Addition of Brain Infarction to the ABCD 2 Score (ABCD 2 I)

TIA Management: Should TIA Patients be Admitted? Should TIA Patients Get Combination Antiplatelet Therapy?

Transient ischemic attack (TIA) has gained increasing attention over the last 2 decades with the realization that the condition is common, portends potentially serious consequences, and, when identified early, can be evaluated and treated to modify future risk. In this review, we examine the issues of whether all TIA patients need admission and whether such patients should receive short-term dual antiplatelet therapy. Not all patients require admission if evaluation and treatment are done promptly. There may be a role for dual antiplatelet therapy, but the results of further clinical trials will help provide better clarity on which patients are the best candidates for this treatment.

ABCD2 score and secondary stroke prevention: meta-analysis and effect per 1,000 patients triaged

OBJECTIVE

Patients with TIA have high risk of recurrent stroke and require rapid assessment and treatment. The ABCD2 clinical risk prediction score is recommended for patient triage by stroke risk, but its ability to stratify by known risk factors and effect on clinic workload are unknown.

METHODS

We performed a systematic review and meta-analysis of all studies published between January 2005 and September 2014 that reported proportions of true TIA/minor stroke or mimics, risk factors, and recurrent stroke rates, dichotomized to ABCD2 score </≥4. We calculated the effect per 1,000 patients triaged on stroke prevention services.

RESULTS

Twenty-nine studies, 13,766 TIA patients (range 69-1,679), were relevant: 48% calculated the ABCD2 score retrospectively; few reported on the ABCD2 score's ability to identify TIA mimics or use by nonspecialists. Meta-analysis showed that ABCD2 ≥4 was sensitive (86.7%, 95% confidence interval [CI] 81.4%-90.7%) but not specific (35.4%, 95% CI 33.3%-37.6%) for recurrent stroke within 7 days. Additionally, 20% of patients with ABCD2 <4 had >50% carotid stenosis or atrial fibrillation (AF); 35%-41% of TIA mimics, and 66% of true TIAs, had ABCD2 score ≥4. Among 1,000 patients attending stroke prevention services, including the 45% with mimics, 52% of patients would have an ABCD2 score ≥4.

CONCLUSION

The ABCD2 score does not reliably discriminate those at low and high risk of early recurrent stroke, identify patients with carotid stenosis or AF needing urgent intervention, or streamline clinic workload. Stroke prevention services need adequate capacity for prompt specialist clinical assessment of all suspected TIA patients for correct patient management.

Prediction factors of recurrent ischemic events in one year after minor stroke

Background

The risk of a subsequent stroke following a minor stroke is high. However, there are no effective rating scales to predict recurrent stroke following a minor one. Therefore, we assessed the risk factors associated with recurrent ischemic stroke or transient ischemic attack (TIA) within one year of minor stroke onset in order to identify possible risk factors.

Methods

Eight hundred and sixty-three non-cardioembolic ischemic stroke patients in the Chinese IntraCranial AtheroSclerosis Study that presented with minor stroke, defined as an admission National Institutes of Health stroke scale (NIHSS) score of ≤3, were consecutively enrolled in our study. Clinical information and imaging features upon admission, and any recurrent ischemic stroke or TIA within one year was recorded. Cox regression was used to identify risk factors associated with recurrent ischemic stroke or TIA within the year following stroke onset.

Results

A total of 50 patients (6.1%) experienced recurrent ischemic stroke or TIA within one year of minor stroke onset. Multivariate Cox regression model identified lower admission NIHSS score (HR, 1.75; 95% CI, 1.32 to 2.33; P<0.0001), history of coronary heart disease (HR, 2.62; 95% CI, 1.17 to 5.86; P = 0.02), severe stenosis or occlusion of large cerebral artery (HR, 4.68; 95% CI, 1.87 to 11.7; P = 0.001), and multiple acute cerebral infarcts (HR, 2.61; 95% CI, 1.01 to 6.80; P = 0.05) as independent risk factors for recurrent ischemic stroke or TIA within one year.

Conclusions

Some minor stroke patients are at higher risk for recurrent ischemic stroke or TIA. Urgent and intensified therapy may be reasonable in these patients.

Prediction of myocardial infarction in patients with transient ischaemic attack

BACKGROUND

Determinants of risk of myocardial infarction (MI) after transient ischaemic attack (TIA) are not well defined. The aim of our study was to determine the risk and risk factors for MI after TIA.

METHODS

We prospectively recruited patients within 24 h of transient ischaemic cerebrovascular events between October 2006 and January 2013. A total of 628 TIA patients were followed for six months or more. MI and stroke recurrence (SR) were recorded. The duration and typology of clinical symptoms, vascular risk factors and aetiological work-ups were prospectively recorded and established prognostic scores (ABCD2, ABCD2I, ABCD3I, Essen Stroke Risk Score, California Risk Score and Stroke Prognosis Instrument) were calculated.

RESULTS

Twenty-eight (4.5%) MI and 68 (11.0%) recurrent strokes occurred during a median follow-up period of 31.2 months (16.1-44.9). In Cox proportional hazards multivariate analyses, we identify previous coronary heart disease (CHD) (hazard ratio [HR] 5.65, 95% confidence interval [CI] 2.45-13.04, P < 0.001) and sex male (HR 2.72, 95% CI 1.02-7.30, P = 0.046) as independent predictors of MI. Discrimination for the prognostic scores only ranged from 0.60 to 0.71. The incidence of MI did not vary among the different aetiological subtypes. Positive diffusion weighted imaging (DWI) (7.5% vs 2.5%, P = 0.007), and ECG abnormalities (Q wave or ST-T wave changes) (13.6% vs 3.6%, P = 0.001) were associated to MI.

CONCLUSION

According to our results, discrimination was poor for all previous risk prediction models evaluated. Variables such as previous CHD, male sex, DWI and ECG abnormalities should be considered in new prediction models.

Computed Tomography Identifies Patients at High Risk for Stroke After Transient Ischemic Attack/Nondisabling Stroke

Background and Purpose—

Ischemia on computed tomography (CT) is associated with subsequent stroke after transient ischemic attack. This study assessed CT findings of acute ischemia, chronic ischemia, or microangiopathy for predicting subsequent stroke after transient ischemic attack.

Methods—

This prospective cohort study enrolled patients with transient ischemic attack or nondisabling stroke that had CT scanning within 24 hours. Primary outcome was subsequent stroke within 90 days. Secondary outcomes were stroke at ≤2 or >2 days. CT findings were classified as ischemia present or absent and acute or chronic or microangiopathy. Analysis used Fisher exact test and multivariate logistic regression.

Results—

A total of 2028 patients were included; 814 had ischemic changes on CT. Subsequent stroke rate was 3.4% at 90 days and 1.5% at ≤2 days. Stroke risk was greater if baseline CT showed acute ischemia alone (10.6%; P =0.002), acute+chronic ischemia (17.4%; P =0.007), acute ischemia+microangiopathy (17.6%; P =0.019), or acute+chronic ischemia+microangiopathy (25.0%; P =0.029). Logistic regression found acute ischemia alone (odds ratio [OR], 2.61; 95% confidence interval [CI[, 1.22–5.57), acute+chronic ischemia (OR, 5.35; 95% CI, 1.71–16.70), acute ischemia+microangiopathy (OR, 4.90; 95% CI, 1.33–18.07), or acute+chronic ischemia+microangiopathy (OR, 8.04; 95% CI, 1.52–42.63) was associated with a greater risk at 90 days, whereas acute+chronic ischemia (OR, 10.78; 95% CI, 2.93–36.68), acute ischemia+microangiopathy (OR, 8.90; 95% CI, 1.90–41.60), and acute+chronic ischemia+microangiopathy (OR, 23.66; 95% CI, 4.34–129.03) had greater risk at ≤2 days. Only acute ischemia (OR, 2.70; 95% CI, 1.01–7.18; P =0.047) was associated with a greater risk at >2 days.

Conclusions—

In patients with transient ischemic attack/nondisabling stroke, CT evidence of acute ischemia alone or acute ischemia with chronic ischemia or microangiopathy was associated with increased subsequent stroke risk within 90 days.

[Contribution of arterial spin labeling to the diagnosis of sudden and transient neurological deficit]

MRI is the gold standard exploration for sudden transient neurological events. If diffusion MRI is negative, there may be a diagnostic doubt between transient ischemic attack and other causes of transient neurological deficit. We illustrate how sequence arterial spin labeling (ASL), which evaluates cerebral perfusion, contributes to the exploration of transient neurological events. An ASL sequence was performed in seven patients with a normal diffusion MRI explored for a transient deficit. Cortical hyperperfusion not systematized to an arterial territory was found in three and hypoperfusion systematized to an arterial territory in four. ASL helped guide early management of these patients.

An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation

BACKGROUND

Patients with transient ischaemic attack (TIA) or minor stroke need rapid treatment of risk factors to prevent recurrent stroke. ABCD2 score or magnetic resonance diffusion-weighted brain imaging (MR DWI) may help assessment and treatment.

OBJECTIVES

Is MR with DWI cost-effective in stroke prevention compared with computed tomography (CT) brain scanning in all patients, in specific subgroups or as 'one-stop' brain-carotid imaging? What is the current UK availability of services for stroke prevention?

DATA SOURCES

Published literature; stroke registries, audit and randomised clinical trials; national databases; survey of UK clinical and imaging services for stroke; expert opinion.

REVIEW METHODS

Systematic reviews and meta-analyses of published/unpublished data. Decision-analytic model of stroke prevention including on a 20-year time horizon including nine representative imaging scenarios.

RESULTS

The pooled recurrent stroke rate after TIA (53 studies, 30,558 patients) is 5.2% [95% confidence interval (CI) 3.9% to 5.9%] by 7 days, and 6.7% (5.2% to 8.7%) at 90 days. ABCD2 score does not identify patients with key stroke causes or identify mimics: 66% of specialist-diagnosed true TIAs and 35-41% of mimics had an ABCD2 score of ≥ 4; 20% of true TIAs with ABCD2 score of < 4 had key risk factors. MR DWI (45 studies, 9078 patients) showed an acute ischaemic lesion in 34.3% (95% CI 30.5% to 38.4%) of TIA, 69% of minor stroke patients, i.e. two-thirds of TIA patients are DWI negative. TIA mimics (16 studies, 14,542 patients) make up 40-45% of patients attending clinics. UK survey (45% response) showed most secondary prevention started prior to clinic, 85% of primary brain imaging was same-day CT; 51-54% of patients had MR, mostly additional to CT, on average 1 week later; 55% omitted blood-sensitive MR sequences. Compared with 'CT scan all patients' MR was more expensive and no more cost-effective, except for patients presenting at > 1 week after symptoms to diagnose haemorrhage; strategies that triaged patients with low ABCD2 scores for slow investigation or treated DWI-negative patients as non-TIA/minor stroke prevented fewer strokes and increased costs. 'One-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.

LIMITATIONS

Data on sensitivity/specificity of MR in TIA/minor stroke, stroke costs, prognosis of TIA mimics and accuracy of ABCD2 score by non-specialists are sparse or absent; all analysis had substantial heterogeneity.

CONCLUSIONS

Magnetic resonance with DWI is not cost-effective for secondary stroke prevention. MR was most helpful in patients presenting at > 1 week after symptoms if blood-sensitive sequences were used. ABCD2 score is unlikely to facilitate patient triage by non-stroke specialists. Rapid specialist assessment, CT brain scanning and identification of serious underlying stroke causes is the most cost-effective stroke prevention strategy.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Prediction of recurrent stroke with ABCD2 and ABCD3 scores in patients with symptomatic 50-99% carotid stenosis

BACKGROUND

Although it is preferable that all patients with a recent Transient Ischemic Attack (TIA) undergo acute carotid imaging, there are centers with limited access to such acute examinations. It is controversial whether ABCD2 or ABCD3 scores can be used to triage patients to acute or delayed carotid imaging. It would be acceptable that some patients with a symptomatic carotid stenosis are detected with a slight delay as long as those who will suffer an early recurrent stroke are detected within 24 hours. The aim of this study is to analyze the ability of ABCD2 and ABCD3 scores to predict ipsilateral ischemic stroke among patients with symptomatic 50-99% carotid stenosis.

METHODS

In this secondary analysis of the ANSYSCAP-study, we included 230 consecutive patients with symptomatic 50-99% carotid stenosis. We analyzed the risk of recurrent ipsilateral ischemic stroke before carotid endarterectomy based on each parameter of the ABCD2 and ABCD3 scores separately, and for total ABCD2 and ABCD3 scores. We used Kaplan-Meier analysis.

RESULTS

None of the parameters in the ABCD2 or ABCD3 scores could alone predict all 12 of the ipsilateral ischemic strokes that occurred within 2 days of the presenting event, but clinical presentation tended to be a statistically significant risk factor for recurrent ipsilateral ischemic stroke (p = 0.06, log rank test). An ABCD2 score ≥2 and an ABCD3 score ≥4 could predict all 12 of these strokes as well as all 25 ipsilateral ischemic strokes that occurred within 14 days. To use ABCD3 score seems preferable over the ABCD2 score because a higher proportion of low risk patients were identified (17% of the patients had an ABCD3 score <4 while only 6% had an ABCD2 < 2).

CONCLUSIONS

Although it is preferable that carotid imaging be performed within 24 hours, our data support that an ABCD3 score ≥4 might be used for triaging patients to acute carotid imaging in clinical settings with limited access to carotid imaging. However, our findings should be validated in a larger cohort study.

TIA Triage in Emergency Department Using Acute MRI (TIA-TEAM): A Feasibility and Safety Study

Background

Positive diffusion weighted imaging (DWI) on MRI is associated with increased recurrent stroke risk in TIA patients. Acute MRI aids in TIA risk stratification and diagnosis.

Aim

To evaluate the feasibility and safety of TIA triage directly from the emergency department (ED) with acute MRI and neurological consultation.

Methods

Consecutive ED TIA patients assessed by a neurologist underwent acute MRI/MRA of head/neck per protocol and were hospitalized if positive DWI, symptomatic vessel stenosis, or per clinical judgment. Stroke neurologist adjudicated the final TIA diagnosis as definite, possible, or not a cerebrovascular event. Stroke recurrence rates were calculated at 7, 90, 365 days and compared with predicted stroke rates derived from historical DWI and ABCD2 score data.

Results

One hundred twenty-nine enrolled patients had a mean age of 69 years (±17) and median ABCD2 score of 3 (interquartile range [IQR] 3–4). During triage, 112 (87%) patients underwent acute MRI after a median of 16 h (IQR 10–23) from symptom onset. No patients experienced a recurrent event before imaging. Twenty-four (21%) had positive DWI and 8 (7%) had symptomatic vessel stenosis. Of the total cohort, 83 (64%) were discharged and 46 (36%) were hospitalized. By one-year follow-up, one patient in each group had experienced a stroke. Of 92 patients with MRI and index cerebrovascular event, recurrent stroke rates were 1·1% at 7 and 90 days. These were similar to predicted recurrence rates.

Conclusion

TIA triage in the ED using a protocol with neurological consultation and acute MRI is feasible and safe. The majority of patients were discharged without hospitalization and rates of recurrent stroke were not higher than predicted.

Population-based study of blood biomarkers in prediction of subacute recurrent stroke

BACKGROUND AND PURPOSE

Risk of recurrent stroke is high in the first few weeks after transient ischemic attack or stroke and clinical risk prediction tools have only limited accuracy, particularly after the hyperacute phase. Previous studies of the predictive value of biomarkers have been small, been done in selected populations, and have not concentrated on the acute phase or on intensively treated populations. We aimed to determine the predictive value of a panel of blood biomarkers in intensively treated patients early after transient ischemic attack and stroke.

METHODS

We studied 14 blood biomarkers related to inflammation, thrombosis, atherogenesis, and cardiac or neuronal cell damage in early transient ischemic attack or ischemic stroke in a population-based study (Oxford Vascular Study). Biomarker levels were related to 90-day risk of recurrent stroke as hazard ratio (95% confidence interval) per decile increase, adjusted for age and sex.

RESULTS

Among 1292 eligible patients, there were 53 recurrent ischemic strokes within 90 days. There were moderate correlations (r=0.40-0.61; P<0.0001) between the inflammatory biomarkers and between the cell damage and thrombotic subsets. Associations with risk of early recurrent stroke were weak, with significant associations limited to interleukin-6 (adjusted hazard ratio, 1.12; 1.01-1.24; P=0.033) and C-reactive protein (adjusted hazard ratio, 1.15; 1.02-1.30; P=0.022) after adjusting for age, sex, hypertension, smoking, and diabetes mellitus although P-selectin seemed to predict stroke after transient ischemic attack (adjusted hazard ratio, 1.28; 1.00-1.63; P=0.046).

CONCLUSIONS

In the largest study to date, we found limited predictive use for early recurrent stroke for a panel of inflammatory, thrombotic, and cell damage biomarkers.

[Prediction in cerebrovascular diseases]

Prediction of the outcome of cerebrovascular diseases or of the effects and complications of various forms of treatment are essential components of all stroke treatment regimens. This review focuses on the prediction of the stroke risk in primary prevention, the prediction of the risk of secondary stroke following a transient ischemic attack (TIA), the estimation of the outcome following manifest stroke and the treatment effects, the prediction of secondary cerebrovascular events and the prediction of vascular cognitive impairment following stroke. All predictive activities in cerebrovascular disease are hindered by the translation of predictive results from studies and patient populations to the individual patient. Future efforts in genetic analyses may be able to overcome this barrier and to enable individual prediction in the area of so-called personalized medicine. In all the various fields of prediction in cerebrovascular diseases, three major variables are always important: age of the patient, severity and subtype of the stroke. Increasing age, more severe stroke symptoms and the cardioembolic stroke subtype predict a poor outcome regarding both survival and permanent disability. This finding is somewhat banal and will therefore never replace the well experienced clinician judging the chances of a patient and taking into account the personal situation of this patient, e.g. for initiation of a rehabilitation program. Besides the individualized prediction, in times of restricted economic resources and increasing tendency to clarify questions of medical treatment in court, it seems unavoidable to use prediction in economic and medicolegal interaction with clinical medicine. This tendency will be accompanied by difficult ethical problems which neurologists must be aware of. Improved prediction should not be used to allocate or restrict resources or to restrict medically indicated treatment.

Alterations in the gray matter volume in transient ischemic attack: a voxel-based morphometry study

BACKGROUND

Several studies have emphasized that transient ischemic attack (TIA) patients suffered functional impairments, but whether underlying morphological alterations exist remains unclear. This study aims to detect possible gray matter volume (GMV) alterations in patients with TIA using voxel-based morphometry (VBM) method.

METHODS

High-resolution T1-weighted anatomical images of 21 patients were compared with 21 healthy controls of matching age, gender, and education. Changes in the GMV were observed using VBM technique, followed by two-sample t-test analysis to detect the differences in the GMV between TIA patients and healthy controls. Correlations between the clinical parameters and the Montreal cognitive assessment (MoCA) scores, and the altered GMV in TIAs, were investigated.

RESULTS

Two-sample t-test analysis revealed a significant GMV reduction in specific regions in the default mode network (DMN) in TIA patients, including the bilateral medial frontal gyrus, anterior cingulate cortex (ACC), and precuneus. No correlation was found between the reduced GMV and MoCA scores and clinical parameters.

CONCLUSION

Transient ischemic attack patients showed widespread morphology atrophy in DMN, suggesting that, despite the absence of a cerebral infarction, ischemic injury may induce structural abnormalities and eventually contribute to functional impairments in TIA patients. Our results may provide a valuable basis for the pathophysiological mechanism related to the cognitive dysfunction of TIA from the view of brain morphology.

Incorporating diffusion-weighted magnetic resonance imaging into an observation unit transient ischemic attack pathway: a prospective study

BACKGROUND AND PURPOSE

National guidelines advocate for early, aggressive transient ischemic attack (TIA) evaluations and recommend diffusion-weighted magnetic resonance imaging (MRI) for brain imaging. The purpose of this study is to examine clinician compliance, the yield of MRI, and patient-centered clinical outcomes following implementation of an emergency department observation unit (EDOU) clinical pathway incorporating routine MRI into the acute evaluation of patients with TIA.

METHODS

This is a prospective observational study of patients with TIA admitted from the ED. Patients with low-risk TIA were transferred to an EDOU for diagnostic testing including MRI; high-risk patients were directed to hospital admission. Clinical variables, diagnostic tests, and treatment were recorded for all patients. The primary clinical outcome was the rate of stroke or recurrent TIA, determined through telephone follow-up and medical record review at 7 and 30 days.

RESULTS

A total of 116 patients with TIA were enrolled. In all, 92 (79.3%) patients were transferred to the EDOU, of whom 69 (59.5%) were discharged without hospitalization. Compliance with the EDOU pathway was 83 (91.2%) of 92. Magnetic resonance imaging demonstrated acute infarct in 16 (15.7%) of 102 patients. Stroke (n = 2) or TIA (n = 3) occurred in 5 patients with TIA (4.3%, 95% confidence interval: 1.6%-10.0%) within 30 days; no strokes occurred after discharge.

CONCLUSIONS

Implementation of a TIA clinical pathway incorporating MRI effectively encouraged guideline-compliant diagnostic testing; however, patient-important outcomes appear similar to diagnostic protocols without routine MRI. Further study is needed to assess the benefits and costs associated with routinely incorporating MRI into TIA evaluation.

Predicting outcomes after transient ischemic attack and stroke

PURPOSE OF REVIEW

Predicting functional outcome and mortality after stroke, with or without thrombolysis, is a critical role of neurologists. This article reviews the predictors of outcome after ischemic stroke.

RECENT FINDINGS

Several scores were recently designed to predict (1) mortality and poor functional outcome after ischemic stroke, (2) the functional outcome and risk of symptomatic intracranial hemorrhage (sICH) after thrombolysis, and (3) the risk of stroke following TIA. Validation of these prediction instruments is ongoing, and studies will be critical to determine the general applicability of these scores.

SUMMARY

Although several scores were developed to predict mortality and outcome after stroke, it may be premature to employ these prediction scores to determine individual patient outcome. Similarly, prediction scores should not be used to deny patients tissue plasminogen activator (tPA), even if the scores predict that the patient has a high likelihood of sICH or poor outcome after thrombolysis.

Transient ischemic attacks: predictability of future ischemic stroke or transient ischemic attack events

The short-term risk of an ischemic stroke after a transient ischemic attack (TIA) is estimated to be approximately 3%–10% at 2 days, 5% at 7 days, and 9%–17% at 90 days, depending on active or passive ascertainment of ischemic stroke. Various risk prediction scores are available to identify high-risk patients. We present here a pragmatic review of the literature discussing the main scoring systems. We also provide the sensitivity, specificity, positive predictive value, and negative predictive value for each scoring system. Our review shows that scoring systems including brain imaging and vascular imaging are better at risk prediction than scores that do not include this information.

Predicting the need for hospital admission of TIA patients

BACKGROUND

It is unknown which patient will benefit most from hospital admission after transient ischemic attack (TIA). Our aim was to define predictors of a positive hospital outcome.

METHODS

We used two cohorts of TIA patients: the University of Texas at Houston Stroke Center (UTH); and Tel-Aviv Sourasky Medical Center in Israel (TASMC) for external validation. We retrospectively reviewed medical records and imaging data. We defined positive yield (PY) of the hospital admission as identification of stroke etiologies that profoundly changes clinical management.

RESULTS

The UTH cohort included 178 patients. 24.7% had PY. In the multivariate analysis, the following were associated with PY: coronary disease (CAD); age; and acute infarct on DWI. We then derived a composite score termed the PY score to predict PY. One point is scored for: age>60, CAD, and acute infarct on DWI. The proportion of PY by PY score was as follows: 0-6%; 1-22%; 2-47%; 3-67% (p<0.001). In the validation cohort PY score was highly predictive of PY and performed in a very similar manner.

CONCLUSIONS

Our data suggest, the PY score may enable physicians to make better admission decisions and result in better, safer and more economical care for TIA patients.

Diagnostic and prognostic value of multimodal MRI in transient ischemic attack

BACKGROUND

The clinical diagnosis of transient ischemic attack is highly subjective, and the risk prediction after transient ischemic attack using the clinical parameters still remains unsatisfactory.

AIMS

We aimed to investigate the diagnostic and prognostic value of multimodal magnetic resonance imaging in transient ischemic attack patients.

METHODS

We prospectively performed diffusion-weighted imaging, perfusion-weighted imaging, and intracranial and extracranial magnetic resonance angiogram within 72 h of symptom onset in 162 transient ischemic attack patients defined by the classical time-based definition. Follow-up diffusion-weighted imaging was obtained three-days later in patients who did not exhibit lesions on the initial diffusion-weighted imaging. The occurrence of clinical events (transient ischemic attack or stroke) three-months after the initial transient ischemic attack was recorded, and the ABCD2 and ABCD3-I scores were calculated. The clinical and imaging parameters were compared between patients with and without initial diffusion-weighted imaging lesion, clinical events, and follow-up diffusion-weighted imaging lesions.

RESULTS

Abnormalities were present on diffusion-weighted imaging, perfusion-weighted imaging, and magnetic resonance angiogram in 38·9%, 44·1%, and 51·9% of patients, respectively. Diffusion-weighted imaging plus perfusion-weighted imaging explained 64·8%, and the addition of magnetic resonance angiogram explained 74% of the transient ischemic attack symptoms. The initial diffusion-weighted imaging positivity was associated with longer time from symptom onset to magnetic resonance imaging examination (odds ratio, 1·039; 95% confidence interval, 1·008-1·071; P=0·013). On follow-up diffusion-weighted imaging, new lesions were found in 46·7% of the patients who initially showed normal diffusion-weighted imaging findings. Initial perfusion-weighted imaging abnormality predicted the appearance of follow-up diffusion-weighted imaging lesion (chi-square=7·774, P=0·005). During the three-months follow-up, 23 patients (14·2%) experienced subsequent transient ischemic attack (n=16) or stroke (n=7). Symptomatic magnetic resonance angiogram abnormality (odds ratio, 12·667; 95% confidence interval, 2·859-56·110; P=0·001) was the only independent factor associated with clinical events with a sensitivity of 91·3% and specificity of 54·7% (C statistics, 0·73). None with initially normal multimodal magnetic resonance imaging findings developed subsequent clinical events.

CONCLUSIONS

Approximately three-quarter of transient ischemic attack is associated with multimodal magnetic resonance imaging abnormality. Initial perfusion-weighted imaging abnormality predicts newly developed diffusion-weighted imaging lesions, and symptomatic magnetic resonance angiogram abnormality seems to be the most important predictor for subsequent clinical events. Multimodal magnetic resonance imaging appears to be useful in assessing transient ischemic attack and predicting outcome in these patients.

Correlation of ABCD2 score with degree of internal carotid artery stenosis: an observational pilot study

BACKGROUND

ABCD(2) is a validated scoring system that predicts the risk of stroke after a transient ischemic attack (TIA). International guidelines suggest that patients with a low score can be investigated on an outpatient basis. The ABCD2 score, however, cannot identify which patients have significant internal carotid artery (ICA) disease, and this group of patients could benefit from rapid access carotid endarterectomy (RACE). Studies have shown that patients with significant carotid artery disease have a higher risk of neurologic events or recurrent stroke. The aim of this study was to document the range of ABCD2 scores in patients with carotid artery-related TIA, and investigate any correlation between the ABCD2 scores and ICA stenosis.

METHODS

Patients undergoing carotid duplex ultrasound scan for TIA from January 2009 to May 2010 from two vascular units were identified from the vascular database retrospectively. Clinical notes were reviewed and outcomes measures were recorded: ABCD2 scores (age, blood pressure, clinical features, diabetes, and duration) and carotid plaque morphology.

RESULTS

Ninety-seven patients with a mean age of 74 (range 56-90) years had ICA stenoses of ≥50% up to 100%. Fifty-seven patients had an ABCD2 score of ≤4. There was no significant correlation between ABCD2 scores and degree of ICA stenosis nor carotid plaque morphology (P=0.2, r=1.0, and P=1.0, r=0.0007, respectively).

CONCLUSIONS

Because no correlation between ABCD2 scores and the degree of ICA stenosis was found, all patients with carotid territory TIA should undergo urgent imaging of the carotid arteries because a high proportion of these patients may benefit from RACE.

Acute brain infarction detected by CCT and stroke risk in patients with transient ischemic attack lasting <1 hour

BACKGROUND AND PURPOSE

This study aimed to determine the frequency and associated factors of acute brain infarction (ABI) detected by noncontrast cranial computed tomography (CCT) in patients with transient ischemic attack (TIA) of symptom duration <1 h and to investigate the association between evidence of ABI and short-term risk of stroke.

METHODS

During a 54-month period (starting November 2007), consecutive patients with TIA (symptom duration <1 h) admitted and imaged with CCT were prospectively evaluated. Adjusted logistic regression was used to estimate odds ratios (ORs).

RESULTS

Of 1021 patients (mean age, 74.5 ± 11 years; 52% female) with TIA (symptom duration <1 h) imaged with CCT at admission, 68 patients (6.7%; 95% CI, 5.3-8.3%) exhibited TIA-related ABI. Adjusted logistic regression showed that ABI was independently correlated with atrial fibrillation (AF) (OR, 3.3; 95% CI, 1.4-7.9; p = 0.006) and time between onset and CT assessment >6 h (OR, 2.5; 95% CI, 1.1-6.1; p = 0.034). During hospitalization (5 ± 3 d), 22 patients (2.2%; 95% CI, 1.4-3.1%) developed a stroke. Patients with ABI had higher stroke rates than those without (10.3% and 1.6%, respectively; p < 0.001). Adjusted logistic regression revealed that stroke risk was independently correlated with ABI (OR, 5.3; 95% CI, 1.8-15.0; p = 0.002) and AF (OR, 2.6; 95% CI, 1.1-6.4; p = 0.026).

CONCLUSIONS

Detection of ABI by CCT in TIA patients with symptom duration <1 h may depend on timing of CCT assessment and presence of AF. Evidence of ABI indicates an elevated stroke risk during hospitalization.

Magnetic Resonance Imaging versus Computed Tomography in Transient Ischemic Attack and Minor Stroke: The More Υou See the More You Know

Background

Magnetic resonance imaging (MRI) is proposed as the preferred imaging modality to investigate patients with transient ischemic attack (TIA). This is mainly based on a higher yield of small acute ischemic lesions; however, direct prospective comparisons are lacking. In this study, we aimed to directly compare the yield of acute ischemic lesions on MRI and computed tomography (CT) in the emergency diagnosis of suspected TIA or minor stroke.

Methods

Consecutive patients aged 18 years or older presenting with minor stroke (NIHSS <4) or high-risk TIA and who were examined by a stroke neurologist within 24 h of symptom onset were prospectively enrolled in the CATCH study. Patients who had undergone both a baseline CT and an MRI within 24 h of symptom onset were included in this substudy. Baseline MRI and CT were interpreted independently to identify an acute ischemic lesion. The rates of acute ischemic lesions on CT and MRI were compared, and the volume of acute ischemic lesions was measured on MRI. In addition, the volume of acute ischemic lesions on MRI was compared between patients who had evidence of acute ischemia on CT and in those who did not.

Results

A total of 347 patients were included, 168 with TIAs, 147 with minor strokes and 32 with a final diagnosis of a mimic. Acute ischemic lesions were detected in 39% of TIAs by using MRI versus 8% by using CT (p < 0.0001) and in 86% of minor strokes by using MRI versus 18% by using CT (p < 0.0001). Compared to MRI, CT had a sensitivity of 20% and a specificity of 98% in identifying an acute ischemic lesion. The infarct volume on diffusion-weighted MRI was larger in cases where the CT also showed an acute ischemic lesion (median 5.07 ml, IQR 10) as compared to lesions seen only on MRI (median 0.68 ml, IQR 1.31, p < 0.0001).

Conclusion

MRI is superior to CT in detecting the small ischemic lesions occurring after TIA and minor stroke. Since these lesions are clinically relevant, MRI should be the preferred imaging modality in this setting.

The Addition of MRI to CT Based Stroke and TIA Evaluation Does Not Impact One year Outcomes

Background:

The 2010 American Academy of Neurology guideline for the diagnosis of acute ischemic stroke recommends MRI with diffusion weighted imaging (DWI) over noncontrast head CT. No studies have evaluated the influence of imaging choice on patient outcome. We sought to evaluate the variables that influenced one-year outcomes of stroke and TIA patients, including the type of imaging utilized.

Methods:

Patients were identified from a prospectively collected stroke and TIA database at a single primary stroke center during a one-year period. Data were abstracted from patient electronic medical records. The primary outcome measure was death, myocardial infarction, or recurrent stroke within the following year. Secondary outcome measures included predictors of getting an MRI study.

Results:

727 consecutive patients with a discharge diagnosis of stroke or TIA were identified (616 and 111 respectively); 536 had CT and MRI, 161 had CT alone, 29 had MRI alone, and one had no neuroimaging. On multiple logistic regression analysis, there were no differences in primary or secondary outcome measures among different imaging strategies. Predictors of the primary outcome measure included age and NIHSS, while performance of a CT angiogram (CTA) predicted a decreased odds of death, stroke, or MI. The strongest predictor of having an MRI was admission to a stroke unit.

Conclusions:

These results suggest that long-term (one-year) patient outcomes may not be influenced by imaging strategy. Performance of a CTA was protective in this cohort. A randomized trial of different imaging modalities should be considered.

Frequent inaccuracies in ABCD2 scoring in non-stroke specialists' referrals to a daily Rapid Access Stroke Prevention service

The 'accuracy' of age, blood pressure, clinical features, duration and diabetes (ABCD(2)) scoring by non-stroke specialists referring patients to a daily Rapid Access Stroke Prevention (RASP) service is unclear, as is the accuracy of ABCD(2) scoring by trainee residents. In this prospective study, referrals were classified as 'confirmed TIAs' if the stroke specialist confirmed a clinical diagnosis of possible, probable or definite TIA, and 'non-TIAs' if patients had a TIA mimic or completed stroke. ABCD(2) scores from referring physicians were compared with scores by experienced stroke specialists and neurology/geriatric medicine residents at a daily RASP clinic; inter-observer agreement was examined. Data from 101 referrals were analysed (mean age=60.0years, 58% male). The median interval between referral and clinic assessment was 1day. Of 101 referrals, 52 (52%) were 'non-TIAs': 45 (86%) of 52 were 'TIA mimics' and 7 (14%) of 52 were completed strokes. There was only 'fair' agreement in total ABCD(2) scoring between referring physicians and stroke specialists (κ=0.37). Agreement was 'excellent' between residents and stroke specialists (κ=0.91). Twenty of 29 patients scored as 'moderate to high risk' (score 4-6) by stroke specialists were scored 'low risk' (score 0-3) by referring physicians. ABCD(2) scoring by referring doctors is frequently inaccurate, with a tendency to underestimate stroke risk. These findings emphasise the importance of urgent specialist assessment of suspected TIA patients, and that ABCD(2) scores by non-stroke specialists cannot be relied upon in isolation to risk-stratify patients. Inter-observer agreement in ABCD(2) scoring was 'excellent' between residents and stroke specialists, indicating short-term training may improve accuracy.

Can lower risk patients presenting with transient ischaemic attack be safely managed as outpatients?

This study aimed to examine outcome in low risk transient ischaemic attack (TIA) patients presenting to emergency departments (ED) in a regional Australian setting discharged on antiplatelet therapy with expedited neurology review. All patients presenting to Gosford or Wyong Hospital ED with TIA, for whom faxed referrals to the neurology department were received between October 2008 and July 2010, were included in this prospective cohort study. Classification of low risk was based on an age, blood pressure, clinical features, duration of symptoms and diabetes (ABCD2) score <4 and the absence of high risk features, including known carotid disease, crescendo TIA, or atrial fibrillation. Patients with ABCD2 scores > or =4 or with high risk features were discussed with the neurologist on call (a decision regarding discharge or admission was then made at the neurologist's discretion). Patients were investigated with a brain CT scan and/or CT angiography, routine pathology, and an electrocardiogram. All discharged patients were commenced on antiplatelet therapy and asked to follow up with their local medical officer within 7 days. The patients were contacted by the neurology department to arrange follow-up. Our primary outcome was the number of subsequent strokes occurring within 90 days. Of 200 discharged patients for whom referrals were received, three patients had a stroke within 90 days. None of these would have been prevented through hospitalisation. In conclusion, medical assessment, expedited investigation with immediate commencement of secondary prevention and outpatient neurology review may be a reasonable alternative to admission for low risk patients presenting to the ED with TIA.

Nonfocal symptoms are more frequent in patients with vertebral artery than carotid artery stenosis

INTRODUCTION

In patients with a transient ischemic attack (TIA) or ischemic stroke, the combination of focal and nonfocal symptoms has been associated with a higher risk of cardiovascular events. We hypothesized that nonfocal symptoms are more frequent in patients with symptomatic stenosis of a vertebral artery (VA) than of a carotid artery (CA). Therefore, we assessed the prevalence of nonfocal symptoms in patients with a recent TIA or nondisabling ischemic stroke and studied their relation with symptomatic CA or VA stenosis.

METHODS

We administered a standardized questionnaire on the occurrence of focal and nonfocal symptoms during the qualifying TIA or nondisabling ischemic stroke and in the preceding 6 months. We included 50 consecutive patients with a recently symptomatic CA stenosis ≥50%, 50 consecutive patients with a recently symptomatic VA stenosis ≥50%, 25 consecutive patients with an anterior circulation event without an ipsilateral CA stenosis ≥50%, and 25 consecutive patients with a posterior circulation event without a relevant VA stenosis ≥50%. Relative risks for the presence of nonfocal symptoms in relation to the presence of a symptomatic stenosis were calculated with univariate and multivariate Poisson regression. Adjustments were made for age, sex, stroke as the qualifying event, and cardiovascular risk factors. A subgroup analysis was performed for patients in whom the vascular territory of the event was confirmed on imaging.

RESULTS

During the qualifying ischemic event, focal symptoms were accompanied by nonfocal symptoms in 80 (53%) patients. Nonfocal symptoms occurred more frequently in patients with a VA stenosis (72%) than in patients with a CA stenosis [26%; adjusted relative risk (aRR), 2.9; 95% confidence interval (CI), 1.8-4.6]. A higher prevalence of nonfocal symptoms was found in patients with posterior circulation TIAs and strokes (73%) than in patients with anterior circulation TIAs and strokes (33%; aRR, 2.2; 95% CI, 1.6-3.1). During the preceding 6 months, 45% of patients with and 20% of patients without a symptomatic stenosis had had nonfocal symptoms (aRR, 2.4; 95% CI, 1.3-4.3). Subgroup analysis for the 89 (59%) patients with ischemia visible on imaging gave essentially the same results.

CONCLUSIONS

More than half of the TIAs or nondisabling ischemic strokes were associated with nonfocal neurological symptoms. Nonfocal symptoms occurred more frequently in patients with a symptomatic VA stenosis than CA stenosis.

Predictive value of brain and vascular imaging including intracranial vessels in transient ischaemic attack patients: external validation of the ABCD3-I score

BACKGROUND AND PURPOSE

Recently, brain and vascular imaging have been added to clinical variables to identify patients with transient ischaemic attack (TIA) with a high risk of stroke recurrence. The aim of our study was to externally validate the ABCD3-I score and the same score taking into account intracranial circulation.

METHODS

We analyzed data from 1137 patients with TIA from the PROMAPA study who underwent diffusion-weighted magnetic resonance imaging (DWI) within 7 days of symptom onset. Clinical variables and diagnostic work-up were recorded prospectively. The end-points were subsequent stroke at 7 and 90 days follow-up.

RESULTS

A total of 463 (40.7%) subjects fulfilled all inclusion criteria. During follow-up, eight patients (1.7%) had a stroke within 7 days, and 14 (3.1%) had a stroke within 3 months. In the Cox proportional hazard multivariate analyses, the combination of large-artery atherosclerosis and positive DWI remained as independent predictors of stroke recurrence at 7- and 90-day follow-up [HR 8.23, 95% confidence interval (CI) 2.89-23.46, P < 0.001]. The ABCD3-I score was a powerful predictor of subsequent stroke. The area under the receiver operating characteristic curve was 0.83 (95% CI 0.72-0.93) at 7 days and 0.69 (95% CI 0.53-0.85) at 90 days. When we include intracranial vessel disease in the score, the area under the curve increases but the difference observed was non-significant.

CONCLUSION

The inclusion of vascular and neuroimaging information to clinical scales (ABCD3-I score) provides important prognostic information and also helps management decisions, although it cannot give a complete distinction between high-risk and low-risk groups.

Evolution of Reperfusion Therapies for Acute Brain and Acute Myocardial Ischemia

Background and Purpose—

Early reperfusion is the most effective therapy for both acute brain and cardiac ischemia. However, the cervicocephalic circulatory bed offers more challenges to recanalization interventions. The historical development of reperfusion interventions has not previously been systematically compared.

Methods—

Medline search identified all multi-arm, controlled trials of coronary revascularization for acute myocardial infarction and multicenter trials of cerebral revascularization for acute ischemic stroke reporting angiographic reperfusion rates.

Results—

Thirty-seven trials of coronary reperfusion enrolled 10 908 patients from 1983 to 2009, and 10 trials of cerebral reperfusion enrolled 1064 patients from 1992 to 2009. Coronary reperfusion trials included 10 of intravenous fibrinolysis alone, 8 combined intravenous fibrinolysis and percutaneous transluminal coronary angioplasty with or without stenting, 3 intra-arterial fibrinolysis, and 16 percutaneous transluminal coronary angioplasty with or without stenting. Cerebral reperfusion trials included 1 of intravenous fibrinolysis alone, 3 intra-arterial fibrinolysis, 3 endovascular device alone, and 3 of endovascular treatment ± intravenous fibrinolysis. In both circulatory beds, endovascular treatments were more efficacious at achieving reperfusion than peripherally administered fibrinolytics. In the coronary bed, rates of achieved reperfusion began at high levels in the 1980s and improved modestly over the subsequent 3 decades. In the cerebral bed, reperfusion rates began at modest levels in the early 1990s and increased more slowly. Most recently, in 2005 to 2009, cardiac reperfusion rates substantially exceeded cerebral, partial reperfusion 86.1% versus 61.1%, complete reperfusion 78.6% versus 23.4%.

Conclusions—

Reperfusion therapies developed more slowly and remain less effective for cerebral than cardiac ischemia. Further, cerebral circulation–specific technical advances are required for physicians to become as capable at safely restoring blood flow to the ischemic brain as the ischemic heart.

Intracranial artery stenosis or occlusion predicts ischemic recurrence after transient ischemic attack

BACKGROUND AND PURPOSE

Patterns of DWI findings that predict recurrent ischemic events after TIA are well-established, but similar assessments of intracranial MRA findings are not available. We sought to determine the imaging characteristics of MRA that are predictive of early recurrent stroke/TIA in patients with TIA.

MATERIALS AND METHODS

We performed a retrospective analysis of 129 consecutive patients with a clinical diagnosis of TIA in whom MR imaging was done within 24 hours of symptom onset. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of >50% stenosis or occlusion of symptomatic intracranial arteries for recurrent stroke/TIA at 7 days after TIA. We used logistic regression analysis to adjust for the clinical ABCD(2) score. We performed this analysis for symptomatic steno-occlusive lesions at any site and symptomatic steno-occlusive lesions on proximal large intracranial arteries (internal carotid artery, vertebral artery, basilar artery, and circle of Willis).

RESULTS

Forty-two (32.5%) patients had acute ischemic lesions on DWI; 16 (12.4%) had significant MRA lesions, of which 11 (8.5%) were on proximal vessels. Nine patients had early recurrence (TIA, 7; minor stroke, 2). Only patients with proximal MRA lesions were at higher risk of early recurrence independent of the ABCD(2) score (adjusted odds ratio, 5.5; 95% confidence interval, 1.1-27.8; P = .04).

CONCLUSIONS

Proximal lesions of cerebral arteries seen on MRA were predictive of recurrent stroke/TIA at 7 days. These findings suggest that MRA could be used to improve the selection of patients with TIA at high risk of early recurrent stroke/TIA.

The role of MRI as a prognostic tool in ischemic stroke

Magnetic resonance imaging (MRI) is an invaluable tool used in the diagnosis of ischemic stroke. Ongoing technological advances in MRI technology and advent of new imaging sequences has now made it possible to use MRI as a prognostic tool both in the acute and chronic stages of cerebral ischemia. This review summarizes the role of MRI in estimating final tissue outcome, specifically by providing information on severity and location of ischemic insult, cerebral blood flow dynamics, vascular status, and cerebral reserve. All of these predictions can then be used to make projections regarding clinical outcome, and can be refined by other prognostic models to estimate recovery and risk of further ischemic events. These algorithms, in the end, can ultimately help the clinician in tailoring therapies on an individual basis and optimize the risk-benefit ratio of therapeutic approaches used in the acute and chronic stages of ischemic stroke. The implementation of such prognostic algorithms to clinical imaging workstations and calculation of all the possible projections within minutes after completion of imaging are likely to become an integral part of clinical practice in the near future.

Yield of CT perfusion for the evaluation of transient ischaemic attack

BACKGROUND

Magnetic resonance diffusion-weighted imaging and perfusion-weighted imaging are able to identify ischaemic 'footprints' in transient ischaemic attack. Computed tomography perfusion (CTP) may be useful for patient triage and subsequent management. To date, less than 100 cases have been reported, and none have compared computed tomography perfusion to perfusion-weighted imaging (PWI). We sought to define the yield of computed tomography perfusion for the evaluation of transient ischaemic attack.

METHODS

Consecutive patients with a discharge diagnosis of possible or definite transient ischaemic event who underwent computed tomography perfusion were included in this study. The presence of an ischaemic lesion was assessed on noncontrast computed tomography, automatically deconvolved CTPTMax (Time till the residue function reaches its maximum), and when available on diffusion-weighted imaging and PWITMax maps.

RESULTS

Thirty-four patients were included and 17 underwent magnetic resonance imaging. Median delay between onset and computed tomography perfusion was 4·4 h (Interquartile range [IQR]: 1·9-9·6), and between computed tomography perfusion and magnetic resonance imaging was 11 h (Interquartile range: 3·8-22). Noncontrast computed tomography was negative in all cases, while CTPTMax identified an ischaemic lesion in 12/34 patients (35%). In the subgroup of patients with multimodal magnetic resonance imaging, an ischaemic lesion was found in six (35%) patients using CTPTMax versus nine (53%) on magnetic resonance imaging (five diffusion-weighted imaging, nine perfusion-weighted imaging). The additional yield of CTPTMax over computed tomography angiography was significant in the evaluation of transient ischaemic attack (12 vs. 3, McNemar, P = 0·004).

CONCLUSIONS

CTPTMax found an ischaemic lesion in one-third of acute transient ischaemic attack patients. Computed tomography perfusion may be an acceptable substitute when magnetic resonance imaging is unavailable or contraindicated, and has additional yield over computed tomography angiography. Further studies evaluating the outcome of patients with computed tomography perfusion lesions in transient ischaemic attack are justified at this time.

Arterial spin labeling imaging findings in transient ischemic attack patients: comparison with diffusion- and bolus perfusion-weighted imaging

BACKGROUND

Since transient ischemic attacks (TIAs) can predict future stroke, it is important to distinguish true vascular events from non-vascular etiologies. Arterial spin labeling (ASL) is a non-contrast magnetic resonance (MR) method that is sensitive to cerebral perfusion and arterial arrival delays. Due to its high sensitivity to minor perfusion alterations, we hypothesized that ASL abnormalities would be identified frequently in TIA patients, and could therefore help increase clinicians' confidence in the diagnosis.

METHODS

We acquired diffusion-weighted imaging (DWI), intracranial MR angiography (MRA), and ASL in a prospective cohort of TIA patients. A subset of these patients also received bolus contrast perfusion-weighted imaging (PWI). Two neuroradiologists evaluated the images in a blinded fashion to determine the frequency of abnormalities on each imaging sequence. Kappa (ĸ) statistics were used to assess agreement, and the χ(2) test was used to detect differences in the proportions of abnormal studies.

RESULTS

76 patients met the inclusion criteria, 48 (63%) of whom received PWI. ASL was abnormal in 62%, a much higher frequency compared with DWI (24%) and intracranial MRA (13%). ASL significantly increased the MR imaging yield above the combined DWI and MRA yield (62 vs. 32%, p < 0.05). Arterial transit artifact in vascular borderzones was the most common ASL abnormality (present in 51%); other abnormalities included focal high or low ASL signal (11%). PWI was abnormal in 31% of patients, and in these, ASL was abnormal in 14 out of 15 cases (93%). In hemispheric TIA patients, both PWI and ASL findings were more common in the symptomatic hemisphere. Agreement between neuroradiologists regarding abnormal studies was good for ASL and PWI [ĸ = 0.69 (95% CI 0.53-0.86) and ĸ = 0.66 (95% CI 0.43-0.89), respectively].

CONCLUSION

In TIA patients, perfusion-related alterations on ASL were more frequently detected compared with PWI or intracranial MRA and were most frequently associated with the symptomatic hemisphere. Almost all cases with a PWI lesion also had an ASL lesion. These results suggest that ASL may aid in the workup and triage of TIA patients, particularly those who cannot undergo a contrast study.

The incidence and clinical predictors of acute infarction in patients with transient ischemic attack using MRI including DWI

INTRODUCTION

According to the most recent definition of transient ischemic attack (TIA) and the recommendations of the American Heart Association, magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) is considered a mandatory tool in evaluating and treating patients with TIA. This study aims to determine the incidence of TIA-related acute infarction, identify the independent predictors of acute infarction, and investigate the correlation between acute infarction detected by DWI-MRI and stroke risk during hospitalization.

METHODS

Over a 36-month period (starting November 2007), all TIA patients (symptom duration of <24 h) who were admitted to hospital within 48 h of symptom onset and who underwent DWI-MRI were included in this population-based prospective study. The incidence of acute infarction, clinical predictors, and association with stroke recurrence during hospitalization were studied.

RESULTS

Of 1,910 patients (mean age, 66.7 ± 13 years; 46 % women), 1,862 met the inclusion criteria. A TIA-related acute infarction was detected in 206 patients (11.1 %). Several independent predictors were identified with logistic regression analysis: motor weakness [odds ratio (OR), 1.5], aphasia (OR, 1.6), National Institutes of Health Stroke Scale (NIHSS) score of ≥10 at admission (OR, 3.2), and hyperlipidemia (OR, 0.6). Of 24 patients (1.3 %) who suffered a stroke during hospitalization (mean, 6 ± 4 days), five had positive DWI. Stroke rate during hospitalization was nonsignificantly higher in patients with positive DWI than those with negative DWI (2.4 vs 1.1 %, respectively; P = 0.12).

CONCLUSION

The evidence of acute infarction by DWI-MRI in TIA patients was detected in 11.1 % of patients and associated with motor weakness, aphasia, and NIHSS score of ≥10 at admission.

Hypoplastic internal carotid artery stenosis with a low-lying carotid bifurcation causing cerebral ischemia

Congenital abnormalities of the internal carotid artery (ICA) are infrequent and can be associated with aberrations of the Circle of Willis. A 47-year-old gentleman presented with transient neurological symptoms and cerebral infarction and carotid Doppler showed a stenotic right ICA. Subsequent computed tomographic angiography showed a hypoplastic ICA with a low-lying bifurcation at the C6 level and aplasia of the anterior communicating artery. This patient was commenced on aggressive medical therapy and at 7-month follow-up was symptom-free. This case report highlights the need for a centralized registry with long-term follow-up data in order to identify optimal management.