Introduction: Recruitments of stroke recovery trials have been challenging. NIH stroke scale (NIHSS) has been universally collected in the acute stroke phase, but stroke recovery trials generally use Fugl-Meyer Motor Scale (FMMS) for outcome measure as well as patient selection criteria. The knowledge gap on the relationship between the two scales potentially jeopardize the accuracy of clinical trial recruitment feasibility survey that is based on NIHSS in the acute phase. We aimed to investigate the correlation between the two scales in a longitudinal stroke recovery study.
Methods: This is a prospective cohort study (Prediction and Imaging biomarker of Post-stroke Motor Recovery) that enrolled patients with first-ever acute ischemic stroke with various degrees of motor impairment. NIHSS and FMMS were assessed 2-7 days after onset of stroke symptoms as well as at 90 days (± 15 days) post-stroke. Modified Rankin Scale (mRS), Stroke Impact Scale-16 (SIS-16) and Personal Health Questionnaire-9 (PHQ-9) were collected at 90 days (±15 days). Correlation analysis were conducted with Pearson Correlation coefficient.
Results: 119 patients met the inclusion criteria and were included in the analysis. NIH Arm scales of 0, 1, 2, 3 and 4 correspond to FM-UE scales at 3 months of 61.1, 59.8, 58.0, 47.3 and 17.0. NIH leg scales of 1, 2, 3 and 4 correspond to FM_LE scales at 3 months of 32.4, 29.8, 27.8, 21.0 and 17.2. The correlation coefficient between of two leg scales is not as good as the two arm scales. (0.76 vs. 0.83). Similarly, mRS of 0, 1, 2, 3, 4 and 5 correspond to FMMS of 99.0, 91.6, 85.5, 51.6, 41.5, 21.6 and SIS-16 of 73.7, 69.6, 64.7, 55.1, 42.8, 25.3.
Conclusions: Our data suggest that there is a strong correlation pattern between the NIH arm scale and FM-UE scale, NIH leg scale and FM-LE scale as well as mRS, FMMS, NIHSS and SIS-16. This information is potentially useful to inform the feasibility assessment for future stroke rehabilitation trials done through the NIH Stroke Trials Network.