Bimanual performance and life balance one year after stroke. Assessment, evolution and prognosis

Stroke remains one of the leading causes of disability with loss of independency for daily activities as a long-term consequence. The vast majority of daily activities demand the use of both hands working together. Up to 85% of stroke survivors present with upper limb impairment, which may compromise bimanual performance. To date, the vast majority of studies focus on unimanual recovery and provides scarce knowledge about recovery and prognosis of bimanual performance. Bimanual performance may play an important role in the involvement in meaningful activities. Stroke survivors reported that they were challenged to re-engage in meaningful activities, which compromised a well-balanced pattern of activities. Therefore, we introduced the concept of life balance as having a well-balanced pattern of activities. Accordingly, the aim of this doctoral thesis was to gain insight in bimanual performance, life balance and the interaction between both concepts.

In the first study, we provided novel evidence regarding reliability and validity of the Adult Assisting Hand Assessment Stroke (Ad-AHA Stroke). This assessment, originally developed to evaluate the use of the affected hand in bimanual task performance in a pediatric population, was previously adapted for use in people with stroke. We demonstrated substantial to excellent reliability and a low standard error of measurement (SEM) for intrarater and interrater agreement respectively in 30 participants. The hypothesis that a high correlation would be found between bimanual performance and unilateral motor function supporting convergent validity, was confirmed in 118 participants. Of note, we found a relatively high variability at the higher and lower end of the Ad-AHA Stroke score range in relation to unilateral motor function, providing evidence that the Ad-AHA Stroke measures a different construct than unilateral motor function. We were able to demonstrate support for discriminative validity, differences in Ad-AHA stroke scores were found between participants with visuospatial neglect and without visuospatial neglect and between participants with the dominant hand affected and those with the nondominant hand affected.

In a subsequent study, we identified the prognostic value of baseline variables on bimanual performance in a cohort of stroke survivors (n=92) until one year after stroke. Baseline variables were collected within the first week of inpatient rehabilitation and the Ad-AHA Stroke was administered at six months (n=81) and at one year (n=69) after stroke. Moderate associations between bimanual performance and hand dominance, somatosensory, cognitive and mental function and activity limitations were found, although the latter were not retained in the multiple prediction model. We revealed that grasp function and stroke severity at baseline after stroke were key predictors of bimanual performance at six months and one year after stroke and both are measured by simple and quick to administer measures, commonly used in stroke rehabilitation, which is an important asset for clinical practice.

The next step in this research project was to establish test-retest reliability and convergent validity of the Flemish version of the Life Balance Inventory (Fl-LBI) in chronic community-dwelling stroke survivors (n=32). Satisfactory test-retest reliability was demonstrated for total Fl-LBI scores and subscale scores: The SEM and minimal detectable difference (MDD) were small and similar to those of other patient-reported outcomes in the field. Furthermore, moderate associations between Fl-LBI and participation, mobility and emotions provided support for convergent validity. The results of this study showed first evidence that the Fl-LBI has satisfactory test-retest reliability, acceptable standard error of measurement and minimal detectable difference and acceptable convergent validity.

Finally, evolution and prognosis of life balance was examined in an observational longitudinal study. Baseline variables were collected within the first week of inpatient rehabilitation and at six months (n=67) and one year (n=59) after stroke, the Fl-LBI was administered. Moderate scores on the Fl-LBI were found at six and at one year after stroke. Small but significant improvement in life balance occurred within the first year after stroke. Mental function and bimanual performance were key predictors of life balance within the first year after stroke.

To conclude, this doctoral project has contributed to the field of stroke recovery and occupational therapy by providing knowledge regarding bimanual performance and life balance, and by demonstrating the interaction between both concepts. With that, a relevant contribution to the field was delivered and further research priorities were identified as well. This doctoral thesis is a valid and essential starting point for further research on bimanual performance and life balance after stroke.