The relationship of small vessel disease burden on cerebral and regional brain atrophy rates and cognitive performance over one year of follow-up after transient ischemic attack.

Background: Stroke, even when minor, increases the risk of dementia. We aimed to determine whether patients with transient ischaemic attack (TIA) exhibit higher rates of cerebral and regional atrophy 1-year after first stroke symptoms and evaluate the relationship with small vessel disease and cognitive performance. Methods: TIA patients and controls without cognitive symptoms underwent high-resolution T1-weighted MRI and cognitive testing at baseline and 1-year. Percent brain volume change (PBVC) was measured, and the location of regional atrophy and small vessel disease (CSVD) burden was evaluated. Neuropsychological testing assessed memory, processing speed, and executive function. Results: A total of 76 TIA patients and 53 controls of mean age 67 (SD = 8) and 68 years (SD = 8) were recruited. TIA patients demonstrated greater improvement of visual memory and executive function at 1-year. TIA patients had greater median PBVC/year compared to controls (-0.79% [(-1.22)-(-0.38)] vs. -0.41% [(-0.62)-0.19]; p < 0.001), and higher rates of volume loss (ml/year) in subcortical gray (-0.53 [(-1.09)-(-0.06)] vs. -0.13 [(-0.61)-0.31]; p < 0.05) and white matter (-2.21 [-5.47, 0.40] vs. -0.93 [(-3.43)-2.10]; p < 0.05). Linear regression showed that TIA, age, and systolic blood pressure (SBP) were associated with greater cerebral volume loss over 1-year. There was no significant relationship between PBVC and 1-year cognition. Conclusion: A near two-fold increase in rate of cerebral atrophy 1-year after TIA is associated with higher SBP emphasizing the need for improved treatment of SBP. Cerebral and regional atrophy rates may be used to select patients for vascular risk reduction trials or novel therapeutics in future dementia prevention trials.

Visualization of atrophy of medial temporal lobes and the septal nuclei in patients with transient ischaemic attack and controls.

Introduction: Transient ischaemic attack (TIA) is associated with increased risk of cognitive decline and dementia as early as one-year post-event. Regional brain atrophy measurements may predict future cognitive decline. Aims: 1) To determine whether Medial Temporal Atrophy (MTA) scores and interseptal distance (ISD) measurements are greater in patients with TIA compared to controls; and 2) To determine whether MTA and ISD predicts cognitive change one year after TIA. Methods: Baseline demographic, vascular risk factors, structural imaging and cognitive tests scores were compared between 103 Patients with TIA and 103 age-and-sex-matched controls from the Predementia Neuroimaging of Transient Ischaemic Attack (PREVENT) Study. MTA was assessed using the Schelten's Scale, and ISD was calculated as the distance between the septal nucleus of each hemisphere. Multiple linear regression models were used to evaluate how MTA and ISD related to cognitive change after adjusting for covariates. Results: Patients with TIA had larger ISD measurements (1.4 mm [SD=1.2] vs. 0.9 mm [SD=1.0]); p < 0.001) and higher right/left MTA scores (both p < 0.05) compared to controls. At baseline, controls performed significantly better on the RAVLT (total recall), BVMT (total and delayed recall) and the Trail Making Task (A and B) compared to patients with TIA. However, at one-year follow-up there was no evidence of decline in the patients with TIA compared with controls. Higher MTA and ISD scores were not associated with cognitive decline. Conclusions: Patients with TIA had higher MTA scores and ISD measurements than controls, but neither were predictors of cognitive decline at one year. Future studies with longer follow-up periods will be required to determine whether higher MTA scores and ISD predict risk of cognitive decline in patients with TIA.

Arterial spin labelling reveals multi-regional cerebral hypoperfusion in patients with transient ischemic attack that are unrelated to ischemia location: A proof-of-concept study.

Background and Aims: Patients with transient ischemic attack (TIA) have a substantially increased risk of early dementia. In this exploratory study, we aim to determine whether patients with TIA have 1) measurable regional cerebral hypoperfusion unrelated to the location of ischemia, and 2) determine the relationship of regional cerebral blood flow (rCBF) with their cognitive profiles. Methods: Patients with TIA (N = 49) and seventy-nine (N = 79) age and sex matched controls underwent formal neuropsychological testing and MRI. Quantitative arterial spin labelling rCBF maps (mL/min/100 g) were registered to the corresponding high resolution T1-weighted image. Linear regression was used to determine the association between demographic, clinical and cognitive variables and rCBF. Results: Patients with TIA had significantly (p < 0.05) lower cognitive scores in the MMSE, MOCA, ACE-R, WAIS-IV DS Coding and Trail Making Tests A and B compared to controls. TIA patients had significantly lower rCBF in the left entorhinal cortex (p = 0.03), right posterior cingulate (p = 0.04), and right precuneus (p = 0.05), after adjusting for age and sex, that were unrelated to the regional anatomical volume and DWI positivity. Regional hypoperfusion in the right posterior cingulate and right precuneus was associated with impaired visual memory (BVMT total, p = 0.05 for both regions) and slower processing speed (TMT A, p = 0.04 and p = 0.01), respectively after adjusting for age and sex. Conclusions: TIA patients have patterns of regional hypoperfusion in multiple cortical regions unrelated to the parcellated regional anatomical volume or the presence of a DWI lesion. Regional hypoperfusion in patients with TIA may be an early marker conferring risk of future cognitive decline that needs to be confirmed by future studies.

FOAM Impact: The Influence of Open-access Medical Education on Practice Uptake.

OBJECTIVES: The FOAM Impact study sought to examine baseline rates of intravenous (IV) lidocaine usage for the treatment of renal colic and to compare rates of use between FOAM utilizers and nonutilizers. We sought to measure the effect of FOAM resources on clinical practice by timing the release of FOAM content with publication of the LIDOKET trial. METHODS: A cross-sectional before-and-after survey was conducted and disseminated on two social media platforms. The 13-question, anonymous survey was posted for 1 week prior following the release of the LIDOKET study. Descriptive statistics, Mann-Whitney t-test, and chi-square test statistics were used to describe survey respondent characteristics and Likert responses. RESULTS: There were a total of 472 survey respondents. A total of 321 physicians (75.7% of total respondents) provided pre- and postpublication survey answers. There was no significant change in the use of analgesics before and after publication of LIDOKET and concurrent REBEL EM blog post. A total of 197 (42%) survey respondents reported using lidocaine for renal colic, of which 60 respondents (13%) reported frequent or occasional use. The mean difference in perceived efficacy of lidocaine before and after publication was -0.30 (95% confidence interval [CI] = -0.80 to 0.19, p = 0.15). Being a FOAM user was not associated with changes in mean difference in perception of lidocaine efficacy (F = 0.127, p = 0.72); however, there was a significant difference in perception of lidocaine's efficacy following LIDOKET and REBEL EM publication (F = 4.718, p = 0.03). CONCLUSIONS: Using an online survey-based technique, no appreciable impact of FOAM resources was immediately apparent; however, engagement with FOAM was associated with a change in perception of IV lidocaine's efficacy. To our knowledge, this is the first study of its kind to evaluate the impact of FOAM on clinical practice. The unique method of coordinating FOAM distribution with traditional medical publication may provide future opportunities for measuring the impact of asynchronous medical education resources on medical practice.

Correction to: Accuracy and Reliability of Multiphase CTA Perfusion for Identifying Ischemic Core.

Correction to: Clin Neuroradiol 2018 https://doi.org/10.1007/s00062-018-0717-x Unfortunately, the author list of the original version of this article contains a mistake. The middle name of the author "Rani Gupta Sah" was erroneously tagged as part of the surname in the article's metadata.This mistake.

Longitudinal Brain Atrophy Rates in Transient Ischemic Attack and Minor Ischemic Stroke Patients and Cognitive Profiles.

Introduction: Patients with transient ischemic attack (TIA) and minor stroke demonstrate cognitive impairment, and a four-fold risk of late-life dementia. Aim: To study the extent to which the rates of brain volume loss in TIA patients differ from healthy controls and how they are correlated with cognitive impairment. Methods: TIA or minor stroke patients were tested with a neuropsychological battery and underwent T1 weighted volumetric magnetic resonance imaging scans at fixed intervals over a 3 years period. Linear mixed effects regression models were used to compare brain atrophy rates between groups, and to determine the relationship between atrophy rates and cognitive function in TIA and minor stroke patients. Results: Whole brain atrophy rates were calculated for the TIA and minor stroke patients; n = 38 between 24 h and 18 months, and n = 68 participants between 18 and 36 months, and were compared to healthy controls. TIA and minor stroke patients demonstrated a significantly higher whole brain atrophy rate than healthy controls over a 3 years interval (p = 0.043). Diabetes (p = 0.012) independently predicted higher atrophy rate across groups. There was a relationship between higher rates of brain atrophy and processing speed (composite P = 0.047 and digit symbol coding P = 0.02), but there was no relationship with brain atrophy rates and memory or executive composite scores or individual cognitive tests for language (Boston naming, memory recall, verbal fluency or Trails A or B score). Conclusion: TIA and minor stroke patients experience a significantly higher rate of whole brain atrophy. In this cohort of TIA and minor stroke patients changes in brain volume over time precede cognitive decline.

Accuracy and Reliability of Multiphase CTA Perfusion for Identifying Ischemic Core.

PURPOSE: Acute stroke treatment requires simple, quick and accurate detection of early ischemic changes to facilitate treatment decisions guided by published selection criteria. The aim of this study was to determine the accuracy and reliability of multiphase computed tomography angiography (mCTA) perfusion hypoattenuation for detecting early severe ischemia. METHODS: Non-contrast CT (NCCT), mCTA for regional leptomeningeal score (mCTA-rLMC), and mCTA perfusion lesion visibility (mCTA-arterial and mCTA-venous) were assessed blinded to clinical information in patients treated with endovascular therapy (EVT). The extent of early ischemia defined by regions of hypoattenuation was evaluated by the Alberta Stroke Program Early CT Score (ASPECTS). The ASPECTS scores were dichotomized based on the American Heart Association (AHA) guidelines for EVT selection, ASPECTS ≥6 vs. <6. The diagnostic accuracy was calculated by comparison to 24-h magnetic resonance imaging (MRI) or CT ASPECTS. Inter-observer reliability of NCCT and mCTA ASPECTS was evaluated. Machine learning models were used to predict the clinical follow-up outcome, e.g. National Institutes of Health Stroke scale (NIHSS) and modified Rankin scale (mRS) from baseline imaging data and patient information. RESULTS: A total of 89 acute stroke patients (68 ± 15 years of age) were analyzed (33 TICI-0, 56 TICI-2b or 3). Median baseline NIHSS was 17. The mCTA-venous had a large effect on accurately identifying early ischemia when dichotomized for ASPECTS ≥6 vs <6 (likelihood ratio [LR+] > 10 vs. [LR-] < 0.29) compared to the moderate effect of NCCT ([LR+] = 6.7; [LR-] = 0.56) and mCTA-rLMC [(LR+ = 8.0; (LR-) = 0.83)]. The inter-observer reliability in mCTA-venous was almost perfect for all ASPECTS regions except the internal capsule. The machine learning support factor regression model identified mCTA-venous as the most important imaging covariate for predicting 24-h NIHSS and 90-day mRS. CONCLUSION: The assessment of mCTA-venous permits a more accurate detection of early ischemia than NCCT and mCTA-rLMC score and is predictive of clinical outcome. We would recommend the inclusion of mCTA perfusion lesion in future endovascular trials aiming at extending current AHA guidelines for EVT in stroke patients with low ASPECTS.