The Impact of Acute Phase Domain-Specific Cognitive Function on Post-stroke Functional Recovery

Normative data for Verbal Fluency and Object Naming Tests in a sample of European Portuguese adult population

The purpose of the present study was to calculate the construct validity, internal consistency and normative data of the Phonological Verbal Fluency Test (letters F, A, S, and M), Semantic Verbal Fluency Test (Animals, Fruits and Professions categories), and Boston Naming Test (short and standard version), and to generate normative data for these tests after adjusting for age, education, and sex. A sample of 293 European Portuguese adults participated in the study. Results showed adequate construct validity and internal consistency for all of the tests and the final multiple regression models found that age and education were significantly associated with P-VFT (letters F, A, S, and M), S-VFT (Animals, Fruits and Professions categories), and BNT performance. Sex was only found to have an effect on the fruit category, with women scoring higher than men. The normative data provided in this study will contribute to improving the clinical practice of neuropsychology in Portugal.

A Meta-Analysis of Neuropsychological Predictors of Outcome Following Stroke and Other Non-Traumatic Acquired Brain Injuries in Adults

A number of cognitive abilities have been reported to predict outcome following a non-traumatic acquired brain injury (ABI) in adults. However, the results are inconsistent. Furthermore, the unique and combined capacity of these cognitive abilities to predict ABI outcome has not been evaluated. Consequently, we employed meta-analysis and multiple regression to evaluate the capacity of various neuropsychological domains to predict two separate outcome variables in adults: (1) activities of daily living; and (2) quality of life. Based on the activities of daily living meta-analysis (N = 2384), we estimated the following significant bivariate effects: memory (r = .31, 95% CI: .20/.41]), language (r = .33, 95% CI:.26/.40), attention (r = .38, 95% CI: .30/.46]), executive functions (r = .29, 95% CI: .19/.39]), and visuospatial abilities (r = .41, 95% CI: .34/ .48). Based on the quality of life meta-analysis (N = 1037), we estimated the following significant bivariate effects: memory (r = .12, 95% CI: .03/.20]), language (r = .19, 95% CI: .06/ .32), attention (r = .30, 95% CI: .16/.44]), executive functions (r = .24, 95% CI: .12/.37) and visuospatial/constructional abilities (r = .30, 95% CI: .14/.46). Meta-analytic structural equation modelling (metaSEM) identified two significant, unique predictors of activities of daily living, attention and visuospatial abilities, and the model accounted for 21% of the variance (multiple R² = .21, 95%CI: .16/.26). For the corresponding quality of life metaSEM, no statistically significant unique predictors were identified, however, a significant multiple correlation was observed, multiple R² = .11 (95%CI: 04/.18). We conclude that practitioners may be able to predict, with some degree of accuracy, functional outcome following a stroke and other non-traumatic ABI in adults. We also provide some critical commentary on the nature and quality of the measures used in this area of research to represent the cognitive dimensions of interest.

Prediction of post-stroke functional mobility from the initial assessment of cognitive function

BACKGROUND

Cognitive impairment is frequently seen in patients with stroke. The possible correlation between cognitive function and functional mobility has been proposed; however, the prognostic importance of early cognitive function in recovery of mobility has not been investigated in patients with stroke.

OBJECTIVE

The objective of this study is to investigate whether the cognitive function in the acute phase can independently predict the recovery of mobility after stroke, and to determine the cut-off value of each cognitive evaluation test for community ambulation at six months.

METHODS

Seventy two patients underwent four domain-specific neuropsychological evaluation tests at about two weeks after stroke; these included the word list memory test (WMT), construction praxis test (CPT), verbal fluency test (VFT) and Boston naming test (BNT). The Functional Ambulation Category (FAC) and ambulatory zone (AZ) at six months after stroke were investigated as outcome variables. The domain-specific cognitive function, along with other possible predictors for functional mobility, was analyzed with regression analysis.

RESULTS

The z-scores of WMT (p = 0.018) and VFT (p = 0.012) were related to the independence in ambulation. The z-scores of VFT (p = 0.006) and CPT (p = 0.009) were predictors for community ambulation, with the cut-off values of -2.215 for VFT, and of -0.845 for CPT.

CONCLUSIONS

Cognitive impairment in the acute phase of stroke can be an independent prognostic factor of functional mobility. Domain-specific neuropsychological evaluation tests should be considered in the acute phase of stroke to predict the recovery of functional mobility.

Correlation Between Montreal Cognitive Assessment and Functional Outcome in Subacute Stroke Patients With Cognitive Dysfunction

Objective

To investigate the correlation between the Montreal Cognitive Assessment (MoCA) and functional outcome among subacute stroke patients with cognitive dysfunction.

Methods

Records of 61 inpatients were reviewed. Patients were divided into two groups based on their initial MoCA score. MoCA score of 11 was set as the differentiating criterion. We compared the improvements in Modified Barthel Index (MBI) from initial assessment to discharge between the two groups.

Results

There were no significant differences between the two groups in relation to age, duration from onset to admission, hospitalization period, or years of education. In a comparison of the results of Mini-Mental Status Examinations (MMSE) administered at admission and again at discharge, there was significantly more improvement in MMSE scores in the group with low MoCA scores than in the group with high MoCA scores. However, the group with high MoCA scores also showed high MBI scores at discharge and exhibited greater MBI improvement.

Conclusion

Higher initial MoCA scores (which reflect preservation of executive function) indicate better functional outcome in the subacute stroke phase.

The Korean Version of the Cognitive Assessment Scale for Stroke Patients (K-CASP): A Reliability and Validity Study

Objective

To develop the Korean version of the Cognitive Assessment Scale for Stroke Patients (K-CASP) and to evaluate the test reliability and validity of the K-CASP in stroke patients.

Methods

The original CASP was translated into Korean, back-translated into English, then reviewed and compared with the original version. Thirty-three stroke patients were assessed independently by two examiners using the K-CASP twice, with a one-day interval, for a total of four test results. To evaluate the reliability of the K-CASP, intra-class correlation coefficients were used. Pearson correlations were calculated and simple regression analyses performed with the Korean version of Mini-Mental State Examination (K-MMSE) and the aphasia quotient (AQ) to assess the validity.

Results

The mean score was 24.42±9.47 (total score 36) for the K-CASP and 21.50±7.01 (total score 30) for the K-MMSE. The inter-rater correlation coefficients of the K-CASP were 0.992 on the first day and 0.995 on the second day. The intra-rater correlation coefficients of the K-CASP were 0.997 for examiner 1 and 0.996 for examiner 2. In the Pearson correlation analysis, the K-CASP score significantly correlated with the K-MMSE score (r=0.825, p<0.001). The coefficients of determination (r²) of the AQ were 0.586 for the K-MMSE and 0.513 for the K-CASP in the simple regression analysis.

Conclusion

The K-CASP is a reliable and valid instrument for cognitive dysfunction screening in post-stroke patients. It is more applicable than other cognitive assessment tools in stroke patients with aphasia.

Obstructive sleep apnea exaggerates cognitive dysfunction in stroke patients

BACKGROUND

Obstructive sleep apnea (OSA) is very common in stroke survivors. It potentially worsens the cognitive dysfunction and inhibits their functional recovery. However, whether OSA independently damages the cognitive function in stroke patients is unclear. A simple method for evaluating OSA-induced cognitive impairment is also missing.

METHODS

Forty-four stroke patients six weeks after onset and 24 non-stroke patients with snoring were recruited for the polysomnographic study of OSA and sleep architecture. Their cognitive status was evaluated with a validated Chinese version of Cambridge Prospective Memory Test. The relationship between memory deficits and respiratory, sleeping, and dementia-related clinical variables were analyzed with correlation and multiple linear regression tests.

RESULTS

OSA significantly and independently damaged time- and event-based prospective memory in stroke patients, although it had less power than the stroke itself. The impairment of prospective memory was correlated with increased apnea-hypopnea index, decreased minimal and mean levels of peripheral oxygen saturation, and disrupted sleeping continuity (reduced sleep efficiency and increased microarousal index). The further regression analysis identified minimal levels of peripheral oxygen saturation and sleep efficiency to be the two most important predictors for the decreased time-based prospective memory in stroke patients.

CONCLUSIONS

OSA independently contributes to the cognitive dysfunction in stroke patients, potentially through OSA-caused hypoxemia and sleeping discontinuity. The prospective memory test is a simple but sensitive method to detect OSA-induced cognitive impairment in stroke patients. Proper therapies of OSA might improve the cognitive function and increase the life quality of stroke patients.