Understanding Neuropathy Features in the Context of Nitrous Oxide Abuse: A Combined Electrophysiological and Metabolic Approach.

BACKGROUND: The incidence of neurological complications associated with nitrous oxide (N2O) abuse, including N2O-induced myelopathy and neuropathy, has risen in the past decade. N2O-induced neuropathy often presents as a subacute axonal pathology; however, demyelinating patterns mimicking Guillain-Barré syndrome have also been observed. This study explores the metabolic pathophysiology of N2O-induced neuropathy, focusing on the alteration in metabolism to provide a deeper understanding of the biochemical pathways influencing the diverse electrophysiological patterns observed. METHODS: We conducted a combined metabolic and electrophysiological exploration of 35 patients who underwent electromyographic exams at our referral center over a three-year period for sensorimotor symptoms linked to recreational N2O use. We collected demographic, clinical, radiological, electrophysiological, and biological data. Patients were categorized into axonal or demyelinating groups based on their electrophysiological patterns, and metabolic parameters were compared. RESULTS: Our cohort predominantly exhibited a length-dependent sensorimotor axonal symmetrical neuropathy affecting the lower limbs. Among the patients, 40% met the demyelinating criteria, with four patients exhibiting conduction blocks. The demyelinating group had a significantly higher peripheral neuropathy disability (PND) score at diagnosis. Elevated homocysteine and methylmalonic acid (MMA) levels were noted in all patients, but these were lower in the demyelinating group. CONCLUSIONS: This study highlights the diverse electrophysiological manifestations of N2O-induced neuropathy and underscores the potential role of metabolic parameters as biomarkers to understand its pathophysiology. Lower hyperhomocysteinemia and MMA levels were observed in demyelinating patterns. In this study, we did not observe further improvement, but it is well-known that demyelinating features have a better prognosis related to the further remyelination. These findings contribute to a better understanding of N2O-related neuropathic damage and could guide future therapeutic interventions based on biochemical-neurophysiological stratifications.

Comparison of biomarker for diagnosis of nitrous oxide abuse: challenge of cobalamin metabolic parameters, a retrospective study.

BACKGROUND: Recreational use of nitrous oxide (N2O) leads to neurological disorders including combined subacute degeneration of spinal cord, psychological disorders, and thrombosis. Serum or urine N2O assays could not be routinely performed. Hence, it is necessary to investigate other biological markers such as metabolic markers. We aimed here to challenge the three main biological markers used for the diagnosis of nitrous oxide abuse as total vitamin B12, homocysteine, and methylmalonic acid. METHODS: We retrospectively collected clinical and biological data from 52 patients with known, documented chronic N2O abuse and associated clinical signs (peripheral neuropathy disability score or thrombosis event). Sera and plasma total vitamin B12, methylmalonic acid (MMA), and homocysteine were performed to identify the most specific marker of chronic N2O intoxication and related clinical outcomes. RESULTS: Plasma homocysteine was almost consistently increased in case of N2O chronic consumption, whereas MMA increase and total vitamin B12 decrease are not systematically found. Our results showed that none of the markers are correlated with levels of N2O consumptions. However, homocysteine and MMA are correlated with clinical severity, but MMA seems to be a better marker of clinical severity. CONCLUSION: There is no specific marker of nitrous oxide abuse according to levels of consumption, total vitamin B12 decrease could not be used either as consumption or as severity marker. However, we showed that homocysteine is consistently increased and could be used as marker of recent N2O consumption. On the other hand, we showed that MMA could be used as a marker of clinical gravity.

Impact on patient management of the implementation of a magnetic resonance imaging dedicated to neurological emergencies.

RATIONALE, AIMS AND OBJECTIVES: Neurological emergencies consumed a high amount of resources in emergency department (ED). We aimed to study the effect of the implementation of a magnetic resonance imaging (MRI) dedicated to emergencies on the management of patients admitted in ED for neurological emergencies. METHODS: We enrolled consecutive patients who underwent computed tomography and/or MRI for neurological disorders categorized as the suspicion of stroke and other reasons, over 2 periods that differed according to the priority access to computed tomography in the first period versus priority access to MRI in the second one. Criteria used to evaluate the effectiveness of the management were door-to-imaging time, ED length of stay, diagnostic performance, patient orientation, and length of hospitalization stay. RESULTS: When priority access to MRI, the door-to-imaging time was 31 minutes longer (P = .005) for patients suspected of stroke or transient ischaemic attack (TIA) and 70 minutes for the others (P < .001). The ED length of stay was 42 minutes shorter (P = .013) for stroke/TIA patients and 26 minutes longer (P = .029) for other patients. The proportion of patients with stroke mimics (no stroke amongst suspected stroke/TIA) increased (16.7% vs 25.6%, P = .017) as well as discharged patients (21.6% vs 29.6%, P = .002). The proportion of patients with stroke/TIA amongst other reasons of admission remained unchanged (P = .114). The median length of hospitalization stay decreased from 9 to 7 days for the stroke/TIA patients (P = .042). CONCLUSIONS: The implementation of a MRI optimized the quality of care and diagnostic accuracy for patients admitted in ED with a better identification of stroke mimics, avoiding unnecessarily hospitalizations. The management of stroke-TIA patients was not modified, but their length of hospital stay reduced.

Use of emergency departments by known epileptic patients: An underestimated problem?

BACKGROUND AND PURPOSE: Seizure is a frequent reason of admission in emergency department (ED) but little is known about the proportion and the characteristics of known epileptic patients (KEPs) who used emergency services. METHODS: Over a 12-month period, we prospectively recruited adults admitted for seizure to a tertiary hospital ED. For KEPs, clinical epilepsy features and characteristics of the admission were collected. RESULTS: Of the 60,578 ED admissions, 990 were related to seizure; 580 of these admissions concerned 448 different KEPs (257 males; median age: 44); 339 were residents in the health district. Epilepsy was structural/metabolic in 268 (59.8%) patients, genetic in 44 (9.8%) and unknown/undetermined in 136 (30.3%); 218 (48.7%) patients were under a single antiepileptic drug and 135 (30.1%) were followed by an epileptologist. Of the 580 KEP admissions, 440 (75.8%) concerned patients who had called the emergency medical assistance number, 252 (43.4%) with a discharge diagnosis of usual seizure and 43 (7.4%) of a status epilepticus. Half the KEPs were discharged without hospitalization. We estimated that 9.0% of KEPs residing in the district had used the ED during the period. CONCLUSION: Proportion of KEPs using ED is high. Most of the admissions concerned usual seizures suggesting that staff training and educational programmes for patients and for their relatives need to be improved. The organization of the prehospital and of the emergency medical services should also be adjusted to this specific need. Further research should be conducted to optimize the seizure care pathway for KEPs.

Which factors influence the resort to surrogate consent in stroke trials, and what are the patient outcomes in this context?

BACKGROUND: The provision of informed consent is a prerequisite for inclusion of a patient in a clinical research project. In some countries, the legislation on clinical research authorizes a third person to provide informed consent if the patient is unable to do so directly (i.e. surrogate consent). This is the case during acute stroke, when the symptoms may prevent the patient from providing informed consent and thus require a third party to be approached. Identification of factors associated with the medical team's decision to resort to surrogate consent may (i) help the care team during the inclusion process and (ii) enable the patient's family circle to be better informed (and thus feel less guilty) about providing surrogate consent. METHODS: Patients included in the BIOSTROKE cohort (initially dedicated to the analysis of factors influencing stroke severity) were divided into two groups: those having provided informed consent directly and those for whom a third party (such as a family member) had provided surrogate consent. We compared the groups in terms of the initial clinical characteristics (age, gender, type of stroke, severity on the National Institutes of Health Stroke Scale (NIHSS), pre-stroke cognitive status according to the Informant Questionnaire on Cognitive Decline in the Elderly, and the stroke's aetiology) and the functional and cognitive impairments (according to the NIHSS, the modified Rankin score (mRS) and the Mini Mental State Examination) on post-stroke days 8 and 90. RESULTS: Three hundred and ninety five patients were included (mean ± SD age: 67 ± 15 years; 53% males). Surrogate consent had been obtained in 228 cases, and 167 patients had provided consent themselves. The patients included with surrogate consent were likely to be older and more aphasic, with a pre-existing cognitive disorder and more severe stroke (relative to the patients having provided consent). In terms of recovery, the patients included with surrogate consent had a worse functional prognosis (day 90 mRS ≥3: 57.6%, compared with 16.8% in patients having provided consent themselves; p < 0.0001) and a worse cognitive prognosis (day 90 MMS < 24: 15.4% and 4.8%, respectively; p < 0.002). The mortality rate was significantly higher in the surrogate consent group. CONCLUSIONS: We found that in addition to age, aphasia and stroke severity, pre-stroke cognitive status is a factor that should prompt the care team to consider requesting surrogate consent for participation in a clinical study. Given that the unfavourable outcome in patients with surrogate consent is often due to their initial clinical state (rather than inclusion in a trial per se), the issue of the family's feelings of guilt (and how to avoid these feelings) should be further addressed.

CSF CA 15-3 in breast cancer-related leptomeningeal metastases.

UNLABELLED: The sensitivity of CSF cytology, the standard method for diagnosis of leptomeningeal metastases (LM), is low. Serum cancer antigen 15-3 (CA 15-3) is frequently used for the monitoring of patients with breast cancer (BC) and is a laboratory test available in most centers. The aim of the current study was to determine the feasibility of measuring CSF CA 15-3 and CA 15-3 CSF/serum ratio in patients with BC-related LM. Serum and CSF CA 15-3 values were evaluated in 20 BC patients with LM (Group 1), 20 patients with LM from other primary cancers (Group 2), 20 BC patients with parenchymal brain metastases only (Group 3) and 20 controls (Group 4). CSF and serum were collected on the same day. Serum and CSF CA 15-3 were assessed by an automatized immuno-enzymatic technology (TRACE(®) technology, KRYPTOR Automate, Brahms Society, France). In univariate analysis, BC patients with LM (Group 1) compared to other groups, a significantly elevated serum CA 15-3 (median 51 U/ml, range 12-2819) and CSF CA 15-3 (median 8.7 U/ml, range 0.1-251) was observed. Additionally, the CSF/serum ratio of CA 15-3 was significantly higher in this group of patients (median 0.18, range 0.002-4.40). Multivariate analysis identified a cut-off for CSF CA15-3 with 80 % sensitivity and 70 % specificity. CONCLUSIONS: The current study confirms the feasibility of determining CSF CA 15-3 using a widely available technology. Evaluation of the CSF CA 15-3 may be useful in the diagnosis and management of BC-related LM but further studies are needed.

Influence of chronic ethanol consumption on the neurological severity in patients with acute cerebral ischemia.

BACKGROUND AND PURPOSE: We tested the hypothesis that excessive chronic ethanol consumption is associated with more severe ischemic strokes. METHODS: We recruited patients with supratentorial cerebral ischemia within 48 hours of symptom onset. We defined heavy drinkers by a weekly consumption of ethanol of ≥300 g and severe strokes by a National Institutes of Health Stroke Scale score≥6. RESULTS: Of 436 patients, 60 were heavy drinkers. Being a heavy drinker was independently associated with baseline National Institutes of Health Stroke Scale scores≥6 (odds ratio, 2.35; 95% confidence interval, 1.12-5.26; P=0.023) at the logistic regression analysis. This result was not modified with the propensity analysis. CONCLUSION: An excessive chronic ethanol consumption is associated with higher baseline stroke severity.

Intra-hospital delays in stroke patients treated with rt-PA: impact of preadmission notification.

Pre-hospital notification enhances thrombolysis rate and improves intra-hospital delays, but the impact of the notification to the neurologist by the emergency medical system (EMS) call centre remains unknown. Our objective was to compare pre-hospital and in-hospital delays in stroke patients treated by intravenous recombinant tissue plasminogen activator (rt-PA), with and without pre-hospital notification. We compared baseline characteristics and in-hospital delays in stroke patients treated by rt-PA with a high-level notification (call to EMS and EMS-neurologist discussion), a low-level notification (call to EMS without EMS-neurologist discussion ) and no pre-hospital notification. Of 302 consecutive patients [165 women, 54.6 %; median age 74 years, interquartile range (IQR) 59-83], patients with high-level, low-level and no notification differed for the severity at admission (median National Institutes of Health Stroke Scale scores, respectively, of: 12, IQR 7-17; 9, IQR 6-15, and 8, IQR 6-14, p = 0.029). Patients with high-level notification had shorter (1) admission-to-completion of imaging times (27 min, IQR 14-35) than patients with low-level notification (35 min, IQR 17-54) or no notification (36 min, IQR 30-58) (p < 0.01); (2) door-to-needle times (49 min, IQR 39-62 vs. 57 min, IQR 39-81 vs. 63 min, IQR 51-97; p = 0.003); and (3) onset-to-needle times (140 min, IQR 110-175 vs. 155 min, IQR 106-230 vs. 182 min, IQR 131-234; p < 0.001). They did not differ for onset-to-admission time and imaging-to-needle time. Pre-hospital notification by the EMS reduces intra-hospital delays in patients eligible for rt-PA, but the benefit is higher in the case of discussion between the EMS and the neurologist before admission.

Intravenous thrombolysis for acute cerebral ischaemia: comparison of outcomes between patients treated at working versus nonworking hours.

BACKGROUND: Stroke outcomes are worse in patients admitted at nonworking hours (NWH), but whether this is also true in patients treated with intravenous (i.v.) thrombolysis has not been definitely proven. OBJECTIVE: Our aim was to test the hypothesis that stroke patients treated by i.v. rt-PA at NWH have a worse outcome than those treated at working hours (WH). METHODS: We compared outcomes at 7 days and at 3 months, between patients treated at NWH and at WH in the stroke unit of the Lille University Hospital. RESULTS: Of 252 consecutive patients [median age: 69 years; 132 men (52.4%); median National Institutes of Health Stroke Scale score: 14; median onset-to-needle time: 150 min], 134 (53.2%) were treated at NWH. They did not differ for baseline characteristics and proportion of patients with modified Rankin Scale scores 0-1 and 0-2 at 3 months. Patients treated at WH were more likely to die before 7 days (12.7 vs. 4.5%; adjusted odds ratio: 3.6; 95% confidence interval: 1.2-10.4) and at 3 months (21.6 vs. 11.4%; adjusted odds ratio: 2.2; 95% confidence interval: 1.02-4.7). The causes of death did not differ between NWH and WH. At NWH, there was no difference in baseline characteristics and outcomes of patients treated by stroke- and nonstroke neurologists. CONCLUSION: The case fatality rates were unexpectedly higher at WH than at NWH. If this finding can be reproduced and is not a chance finding, we should identify explanations, especially organisational issues, chronobiological factors or summation of subtle--nonsignificant--baseline differences.

[Smoking and stroke]. / Rôle du tabagisme dans la pathologie vasculaire cérébrale.

Up to one quarter of all strokes are directly attributable to cigarette smoking, that percentage can get up to 50% for young adults admitted for an cryptogenic ischemic stroke. Cigarette smoking increases the relative risk of ischemic stroke about two-fold, three-fold for subarachnoid haemorrhage. Current smoking is not clearly identified as a risk factor for intra-cerebral haemorrhage. The risk is consistent for all subtypes of stroke according aetiology and is strongest for ischemic stroke caused by arterial atherothromboembolism. The risk is dependent upon the amount of cigarettes smoked and passive smoking is a substantial risk of stroke. The relative risk is maximal in middle age, declining with advancing years. The toxicity is higher among female smokers, especially when they have several risk factors such as oral contraceptiveS and migraine with aura. Whereas it is well known that the effectiveness of cigarette withdrawal reduces the risk of new vascular event, two thirds of young patients continue to smoke.

Predictors of outcome in patients with cerebral venous thrombosis and intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Although intracerebral hemorrhages are frequent in patients with cerebral venous thrombosis, and lead to worse outcome, predictors of outcome in cerebral venous thrombosis patients with intracerebral hemorrhages have never been evaluated in adequately powered studies. METHODS: This study was conducted as a part of the International Study on Cerebral Vein and Dural Sinus Thrombosis. We evaluated predictors of outcome in cerebral venous thrombosis patients who had an "early intracerebral hemorrhage," ie, intracerebral hemorrhages already present at time of diagnosis of cerebral venous thrombosis by a logistic regression analysis, with a modified Rankin scale 3 to 6 at month 6 as dependent variable. The same analysis was performed with "delayed intracerebral hemorrhages," ie, intracerebral hemorrhages that occurred after the diagnosis of cerebral venous thrombosis, as dependent variable. RESULTS: Of 624 patients recruited in International Study on Cerebral Vein and Dural Sinus Thrombosis, 245 (39%) had an early intracerebral hemorrhage: at month 6, 51 (21%) of them had a modified Rankin Scale 3 to 6. Independent predictors of having modified Rankin scale 3 to 6 at month 6 were older age (adjusted odds ratio for 1-year increase in age, 1.05; 95% CI, 1.02 to 1.08); male gender (adjusted odds ratio, 3.25; 95% CI, 1.29 to 8.16); having a deep cerebral venous system thrombosis (adjusted odds ratio, 5.43; 95% CI, 1.67 to 17.61) or a right lateral sinus thrombosis (adjusted odds ratio, 2.56; 95% CI, 1.03 to 6.40); and having a motor deficit (adjusted odds ratio, 2.94; 95% CI, 1.21 to 7.10). Of the 36 patients who had a delayed intracerebral hemorrhage, those who had a modified Rankin scale 3 to 6 at month 6 were less likely to have received heparin at the acute stage, and more likely to have had early intracerebral hemorrhage. CONCLUSIONS: Among patients with early intracerebral hemorrhage, those who were older, men, had a thrombosis of the deep cerebral venous system or of the right lateral sinus, and a motor deficit were at higher risk for death or dependency at month 6. This subgroup of patients with predictors of poor outcome can be the target for new therapeutic strategies.

Prognostic value of hyperintense vessel signals on fluid-attenuated inversion recovery sequences in acute cerebral ischemia.

BACKGROUND: Fluid-attenuated inversion recovery (FLAIR) sequences may reveal hyperintense vessel signals (HVS) at the acute stage of cerebral ischemia. The aim of this study was to test the hypothesis that HVS are associated with a worse outcome. METHODS: We included 30 consecutive patients admitted within 12 h after onset of hemispheric cerebral ischemia. The outcome was assessed with the modified Rankin Scale at month 1. RESULTS: Proximal HVS were present in 9 patients and distal HVS in 16. All patients with proximal occlusions on time-of-flight sequences had distal HVS on FLAIR. Patients with poor outcome at month 1 (modified Rankin Scale 3-6) more frequently had had HVS on MRI (12/13 vs. 4/17; p< 0.001). CONCLUSION: Distal HVS found on FLAIR sequences within 12 h of acute cerebral ischemia are associated with a worse 1-month outcome.

Fluid-attenuated inversion recovery (FLAIR) sequences for the assessment of acute stroke: inter observer and inter technique reproducibility.

BACKGROUND AND PURPOSE: Diffusion-weighted magnetic resonance (MR) imaging (DWI), and three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA), are highly sensitive for the early detection of stroke and arterial occlusion. However, only a few studies have evaluated the sensitivity of conventional MR sequences that are usually included in the imaging protocol. The aim of this study was to evaluate interobserver and intertechnique reproducibility of Fluid-Attenuated Inversion Recovery (FLAIR) sequences for the diagnosis of early brain ischemia and arterial occlusion. METHODS: Over a 30-month period, brain MR examinations were performed in 34 patients within 12 hours after stroke onset. Imaging protocol included FLAIR sequences, DWI and 3D TOF MRA. Ten observers including radiologists and neurologists, performed separately a visual interpretation of FLAIR images for the detection of brain ischemia and arterial occlusion seen as an arterial high signal. DWI and 3D TOF MRA were used as reference and interpreted independently by two senior radiologists. Interobserver agreement was assessed for image quality, detectability and conspicuity of lesions whereas intertechnique agreement was only judged for lesion detectability. RESULTS: On FLAIR sequences, interobserver agreement for the detection of brain ischemia and arterial occlusion was excellent (kappa = 0.81 and 0.87 respectively). The concordance between FLAIR and DWI sequences for the detection of brain ischemia and between FLAIR and 3D TOF MRA for the detection of arterial occlusion were judged as excellent for all observers (kappa = 0.91 and 0.89 respectively). CONCLUSION: Although DWI is the most sensitive technique with which to detect acute stroke, FLAIR imaging may also be useful to demonstrate both acute ischemia and arterial occlusion with an excellent interobserver reproducibility.

Secondary prevention after ischemic stroke. Evolution over time in practice.

BACKGROUND AND OBJECTIVE: An optimal management of vascular risk factors, associated with antithrombotic drugs and carotid surgery when appropriate, reduces the risk of a new vascular event after stroke. Although secondary prevention is not optimal in many patients in practice, the question of whether there is an improvement over time remains unanswered. The aim of our study was to test the hypothesis that secondary prevention measures after cerebral ischemia improve over time. METHOD: We included 123 consecutive patients in 1994, and 125 consecutive patients in 2002, who were admitted to a neurological department for any reason and had had an episode of cerebral ischemia less than 6 years earlier. We compared the groups for the management of arterial hypertension, hypercholesterolemia, diabetes mellitus and smoking. We recorded the values of blood pressure, biological parameters, and presence of antithrombotic therapy, lipid-lowering and anti-hypertensive drugs. Whether patients were properly treated or not, was determined by a comparison between their current treatment and guidelines available when recruited. RESULTS: Prevention was not optimal in 96 of 123 (78%) patients in 1994, and in 77 of 125 (62 %) in 2002. Vascular risk factors were better identified and managed in 2002 than in 1994, especially for hypercholesterolemia. Antithrombotic therapies, statins and antihypertensive drugs, except calcium channel blockers, were more often used in 2002. The proportion of patients in whom arterial hypertension and hypercholesterolemia were identified was higher in 2002, but the proportion of patients identified as diabetics remained stable. However, the proportion of patients with blood pressure >140/90 mmHg, glycemia >or = 126 mg/dl, total cholesterol level > or = 240 mg/dl, or being current smokers, were significantly lower in 2002 than in 1994. CONCLUSION: Although most of patients with previous cerebral ischemia did not receive an optimal management of their risk factors in 2002, there was an improvement over an 8-year period.

Comparison of secondary vascular prevention in practice after cerebral ischemia and coronary heart disease.

BACKGROUND: Secondary prevention measures in patients with cerebral ischemia or coronary heart disease (CHD) consist of vascular risk factors management and antithrombotic therapy. The aim of this study was to compare how secondary prevention measures are applied in practice between patients with a history of CHD or cerebral ischemia. METHOD: We compared vascular risk factors management and antithrombotic therapy between patients with a history of CHD and patients with a history of cerebral ischemia that occurred 2 months to 6 years earlier. Whether patients were properly treated or not was determined by a comparison between their current treatments and European guidelines for stroke and CHD management. RESULTS: We included 107 consecutive patients with a history of cerebral ischemia and 85 consecutive patients with a history of CHD. We found that: (i). most patients did not receive an appropriate secondary prevention in both groups: 76 of 107 patients with previous cerebral ischemia (71 %) and 73 of 85 patients with CHD (85.9 %); (ii). identification of risk factors, such as hypercholesterolemia, diabetes mellitus and smoking, did not differ between both groups, but arterial hypertension was more frequent in CHD patients; (iii). an inappropriate management of risk factors was more frequent in patients with TIA vs. ischemic stroke, and angina pectoris vs. myocardial infarction; (iv). arterial hypertension and hypercholesterolemia were the 2 more frequent risk factors that were not properly treated; (v). more than half diabetic patients had hyperglycemia > or= 126 mg/dl in both groups; (vi). patients with previous CHD had twice more frequently stopped smoking than those with cerebral ischemia. CONCLUSION: Many patients were not properly treated in both groups, and differences between practice and guidelines were more frequent in the CHD group, where guidelines are more strict.

Cerebral magnetic resonance imaging within 6 hours of stroke onset: inter- and intra-observer reproducibility.

BACKGROUND: Magnetic resonance imaging (MRI) provides valuable pathophysiological information during the very first hours of cerebral ischemia. However, the reliability of prime-time MRI in the setting of emergency care remains unknown. AIM: To evaluate the reproducibility between and within observers of the assessment of MRI scans in stroke patients. METHOD: We performed a MRI scan within 6 h of stroke onset, with time-of-flight (TOF), T2* gradient echo, FLAIR, diffusion- (DWI) and perfusion- (PWI) weighted images, in 17 consecutive patients. Four observers, blinded to the clinical history, separately performed a visual assessment of all scans, and repeated the assessment 2-8 days later. Two neuroradiologists made volumetric measures of diffusion and perfusion abnormalities using a semi-automatic technique 2 weeks after the 2nd visual assessment. We evaluated: (i) in the whole set of MRI scans, the quality of scans and their ability to identify primary hemorrhages on T2* gradient echo sequences; (ii) in patients with acute cerebral ischemia only, the inter- and intra-observer agreement for the presence of arterial occlusion and cerebral abnormalities on TOF sequences, and (iii) on DWI and PWI sequences, the relationship between visual and automatic assessments for the presence of a mismatch (defined as the difference between the perfusion and diffusion abnormalities) of >20%. Statistics used the kappa (kappa) method. RESULTS: The median delay between clinical onset and MRI was 285 min. Two patients had primary cerebral hemorrhages, 1 a post-ictal deficit, and 14 cerebral ischemia. The quality of the scans was judged as appropriate for all scans in all sequences except for FLAIR. All observers identified the 2 patients with hemorrhages. The inter- and intra-observer reliability was substantial to excellent (kappa values ranging from 0.63 to 1.00) for all sequences. The agreement between visual and automatic assessments for the presence of a mismatch of >20% was excellent in all observers. CONCLUSION: The visual assessment of T2* gradient echo, TOF, diffusion and perfusion sequences at the acute stage of stroke is reproducible between and within observers. The visual assessment is as good as the volumetric assessment to detect a mismatch of >20%.