Predictive value of upper-limb accelerometry in acute stroke with hemiparesis

Few studies have investigated how well early activity measurements by accelerometers predict recovery after stroke. First, we assessed the predictive value of accelerometer-based measurements of upper-limb activity in patients with acute stroke with a hemiplegic arm. Second, we established the difference in arm activity between hospitalized stroke and nonstroke patients. In total, 129 patients with acute stroke and 19 controls participated. Activity of the upper limbs was monitored for 48 h, and these data were used to determine the predictive value of the activity variables compared with the modified Rankin Scale (mRS), which was assessed at 3 mo poststroke onset. The sensitivity and specificity in relation to the mRS were 0.80 and 0.77, respectively, for the activity of impaired arm (AIA) and 0.85 and 0.75, respectively, for the ratio variable calculated by dividing the AIA by the activity of the nonimpaired arm. The corresponding cutoff values were 597,546 counts for AIA and 0.33 for the ratio. The predictive value of AIA combined with age was 85% to the disability status defined as an mRS score of 2 or less.