Cognitive and functional assessments of stroke patients: an analysis of their relation.

Objectives: To improve the assessment of stroke patients for the purpose of designing rehabilitation treatments and predicting rehabilitation outcomes. Specific objectives included the evaluation of the power of functional scales to properly assess both physical and cognitive disabilities, and the evaluation of the relations between functional, neurological, physical, and cognitive assessments. The hypothesis was that the relations between different assessment types (eg, functional, neurological, etc) can be assessed by the relations between the results of these assessments when administered to stroke patients.

Design: Sixty-six stroke patients were administered a series of tests including functional assessments (Functional Independence Measure, barthel Index, Rankin Functional Scale), neurological assessments (Canadian Neurological Scale, National Institute of Health Stroke Scale), physical assessments (Stages of Motor Recovery, Clinical Outcome Variables Scale), and cognitive assessments (Stroke Unit Mental Status Examination, Mini Mental State, Raven Matrices, Boston Naming Test).

Results: Analysis of correlation coefficients revealed that the stronger relationships were observed between functional assessments and physical assessments, and between functional assessments and neurological assessments. Cognitive tests did not correlate highly with any of the functional tests used in this study. Three factors were extracted using factor analysis. They were interpreted as being a physical disability factor (50% of the variance), a cognitive disability factor (23% of the variance), and a dementia factor (12% of variance). Functional scales obtained higher loads on the physical disability factor only.

Conclusions: Considering that cognitive functions are frequently affected in stroke patients, cognitive impairment needs to be more seriously considered when describing and/or predicting a patient's level of independence. In brain injured patients, such as stroke patients, we suggest that the total score provided by standardized functional scales should be interpreted with care. We believe that rehabilitation outcome could be better predicted if the results of functional assessment were coupled with in-depth cognitive assessment.