Accelerometry in early sub-acute stroke patients – quantitative spontaneous motor activity displays improvement in rehabilitation progress

Objective: The aim of the study was to investigate the feasibility and practicability of accelerometric measurement of the upper limb in early sub-acute stroke patients to display possible improvement during rehabilitation.Participants: 47 sub-acute stroke patients with severe (mean NIHSS 14±6) motor deficits were recruited within the early phase of rehabilitation (mean 5th day post stroke onset). Interventions: Spontaneous arm activity of the upper extremities was measured by means of an accelerometer at the beginning and at two predefined time points, i.e., the beginning and end of a two week time period and correlated to established Stroke Scales. Changes in rehabilitative development as captured by the Stroke Scales were correlated to the accelerometric data. Results: We found significant correlations between the accelerometric measurements to Stroke Scales with the strongest correlation observed between 24hrs-accelerometric measurement of the impaired arm and the arm section of the Fugl-Meyer-Assessment (FMA). FMA, National Institute of Health Stroke Scale (NIHSS), modified Ranking Scale (mRS) and early Rehabilitation Barthel-Index (FR-BI) also showed significant improvement over a 14 day time period, while accelerometric data did not detect a significant change over time. Conclusions: Accelerometry correlated well to established Stroke Scales. However, we found that qualitative improvement of the hand-function, as captured by the FMA, is not necessarily associated with changes in the overall-activity. Accelerometry proved to be a useful, objective and examiner-independent, feasible method, which is easy to handle. A great benefit is that compared to assessments accelerometric measurement does not need the patient's collaboration, and can therefore be performed in patients with severe aphasia or apraxia.