Abstract W P142: White Matter Lesion Severity and Functional Recovery Following Inpatient Rehabilitation After Ischemic Stroke

Abstract

Background and purpose: Functional outcome after stroke mainly depends on the stroke severity. However, extent of functional recovery varies between individual patients of same degree of disability in stroke rehabilitation. The aim of this study is to investigate the association between white matter lesion (WML) severity and the extent of functional recovery following intensive rehabilitation after ischemic stroke. Methods: The study included patients who were moved to a rehabilitation unit within 2 months after onset of ischemic stroke. Patients with diagnosed dementia or patients with cognitive decline who needed care before stroke were excluded. The degree of WMLs, the location and size of stroke lesions were assessed using brain MRI performed in an acute phase. Separate visual ratings were made for the periventricular hyperintensities and deep white matter hyperintensities on FLAIR images. Functional status was measured using the Functional Independence Measure (FIM) when a patient was moved to a rehabilitation unit and at the time of discharge. Functional recovery was quantified by the change in FIM score (FIM gain). We retrospectively investigated the association between WML severity and FIM gain. Results: A total of 292 patients (166 men and 126 women, mean age 73.3 ± 9.8 years) were included in the study. The mean time interval between stroke onset and rehabilitation start was 35.0 days and the mean length of stay in the unit was 71.6 days. FIM gain was associated with age, stroke severity, functional status before stroke, lobar stroke lesions, and both periventricular and deep white matter hyperintensity scores. Infarct size was not significantly associated with FIM gain. On the other hand, deep white matter hyperintensity score was independently associated with lower FIM gain after adjusting for age, sex, timing of rehabilitation start, length of stay, functional status before stroke, and NIHSS score on admission. Conclusion: In patients with subacute ischemic stroke, severity of cerebral WMLs is an independent factor affecting functional recovery following intensive rehabilitation.