Significance of arterial spin labeling perfusion and susceptibility weighted imaging changes in patients with transient ischemic attack: a prospective cohort study.

BACKGROUND: In a prospective cohort of patients with transient ischemic attack (TIA), we investigated usefulness and feasibility of arterial spin labeling (ASL) perfusion and susceptibility weighted imaging (SWI) alone and in combination with standard diffusion weighted (DWI) imaging in subacute diagnostic work-up. We investigated rates of ASL and SWI changes and their potential correlation to lasting infarction 8 weeks after ictus. METHODS: Patients with TIA underwent 3T-MRI including DWI, ASL and SWI within 72 h of symptom onset. We defined lasting infarction as presence of 8-week MRI T2-fluid attenuated inversion recovery (FLAIR) hyperintensity or atrophy in the area of initial DWI-lesion. RESULTS: We included 116 patients. Diffusion and perfusion together identified more patients with ischemia than either alone (59% vs. 40%, p < 0.0001). The presence of both diffusion and perfusion lesions had the highest rate of 8-week gliosis scars, 65% (p < 0.0001). In white matter, DWI-restriction was the determinant factor for scar development. However, in cortical gray matter half of lesions with perfusion deficit left a scar, while lesions without perfusion change rarely resulted in scars (56% versus 21%, p = 0.03). SWI lesions were rare (6%) and a subset of perfusion lesions. SWI-lesions with DWI-lesions were all located in cortical gray matter and showed high scar rate. CONCLUSIONS: ASL perfusion increased ischemia detection in patients with TIA, and was most useful in conjunction with DWI. ASL was fast, robust and useful in a subacute clinical diagnostic setting. SWI had few positive findings and did not add information. TRIAL REGISTRATION: http://www.clinicaltrials.gov . Unique Identifier NCT01531946 , prospectively registered February 9, 2012.

Computed Tomography--Verified Leukoaraiosis Is a Risk Factor for Post-thrombolytic Hemorrhage.

BACKGROUND: Is computed tomography (CT)-verified leukoaraiosis (LA) a risk factor for post-thrombolytic hemorrhagic transformation and symptomatic hemorrhage? METHODS: (1) Retrospective analysis based on a prospectively planned single-center registry of consecutive tissue plasminogen activator (tPA)-treated patients within 4.5 hours from symptom onset. Standard work-up included baseline noncontrast CT and CT angiography and next day follow-up noncontrast CT. Baseline noncontrast CT LA was graded using Fazekas' score and dichotomized as the absence (Fazekas, 0) or the presence (Fazekas, 1-3). Hemorrhagic transformation was rated using European Cooperative Acute Stroke Study (ECASS) criteria. Symptomatic intracerebral hemorrhage was defined as hemorrhage and deterioration of National Institutes of Health Stroke Scale (NIHSS) of 4 or greater within 36 hours from symptom onset. Endovascularly treated patients were excluded. (2) Pooled analysis with 1312 tPA-treated patients from literature. RESULTS: In all, 311 tPA-treated patients were included between April 2009 and July 2012. LA was present in 113 (36%). Twenty-three (7%) showed hemorrhagic transformation. LA positive patients had significantly higher hemorrhagic transformation frequency (11.5%, P = .04). LA doubled hemorrhagic transformation risk (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.4-5.8). Only 4 patients developed symptomatic intracerebral hemorrhage, 3 with LA. LA was not an independent risk factor for hemorrhagic transformation (P = .2). Pooled analysis of 1623 patients in total, hereof 479 LA positive patients, showed significantly higher symptomatic intracerebral hemorrhage frequency in 35 (7.3%) LA positive than that in 44 (3.8%) LA negative patients, (P = .005) and doubled symptomatic intracerebral hemorrhage risk in LA positives (OR, 1.97; 95% CI 1.22-3.19). CONCLUSIONS: LA doubles the risk of post-thrombolytic hemorrhagic transformation and symptomatic hemorrhage; this finding does not support withholding thrombolysis from patients with LA.

Small cortical grey matter lesions show no persistent infarction in transient ischaemic attack? A prospective cohort study.

OBJECTIVES: To find determining factors for persistent infarction signs in patients with transient ischaemic attack (TIA), herein initial diffusion lesion size, visibility on apparent diffusion coefficient (ADC) or fluid-attenuated inversion recovery (FLAIR) and location. DESIGN: Prospective cohort study of patients with clinical TIA receiving 3T-MRI within 72 hours of symptom onset and at 8-week follow-up. SETTING: Clinical workflow in a single tertiary stroke centre between February 2012 and June 2014. PARTICIPANTS: 199 candidate patients were recruited, 64 patients were excluded due to non-TIA discharge diagnosis or no 8-week MRI. 122 patients completed the study. PRIMARY OUTCOME MEASURES: The primary outcome was visible persistent infarction defined as 8-week FLAIR hyperintensity or atrophy corresponding to the initial diffusion-weighted imaging (DWI) lesion. RESULTS: 50 patients showed 84 initial DWI lesions. 29 (35%) DWI lesions did not result in infarction signs on 8-week FLAIR. 26 (90%, P<0.0001) reversing lesions were located in the cortical grey matter (cGM). cGM location (vs any other location) strongly predicted no 8-week infarction sign development (OR 0.02, 95% CI 0.001 to 0.17) or partial lesion area decrease (>30% of initial DWI-area, OR 14.10, 95% CI 3.61 to 54.72), adjusted for FLAIR-visibility, DWI-area, ADC-confirmation and time to scan (TTS) from symptom onset to baseline MRI. Acute FLAIR-visibility was a strong associated factor for persistent infarction signs (OR 33.06, 95% CI 2.94 to 1432.34). For cGM lesions area size was sole associated factor for persistent infarction signs with a 0.31 cm2 (area under the curve (AUC), 0.97) threshold. In eight (16%) DWI-positive patients, all lesions reversed fully. CONCLUSIONS: 16% of DWI-positive patients and one-third of acute DWI lesions caused no persistent infarction signs, especially small cGM lesions were not followed by development of persistent infarction signs. Late MRI after TIA is likely to be less useful in the clinical setting, and it is dubious if the absence of old vascular lesions can be taken as evidence of no prior ischaemic attacks. TRIAL REGISTRATION NUMBER: NCT01531946; Results.

Comparison of 3- and 20-Gradient Direction Diffusion-Weighted Imaging in a Clinical Subacute Cohort of Patients with Transient Ischemic Attack: Application of Standard Vendor Protocols for Lesion Detection and Final Infarct Size Projection.

OBJECTIVE: Diffusion tensor imaging may aid brain ischemia assessment but is more time consuming than conventional diffusion-weighted imaging (DWI). We compared 3-gradient direction DWI (3DWI) and 20-gradient direction DWI (20DWI) standard vendor protocols in a hospital-based prospective cohort of patients with transient ischemic attack (TIA) for lesion detection, lesion brightness, predictability of persisting infarction, and final infarct size. METHODS: We performed 3T-magnetic resonance imaging including diffusion and T2-fluid attenuated inversion recovery (FLAIR) within 72 h and 8 weeks after ictus. Qualitative lesion brightness was assessed by visual inspection. We measured lesion area and brightness with manual regions of interest and compared with homologous normal tissue. RESULTS: 117 patients with clinical TIA showed 78 DWI lesions. 2 lesions showed only on 3DWI. No lesions were uniquely 20DWI positive. 3DWI was visually brightest for 34 lesions. 12 lesions were brightest on 20DWI. The median 3DWI lesion area was larger for lesions equally bright, or brightest on 20DWI [median (IQR) 39 (18-95) versus 18 (10-34) mm2, P = 0.007]. 3DWI showed highest measured relative lesion signal intensity [median (IQR) 0.77 (0.48-1.17) versus 0.58 (0.34-0.81), P = 0.0006]. 3DWI relative lesion signal intensity was not correlated to absolute signal intensity, but 20DWI performed less well for low-contrast lesions. 3DWI lesion size was an independent predictor of persistent infarction. 3-gradient direction apparent diffusion coefficient areas were closest to 8-week FLAIR infarct size. CONCLUSION: 3DWI detected more lesions and had higher relative lesion SI than 20DWI. 20DWI appeared blurred and did not add information. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique Identifier NCT01531946.

Cognitive assessment at bedside for iPad: A preliminary validation of a novel cognitive test for stroke patients.

INTRODUCTION: Cognitive impairments are frequent in stroke. Cognitive testing is important for research, prognostication and planning in sub-acute stroke, but poses difficulties due to aphasia, hemineglect, hemiplegia and fatigue. We present the first steps towards a validation of a novel iPad-based test battery: Cognitive Assessment at Bedside for iPad (CABPad). PATIENTS AND METHODS: Stroke patients and age matched healthy controls were tested with CABPad including tests for aphasia, neglect, episodic memory, attention span, executive function, working memory, mental speed, anosognosia, motor speed and depression. A re-test was performed after 1 month. Furthermore, a group of stroke patients was tested with CABPad and traditional neuropsychological tests. RESULTS: Fifty-four patients and 48 healthy controls were included in the first phase. Fifty-three patients (98%) were able to complete at least one test and 50 (92%) all tests at the first test point. Mean test duration in patients was 39 min (range 30-60). We found significant differences in test results at baseline between the two groups. Episodic memory mean difference: 8.5 (95% confidence interval: 4.3, 12.7). Symbol Digit Coding mean difference: 16.3 (95% confidence interval: 10.8, 21.7). The second phase included 16 patients. We found adequate to excellent correlation in the majority of the tests. The CABPad Speech Comprehension test and the Auditory Word Recognition subtest of the Western Aphasia Battery correlated with r = 0.82, p < 0.001. CONCLUSION: CABPad is useful for cognitive testing in stroke patients. It is easy to use for the examiner and patients alike. Immobile patients can be tested at bedside, irrespectively of upper extremity paresis, and the assessment can be performed in a relatively short timespan.