Astrid Corlobé

Heterozygous HTRA1 mutations are associated with autosomal dominant cerebral small vessel disease

Cerebral small vessel disease represents a heterogeneous group of disorders leading to stroke and cognitive impairment. While most small vessel diseases appear sporadic and related to age and hypertension, several early-onset monogenic forms have also been reported. However, only a minority of patients with familial small vessel disease carry mutations in one of known small vessel disease genes. We used whole exome sequencing to identify candidate genes in an autosomal dominant small vessel disease family in which known small vessel disease genes had been excluded, and subsequently screened all candidate genes in 201 unrelated probands with a familial small vessel disease of unknown aetiology, using high throughput multiplex polymerase chain reaction and next generation sequencing. A heterozygous HTRA1 variant (R166L), absent from 1000 Genomes and Exome Variant Server databases and predicted to be deleterious by in silico tools, was identified in all affected members of the index family. Ten probands of 201 additional unrelated and affected probands (4.97%) harboured a heterozygous HTRA1 mutation predicted to be damaging. There was a highly significant difference in the number of likely deleterious variants in cases compared to controls (P = 4.2 × 10(-6); odds ratio = 15.4; 95% confidence interval = 4.9-45.5), strongly suggesting causality. Seven of these variants were located within or close to the HTRA1 protease domain, three were in the N-terminal domain of unknown function and one in the C-terminal PDZ domain. In vitro activity analysis of HTRA1 mutants demonstrated a loss of function effect. Clinical features of this autosomal dominant small vessel disease differ from those of CARASIL and CADASIL by a later age of onset and the absence of the typical extraneurological features of CARASIL. They are similar to those of sporadic small vessel disease, except for their familial nature. Our data demonstrate that heterozygous HTRA1 mutations are an important cause of familial small vessel disease, and that screening of HTRA1 should be considered in all patients with a hereditary small vessel disease of unknown aetiology.

Deep brain stimulation for Huntington's disease: long-term results of a prospective open-label study

UNLABELLED OBJECT.: To date, experience of globus pallidus internus (GPi) deep brain stimulation (DBS) in the treatment of Huntingtons disease (HD) has been limited to a small number of case reports. The aim of this study was to analyze long-term motor outcome of a cohort of HD patients treated with GPi DBS. METHODS Seven patients with pharmacologically resistant chorea and functional impairment were included in a prospective open-label study from 2008 to 2011. The main outcome measure was the motor section of the Unified Huntingtons Disease Rating Scale. The primary end point was reduction of chorea. RESULTS Patients underwent MRI-guided bilateral GPi implantation. The median duration of follow-up was 3 years. A significant reduction of chorea was observed in all patients, with sustained therapeutic effect; the mean improvement on the chorea subscore was 58.34% at the 12-month follow-up visit (p = 0.018) and 59.8% at the 3-year visit (p = 0.040). Bradykinesia and dystonia showed a nonsignificant trend toward progressive worsening related to disease evolution and partly to DBS. The frequency of stimulation was 130 Hz for all patients. DBS-induced bradykinesia was managed by pulse-width reduction or bipolar settings. Levodopa mildly improved bradykinesia in 4 patients. Regular off-stimulation tests confirmed a persistent therapeutic effect of DBS on chorea. CONCLUSIONS GPi DBS may provide sustained chorea improvement in selected HD patients with pharmacologically resistant chorea, with transient benefit in physical aspects of quality of life before progression of behavioral and cognitive disorders. DBS therapy did not improve dystonia or bradykinesia. Further studies including quality of life measures are needed to evaluate the impact of DBS in the long-term outcome of HD.

Staged implantation of multiple electrodes in the internal globus pallidus in the treatment of primary generalized dystonia

OBJECT Deep brain stimulation (DBS) is used for treating various types of dystonia. Multiple electrodes could be proposed to improve the therapeutic outcome enabling the targeting of specific neuronal populations not reached by the electrical field generated by the initially implanted electrode. The authors address the question of the feasibility and safety of staged multiple lead implantations in the sensorimotor internal globus pallidus (GPi) in primary generalized dystonia (PGD). Criteria for patient selection, surgical technique, target selection, electrical settings management, and clinical outcome are presented. METHODS Sixteen patients (8 harbored the DYT1 gene mutation) presented with PGD and were enrolled in this study. Patients underwent clinical assessment using the Burke-Fahn-Marsden Dystonia Rating Scale preoperatively and during follow-up with DBS. Prior to the addition of electrodes, the authors confirmed, by turning off stimulation, that the patient was still benefiting from DBS and that DBS settings adjustment did not provide further improvement. The second target was defined according to the position of the first electrode, to the residual volume within the sensorimotor GPi, and according to residual symptoms. The second surgery followed the same protocol as the first and the new electrode were inserted using the same bur hole as the first electrode. RESULTS The addition of a new pair of electrodes was followed by significant improvement in the whole population (p = 0.005), as well as in the DYT1-negative subgroup (p = 0.012) but not in the DYT1 subgroup (p = not significant). Nevertheless, some patients did not exhibit significant additional benefit. Seven hardware-related complications occurred during the entire follow-up, 3 prior to it, and 4 after the addition of the second pair of electrodes. CONCLUSIONS The addition of a second pair of electrodes in the GPi in patients with PGD with suboptimal or decaying benefit following the first surgery seems to be a safe procedure and is not followed by an increase in surgery-related complications. This staged procedure may provide further clinical improvement in patients with PGD in whom DBS effect is initially incomplete or when disease progression occurs over time. The position of the additional electrode within the GPi is determined by the available volume within the posteroventral GPi and by the distribution of the dystonic symptoms that need to be controlled.

COL4A1 mutation revealed by an isolated brain hemorrhage.

Discussion The spectrum of COL4A1-related disorders includes perinatal cerebral hemorrhage and porencephaly [2] , cerebral small vessel disease with retinal arteriolar tortuosity and leukoencephalopathy [3] , HANAC syndrome (Hereditary Angiopathy, Nephropathy, Aneurysms, and Muscle Cramps) and other eye abnormalities, including the Axenfeld-Rieger anomaly and cataract. A frequent white matter involvement is reported [3, 4] . Interestingly, some HANAC patients may have a normal brain MRI. However, except for one patient who suffered from migraine, these patients were free from neurologic symptoms [5, 6] . Recently, Weng et al. [7] reported COL4A1 variants in 2/96 patients with sporadic ICH. Their phenotype was not described in Introduction Ten to fifteen percent of strokes are related to an intracerebral hemorrhage (ICH). Etiologies are mainly arterial hypertension, amyloid deposition, and vascular malformations. In cases of a young age without vascular risk factors and vascular malformations, a genetic cause has to be suspected, especially a mutation in the gene coding for type IV collagen alpha 1 (COL4A1) [1] . We report a COL4A1 gene mutation in a 45-year-old woman with an isolated ICH in the absence of any other MRI abnormality, which further extends the clinical spectrum of COL4A1 mutations.

High CD3+ Cells in Intracranial Thrombi Represent a Biomarker of Atherothrombotic Stroke

Background and Purpose Approximately 30% of strokes are cryptogenic despite an exhaustive in-hospital work-up. Analysis of clot composition following endovascular treatment could provide insight into stroke etiology. T-cells already have been shown to be a major component of vulnerable atherosclerotic carotid lesions. We therefore hypothesize that T-cell content in intracranial thrombi may also be a biomarker of atherothrombotic origin. Materials and Methods We histopathologically investigated 54 consecutive thrombi retrieved after mechanical thrombectomy in acute stroke patients. First, thrombi were classified as fibrin-dominant, erythrocyte-dominant or mixed pattern. We then performed quantitative analysis of CD3+ cells on immunohistochemically-stained thrombi and compared T-cell content between “atherothrombotic”, “cardioembolism” and “other causes” stroke subtypes. Results Fourteen (26%) thrombi were defined as fibrin-dominant, 15 (28%) as erythrocyte-dominant, 25 (46%) as mixed. The stroke cause was defined as “atherothrombotic” in 10 (18.5%), “cardioembolism” in 25 (46.3%), and “other causes” in 19 (35.2%). Number of T-cells was significantly higher in thrombi from the “atherothrombotic” group (53.60 ± 28.78) than in the other causes (21.77 ± 18.31; p<0.0005) or the “cardioembolism” group (20.08 ± 15.66; p<0.0003). Conclusions The CD3+ T-cell count in intracranial thrombi was significantly higher in “atherothrombotic” origin strokes compared to all other causes. Thrombi with high content of CD3+ cells are more likely to originate from an atherosclerotic plaque.

Brain magnetic resonance imaging helps to differentiate atypical multiple sclerosis with cavitary lesions and vanishing white matter disease

Multiple sclerosis (MS) patients can present with atypical cavitary lesions mimicking vanishing white matter disease (VWMD). Our objective was to identify brain magnetic resonance imaging (MRI) findings that differentiate these two disorders.

Quantitative susceptibility mapping in superficial hemosiderosis of the central nervous system.

Journal of Neuroradiology - In Press.Proof corrected by the author Available online since lundi 8 juin 2015

Mechanical Thrombectomy for Minor and Mild Stroke Patients Harboring Large Vessel Occlusion in the Anterior Circulation: A Multicenter Cohort Study.

Background and Purpose— Proximal large vessel occlusion (LVO) is present in up to 30% of minor strokes. The effectiveness of mechanical thrombectomy (MT) in the subgroup of minor stroke with LVO in the anterior circulation is still open to debate. Data about MT in this subgroup of patients are sparse, and their optimal management has not yet been defined. The purpose of this multicenter cohort study was to evaluate the effectiveness of MT in patients experiencing acute ischemic stroke (AIS) because of LVO in the anterior circulation, presenting with minor-to-mild stroke symptoms (National Institutes of Health Stroke Scale score of <8). Methods— Multicenter cohort study involving 4 comprehensive stroke centers having 2 therapeutic approaches (urgent thrombectomy associated with best medical treatment [BMT] versus BMT first and MT if worsening occurs) about management of patients with minor and mild acute ischemic stroke harboring LVO in the anterior circulation. An intention-to-treat analysis was conducted. The primary end point was the rate of excellent outcome defined as the achievement of a modified Rankin Scale score of 0 to 1 at 3 months. Results— Three hundred one patients were included, 170 with urgent MT associated with BMT, and 131 with BMT alone as first-line treatment. Patients treated with MT were younger, more often received intravenous thrombolysis, and had shorter time to imaging. Twenty-four patients (18.0%) in the medical group had rescue MT because of neurological worsening. Overall, excellent outcome was achieved in 64.5% of patients, with no difference between the 2 groups. Stratified analysis according to key subgroups did not find heterogeneity in the treatment effect size. Conclusions— Minor-to-mild stroke patients with LVO achieved excellent and favorable functional outcomes at 3 months in similar proportions between urgent MT versus delayed MT associated with BMT. There is thus an urgent need for randomized trials to define the effectiveness of MT in this patient subgroup.

HIV-associated vasculopathy: Potential pitfall for IV thrombolysis and indication for vessel wall imaging.

http://dx.doi.org/10.1016/j.neurad.2016.04.002 0150-9861/© 2016 Elsevier Masson SAS. All rights reserved. On admission, the NIH stroke score was 7 (right hemipleia and dysarthria). Brain MRI (Fig. 1A and B) showed an acute cerebral nfarct involving the left middle cerebral artery territory. roximal intracranial arteries were considered normal on ime-of-flight (TOF) sequence. Ischemic sequels were visible Fig. 1C). Some foci of punctuate enhancement were present Fig. 1D). Intravenous (IV) thrombolysis was administered, hours after the onset of symptoms. Three hours after IV thrombolysis, she elicited a sudden

Formes cavitaires de sclérose en plaques : étude multicentrique sur vingt patients

INTRODUCTION Cavitary white matter changes are mainly described in leukodystrophies and especially in vanishing white matter disease. Large cavitary lesions are not typical for multiple sclerosis (MS). METHODS We studied MS patients with large cavitary brain lesions. Patient characteristics, disease onset/duration/subtype, expanded disability status scale (EDSS), mini mental state (MMS), vanishing white matter disease genetic analysis, and MRI characteristics of the cavitary lesions were analyzed. RESULTS Twenty patients were analyzed (6 men and 14 women). Mean age at disease onset was 37.6 (range 17-58). Mean disease duration was 10 years (range 2-20). Five patients had initial relapsing-remitting MS and nine patients had primary-progressive MS. Mean EDSS was 5.5 (range 2-8). Mean MMS was 20/30. Vanishing white matter disease genetic analysis was performed and negative in seven patients. Inferior corpus callosum lesions were seen in all patients with available sagittal FLAIR sequences. Cavitary lesions were strictly supratentorial, and located inside the diffuse leukoencephalopathy, with often a posterior predominance. CONCLUSION MS patients with large cavitary lesions seem to represent a MS subgroup, predominantly women, with relatively late disease onset, predominantly primary-progressive type, relatively high EDSS scores, and severe cognitive dysfunction.