Emmanuel Touzé

Spinal cord infarction: clinical and magnetic resonance imaging findings and short term outcome

Background: Most studies on spinal cord infarction have been conducted in single centres; they usually consisted of case reports, or of larger series of patients recruited over a large period of time, with heterogeneous diagnostic procedures. Therefore, the clinical and radiological presentation of spinal cord infarcts and their short term outcome remain poorly understood. Objective: To define clinical and magnetic resonance imaging (MRI) findings, and short term outcome in patients with spinal cord infarcts. Methods: The authors prospectively included patients within 10 days of onset. An MRI scan was required and repeated when initially normal. Results: Twenty eight consecutive patients were included over a 24 month period in 16 neurological centres. The infarct was cervical in seven patients, thoracic in three, thoracolumbar in 15, and restricted to the conus in three. On axial MRI scans the infarct was located in the central territory of the anterior spinal artery in 21 patients, and in the peripheral arterial territory in three. At month two, 15 patients had a good outcome and 13 had a poor outcome, including three deaths. Patients who, at onset, could not walk, had bladder dysfunction, or proprioceptive deficits were more likely to have a poor outcome. At month two, pain had occurred in 10 of the 25 survivors and was associated neither with the initial severity, nor the extent of the infarct on MRI. Conclusion: The two month outcome mainly depends on the initial severity of the neurological deficit; however, a few patients with a severe impairment at onset had a good outcome, especially when proprioception remained normal at onset. The study does not support the hypothesis that pain occurs more frequently in small spinal infarcts.

Hepatitis B Vaccination and First Central Nervous System Demyelinating Event: A Case-Control Study

Objective: To investigate the relationship between hepatitis B (HB) vaccination and a first central nervous system (CNS) demyelinating event in adults. Methods: In 1998, we conducted a multicentre, hospital-based case-control study which enrolled 402 cases of first CNS demyelinating event occurring between 1994 and 1995 and 722 controls matched for centre, age, sex and date of admission. An independent expert committee validated the diagnoses of cases and controls. Data on vaccinations were obtained from a standardized phone interview. Forty percent of eligible cases and 50% of eligible controls could not be localized or were excluded because they did not satisfy inclusion or matching criteria. Results: Conditional logistic regression performed on 236 and 355 matched controls showed that adjusted odds ratios for the first CNS demyelinating event within 2 months following an injection of HB vaccine were 1.8 [95% confidence interval (CI), 0.7–4.6] in the whole group and 1.4 (95% CI, 0.4–4.5) in the subgroup of cases (n = 152) and controls (n = 253) referring to vaccination certificates during the phone interview. Restricting the analyses to the cases with definite or probable multiple sclerosis, these odds ratios were 2.0 (95% CI, 0.8–5.4) and 1.6 (95% CI, 0.4–5.6), respectively. Odds ratios tend towards 1 for a longer interval between HB vaccine and demyelinating event. Conclusions: This study was sufficiently powerful to rule out a strong association between HB vaccine exposure and a subsequent demyelinating event. However, it could not provide a clear indication of a moderately increased risk of a CNS demyelinating event shortly after HB vaccination in adults.

Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection

Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.

Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection

Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69–0.82; P = 4.46 × 10−10), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10−3; combined P = 1.00 × 10−11). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions.

European consensus on the diagnosis and management of fibromuscular dysplasia

The main objectives of this expert consensus are to raise awareness about fibromuscular dysplasia, which is more frequent and more often systemic than previously thought and can sometimes have devastating consequences; to provide up-to-date recommendations for the diagnosis, evaluation, and management of the disease; and to identify research priorities. The emphasis has been put on recommendations for daily practice. The main topics covered include definition, classification, diagnosis, and management of fibromuscular dysplasia in adult patients with symptomatic involvement of the renal arteries, supra-aortic trunks, and digestive and peripheral arteries.

Reversible angiopathy and encephalopathy after blood transfusion.

Sirs: Neurological complications have rarely been described after blood transfusion [1, 2]. We report a case of reversible angiopathy and encephalopathy after a blood transfusion in a patient with chronic severe anaemia. Case report – A 48-year-old black woman with a 11-year history of schizophrenia was admitted in a psychiatric department on 16 January 2001 for dysthymic and behaviour disturbances. She had been receiving neuroleptics (haloperidol: Haldol® and cyamemamazine: Tercian®) and antihistamine drug (hydroxysine: Atarax®) for 2 years. She had had a moderate hypertension since 1998, but received no treatment. A severe chronic anaemia (haemoglobin: 3 g/dl, haematocrit: 13 %, reticulocytes: 73.109/dl) due to chronic bleeding from myoma uteri was discovered. She received 5 packed red blood cell transfusion of 200 ml. Haemoglobin subsequently increased to 8 g/dl and haematocrit to 29 % in seven hours. Six days after the transfusion, she had a first generalized seizure. She underwent a conservative hysterectomy on 14 February. Ketamine (Ketalar®), propofol (Diprivan®), sufentanil (Sufenta®)and rocuronium (Esmeron®) were used for anaesthesia. Four days later, she developed repeated focal and generalized seizures with stupor, loss of consciousness rapidly leading to status epilepticus. A right hemiparesis was observed. She was referred to an intensive care unit and required assisted ventilation. Seizures disappeared within 48 hours after being treated by sodium valproate. On 24 February she had a recurrence of status epilepticus. Phenobarbital was added and she improved rapidly. Repeated measures of blood pressure showed values under 160/95 mm Hg. Blood glucose, electrolytes, urea, ESR and coagulation tests were normal. Antinuclear antibodies, neutrophil antinuclear cytoplasm antibodies, rheumatoid factor, blood cultures, serum titres for Treponema, Chlamydia, Mycoplasma, Coxiella, Rickettsia, Lyme Borrelia, cytomegalovirus, HIV, hepatitis B and C were all negative. Haemoglobin electrophoresis was normal. Analysis of CSF showed 8/mm3 white cells, 22/mm3 red cells; CSF glucose was 4.8 mmol/L and protein was 0.58 g/L. Transthoracic echocardiography was normal. MRI performed just before the first admission in intensive care medicine showed slight cortical and subcortical hyperintensities on Fluid Attenuated Inversion Recovery (FLAIR) sequences with normal to increased apparent diffusion coefficient (up to 126 % with respect to controlateral normal appearing brain region) (ADC) on diffusion-weighted sequences (Fig. 1). One lesion located on the left putamino-caudate nucleus was haemorrhagic on T1-weighted sequences. Multiple segmental narrowing of the circle of Willis and its branches were seen on 3D TOF MR angiography and on conventional cerebral angiography (Fig. 2). Transcranial Doppler ultrasound showed increased peak systolic velocity to 140 cm/s in the left middle cerebral artery. Spontaneously the patient regained consciousness and the focal deficit resolved within 7 days. On MRI performed 10 days later, all lesions had disappeared except for the left putamino-caudate one. Arterial stenosis was no longer visible on 3-months MRA followup. Discussion – Our patient had reversible angiopathy and encephalopathy for which blood transfusion was the only trigger found after an extensive search for other aetiology. None of the drugs used has known sympathomimetic effects and could explain vasospasm [3]. Neurological complications of blood transfusion seem rare. A few cases of acute hypertensive leukoencephalopathy have been observed in anaemic patients with chronic renal failure who received blood transfusion or erythropoietin [2, 4]. But, to date, only one case of angiopathy, attributed to a LETTER TO THE EDITORS

Added Value of High-Resolution MR Imaging in the Diagnosis of Vertebral Artery Dissection

BACKROUND AND PURPOSE: The optimal imaging method for the diagnosis of VAD remains undefined. Our aim was to evaluate the added value of HR-MR imaging for the diagnosis of VAD. MATERIALS AND METHODS: We retrospectively extracted 35 consecutive patients suspected of having acute VAD who had the following: 1) a focal lumen abnormality of the VA on CE-MRA, 2) HR-MR imaging during the initial hospital stay, and 3) clinical and imaging follow-up within 6 months. Two neurologists classified patients as either VAD (group A) or non-VAD (group B) by reviewing all the available data at hospital discharge, except HR-MR imaging data. On HR-MR imaging, 2 radiologists searched for signs of acute VAD. The 2 classifications were compared. In case of discordance, CE-MRA follow-up and axial fat-suppressed T1WI, used to obtain supportive evidence for or against VAD, were considered as the standard of reference. RESULTS: In 4/18 patients in group A, HR-MR imaging did not demonstrate any signs of acute VAD and perivertebral signal-intensity changes were attributed to venous plexus, with an unchanged lumen on follow-up. In 4/17 patients in group B, HR-MRI demonstrated a mural hematoma, with lumen normalization on follow-up CE-MRA. CONCLUSIONS: Our results encourage the use of HR-MR imaging as a second-line diagnostic tool in the event of suspicion of acute VAD and doubtful findings on standard imaging.

Relationships Between Recent Intraplaque Hemorrhage and Stroke Risk Factors in Patients With Carotid Stenosis The HIRISC Study

Objective—Intraplaque hemorrhage (IPH) is an emerging marker of plaque instability. However, little is known about the relationships between IPH and traditional risk factors and whether these relationships differ between symptomatic and asymptomatic disease. Methods and Results—Two hundred thirty-four patients with symptomatic (n=114) or asymptomatic (n=120) carotid stenosis underwent high-resolution plaque magnetic resonance imaging. Seventy-five patients had recent IPH (symptomatic, 33%; asymptomatic, 31%). In symptomatic stenosis, recent IPH was independently associated with degree of stenosis (odds ratio [OR]=4.21, 1.61–10.98 for North American Symptomatic Carotid Endarterectomy Trial >35%; OR=2.92, 1.18–7.24 for European Carotid Surgery Trial >60%), qualifying event (OR=4.13; 1.11–15.32 for stroke or hemispheric transient ischemic attack ≥1 hour versus transient ischemic attack <1 hour or ocular symptoms), time from ischemic event (OR=6.65, 1.56–28.35 for ⩽2 weeks; OR=2.24, 0.87–5.81 for 2–12 weeks versus >12 weeks; P for trend=0.03). In asymptomatic stenosis, IPH was only associated with stenosis severity >70% by ECST (OR=6.65; 1.95–22.73) but not by the NASCET method. Conclusion—Our findings support the potential link between recent IPH and risk of ipsilateral stroke in symptomatic disease but also imply that prognostic studies should adjust for known stroke risk factors in multivariate analyses. In asymptomatic stenosis, the potential predictive value of recent IPH is less likely to be confounded by stroke risk factors.

Mechanical and Structural Characteristics of Carotid Plaques by Combined Analysis With Echotracking System and MR Imaging

OBJECTIVESnThe purpose of this study was to correlate the arterial mechanics of carotid atherosclerotic plaques assessed from echotracking with their composition by high-resolution magnetic resonance imaging (HR-MRI).nnnBACKGROUNDnAnalysis of the relationship between mechanical parameters and structure of the plaque allows better understanding of the mechanisms leading to mechanical fatigue of plaque material, plaque rupture, and ischemic events. A specific longitudinal gradient of strain (reduced strain, i.e., lower radial strain at the plaque level than at the adjacent segment) has been shown in atherosclerotic plaques on the common carotid artery (CCA) in patients with hypertension, dyslipidemia, or type 2 diabetes mellitus. The structural abnormalities underlying this functional behavior have not been determined.nnnMETHODSnForty-six carotid plaques from 27 patients were evaluated; plaques were present at the site of the carotid bifurcation and extended to the CCA. Among the 27 patients, 9 had previous ischemic stroke ipsilateral to carotid stenosis (symptomatic) and 18 had not (asymptomatic). Mechanical parameters were measured at 128 sites on a 4-cm long CCA segment by noninvasive echotracking system, and strain gradient was calculated. Plaque composition was noninvasively determined by HR-MRI.nnnRESULTSnComplex plaques at HR-MRI (i.e., American Heart Association [AHA] stages IV to VIII) more often displayed a reduced strain than the simple plaques (i.e., AHA stages I to III; p = 0.046). HR-MRI verified complex plaques were associated with an outer remodeling upon echotracking, and had a lower distensibility than adjacent CCA (17.0 ± 5.0 MPa⁻¹ vs. 21.7 ± 7.3 MPa⁻¹; p = 0.007). An outer remodeling was observed in plaques with a lipid core at HR-MRI and was more frequent in symptomatic carotids.nnnCONCLUSIONSnThese findings indicate that the longitudinal mechanics of complex plaques follows a specific pattern of reduced strain. They also suggest that reduced strain, associated with an outer remodeling, may be a feature of high-risk plaques.

Thrombolysis and thrombectomy in patients treated with dabigatran with acute ischemic stroke: Expert opinion

Systemic thrombolysis with rt-PA is contraindicated in patients with acute ischemic stroke anticoagulated with dabigatran. This expert opinion provides guidance on the use of the specific reversal agent idarucizumab followed by rt-PA and/or thrombectomy in patients with ischemic stroke pre-treated with dabigatran. The use of idarucizumab followed by rt-PA is covered by the label of both drugs.