Interobserver agreement for the diagnosis of transient ischemic attacks

Emergency medicine updates: Transient ischemic attack

INTRODUCTION

Transient ischemic attack (TIA) is a condition commonly evaluated for in the emergency department (ED). Therefore, it is important for emergency clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning TIA for the emergency clinician.

DISCUSSION

TIA is a harbinger of ischemic stroke and can result from a variety of pathologic causes. While prior definitions incorporated symptoms resolving within 24 h, modern definitions recommend a tissue-based definition utilizing advanced imaging to evaluate for neurologic injury and the etiology. In the ED, emergent evaluation includes assessing for current signs and symptoms of neurologic dysfunction, appropriate imaging to investigate for minor stroke or stroke risk, and arranging appropriate disposition and follow up to mitigate risk of subsequent ischemic stroke. Imaging should include evaluation of great vessels and intracranial arteries, as well as advanced cerebral imaging to evaluate for minor or subclinical stroke. Non-contrast computed tomography (CT) has limited utility for this situation; it can rule out hemorrhage or a large mass causing symptoms but should not be relied on for any definitive diagnosis. Noninvasive imaging of the cervical vessels can also be used (CT angiography or Doppler ultrasound). Treatment includes antithrombotic medications if there are no contraindications. Dual antiplatelet therapy may reduce the risk of recurrent ischemic events in higher risk patients, while anticoagulation is recommended in patients with a cardioembolic source. A variety of scoring systems or tools are available that seek to predict stroke risk after a TIA. The Canadian TIA risk score appears to have the best diagnostic accuracy. However, these scores should not be used in isolation. Disposition may include admission, management in an ED-based observation unit with rapid diagnostic protocol, or expedited follow-up in a specialty clinic.

CONCLUSIONS

An understanding of literature updates concerning TIA can improve the ED care of patients with TIA.

Recognizing Posterior Circulation Transient Ischemic Attacks Presenting as Episodic Isolated Dizziness

Diagnosing patients presenting to the emergency department with self-limited episodes of isolated dizziness (the episodic vestibular syndrome) requires a broad differential diagnosis that includes posterior circulation transient ischemic attack. Because these patients are, by definition, asymptomatic without new neurologic findings on examination, the diagnosis, largely based on history and epidemiologic context, can be challenging. We review literature that addresses the frequency of posterior circulation transient ischemic attack in this group of patients compared with other potential causes of episodic vestibular syndrome. We present ways of distinguishing posterior circulation transient ischemic attack from vestibular migraine, the most common cause of episodic vestibular syndrome. We also present a diagnostic algorithm that may help clinicians to work their way through the differential diagnosis.

Clinical Diagnosis and Magnetic Resonance Imaging in Patients With Transient and Minor Neurological Symptoms: A Prospective Cohort Study

BACKGROUND

The utility of magnetic resonance imaging (MRI) brain in patients with transient or minor neurological symptoms is uncertain. We sought to determine the proportion of participants with transient or minor neurological symptoms who had MRI evidence of acute ischemia at different clinical probabilities of transient ischemic attack (TIA) or minor stroke.

METHODS

Cohort of participants with transient or minor neurological symptoms from emergency and outpatient settings. Clinicians at different levels of training gave each participant a diagnostic probability (probable when TIA/stroke was the most likely differential diagnosis; possible when TIA/stroke was not the most likely differential diagnosis; or uncertain when diagnostic probability could not be given) before 1.5 or 3T brain MRI ≤5 days from onset. Post hoc, each clinical syndrome was defined blind to MRI findings as National Institute of Neurological Disorders and Stroke criteria TIA/stroke; International Headache Society criteria migraine aura; non-TIA focal symptoms; or nonfocal symptoms. MRI evidence of acute ischemia was defined by 2 reads of MRI. Stroke was ascertained for at least 90 days and up to 18 months after recruitment.

RESULTS

Two hundred seventy-two participated (47% female, mean age 60, SD 14), 58% with MRI ≤2 days of onset. Most (92%) reported focal symptoms. MR evidence of acute ischemia was found, for stroke/TIA clinical probabilities of probable 23 out of 75 (31% [95% CI, 21%-42%]); possible 26 out of 151 (17% [12%-24%]); and uncertain 9 out of 43, (20% [10%-36%]). MRI evidence of acute ischemia was found in National Institute of Neurological Disorders and Stroke criteria TIA/stroke 40 out of 95 (42% [32%-53%]); migraine aura 4 out of 38 (11% [3%-25%]); non-TIA focal symptoms 16 out of 99 (16% [10%-25%]); and no focal features 1 out of 29 (3% [0%-18%]). After MRI, a further 14 (5% [95% CI, 3-8]) would be treated with an antiplatelet drug compared with treatment plan before MRI. By 18 months, a new ischemic stroke occurred in 9 out of 61 (18%) patients with MRI evidence of acute ischemia and 2 out of 211 (1%) without (age-adjusted hazard ratio, 13 [95% CI, 3-62]; P<0.0001).

CONCLUSIONS

MRI evidence of acute brain ischemia was found in about 1 in 6 transient or minor neurological symptoms patients with a nonstroke/TIA initial diagnosis or uncertain diagnosis. Methods to determine the clinical and cost-effectiveness of MRI are needed in this population.

Clinical Features Differ Between Patients With Vertigo Attack Only and Weakness Attack Accompanying Vertigo Before Vertebrobasilar Stroke: A Retrospective Study

Objective

To determine the different clinical features of patients with vertigo attacks alone and of those with weakness accompanying vertigo attacks before the vertebrobasilar ischemic stroke.

Methods

In this 4-year retrospective study, we manually screened the medical records of 209 patients, hospitalized with vertigo attack as the main complaint who were finally diagnosed with acute vertebrobasilar ischemic stroke. Patients were divided into two groups according to their symptoms: patients who only experienced vertigo attacks prior to the vertebrobasilar stroke (VO group) and patients who had both vertigo and weakness attacks (VW group) prior to the stroke. Clinical parameters, such as infarction site and volume, relative risk factors, ABCD² score, and medical intervention, were compared between the two groups.

Results

The prevalence of hypertension was higher in the Vertigo attacks only (VO) group (42.2 vs. 29.0%, p < 0.05). The total cerebral infarction volume in the VO group was larger than the Vertigo and weakness attacks (VW) group (4.44 vs. 2.12 cm³, p < 0.05). Additionally, the cerebellum was more likely to be affected in the VO group. In contrast, patients in the VW group had higher carotid stenosis (14.2 vs. 27.2%, p < 0.05) and ABCD² score (2.1 ± 1.2 vs. 3.6 ± 1.5, p = 0.02). The percentage of patients with medullary infarctions also increased in the VW group. Vertigo attack events occurred more frequently in the VW group (median 2.4 vs. 4.3, p < 0.04). We also found that the patients in the VW group were more likely to seek medical intervention after vertigo.

Conclusions

Clinical parameters, such as infarction location, relative risk factors, and ABCD² score, differed between patients with vertigo symptoms with or without weakness attacks. These findings highlight the different clinical features of patients with vertigo attack only and those with weakness attacks accompanying vertigo prior to vertebrobasilar ischemic stroke.

Validation of the Canadian TIA Score to Predict Subsequent Stroke Risk in Chinese TIA Patients

BACKGROUND AND OBJECTIVES

The Canadian TIA Score has been verified as a good predictive tool for subsequent stroke risk in Caucasian patients; however, it had insufficient external verification of other races. We aimed to validate the Canadian TIA Score in Chinese patients and compared it with ABCD2 for subsequent stroke risk after transient ischemic attack (TIA).

METHODS

The Third China National Stroke Registry (CNSR-III) was a nationwide, multicenter prospective registry recruiting consecutive patients with acute ischemic stroke or TIA within 7 days of the onset from August 2015 to March 2018. The Canadian TIA Score was verified in patients diagnosed with TIA from the CNSR-III (N = 1,184). The outcomes were subsequent stroke at 7 days, 14 days/discharge, 3 months, and 1 year. Outcomes were recorded by face-to-face assessment or telephone interview. The prognostic performance of the scoring system was assessed by the area under the receiver operator characteristic curve (AUC).

RESULTS

Of 1,184 TIA patients (mean [IQR] age, 61.00 [53.00-69.00] years; 413 women [34.88%]), there were 40 patients (3.38%) having subsequent stroke within 7 days, 45 (3·80%) within 14 days/hospitalization, 66 (5·57%) within 3 months, and 100 (8·45%) within 1 year. The Canadian TIA Score (AUC 0 63-0·68) seemed to be a better prognostic score of stroke risk than the ABCD2 score (AUC 0·61-0·62), although no significant differences were noted. In the subgroup of atypical TIA, the Canadian TIA Score showed significantly stronger predictivity than the ABCD2 score within 7 days (0.80 [0.62-0.98] vs. 0.52 [0.30-0.73]; difference in AUC, 0.28 [0.03-0.53]; p, 0.026), and marginal significantly stronger predictivity within 1 year (0.71 [0.61-0.80] vs. 0.58 [0.48-0.68]; difference in AUC, 0.12 [-0.01 to 0.25]; p, 0.06).

CONCLUSION

The Canadian TIA Score might be a better prognostic score than the ABCD2 score for post-TIA stroke risk, especially in patients with atypical TIA.

Risk of Subsequent Stroke Among Patients Receiving Outpatient vs Inpatient Care for Transient Ischemic Attack: A Systematic Review and Meta-analysis

IMPORTANCE

Transient ischemic attack (TIA) often indicates a high risk of subsequent cerebral ischemic events. Timely preventive measures improve the outcome.

OBJECTIVE

To estimate and compare the risk of subsequent ischemic stroke among patients with TIA or minor ischemic stroke (mIS) by care setting.

DATA SOURCES

MEDLINE, Web of Science, Scopus, Embase, International Clinical Trials Registry Platform, ClinicalTrials.gov, Trip Medical Database, CINAHL, and all Evidence-Based Medicine review series were searched from the inception of each database until October 1, 2020.

STUDY SELECTION

Studies evaluating the occurrence of ischemic stroke after TIA or mIS were included. Cohorts without data on evaluation time for reporting subsequent stroke, with retrospective diagnosis of the index event after stroke occurrence, and with a report of outcomes that were not limited to patients with TIA or mIS were excluded. Two authors independently screened the titles and abstracts and provided the list of candidate studies for full-text review; discrepancies and disagreements in all steps of the review were addressed by input from a third reviewer.

DATA EXTRACTION AND SYNTHESIS

The study was prepared and reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses, Meta-analysis of Observational Studies in Epidemiology, Methodological Expectations of Cochrane Intervention Reviews, and Enhancing the Quality and Transparency of Health Research guidelines. The Risk of Bias in Nonrandomized Studies-of Exposures (ROBINS-E) tool was used for critical appraisal of cohorts, and funnel plots, Begg-Mazumdar rank correlation, Kendall τ2, and the Egger bias test were used for evaluating the publication bias. All meta-analyses were conducted under random-effects models.

MAIN OUTCOMES AND MEASURES

Risk of subsequent ischemic stroke among patients with TIA or mIS who received care at rapid-access TIA or neurology clinics, inpatient units, emergency departments (EDs), and unspecified or multiple settings within 4 evaluation intervals (ie, 2, 7, 30, and 90 days).

RESULTS

The analysis included 226 683 patients from 71 articles recruited between 1981 and 2018; 5636 patients received care at TIA clinics (mean [SD] age, 65.7 [3.9] years; 2291 of 4513 [50.8%] men), 130 139 as inpatients (mean [SD] age, 78.3 [4.0] years; 49 458 of 128 745 [38.4%] men), 3605 at EDs (mean [SD] age, 68.9 [3.9] years; 1596 of 3046 [52.4%] men), and 87 303 patients received care in an unspecified setting (mean [SD] age, 70.8 [3.8] years, 43 495 of 87 303 [49.8%] men). Among the patients who were treated at a TIA clinic, the risk of subsequent stroke following a TIA or mIS was 0.3% (95% CI, 0.0%-1.2%) within 2 days, 1.0% (95% CI, 0.3%-2.0%) within 7 days, 1.3% (95% CI, 0.4%-2.6%) within 30 days, and 2.1% (95% CI, 1.4%-2.8%) within 90 days. Among the patients who were treated as inpatients, the risk of subsequent stroke was to 0.5% (95% CI, 0.1%-1.1%) within 2 days, 1.2% (95% CI, 0.4%-2.2%) within 7 days, 1.6% (95% CI, 0.6%-3.1%) within 30 days, and 2.8% (95% CI, 2.1%-3.5%) within 90 days. The risk of stroke among patients treated at TIA clinics was not significantly different from those hospitalized. Compared with the inpatient cohort, TIA clinic patients were younger and had had lower ABCD2 (age, blood pressure, clinical features, duration of TIA, diabetes) scores (inpatients with ABCD2 score >3, 1101 of 1806 [61.0%]; TIA clinic patients with ABCD2 score >3, 1933 of 3703 [52.2%]).

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, the risk of subsequent stroke among patients who were evaluated in a TIA clinic was not higher than those hospitalized. Patients who received treatment in EDs without further follow-up had a higher risk of subsequent stroke. These findings suggest that TIA clinics can be an effective component of the TIA care component pathway.

A scoping review of psychoeducational interventions for people after transient ischemic attack and minor stroke

BACKGROUND

Psychoeducation can provide information and support to cope with the physical and emotional effects of a health condition. This scoping review aimed to identify the evidence regarding psychoeducational interventions for people after a Transient Ischemic Attack (TIA) and minor stroke.

METHODS

This review was conducted in accordance with the PRISMA Extension for Scoping Reviews. Three electronic databases (MEDLINE, Embase, PsycINFO) were searched for articles on interventions related to psychoeducational support post-TIA and minor/mild stroke. Search retrieved 3722 articles. Three reviewers independently screened titles, abstracts, full-texts, and extracted data for included studies. Study quality was assessed using the JADAD scale. TIDieR checklist was used to describe interventions.

RESULTS

Fifteen RCTs were included. Twelve studies were of high quality (JADAD score ≥2), two were of low quality. A total of 1500 participants were recruited across studies. Definition of TIA and minor stroke was unclear, leading to the exclusion of several studies. Various interventions were included, including education/psychoeducation (n = 4); exercise and lifestyle advice (n = 3); telephone-based education/counseling (n = 3); secondary prevention education (n = 1); motivational interviewing (n = 2); self-management (n = 2). Interventions were inconsistently described, with information missing about who delivered it and tailoring.

CONCLUSIONS

Definitions of stroke severity are not adequately reported. There are a variety of interventions including education about a range of stroke-specific topics. Many interventions are not adequately described, thus making it difficult to determine if the aim was to provide information or support post-TIA/minor stroke. There is a need for an in-depth systematic review to develop a clear definition of psychoeducation.

Changes in Health-Related Quality of Life After Transient Ischemic Attack

IMPORTANCE

Numerous studies have found that patients diagnosed with TIA have decreased health-related quality of life, which has been interpreted as suggesting that patients with TIA have residual symptoms after the event. Studies assessing health status in the same patients before and after an event are lacking but may allow a direct determination of the association of TIA with postevent health status.

OBJECTIVE

To examine patient-reported health before transient ischemic attack (TIA) among individuals diagnosed with this event and evaluate change in patient-reported health after the event overall and by TIA characterization subgroups.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted among 236 patients with a clinical diagnosis of TIA from October 2015 to December 2017 in a large US health system that collects a patient-reported outcome measure in ambulatory setting as part of routine care. Included patients had patient-reported global health scale assessments completed as part of routine care before and after a TIA event. Data were analyzed from March through July 2020.

MAIN OUTCOMES AND MEASURES

The main outcome was Patient-Reported Outcome Measurement Information System Global Health (PROMIS GH) scale score before and after TIA. A change of 5 or more points in this score is considered clinically relevant. The secondary outcomes included change in patient-reported global health by clinical impression of the probability of a TIA event, pattern of neurological deficits, and short-term risk of stroke, as assessed by the ABCD2 score.

RESULTS

Among 263 patients who experienced TIA, mean (SD) age was 67.9 (13.4) years and 138 (52.5%) were women. The median (interquartile range) time between patient-reported global health scores was 152 (94-284) days. Mean (SD) baseline patient-reported global physical health and mental health scale summary scores were 43.4 (8.2) and 47.7 (9.7), respectively, and were statistically significantly decreased compared with the general population mean (SD) scores of 50 (10; P < .001) for physical and mental health. The difference between physical health summary score among study participants and the general population was clinically relevant. Mean (SD) summary scores were not statistically significantly different after the event compared with before the event overall (physical health: 44.1 [8.2], for a mean [SE] improvement of 0.65 [0.38] points; P = .09; mental health: 47.4 [9.1], for a mean [SE] worsening of 0.25 [0.38] points; P = .51) or within subgroups.

CONCLUSIONS AND RELEVANCE

These findings suggest that impaired health status among patients diagnosed with TIA reflect, at least in part, an impaired premorbid state of health. This study did not find that TIA events were associated with worsening of health status overall or within subgroups.

Systematic Review and Meta-Analysis of Diagnostic Agreement in Suspected TIA

Objective

To determine the interrater variability for TIA diagnostic agreement among expert clinicians (neurologists/stroke physicians), administrative data, and nonspecialists.

Methods

We performed a meta-analysis of studies from January 1984 to January 2019 using MEDLINE, EMBASE, and PubMed. Two reviewers independently screened for eligible studies and extracted interrater variability measurements using Cohen's kappa scores to assess diagnostic agreement.

Results

Nineteen original studies consisting of 19,421 patients were included. Expert clinicians demonstrate good agreement for TIA diagnosis (κ = 0.71, 95% confidence interval [CI] = 0.62-0.81). Interrater variability between clinicians' TIA diagnosis and administrative data also demonstrated good agreement (κ = 0.68, 95% CI = 0.62-0.74). There was moderate agreement (κ = 0.41, 95% CI = 0.22-0.61) between referring clinicians and clinicians at TIA clinics receiving the referrals. Sixty percent of 748 patient referrals to TIA clinics were TIA mimics.

Conclusions

Overall agreement between expert clinicians was good for TIA diagnosis, although variation still existed for a sizeable proportion of cases. Diagnostic agreement for TIA decreased among nonspecialists. The substantial number of patients being referred to TIA clinics with other (often neurologic) diagnoses was large, suggesting that clinicians, who are proficient in managing TIAs and their mimics, should run TIA clinics.

Diagnosis of non-consensus transient ischaemic attacks with focal, negative, and non-progressive symptoms: population-based validation by investigation and prognosis

BACKGROUND

Diagnosis of transient ischaemic attacks (TIAs) can be difficult. There is consensus on classic symptoms (eg, motor weakness, dysphasia, hemianopia, monocular visual loss) but no consensus on several monosymptomatic events with sudden-onset, non-progressive, focal negative symptoms (eg, isolated diplopia, dysarthria, vertigo, ataxia, sensory loss, and bilateral visual disturbance), with much variation in investigation and treatment.

METHODS

We prospectively ascertained and investigated all strokes and sudden onset transient neurological symptoms in a population of 92 728 people (no age restrictions) from Oxfordshire, UK, who sought medical attention at nine primary care practices or at the John Radcliffe Hospital, Oxford, UK (Oxford Vascular Study). Patients classified at baseline with minor ischaemic stroke (National Institutes of Health Stroke Score <5), classic TIA, or non-consensus TIA were treated according to secondary prevention guidelines. Risks of stroke (7-day, 90-day, and 10-year risks) and risks of all major vascular events (from the time of first event, and from the time of seeking medical attention) were established by face-to-face follow-up visits and were compared with the risk expected from age and sex-specific stroke incidence in the underlying study population.

FINDINGS

Between April 1, 2002, and March 31, 2018, 2878 patients were identified with minor ischaemic stroke (n=1287), classic TIA (n=1021), or non-consensus TIA (n=570). Follow-up was to Oct 1, 2018 (median 5·2 [IQR 2·6-9·2] years). 577 first recurrent strokes after the index event occurred during 17 009 person-years of follow-up. 90-day stroke risk from time of the index event after a non-consensus TIA was similar to that after classic TIA (10·6% [95% CI 7·8-12·9] vs 11·6% [95% CI 9·6-13·6]; hazard ratio 0·87, 95% CI 0·64-1·19; p=0·43), and higher than after amaurosis fugax (4·3% [95% CI 0·6-8·0]; p=0·042). However, patients with non-consensus TIA were less likely to seek medical attention on the day of the event than were those with classic TIA (336 of 570 [59%] vs 768 of 1021 [75%]; odds ratio [OR] 0·47, 95% CI 0·38-0·59; p<0·0001) and were more likely to have recurrent strokes before seeking attention (45 of 570 [8%] vs 47 of 1021 [5%]; OR 1·77, 95% CI 1·16-2·71; p=0·007). After excluding such recurrent strokes, 7-day stroke risk after seeking attention for non-consensus TIA (2·9% [95% CI 1·5-4·3]) was still considerably higher than the expected background risk (relative risk [RR] 203, 95% CI 113-334), particularly if the patient sought attention on the day of the index event (5·0% [2·1-7·9]; RR 300, 137-569). 10-year risk of all major vascular events was similar for non-consensus and classic TIAs (27·1% [95% CI 22·8-31·4] vs 30·9% [27·2-33·7]; p=0·12). Baseline prevalence of atrial fibrillation, patent foramen ovale, and arterial stenoses were also similar for non-consensus TIA and classic TIA, although stenoses in the posterior circulation were more frequent with non-consensus TIA (OR 2·21, 95% CI 1·59-3·08; p<0·0001).

INTERPRETATION

Patients with non-consensus TIA are at high early and long-term risk of stroke and have cardiovascular pathological findings on investigation similar to those of classic TIA. Designation of non-consensus TIAs as definite cerebrovascular events will increase overall TIA diagnoses by about 50%.

FUNDING

Wellcome Trust, National Institute for Health Research Oxford Biomedical Research Centre, Wolfson Foundation, Masonic Charitable Foundation, and British Heart Foundation.

Explicit Diagnostic Criteria for Transient Ischemic Attacks Used in the Emergency Department Are Highly Sensitive and Specific

BACKGROUND

Making a correct diagnosis of a transient ischemic attack (TIA) is prone to errors because numerous TIA mimics exist and there is a shortage of evidence-based diagnostic criteria for TIAs. In this study, we applied for the first time the recently proposed explicit diagnostic criteria for transient ischemic attacks (EDCT) to a group of patients presenting to the emergency department of a large German tertiary care hospital with a suspected TIA. The aim was to determine the sensitivity and specificity of the EDCT in its clinical application.

METHODS

A total of 128 patients consecutively presenting to the emergency department of the University Hospital of Lübeck, Germany, under the suspicion of a TIA were prospectively interviewed about their clinical symptoms at the time of presentation. The diagnosis resulting from applying the EDCT was compared to the diagnosis made independently by the senior physicians performing the usual diagnostic work-up ("gold standard"), allowing calculation of sensitivity and specificity of the EDCT.

RESULTS

EDCT achieved a sensitivity of 96% and a specificity of 88%. When adding the additional criterion F ("the symptoms may not be better explained by another medical or mental disorder"), specificity significantly increased to 98%.

CONCLUSIONS

The data show that the EDCT in its modified version as proposed by us are a highly useful tool for clinicians. They display a high sensitivity and specificity to accurately diagnose TIAs in patients referred to the emergency department with a suspected TIA.

Reperfusion therapies and poststroke seizures

Seizures are not only a frequent complication of stroke but have been associated with an unfavorable functional and vital outcome of patients who have had stroke. Facing a new paradigm of acute standard stroke care, acute symptomatic seizures in this clinical setting deserve to be rethought. Reperfusion therapies, the gold standard treatment for acute ischemic stroke, improve long-term survival and outcome of patients who have had stroke and have been associated both with clinical seizures and the occurrence of epileptiform activity in the electroencephalogram (EEG). This narrative review describes the different physiopathological mechanisms underlying the possible association between reperfusion therapies and seizures, both acute symptomatic seizures and unprovoked seizures, and the current evidence regarding the risk of poststroke seizures in treated patients. It also identifies the gaps in our knowledge to foster future studies in this field. By different mechanisms, reperfusions therapies may have opposing effects on the risk of poststroke seizures. There is a need for a better definition of the specific physiopathology of seizures in clinical practice, as many factors can be recognized. Additionally, most of the current clinical evidence refers to acute symptomatic seizures and not to unprovoked seizures or poststroke epilepsy, and our analysis does not support the existence of a strong association between thrombolysis and poststroke seizures. So far, the impact of reperfusion therapies on the frequency of poststroke seizures is unclear. To study this effect, many clinical challenges must be overcome, including a better and clear operational definition of seizures and stroke characteristics, the standard of stroke and epilepsy care and EEG monitoring, and the degree of reperfusion success. Prospective, high quality, larger, and longer follow-up multicentric studies are urgently needed. Additionally, stroke registries can also prove useful in better elucidate whether there is an association between reperfusion therapies and seizures. This article is part of the Special Issue "Seizures & Stroke".

Systolic blood pressure as a predictor of transient ischemic attack/minor stroke in emergency department patients under age 80: a prospective cohort study

BACKGROUND

Elevated blood pressure (BP) at emergency department (ED) presentation and advancing age have been associated with risk of ischemic stroke; however, the relationship between BP, age, and transient ischemic attack/minor stroke (TIA/MS) is not clear.

METHODS

A multi-site, prospective, observational study of 1084 ED patients screened for suspected TIA/MS (symptom onset < 24 h, NIHSS< 4) between December 2013 and April 2016. Systolic and diastolic BP measurements (SBP, DBP) were taken at ED presentation. Final diagnosis was consensus adjudication by stroke neurologists; patients were diagnosed as either TIA/MS or stroke-mimic (non-cerebrovascular conditions). Conditional inference trees were used to define age cut-points for predicting binary diagnosis (TIA/MS or stroke-mimic). Logistic regression models were used to estimate the effect of BP, age, sex, and the age-BP interaction on predicting TIA/MS diagnosis.

RESULTS

Over a 28-month period, 768 (71%) patients were diagnosed with TIA/MS: these patients were older (mean 71.6 years) and more likely to be male (58%) than stroke-mimics (61.4 years, 41%; each p < 0.001). TIA/MS patients had higher SBP than stroke-mimics (p < 0.001). DBP did not differ between the two groups (p = 0.191). SBP was predictive of TIA/MS diagnosis in younger patients, after accounting for age and sex; an increase of 10 mmHg systolic increased the odds of TIA/MS 18% (odds ratio [OR] 1.18, 95% CI 1.00-1.39) in patients < 60 years, and 23% (OR 1.23, 95% CI 11.12-1.35) in those 60-79 years, while not affecting the odds of TIA/MS in patients ≥80 years (OR 0.99, 95% CI 0.89-1.07).

CONCLUSIONS

Raised SBP in patients younger than 80 with suspected TIA/MS may be a useful clinical indicator upon initial presentation to help increase clinicians' suspicion of TIA/MS.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03050099 (10-Feb-2017) and NCT03070067 (3-Mar-2017). Retrospectively registered.

Diagnosis and management of transient ischemic attacks in primary care: a systematic review

INTRODUCTION Many patients who suffer a transient ischaemic attack (TIA) present to their general practitioner (GP). Early identification and treatment reduces the risk of subsequent stroke, disability and mortality. AIM To review the accuracy of TIA diagnosis in primary care, immediate management and interventions to assist GPs with the condition. METHODS This study included the search of Medline, Embase, Web of Science and Scopus databases (1995-2015). Relevant titles and abstracts were obtained using structured criteria (diagnosis, immediate management or intervention of TIAs in primary care), with full review and data extraction for eligible publications. RESULTS Most studies found limitations in GPs' knowledge and ability to diagnose TIAs to varying extent over time and between countries. GPs tended to over-interpret non-specific symptoms (e.g. isolated vertigo) when considering a TIA diagnosis. Reported referral behaviour varied between countries, with some favouring admission and others preferring outpatient management. Consistent under-referral and under-use of effective medication was reported. However, GPs may refer some patients to exclude rather than confirm a final diagnosis. This, alongside evidence of under-referral, suggests the need for education and decision support tools to enhance referral patterns. Intervention studies suggested that electronic decision support may increase referrals and timely management. CONCLUSION This review revealed deficiencies in knowledge and clinical practice, and identified potential avenues to addressing these. Issues for future research were also identified.

Clinical diagnosis of TIA or minor stroke and prognosis in patients with neurological symptoms: A rapid access clinic cohort

BACKGROUND

The long-term risk of stroke or myocardial infarction (MI) in patients with minor neurological symptoms who are not clinically diagnosed with transient ischaemic attack (TIA) or minor stroke is uncertain.

METHODS

We used data from a rapid access clinic for patients with suspected TIA or minor stroke and follow-up from four overlapping data sources for a diagnosis of ischaemic or haemorrhagic stroke, MI, major haemorrhage and death. We identified patients with and without a clinical diagnosis of TIA or minor stroke. We estimated hazard ratios of stroke, MI, major haemorrhage and death in early and late time periods.

RESULTS

5,997 patients were seen from 2005-2013, who were diagnosed with TIA or minor stroke (n = 3604, 60%) or with other diagnoses (n = 2392, 40%). By 5 years the proportion of patients who had a subsequent ischaemic stroke or MI, in patients with a clinical diagnosis of minor stroke or TIA was 19% [95% confidence interval (CI): 17-20%], and in patients with other diagnoses was 10% (95%CI: 8-15%). Patients with clinical diagnosis of TIA or minor stroke had three times the hazard of stroke or MI compared to patients with other diagnoses [hazard ratio (HR)2.83 95%CI:2.13-3.76, adjusted age and sex] by 90 days post-event; however from 90 days to end of follow up, this difference was attenuated (HR 1.52, 95%CI:1.25-1.86). Older patients and those who had a history of vascular disease had a high risk of stroke or MI, whether or not they were diagnosed with minor stroke or TIA.

CONCLUSIONS

Careful attention to vascular risk factors in patients presenting with transient or minor neurological symptoms not thought to be due to stroke or TIA is justified, particularly those who are older or have a history of vascular disease.

Pre-existing White Matter Hyperintensity Lesion Burden and Diagnostic Certainty of Transient Ischemic Attack

GOALS

There are no validated biomarkers that allow for reliable distinction between TIA and other transient neurological symptoms that mimic TIA. We sought to determine whether the degree of pre-existing white matter hyperintensity (WMH) lesion burden relates to the diagnostic certainty of TIA in a cohort of patients presenting with transient neurological symptoms.

MATERIALS AND METHODS

We retrospectively analyzed 144 consecutive patients with available brain MRI to quantify and normalize the WMH volume for brain atrophy (adjusted white matter hyperintensity [aWMHV]). We first stratified subjects to probable (n = 62) versus possible (n = 82) TIA as per existing guidelines. Receiver-operating characteristic curves were used to determine a critical aWMHV-threshold (7.8 mL) that best differentiated probable from possible TIA. We then further stratified patients with possible TIA to likely (n = 52) versus unlikely (n = 30) TIA after independent chart review and adjudication. Finally, multivariable logistic and multinomial regression was used to determine whether the defined aWMHV independently related to probable and likely TIA after adjustment for pertinent confounders.

FINDINGS

With the exception of age (P < .001) and use of antiplatelets (P = .017), baseline characteristics were similar between patients with probable, likely, and unlikely TIA. In the fully adjusted multinomial model, the aWMHV cut-off greater than 7.8 mL (odds ratio 3.8, 95% confidence interval 1.3-10.9, P = .012) was significantly more frequent in patients with a probable TIA as compared to those with an unlikely TIA diagnosis.

CONCLUSIONS

We provide proof-of-principle that WMH may serve as a neuroimaging marker of diagnostic certainty of TIA after neurological workup has been completed.

Validation of a proteomic biomarker panel to diagnose minor-stroke and transient ischaemic attack: phase 2 of SpecTRA, a large scale translational study

OBJECTIVE

To validate our previously developed 16 plasma-protein biomarker panel to differentiate between transient ischaemic attack (TIA) and non-cerebrovascular emergency department (ED) patients.

METHOD

Two consecutive cohorts of ED patients prospectively enrolled at two urban medical centers into the second phase of SpecTRA study (training, cohort 2A, n = 575; test, cohort 2B, n = 528). Plasma samples were analyzed using liquid chromatography/multiple reaction monitoring-mass spectrometry. Logistic regression models which fit cohort 2A were validated on cohort 2B.

RESULTS

Three of the panel proteins failed quality control and were removed from the panel. During validation, panel models did not outperform a simple motor/speech (M/S) deficit variable. Post-hoc analyses suggested the measured behaviour of L-selectin and coagulation factor V contributed to poor model performance. Removal of these proteins increased the external performance of a model containing the panel and the M/S variable.

CONCLUSIONS

Univariate analyses suggest insulin-like growth factor-binding protein 3 and serum paraoxonase/lactonase 3 are reliable and reproducible biomarkers for TIA status. Logistic regression models indicated L-selectin, apolipoprotein B-100, coagulation factor IX, and thrombospondin-1 to be significant multivariate predictors of TIA. We discuss multivariate feature subset analyses as an exploratory technique to better understand a panel's full predictive potential.

Towards phenotyping stroke: Leveraging data from a large-scale epidemiological study to detect stroke diagnosis

Objective

1) To develop a machine learning approach for detecting stroke cases and subtypes from hospitalization data, 2) to assess algorithm performance and predictors on real-world data collected by a large-scale epidemiology study in the US; and 3) to identify directions for future development of high-precision stroke phenotypic signatures.

Materials and methods

We utilized 8,131 hospitalization events (ICD-9 codes 430–438) collected from the Greater Cincinnati/Northern Kentucky Stroke Study in 2005 and 2010. Detailed information from patients’ medical records was abstracted for each event by trained research nurses. By analyzing the broad list of demographic and clinical variables, the machine learning algorithms predicted whether an event was a stroke case and, if so, the stroke subtype. The performance was validated on gold-standard labels adjudicated by stroke physicians, and results were compared with stroke classifications based on ICD-9 discharge codes, as well as labels determined by study nurses.

Results

The best performing machine learning algorithm achieved a performance of 88.57%/93.81%/92.80%/93.30%/89.84%/98.01% (accuracy/precision/recall/F-measure/area under ROC curve/area under precision-recall curve) on stroke case detection. For detecting stroke subtypes, the algorithm yielded an overall accuracy of 87.39% and greater than 85% precision on individual subtypes. The machine learning algorithms significantly outperformed the ICD-9 method on all measures (P value<0.001). Their performance was comparable to that of study nurses, with better tradeoff between precision and recall. The feature selection uncovered a subset of predictive variables that could facilitate future development of effective stroke phenotyping algorithms.

Discussion and conclusions

By analyzing a broad array of patient data, the machine learning technologies held promise for improving detection of stroke diagnosis, thus unlocking high statistical power for subsequent genetic and genomic studies.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5-10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.

Usefulness of EEG for the differential diagnosis of possible transient ischemic attack

OBJECTIVE

EEG value in possible transient ischemic attacks (TIA) is unknown. We aim to quantify focal slow wave activity (FSWA) and epileptiform activity (EA) frequency in possible TIA, and to analyse its contribution to the final diagnosis of seizures and/or definitive TIA.

METHODS

Prospective longitudinal study of possible TIA patients evaluated at a tertiary centre during 36 months and with 1-3 months follow-up. EEG was performed as soon as possible (early EEG) and one month later (late EEG). A stroke neurologist established final diagnosis after reassessing all clinical and diagnostic tests.

RESULTS

80 patients underwent an early EEG (45.8 h after possible TIA): 52 had FSWA and 6 of them also EA. Early FSWA was associated with epileptic seizure or definitive TIA final diagnosis (p = .041). Patients with these diagnoses had more frequently early FSWA (19/23; 82.6%) than EA (6/23; 26.1%). 6/13 (46.2%) patients with epileptic seizure final diagnosis had EA.In the late EEG, 43 (58.1%) patients demonstrated persistent FSWA and 3 of them also EA. Persistent FSWA in the late EEG was more frequent in seizures than in TIA patients (91.7% vs. 45.5%). FSWA disappearance was associated with acute vascular lesion on neuroimage.

CONCLUSIONS

FSWA was the commonest EEG abnormality found in the early EEG of patients with possible TIA, but did not distinguish between TIA and seizure patients. In patients with seizures, FSWA was more common than EA and its presence in the late EEG was more likely in patients with epileptic seizures than with TIA.

SIGNIFICANCE

The majority of possible TIA patients with the final diagnosis of epileptic seizures do not have EA in the early or late EEG.

Explicit diagnostic criteria for transient ischemic attacks to differentiate it from migraine with aura

Background The diagnosis of transient ischemic attacks is fraught with problems. The inter-observer agreement has repeatedly been shown to be low even in a neurological setting, and the specificity of the diagnosis is modest to low, reflected in a poor separation of transient ischemic attacks and mimics, particularly migraine with aura with its varied symptomatology. In other disease areas, explicit diagnostic criteria have improved sensitivity and specificity of diagnoses. We therefore present novel explicit diagnostic criteria for transient ischemic attacks tested for sensitivity and for specificity against migraine with aura. Methods The proposed criteria were developed using the format of the international headache classification. We drew upon the existing literature about clinical characteristics and diagnosis of migraine with aura and transient ischemic attacks. We tested the criteria for sensitivity in a prospectively-collected material of 120 patients with transient ischemic attacks diagnosed before we developed the criteria using extensive semi-structured interview forms in the acute phase after admission. Eligible patients had focal brain or retinal ischemia with resolution of symptoms within 24 hours without presence of new infarction on magnetic resonance imaging with diffusion weighted imaging (n = 112) or computed tomography (n = 8). These criteria were also tested for specificity against a Danish (n = 1390) and a Russian (n = 152) material of patients with migraine with aura diagnosed according to the International Classification of Headache Disorders edition 3 (beta). Results The sensitivity of the proposed criteria was 99% in patients with transient ischemic attacks. The specificity was 95% in the Danish material of patients with migraine with aura and 96% in the Russian material. Conclusions Proposed explicit diagnostic criteria for transient ischemic attacks showed both high specificity and sensitivity. They are likely to improve the emergency room diagnosis of transient ischemic attacks. Further testing in unselected materials referred to transient ischemic attacks clinics was beyond the scope of the present study but is recommended for future study.

Clinical Significance of Isolated Atypical Transient Symptoms in a Cohort With Transient Ischemic Attack

BACKGROUND AND PURPOSE

Contrary to typical transient symptoms (TS), atypical TS, such as partial sensory deficit, dysarthria, vertigo/unsteadiness, unusual cortical visual deficit, and diplopia, are not usually classified as symptoms of transient ischemic attack when they occur in isolation, and their clinical relevance is frequently denied.

METHODS

Consecutive patients with recent TS admitted in our transient ischemic attack clinic (2003-2008) had systematic brain, arterial, and cardiac investigations. We compared the prevalence of recent infarction on brain imaging, major investigational findings (symptomatic intracranial or extracranial atherosclerotic stenosis ≥50%, cervical arterial dissection, and major source of cardiac embolism), and 1-year risk of major vascular events in patients with isolated typical or atypical TS and nonisolated TS, after exclusion of the main differential diagnoses.

RESULTS

Among 1850 patients with possible or definite ischemic diagnoses, 798 (43.1%) had isolated TS: 621 (33.6%) typical and 177 (9.6%) atypical. Acute infarction on brain imaging was similar in patients with isolated atypical and typical TS but less frequent than in patients with nonisolated TS, observed in 10.0%, 11.5%, and 15.3%, respectively (P<0.0001). Major investigational findings were found in 18.1%, 26.4%, and 26.3%, respectively (P=0.06). One-year risk of a major vascular events was not significantly different in the 3 groups.

CONCLUSIONS

Transient ischemic attack diagnosis should be considered and investigated in patients with isolated atypical TS.

Diagnosis and Management of Transient Ischemic Attack

PURPOSE OF REVIEW

This article reviews the diagnosis, investigation, and recommended management after a transient ischemic attack (TIA) and discusses how to make an accurate diagnosis, including the diagnosis of mimics of TIAs.

RECENT FINDINGS

Up to a 10% risk of recurrent stroke exists after a TIA, and up to 80% of this risk is preventable with urgent assessment and treatment. Imaging of the brain and intracranial and extracranial blood vessels using CT, CT angiography, carotid Doppler ultrasound, and MRI is an important part of the diagnostic assessment. Treatment options include anticoagulation for atrial fibrillation, carotid revascularization for symptomatic carotid artery stenosis, antiplatelet therapy, and vascular risk factor reduction strategies.

SUMMARY

TIA offers the greatest opportunity to prevent stroke that physicians encounter. A TIA should be treated as a medical emergency, as up to 80% of strokes after TIA are preventable.

Tissue-Negative Transient Ischemic Attack: Is There a Role for Perfusion MRI?

OBJECTIVE

Approximately 60% of patients with a clinical transient ischemic attack (TIA) do not have DWI evidence of cerebral ischemia. The purpose of this study was to assess the added diagnostic value of perfusion MRI in the evaluation of patients with TIA who have normal DWI findings.

MATERIALS AND METHODS

The inclusion criteria for this retrospective study were clinical presentation of TIA at admission with a discharge diagnosis of TIA confirmed by a stroke neurologist, MRI including both DWI and perfusion-weighted imaging within 48 hours of symptom onset, and no DWI lesion. Cerebral blood flow (CBF) and time to maximum of the residue function (Tmax) maps were evaluated independently by two observers. Multivariate analysis was used to assess perfusion findings; clinical variables; age, blood pressure, clinical symptoms, diabetes (ABCD2) score; duration of TIA; and time between MRI and onset and resolution of symptoms.

RESULTS

Fifty-two patients (33 women, 19 men; age range, 20-95 years) met the inclusion criteria. A regional perfusion abnormality was identified on either Tmax or CBF maps of 12 of 52 (23%) patients. Seven (58%) of the patients with perfusion abnormalities had hypoperfused lesions best detected on Tmax maps; the other five had hyperperfusion best detected on CBF maps. In 11 of 12 (92%) patients with abnormal perfusion MRI findings, the regional perfusion deficit correlated with the initial neurologic deficits. Multivariable analysis revealed no significant difference in demographics, ABCD2 scores, or presentation characteristics between patients with and those without perfusion abnormalities.

CONCLUSION

Perfusion MRI that includes Tmax and CBF parametric maps adds diagnostic value by depicting regions with delayed perfusion or postischemic hyperperfusion in approximately one-fourth of TIA patients who have normal DWI findings.

Diagnosis of TIA (DOT) score--design and validation of a new clinical diagnostic tool for transient ischaemic attack

BACKGROUND

The diagnosis of Transient Ischaemic Attack (TIA) can be difficult and 50-60% of patients seen in TIA clinics turn out to be mimics. Many of these mimics have high ABCD2 scores and fill urgent TIA clinic slots inappropriately. A TIA diagnostic tool may help non-specialists make the diagnosis with greater accuracy and improve TIA clinic triage. The only available diagnostic score (Dawson et al) is limited in scope and not widely used. The Diagnosis of TIA (DOT) Score is a new and internally validated web and mobile app based diagnostic tool which encompasses both brain and retinal TIA.

METHODS

The score was derived retrospectively from a single centre TIA clinic database using stepwise logistic regression by backwards elimination to find the best model. An optimum cutpoint was obtained for the score. The derivation and validation cohorts were separate samples drawn from the years 2010/12 and 2013 respectively. Receiver Operating Characteristic (ROC) curves and area under the curve (AUC) were calculated and the diagnostic accuracy of DOT was compared to the Dawson score. A web and smartphone calculator were designed subsequently.

RESULTS

The derivation cohort had 879 patients and the validation cohort 525. The final model had seventeen predictors and had an AUC of 0.91 (95% CI: 0.89-0.93). When tested on the validation cohort, the AUC for DOTS was 0.89 (0.86-0.92) while that of the Dawson score was 0.77 (0.73-0.81). The sensitivity and specificity of the DOT score were 89% (CI: 84%-93%) and 76% (70%-81%) respectively while those of the Dawson score were 83% (78%-88%) and 51% (45%-57%). Other diagnostic accuracy measures (DOT vs. Dawson) include positive predictive values (75% vs. 58%), negative predictive values (89% vs. 79%), positive likelihood ratios (3.67 vs. 1.70) and negative likelihood ratios (0.15 vs. 0.32).

CONCLUSION

The DOT score shows promise as a diagnostic tool for TIA and requires independent external validation before it can be widely used. It could potentially improve the triage of patients assessed for suspected TIA.

Inter-rater agreement analysis of the Precise Diagnostic Score for suspected transient ischemic attack

Background

No definitive criteria are available to confirm the diagnosis of transient ischemic attack. Inter-rater agreement between physicians regarding the diagnosis of transient ischemic attack is low, even among vascular neurologists. We developed the Precise Diagnostic Score, a diagnostic score that consists of discrete and well-defined clinical and imaging parameters, and investigated inter-rater agreement in patients with suspected transient ischemic attack.

Methods

Fellowship-trained vascular neurologists, blinded to final diagnosis, independently reviewed retrospectively identical history, physical examination, routine diagnostic studies, and brain magnetic resonance imaging (diffusion and perfusion images) from consecutive patients with suspected transient ischemic attack. Each patient was rated using the 8-point Precise Diagnostic Score score, composed of a clinical score (0–4 points) and an imaging score (0–4 points). The composite Precise Diagnostic Score determines a Precise Diagnostic Score Likelihood of Brain Ischemia Scale: 0–1 = unlikely, 2 = possible, 3 = probable, 4–8 = very likely.

Results

Three raters reviewed data from 114 patients. Using Precise Diagnostic Score, all three raters scored a similar percentage of the clinical events as being “probable” or “very likely” caused by brain ischemia: 57, 55, and 58%. Agreement was high for both total Precise Diagnostic Score (intraclass correlation coefficient of 0.94) and for the Likelihood of Brain Ischemia Scale (agreement coefficient of 0.84).

Conclusions

Compared with prior studies, inter-rater agreement for the diagnosis of transient brain ischemia appears substantially improved with the Precise Diagnostic Score scoring system. This score is the first to include specific criteria to assess the clinical relevance of diffusion-weighted imaging and perfusion lesions and supports the added value of magnetic resonance imaging for assessing patients with suspected transient ischemic attack.

Ocular fundus photography of patients with focal neurologic deficits in an emergency department

OBJECTIVES

We evaluated the frequency and predictive value of ocular fundus abnormalities among patients who presented to the emergency department (ED) with focal neurologic deficits to determine the utility of these findings in the evaluation of patients with suspected TIA and stroke.

METHODS

In this cross-sectional pilot study, ocular fundus photographs were obtained using a nonmydriatic fundus camera. Demographic, neuroimaging, and ABCD(2) score components were collected. Photographs were reviewed for retinal microvascular abnormalities. The results were analyzed using univariate statistics and logistic regression modeling.

RESULTS

Two hundred fifty-seven patients presented to the ED with focal neurologic deficits, of whom 81 patients (32%) had cerebrovascular disease (CVD) and 144 (56%; 95% confidence interval: 50%-62%) had retinal microvascular abnormalities. Focal and general arteriolar narrowing increased the odds of clinically diagnosed CVD by 5.5 and 2.6 times, respectively, after controlling for the ABCD(2) score and diffusion-weighted imaging. These fundus findings also significantly differentiated TIA from non-CVD, even after controlling for the ABCD(2) score.

CONCLUSIONS

Focal and general arteriolar narrowing were independent predictors of CVD overall, and TIA alone, even after controlling for the ABCD(2) score and diffusion-weighted imaging lesions. The inclusion of nonmydriatic ocular fundus photographs in the evaluation of patients presenting to the ED with focal neurologic deficits may assist in the differentiation of stroke and TIA from other causes of focal neurologic deficits.

Patients Referred for TIA May Still Have Persisting Neurological Deficits

Background:

The presence of residual neurological deficits after neurological symptoms is important information for making a diagnosis of Transient Ischemic Attack (TIA) versus stroke. The purpose of this study was to establish the reliability of the referring physician (non neurologist) to report focal neurological deficits in the context of an urgent referral for TIA.

Methods:

Prospectively recorded urgent physician-to-physician phone referrals for TIA through the Southern Alberta TIA hotline from March 2009 to July 2010 were reviewed. “Has the neurological deficit completely resolved?” was asked to the referring physician (family or emergency room physician) and recorded prospectively as a yes/no response. Patients were included if a neurological examination was performed by a neurologist on the same day as referral. The neurologist's assessment of whether the deficit had resolved was compared to that of the referring physician.

Results:

78 patients were included in this study. 62 patients had resolved as per the referring physician's assessment. Of these 62 patients, 16 (25.8% 95%CI 16-38) had evidence of persisting neurological deficits on the neurologist's assessment. A wide variety of mild neurological deficits were identified. None of these deficits appeared to be explained by progression of symptoms.

Conclusion:

Physicians referring patients with TIA syndromes for emergent assessment do not reliably detect mild residual deficits in one-quarter of patients. We are questioning the validity of neurological deficit resolution as a triage rule. The findings suggest that studies of TIA likely include a proportion of minor stroke patients and this should be remembered when extrapolating the results to other populations.

Transient ischaemic attack clinic: an evaluation of diagnoses and clinical decision making

The diagnosis of transient ischaemic attack (TIA) is based largely on the patient's symptom recall and clinical judgement. This decision-making process is highly subjective and the inter-observer reliability of TIA diagnosis is at best moderate, even among neurologists. The aim of this study is to examine the presenting features and final diagnoses of referrals to a TIA clinic and to evaluate characteristics that favoured the diagnosis of TIA over other TIA "mimics". Consecutive new referrals to a tertiary metropolitan hospital TIA clinic over a 9month period were examined. Characteristics between TIA and non-TIA diagnoses were compared and analysed. Eighty-two patients were recruited. Eighteen (22%) were given a final diagnosis of TIA or stroke. Major alternative diagnoses included migraine (n=17, 21%), presyncope/syncope (n=13, 16%) and anxiety (n=7, 9%). Four (5%) patients had unclassifiable symptoms with no clear final diagnosis. Mean age was 67±a standard deviation of 17years and patients diagnosed with TIA/stroke were on average older than those with non-TIA diagnoses (77±10 versus 64±17years, p=0.003). A diagnosis of TIA/stroke was favoured in the presence of moderate to severe weakness (p=0.032), dysphasia (p=0.037) or dysarthria (p=0.005). Unclassifiable symptoms (for example, palpitations, confusion, headache) were reported in 27 patients (33%) and their presence favoured non-TIA diagnoses (p=0.0003). TIA constituted a minority of the referrals to our clinic. Accurate clinical diagnosis of TIA facilitates early stroke prevention and avoids unnecessary investigations and prescriptions. Attempts to improve diagnostic accuracy of TIA should target improving the education and awareness of frontline medical practitioners.

Transient ischaemic attacks: mimics and chameleons

Suspected transient ischaemic attack (TIA) is a common diagnostic challenge for physicians in neurology, stroke, general medicine and primary care. It is essential to identify TIAs promptly because of the very high early risk of ischaemic stroke, requiring urgent investigation and preventive treatment. On the other hand, it is also important to identify TIA ‘mimics’, to avoid unnecessary and expensive investigations, incorrect diagnostic labelling and inappropriate long-term prevention treatment. Although the pathophysiology of ischaemic stroke and TIA is identical, and both require rapid and accurate diagnosis, the differential diagnosis differs for TIA owing to the transience of symptoms. For TIA the diagnostic challenge is greater, and the ‘mimic’ rate higher (and more varied), because there is no definitive diagnostic test. TIA heralds a high risk of early ischaemic stroke, and in many cases the stroke can be prevented if the cause is identified, hence the widespread dissemination of guidelines including rapid assessment and risk tools like the ABCD2 score. However, these guidelines do not emphasise the substantial challenges in making the correct diagnosis in patients with transient neurological symptoms. In this article we will mainly consider the common TIA mimics, but also briefly mention the rather less common situations where TIAs can look like something else (‘chameleons’).

Spectrum of transient visual symptoms in a transient ischemic attack cohort

BACKGROUND AND PURPOSE

Transient visual symptoms (TVS) are common complaints. They can be related to transient ischemic attacks, but the nature of the symptoms often remains uncertain, and data on prognosis are scarce. We studied the prevalence, presentation, and effect of different types of TVS, paying particular attention to the association with high-risk pathology of embolism.

METHODS

A total of 2398 patients with suspected transient ischemic attack admitted to the SOS-TIA clinic between January 2003 and December 2008 underwent immediate evaluation and treatment.

RESULTS

Eight hundred twenty-six (34.5%) patients had TVS, including 422 (17.6%) patients with isolated TVS. Transient monocular blindness was the most frequent TVS (36.3%), followed by diplopia (13.4%), homonymous lateral hemianopia (12.3%), bilateral positive visual phenomena (10.8%), and lone bilateral blindness (4.5%). Positive diffusion-weighted imaging was found in 11.8%, 8.1%, 8.1%, and 5.0% of patients with homonymous lateral hemianopia, diplopia, lone bilateral blindness, and transient monocular blindness, respectively. Among 1850 patients (595 patients with TVS) with definite/possible transient ischemic attack or minor stroke, a major source of embolism of cardiac or arterial origin was found less frequently in patients with isolated or nonisolated TVS than in patients without TVS (19.6%; 19.7% versus 28.1%, respectively; P<0.001). However, we found a higher rate of atrial fibrillation in patients with homonymous lateral hemianopia (23.2%) than in patients with other TVS (4.0%; adjusted odds ratio, 6.71; 95% confidence interval, 2.99-15.06) or nonvisual symptoms (9.1%; adjusted odds ratio, 4.39; 95% confidence interval, 2.26-8.50).

CONCLUSIONS

Approximately 20% of patients with TVS had a major source of embolism detected, requiring urgent management. Atrial fibrillation was particularly frequent in patients with transient homonymous lateral hemianopia.

Clinical implications of increased use of MRI in TIA

BACKGROUND

Transient ischemic attack has been redefined as a tissue-based diagnosis and MRI recommended as the preferred imaging modality. We aimed to investigate whether an increased use of MRI leads to a decrease in the proportion of TIA as compared to cerebral infarction. We also sought to see whether DWI-positive patients with transient ischemic symptoms <24 h differ from DWI-negative TIA patients in terms of performed diagnostic investigations and clinical characteristics.

METHODS

Patients admitted with cerebral infarction or TIA in the period 2006-2011 were prospectively registered. The use of MRI in patients with transient ischemic symptoms <24 h and proportion of TIA were annually recorded. DWI-positive and DWI-negative patients with transient ischemic symptoms <24 h were compared in univariate analyses regarding baseline data, diagnostic investigations, and etiology. Multivariate analyses were performed to identify predictors of DWI lesions.

RESULTS

The use of MRI increased from 65.0% in 2006-2008 to 89.0% in 2009-2011 (P < 0.001). The proportion of TIA as compared to cerebral infarction decreased from 12.2% in 2006-2008 to 8.3% in 2009-2011 (P = 0.002). DWI-positive patients were more often examined with 24-h Holter monitoring (P < 0.001) and echocardiography (P < 0.001). Lower age (P < 0.001) and prior myocardial infarction (P < 0.029) were independently associated with DWI lesions in patients with transient ischemic symptoms <24 h.

CONCLUSIONS

An increased use of MRI and a tissue-based TIA definition resulted in a decrease in the proportion of TIA at discharge as compared to cerebral infarction. DWI-positive patients had a more extensive cardiac work-up and were associated with lower age and prior myocardial infarction.

Early magnetic resonance imaging in transient ischemic attack and minor stroke: do it or lose it

BACKGROUND AND PURPOSE

The use of magnetic resonance imaging (MRI) after transient ischemic attack (TIA) or minor stroke may be affected by the relative timing of imaging. We measured the impact of scanning an individual patient late versus early after TIA and minor stroke.

METHODS

Two hundred sixty-three TIA or minor stroke (National Institute of Health Stroke Scale score ≤3) patients with a baseline MRI completed within 24 hours of symptom onset and a follow-up MRI at 90 days were included. Baseline and 90-day scans were assessed independently for the presence of any stroke lesions that could explain the presenting symptoms. The presence and pattern of any stroke lesions were compared at the 2 time points.

RESULTS

The presence of a stroke (acute or chronic) in any location was more common on baseline MRI versus 90-day MRI (68% vs 56%; P=0.005). Thirty percent of subjects with negative scans at 90 days had a clearly identifiable stroke at baseline. When interpreted blinded to the baseline scan, the presumed relevant lesion on the 90-day MR scan was the correct lesion in only 53% patients. One-third (34%) of patients had a different lesion pattern on the baseline scan compared with the 90-day scan. Ninety percent (80/89) of these patients had more lesions on the baseline MRI and 10% (9/89) had new lesions on the 90-day MRI.

CONCLUSIONS

Delayed MRI after TIA or minor stroke reduces the diagnostic yield and results in missed understanding of the lesion pattern. MRI of minor stroke and TIA patients should occur early after symptom onset, and delayed imaging should be interpreted with caution.

Transient Focal Neurological Episodes, Cerebral Amyloid Angiopathy, and Intracerebral Hemorrhage Risk: Looking beyond TIAs

When most doctors encounter older patients with transient focal neurological symptoms, they usually suspect a diagnosis of transient ischemic attacks or some of their known mimics (including migraine auras or focal seizures). This article emphasizes new observations on transient focal neurological episodes in the context of cerebral amyloid angiopathy, a common but under-recognized small vessel disease most often encountered as a cause of symptomatic lobar intracerebral hemorrhage. Transient focal neurological episodes in cerebral amyloid angiopathy are of clinical and pathophysiological interest because they can mimic transient ischemic attacks, but are probably more often related to bleeding (especially superficial cortical siderosis or focal convexity sub-arachnoid hemorrhage) rather than ischemia. Importantly, such episodes may also herald a very high future risk of symptomatic intracerebral hemorrhage. The article highlights scenarios encountered in clinical practice and discusses implications for patient care including: (a) the value of blood-sensitive magnetic resonance imaging sequences in investigating transient focal neurological episodes; and (b) treatment implications, as giving antiplatelet or anticoagulant drugs for these episodes could increase the risk of serious intracerebral hemorrhage.

Transient isolated brainstem symptoms preceding posterior circulation stroke: a population-based study

BACKGROUND

Transient isolated brainstem symptoms (eg, isolated vertigo, dysarthria, diplopia) are not consistently classified as transient ischaemic attacks (TIAs) and data for prognosis are limited. If some of these transient neurological attacks (TNAs) are due to vertebrobasilar ischaemia, then they should be common during the days and weeks preceding posterior circulation strokes. We aimed to assess the frequency of TNAs before vertebrobasilar ischaemic stroke.

METHODS

We studied all potential ischaemic events during the 90 days preceding an ischaemic stroke in patients ascertained within a prospective, population-based incidence study in Oxfordshire, UK (Oxford Vascular Study; 2002-2010) and compared rates of TNA preceding vertebrobasilar stroke versus carotid stroke. We classified the brainstem symptoms isolated vertigo, vertigo with non-focal symptoms, isolated double vision, transient generalised weakness, and binocular visual disturbance as TNAs in the vertebrobasilar territory; atypical amaurosis fugax and limb-shaking as TNAs in the carotid territory; and isolated slurred speech, migraine variants, transient confusion, and hemisensory tingling symptoms as TNAs in uncertain territory.

FINDINGS

Of the 1141 patients with ischaemic stroke, vascular territory was categorisable in 1034 (91%) cases, with 275 vertebrobasilar strokes and 759 carotid strokes. Isolated brainstem TNAs were more frequent before a vertebrobasilar stroke (45 of 275 events) than before a carotid stroke (10 of 759; OR 14·7, 95% CI 7·3-29·5, p<0·0001), particularly during the preceding 2 days (22 of 252 before a vertebrobasilar stroke vs two of 751 before a carotid stroke, OR 35·8, 8·4-153·5, p<0·0001). Of all 59 TNAs preceding (median 4 days, IQR 1-30) vertebrobasilar stroke, only five (8%) fulfilled the National Institute of Neurological Disorders and Stroke (NINDS) criteria for TIA. The other 54 cases were isolated vertigo (n=23), non-NINDS binocular visual disturbance (n=9), vertigo with other non-focal symptoms (n=10), isolated slurred speech, hemisensory tingling, or diplopia (n=8), and non-focal events (n=4). Only 10 (22%) of the 45 patients with isolated brainstem TNAs sought medical attention before the stroke and a vascular cause was suspected by their physician in only one of these cases.

INTERPRETATION

In patients with definite vertebrobasilar stroke, preceding transient isolated brainstem symptoms are common, but most symptoms do not satisfy traditional definitions of TIA. More studies of the prognosis of transient isolated brainstem symptoms are required.

FUNDING

Wellcome Trust, UK Medical Research Council, Dunhill Medical Trust, Stroke Association, National Institute for Health Research (NIHR), Thames Valley Primary Care Research Partnership, and the NIHR Biomedical Research Centre, Oxford.

Transient neurological attack before vertebrobasilar stroke

BACKGROUND

Patients with vertebrobasilar (VB) circulation ischemia can present with nonspecific symptoms, which complicate the distinction of transient ischemic attack (TIA) from other benign disorders. According to previously accepted classifications, typical TIA does not occur with VB symptom such as vertigo, diplopia, or dysarthria in isolation. However, there is a lack of evidence to support this hypothesis.

METHODS

This hospital-based study included 214 consecutive patients with acute ischemic VB stroke. We defined transient neurological attacks (TNAs) as temporary (<24h) episodes with neurological symptoms, and further divided them into TIA, nonspecific TNA, or other specific disorder groups. We investigated the incidence and clinical symptoms of TNAs within 3months prior to the stroke episode, and comparisons were made between patients with and without previous TNA history with respect to their background and stroke profiles.

RESULTS

Among 214 patients with VB stroke, 56 (26.2%) had previous TNAs. Six of them were diagnosed with other specific disorders and excluded from the analysis. The remaining 33 and 17 were diagnosed with TIA and nonspecific TNA, respectively. Twenty-one (42.0%) had attacks with a nonfocal symptom in isolation, and acute infarction in neuroimaging was confirmed in 4 of these patients. Vertigo was the most frequent nonspecific TNA symptom. Patients with prior TNA had a significantly higher rate of atherothrombotic stroke than those without TNA (40.0% vs. 21.5%, P=0.009).

CONCLUSIONS

A considerable fraction of TIAs due to VB circulation ischemia may be overlooked among clinically nonfocal TNAs.

Transient ischaemic attack (TIA) knowledge in general practice: a cross-sectional study of Western Adelaide general practitioners

Background

With evidence to support early assessment and management of TIAs, the role of the general practitioner (GP) needs to be considered in developing a TIA service in Western Adelaide. We thus aimed to determine GP knowledge of TIA assessment and management and identify perceived barriers, in order to tailor subsequent GP education and engage primary care in the co-ordinated care of TIA patients.

Findings

A self-administered questionnaire was mailed to all GPs (n = 202) in the Adelaide Western General Practice Network. Response frequencies were calculated for all variables, and associations examined by univariate analysis.

32 GPs responded. All respondents correctly identified early risk of stroke following a TIA. Difficulty accessing neurological expertise was identified as a barrier (40.6 %), as was a lack of GP knowledge (18.8 %). Areas for improvement included access to neurologists (36.7 %), relevant guidelines and education (43.3 %).

Conclusions

Diagnosis of TIA is difficult and this study highlights the need for further education and practical guidelines for GPs. With this training, GPs could be better equipped to assess and manage TIAs effectively in the community in consultation with stroke physicians.

Automated perfusion imaging for the evaluation of transient ischemic attack

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) is recommended for the evaluation of transient ischemic attack. Perfusion imaging can increase the yield of MRI in transient ischemic attack. We evaluated automated bolus perfusion (the time when the residue function reaches its maximum [TMax] and mean transit time [MTT]) and arterial spin labeling (ASL) sequences for the detection of ischemic lesions in patients with transient ischemic attack.

METHODS

We enrolled consecutive patients evaluated for suspicion of acute transient ischemic attack by multimodal MRI within 36 hours of symptom onset. Two independent raters assessed the presence and location of ischemic lesions blinded to the clinical presentation. The prevalence of ischemic lesions and the interrater agreement were 1,410 assessed.

RESULTS

From January 2010 to 2011, 93 patients were enrolled and 90 underwent perfusion imaging (69 bolus perfusion and 76 ASL). Overall, 25 of 93 patients (27%) were DWI-positive and 14 (15%) were perfusion-positive but DWI-negative (ASL n=9; TMax n=9; MTT n=2). MTT revealed an ischemic lesion in fewer patients than TMax (7 versus 20, P=0.004). Raters agreed on 89% of diffusion-weighted imaging cases, 89% of TMax, 87% o10f010 MTT, and 90% of ASL cases. The interrater agreement was good for DWI, TMax, and ASL (κ=0.73, 0.72, and 0.74, respectively) and fair for MTT (κ=0.43). Diffusion and/or perfusion were positive in 39 of 69 (57%) patients with a discharge diagnosis of possible ischemic event.

CONCLUSIONS

Our results suggest that in patients referred for suspicion of transient ischemic attack, automated TMax is more sensitive than MTT, and both ASL and TMax increase the yield of MRI for the detection of ischemic lesions.

Ischemic transient neurological events identified by immune response to cerebral ischemia

BACKGROUND AND PURPOSE

Deciphering whether a transient neurological event (TNE) is of ischemic or nonischemic etiology can be challenging. Ischemia of cerebral tissue elicits an immune response in stroke and transient ischemic attack (TIA). This response, as detected by RNA expressed in immune cells, could potentially distinguish ischemic from nonischemic TNE.

METHODS

Analysis of 208 TIAs, ischemic strokes, controls, and TNE was performed. RNA from blood was processed on microarrays. TIAs (n=26) and ischemic strokes (n=94) were compared with controls (n=44) to identify differentially expressed genes (false discovery rate <0.05, fold change ≥1.2). Genes common to TIA and stroke were used predict ischemia in TIA diffusion-weighted imaging-positive/minor stroke (n=17), nonischemic TNE (n=13), and TNE of unclear etiology (n=14).

RESULTS

Seventy-four genes expressed in TIA were common to those in ischemic stroke. Functional pathways common to TIA and stroke related to activation of innate and adaptive immune systems, involving granulocytes and B cells. A prediction model using 26 of the 74 ischemia genes distinguished TIA and stroke subjects from control subjects with 89% sensitivity and specificity. In the validation cohort, 17 of 17 TIA diffusion-weighted imaging-positive/minor strokes were predicted to be ischemic, and 10 of 13 nonischemic TNE were predicted to be nonischemic. In TNE of unclear etiology, 71% were predicted to be ischemic. These subjects had higher ABCD(2) scores.

CONCLUSIONS

A common molecular response to ischemia in TIA and stroke was identified, relating to activation of innate and adaptive immune systems. TNE of ischemic etiology was identified based on gene profiles that may be of clinical use once validated.

Relative Survival After Transient Ischaemic Attack

Background and Purpose—

There is a lack of modern-day data quantifying the effect of transient ischemic attack (TIA) on survival, and recent data do not take into account expected survival.

Methods—

Data for 22 157 adults hospitalized with a TIA from July 1, 2000, to June 30, 2007, in New South Wales, Australia, were linked with registered deaths to June 30, 2009. We estimated survival relative to the age- and sex-matched general population up to 9-years after hospitalization for TIA comparing relative risk of excess death between selected subgroups.

Results—

At 1 year, 91.5% of hospitalized patients with TIA survived compared with 95.0% expected survival in the general population. After 5 years, observed survival was 13.2% lower than expected in relative terms. By 9 years, observed survival was 20% lower than expected. Females had higher relative survival than males (relative risk, 0.79; 95% CI, 0.69–0.90; P <0.001). Increasing age was associated with an increasing risk of excess death compared with the age-matched population. Prior hospitalization for stroke (relative risk, 2.63; 95% CI, 1.98–3.49) but not TIA (relative risk, 1.42; 95% CI, 0.86–2.35) significantly increased the risk of excess death. Of all risk factors assessed, congestive heart failure, atrial fibrillation, and prior hospitalization for stroke most strongly impacted survival.

Conclusions—

This study is the first to quantify the long-term effect of hospitalized TIA on relative survival according to age, sex, and medical history. TIA reduces survival by 4% in the first year and by 20% within 9 years. TIA has a minimal effect on mortality in patients <50 years but heralds significant reduction in life expectancy in those >65 years.

Why do acute ischemic stroke patients with a preceding transient ischemic attack present with less severe strokes? Insights from the German Stroke Study

BACKGROUND

The effect of ischemic preconditioning (IP) is well established in animal models of brain ischemia. There are conflicting data from human observational studies whether IP is also induced by a preceding transient ischemic attack (TIA) resulting in a lower stroke severity in these patients.

METHODS

Data from 7,611 consecutive patients with first-ever acute ischemic stroke from the prospective German Stroke Study Collaboration were analyzed. A multivariate linear regression analysis was used to evaluate whether a preceding TIA was associated with a lower National Institutes of Health Stroke Scale (NIH-SS) score at admission. Furthermore, stroke severity was stratified by the latency between a preceding TIA and subsequent acute ischemic stroke (≤7 days vs. >7 days and ≤72 h vs. >72 h).

RESULTS

A previous TIA was documented in 452 (5.9%) patients, and a significantly lower NIH-SS score at admission was found in these patients compared with patients without TIA. A previous TIA remained significantly associated with a lower NIH-SS score in multivariate analysis corrected for the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, cardiovascular risk factors, age, sex and premorbid disability. The NIH-SS score at admission did not significantly differ in 96 patients with a TIA within 7 days compared with 137 patients with a TIA more than 7 days before ischemic stroke. Similarly, there were no significant differences in stroke severity in patients with a TIA within 72 h.

CONCLUSIONS

The significantly lower stroke severity observed in patients with a preceding TIA is not confounded by stroke etiology in our large-scale observational study. Data on latency between the TIA and subsequent ischemic stroke do not support a neuroprotective effect caused by TIA-induced IP in human ischemic stroke.