Association between National Institutes of Health Stroke Scale and Functional Independence Measure scores in patients with ischemic stroke from convalescent rehabilitation outcomes

We investigated the associations among neurological severity, activities of daily living (ADLs), and clinical factors in patients with ischemic stroke in convalescent rehabilitation outcome. The study sample included 723 patients with ischemic stroke (484 men and 239 women; mean age, 73.2 ± 8.5 years) for inpatient convalescent rehabilitation. National Institutes of Health Stroke Scale (NIHSS) was used to measure the neurological severity, and Functional Independence Measure (FIM) was used to assess ADLs at discharge. Leukoaraiosis was graded based on periventricular hyperintensity (PVH) and deep white matter hyperintensity (DWMH) on magnetic resonance imaging. The correlations between NIHSS scores and total FIM scores were significant but relatively mild (r = –0.684, P < 0.001). Multiple regression analysis revealed that age and PVH grade significantly decreased their total FIM scores and affected the discrepancies between NIHSS scores at discharge (P < 0.001), but DWMH scores did not affect these results. Factors such as positive history of heart disease (P = 0.008) and bilateral infarction (P = 0.038) additionally decreased their total FIM scores and affected the discrepancies between NIHSS scores. These findings suggest that age, PVH, history of heart disease positive, and bilateral infarction in patients with ischemic stroke affected their performance of ADLs and the discrepancies between their neurological severities in convalescent rehabilitation outcomes, probably because the pathophysiological background of leukoaraiosis and these factors strongly decrease their ADL performance in post-phase ischemic stroke.