Martinique. In patients scheduled for surgery, MRI of the carotid bifurcation was analyzed preoperatively, with subsequent histological examination of the excised specimen. The first four black stroke patients with MRI and histological findings are described. RESULTS On imaging, aFMD lesion was homogeneous with isosignal on T2-weighted sequences and slight hypersignal on T1-weighted sequences with mild gadolinium enhancement of the inner layer. Histological findings confirmed the aFMD mainly located in the intima. CONCLUSIONS aFMD generates a particular MRI pattern in our four patients, which could increase the diagnosis accuracy. Carotid bulb lesion in black stroke patients should suggest aFMD and MRI analysis may contribute to rule out differential diagnoses.

Incidence and Mortality of Spontaneous Subarachnoid Hemorrhage in Martinique

Background Incidence of spontaneous subarachnoid hemorrhages (SAH) varies wildly across the world and seems to be low in Central and South America (4.2 per 100 000 person-years; CI 95%; 3.1–5.7). The objective of our study was to describe the characteristics of SAH and to estimate its incidence and severity in Martinique, a small French island located in the Caribbean Sea. Methods Due to its insular nature and small captive population, Martinique is ideal for the setting up of population-based epidemiological studies with good exhaustiveness. Our study, spanning a 7 year period (2007–2013), consisted of retrospective case ascertainment with multiple overlapping methods. Crude incidence and 30 day case-fatality rates for SAH among the Martinican population were computed for the study period. Incidence and disease severity was also analyzed according to age, gender and aneurysm presence. World age-standardized incidence rates were also calculated. Results A total of 121 patients had a SAH during the study period, with a higher frequency of female cases (71.1% versus 28.9%, p<0.001). Patient mean age was 57.1 years (median = 55 [46–66]). An aneurysmal origin was found in 96 SAH cases (79.3%). Crude annual incidence was 4.36 per 100 000 person-years (CI 95% 2.30–6.42). World age-standardized incidence was 3.29 per 100 000 person-years (CI 95% 1.74–4.84). During the 30 days following SAH diagnosis, 29 patients died (case fatality rate: 24% (CI 95% 16.4–31.6)). Conclusions The incidence of spontaneous subarachnoid hemorrhage in Martinique is much lower than in other parts of the world and similar to countries in Central and South America. These results are possibly related to environmental factors and most particularly to a low rate of smoking in the Martinican population. Thirty-day case-fatality rate is similar to what is observed in developed countries.

Kyste épidermoïde intracrânien secondaire à la chirurgie d'une mucocèle

Un homme de 63 ans a été hospitalisé en 1996 à la suite d’une crise comitiale généralisée. Il n’avait pas d’antécédent hormis une sinusite chronique. La tomodensitométrie (TDM) cérébrale (fig. 1) a révélé une formation sphérique à paroi osseuse et contenu tissulaire développée à la face postérieure du sinus frontal droit. Cette formation s’enclavait dans le lobe frontal droit au sein d’une cavité pseudo-kystique. L’opération a mis en évidence une mucocèle ayant soufflé la paroi postérieure du sinus frontal puis traversé la dure-mère. L’exérèse de la mucocèle a laissé une petite solution de continuité osseuse à la face postérieure du sinus frontal qui a été comblée par du muscle, de la poudre d’os et un morceau de voûte crânienne prélevé sur la table interne du volet. La dure-mère a été soigneusement suturée. Les suites opératoires ont été simples. Le patient était sorti du service de neurochirurgie avec un traitement anti-épileptique et une antibiothérapie. L’anatomopathologie a confirmé le diagnostic de mucocèle. Les consultations et l’imagerie de contrôle (fig. 2 ) n’ont pas révélé de complication et le traitement anti épileptique a été arrêté en 1999. L’

Adrénoleucodystrophie liée à l’X, forme cérébrale de l’adulte: À propos d’un cas

The authors report a case of an X-linked-adrenoleukodystrophy (ALD) in a young adult presenting with hemianopsia. Adult onset cerebral ALD is rare and represents only 3% of cases of ALD. The observation describes clinical data, as well as conventional and spectroscopic MR imaging and related value in prognosis evaluation.Resume Les auteurs rapportent le cas d’une forme cerebrale d’adrenoleucodystrophie (ALD), decouverte chez un adulte jeune a l’occasion d’un bilan realise pour hemianopsie laterale homonyme. La forme cerebrale de l’adulte represente environ 3 % des cas decrits d’ALD. L’observation decrit la presentation clinique, l’imagerie IRM conventionnelle et spectroscopique ainsi que son interet dans la prise en charge du patient.

Transoceanic Management and Treatment of Aneurysmal Subarachnoid Hemorrhage: A 10-Year Experience

Background and Purpose— Because of the small number of yearly cases of ruptured cerebral aneurysms, endovascular treatment is not performed in Martinique. Therefore, patients from Martinique are sent 7000 km to Paris on commercial flights as soon as possible, where treatment is performed. Nontransportable patients are treated locally with either surgery or symptomatic care. The objective of our study was to assess patient outcomes and safety of this treatment strategy. Methods— We retrospectively examined all cases of aneurysmal subarachnoid hemorrhage in Martinique diagnosed during 2004 to 2013. Medical case records were searched for the type and location of treatment, clinical status, and transfer duration. Results— A total of 119 patients had an aneurysmal subarachnoid hemorrhage during the 10-year period. Of these, 91 were transferred to Paris, 12 were surgically treated locally, and 16 received symptomatic treatment. None of the transferred patients experienced any hemorrhagic recurrence, and none suffered a significant complication related to the air transportation. The median time between aneurysmal subarachnoid hemorrhage diagnosis and arrival at the referral center was 32 hours. The 30-day case fatality rate for treated cases was 14.6% (8.8% for those treated in Paris and 58.3% for those treated locally). Conclusions— Our treatment strategy for aneurysmal subarachnoid hemorrhage resulted in a 30-day case fatality rate similar to those observed elsewhere, despite an 8-hour flight and a median treatment delay of 32 hours. This strategy therefore seems to be safe and reliable for isolated regions with small populations.

Can MRI water apparent diffusion coefficient (ADC) value discriminate between idiopathic normal pressure hydrocephalus, Alzheimer's disease and subcortical vascular dementia?

Numerous similarities in MRI and clinical symptoms exist between Alzheimers disease (AD), subcortical vascular dementia (sVD) and possible idiopathic normal pressure hydrocephalus (iHPN). The aim of this study is to explore mean apparent coefficient diffusion (ADC) difference between theses diseases in different periventricular and deep white matter areas, as compared to healthy controls. This retrospective study analyzed mean ADC values of 120 patients in normal appearing deep white matter and lenticular nuclei, frontal, caudate nuclei corpus and parietal periventricular and deep white matter areas INPH group showed significantly lower ADC than sVD group in frontal periventricular region (1567.10-6mm2/s vs 1755.10-6mm2/s; P=0.0009) and in parietal deep region (1087.10-6mm2/s vs 1271.10-6mm2/s; P=0.0052), but showed significantly higher ADC in lenticular nuclei ROI (834.10-6mm2/s vs 753.10-6mm2/s; P=0.002). The comparison between iNPH and sVD showed a cut-off value of 1676.10-6mm2/s (sensitivity 0.70, specificity 0.77) in periventricular frontal area. INPH group, in comparison with NA group, showed significantly higher ADC in all ROIs. The iNPH group also showed significantly higher ADC than AD group in all ROIs. AD group showed significantly lower ADC than sVD group in all regions, except in normal appearing lenticular nuclei and caudate nuclei corpus deep ROI. SVD group showed significantly higher ADC than NA in all ROIs, except in normal appearing lenticular nucleus ROI. Different patterns of ADC values can differentiate between AD, sVD and iNPH, even when other MRI sequences appear morphologically similar.

Measuring Cerebral Hypoperfusion Induced by Hyperventilation Challenge With Intravoxel Incoherent Motion Magnetic Resonance Imaging in Healthy Volunteers

Objectives The aim of this study was to demonstrate the feasibility to assess cerebral hypoperfusion with a hyperventilation (HV) challenge protocol using intravoxel incoherent motion (IVIM) magnetic resonance imaging. Materials and Methods Magnetic resonance imaging experiments were performed on 10 healthy volunteers at 1.5 T, with a diffusion IVIM magnetic resonance imaging protocol using a set of b-values optimized by Cramer-Rao Lower Bound analysis. Hypoperfusion was induced by an HV maneuver. Measurements were performed in normoventilation and HV conditions. Biexponential curve fitting was used to obtain the perfusion fraction (f), pseudodiffusion coefficient (D*), and the product fD* in gray matter (GM) regions of interest (ROIs). Regional cerebral blood flow in the same ROIs was also assessed with arterial spin labeling. Results The HV challenge led to a diminution of IVIM perfusion-related parameters, with a decrease of f and fD* in the cerebellum (P = 0.03 for f; P = 0.01 for fD*), thalamus GM (P = 0.09 for f; P = 0.01 for fD*), and lenticular nuclei (P = 0.03 for f; P = 0.02 for fD*). Mean GM cerebral blood flow (in mL/100 g tissue/min) measured with arterial spin labeling averaged over all ROIs also decreased (normoventilation: 42.7 ± 4.1 vs HV: 33.2 ± 2.2, P = 0.004) during the HV challenge. Conclusions The optimized IVIM protocol proposed in the current study allows for measurements of cerebral hypoperfusion that might be of great interest for pathologies diagnosis such as ischemic stroke.