Screening tests for aphasia in patients with stroke: a systematic review

Diagnosis of aphasia in stroke populations: A systematic review of language tests

Background and purpose

Accurate aphasia diagnosis is important in stroke care. A wide range of language tests are available and include informal assessments, tests developed by healthcare institutions and commercially published tests available for purchase in pre-packaged kits. The psychometrics of these tests are often reported online or within the purchased test manuals, not the peer-reviewed literature, therefore the diagnostic capabilities of these measures have not been systematically evaluated. This review aimed to identify both commercial and non-commercial language tests and tests used in stroke care and to examine the diagnostic capabilities of all identified measures in diagnosing aphasia in stroke populations.

Methods

Language tests were identified through a systematic search of 161 publisher databases, professional and resource websites and language tests reported to be used in stroke care. Two independent reviewers evaluated test manuals or associated resources for cohort or cross-sectional studies reporting the tests’ diagnostic capabilities (sensitivity, specificity, likelihood ratios or diagnostic odds ratios) in differentiating aphasic and non-aphasic stroke populations.

Results

Fifty-six tests met the study eligibility criteria. Six “non-specialist” brief screening tests reported sensitivity and specificity information, however none of these measures reported to meet the specific diagnostic needs of speech pathologists. The 50 remaining measures either did not report validity data (n = 7); did not compare patient test performance with a comparison group (n = 17); included non-stroke participants within their samples (n = 23) or did not compare stroke patient performance against a language reference standard (n = 3). Diagnostic sensitivity analysis was completed for six speech pathology measures (WAB, PICA, CADL-2, ASHA-FACS, Adult FAVRES and EFA-4), however all studies compared aphasic performance with that of non-stroke healthy controls and were consequently excluded from the review.

Conclusions

No speech pathology test was found which reported diagnostic data for identifying aphasia in stroke populations. A diagnostically validated post-stroke aphasia test is needed.

A quick aphasia battery for efficient, reliable, and multidimensional assessment of language function

This paper describes a quick aphasia battery (QAB) that aims to provide a reliable and multidimensional assessment of language function in about a quarter of an hour, bridging the gap between comprehensive batteries that are time-consuming to administer, and rapid screening instruments that provide limited detail regarding individual profiles of deficits. The QAB is made up of eight subtests, each comprising sets of items that probe different language domains, vary in difficulty, and are scored with a graded system to maximize the informativeness of each item. From the eight subtests, eight summary measures are derived, which constitute a multidimensional profile of language function, quantifying strengths and weaknesses across core language domains. The QAB was administered to 28 individuals with acute stroke and aphasia, 25 individuals with acute stroke but no aphasia, 16 individuals with chronic post-stroke aphasia, and 14 healthy controls. The patients with chronic post-stroke aphasia were tested 3 times each and scored independently by 2 raters to establish test-retest and inter-rater reliability. The Western Aphasia Battery (WAB) was also administered to these patients to assess concurrent validity. We found that all QAB summary measures were sensitive to aphasic deficits in the two groups with aphasia. All measures showed good or excellent test-retest reliability (overall summary measure: intraclass correlation coefficient (ICC) = 0.98), and excellent inter-rater reliability (overall summary measure: ICC = 0.99). Sensitivity and specificity for diagnosis of aphasia (relative to clinical impression) were 0.91 and 0.95 respectively. All QAB measures were highly correlated with corresponding WAB measures where available. Individual patients showed distinct profiles of spared and impaired function across different language domains. In sum, the QAB efficiently and reliably characterized individual profiles of language deficits.

The Role of the BDNF Val66Met Polymorphism in Recovery of Aphasia After Stroke

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is assumed to play a role in mediating neuroplasticity after stroke. Carriers of the function-limiting Val66Met (rs6265) single nucleotide polymorphism (SNP) may have a downregulation in BDNF secretion, which may lead to a poorer prognosis after stroke compared to noncarriers in motor learning and motor function recovery. The present study investigates whether this polymorphism may also affect the recovery of poststroke aphasia (ie, language impairment).

OBJECTIVE

To study the influence of the BDNF Val66Met polymorphism on the recovery of poststroke aphasia.

METHODS

We included 53 patients with poststroke aphasia, all participating in an inpatient rehabilitation program with speech and language therapy. All patients were genotyped for the Val66Met SNP and subdivided into carriers (at least one Met allele) and noncarriers (no Met allele). Primary outcome measures included the improvement over rehabilitation time on the Amsterdam-Nijmegen Everyday Language Test (ANELT) and the Boston Naming Test (BNT).

RESULTS

The outcome measures showed a large variability in the improvement scores on both the ANELT and BNT. There was no significant difference between noncarriers and carriers in the primary outcome measures.

CONCLUSION

This study investigated the effect of the BDNF Val66Met polymorphism on clinical recovery of poststroke aphasia. In contrast to earlier studies describing a reducing effect of this polymorphism on motor function recovery after stroke, the present study does not support a reduction in language recovery for carriers compared to noncarriers with poststroke aphasia.

MRI-Based Neuroanatomical Predictors of Dysphagia, Dysarthria, and Aphasia in Patients with First Acute Ischemic Stroke

Background

Due to the high post-stroke frequency of dysphagia, dysarthria, and aphasia, we developed comprehensive neuroanatomical, clinical, and demographic models to predict their presence after acute ischemic stroke.

Methods

The sample included 160 randomly selected first-ever stroke patients with confirmed infarction on magnetic resonance imaging from 1 tertiary stroke center. We documented acute lesions within 12 neuroanatomical regions and their associated volumes. Further, we identified concomitant chronic brain disease, including atrophy, white matter hyperintensities, and covert strokes. We developed predictive models using logistic regression with odds ratios (OR) and their 95% confidence intervals (95% CI) including demographic, clinical, and acute and chronic neuroanatomical factors.

Results

Predictors of dysphagia included medullary (OR 6.2, 95% CI 1.5–25.8), insular (OR 4.8, 95% CI 2.0–11.8), and pontine (OR 3.6, 95% CI 1.2–10.1) lesions, followed by brain atrophy (OR 3.0, 95% CI 1.04–8.6), internal capsular lesions (OR 2.9, 95% CI 1.2–6.6), and increasing age (OR 1.4, 95% CI 1.1–1.8). Predictors of dysarthria included pontine (OR 7.8, 95% CI 2.7–22.9), insular (OR 4.5, 95% CI 1.8–11.4), and internal capsular (OR 3.6, 95% CI 1.6–7.9) lesions. Predictors of aphasia included left hemisphere insular (OR 34.4, 95% CI 4.2–283.4), thalamic (OR 6.2, 95% CI 1.6–24.4), and cortical middle cerebral artery (OR 4.7, 95% CI 1.5–14.2) lesions.

Conclusion

Predicting outcomes following acute stroke is important for treatment decisions. Determining the risk of major post-stroke impairments requires consideration of factors beyond lesion localization. Accordingly, we demonstrated interactions between localized and global brain function for dysphagia and elucidated common lesion locations across 3 debilitating impairments.

Developing Azeri aphasia screening test and preliminary validity and reliability

Background: As there is no standard aphasia screening tool for Azeri language yet, the aim of this study was to develop an aphasia screening test with acceptable validity and reliability. Methods: The present study was conducted in two phases. In the first phase, by literature search, the screening test was designed and to obtain validity it was peer reviewed by expert panel. After collecting experts' ratings and comments, appropriate modifications were applied. For test-retest reliability in the second phase, edited test was administered in 32 patients with brain injuries, then the retest was performed two weeks later. Results: The developed test had eight subscales including: A) picture description, B) syntax, C) linguistic reasoning, D) descriptive naming, E) perception of minimal pairs, F) comprehensive vocabulary, G) expressive vocabulary, H) verbal fluency. Each section had five questions except verbal fluency which had 3 items. Content validity ratio (CVR) according to Lawshe's approach, was 82% for the whole test. Intraclass correlation for all subscales were more than 0.8. Cronbach's alpha coefficient for internal reliability was 0.901. Conclusion: This aphasia screening test seems to have acceptable psychometric properties. This test can probably be used in clinical setting by specialists.