Predicting Arm Nonuse in Individuals with Good Arm Motor Function after Stroke Rehabilitation: A Machine Learning Study

Many stroke survivors demonstrate arm nonuse despite good arm motor function. This retrospective secondary analysis aims to identify predictors of arm nonusers with good arm motor function after stroke rehabilitation. A total of 78 participants were categorized into 2 groups using the Fugl-Meyer Assessment Upper Extremity Scale (FMA-UE) and the Motor Activity Log Amount of Use (MAL-AOU). Group 1 comprised participants with good motor function (FMA-UE ≥ 31) and low daily upper limb use (MAL-AOU ≤ 2.5), and group 2 comprised all other participants. Feature selection analysis was performed on 20 potential predictors to identify the 5 most important predictors for group membership. Predictive models were built with the five most important predictors using four algorithms. The most important predictors were preintervention scores on the FMA-UE, MAL-Quality of Movement, Wolf Motor Function Test-Quality, MAL-AOU, and Stroke Self-Efficacy Questionnaire. Predictive models classified the participants with accuracies ranging from 0.75 to 0.94 and areas under the receiver operating characteristic curve ranging from 0.77 to 0.97. The result indicates that measures of arm motor function, arm use in activities of daily living, and self-efficacy could predict postintervention arm nonuse despite good arm motor function in stroke. These assessments should be prioritized in the evaluation process to facilitate the design of individualized stroke rehabilitation programs to reduce arm nonuse.

Predictors of Arm Nonuse in Chronic Stroke: A Preliminary Investigation

Background. Nonuse (NU) after stroke is characterized by failure to use the contralesional arm despite adequate capacity. It has been suggested that NU is a consequence of the greater effort and/or attention required to use the affected limb, but such accounts have not been directly tested, and we have poor understanding of the predictors of NU. Objective. We aimed to provide preliminary evidence regarding demographic, neuropsychological (ie, apraxia, attention/arousal, neglect), and psychological (ie, self-efficacy) factors that may influence NU in chronic stroke. Methods. Twenty chronic stroke survivors with mild to moderate sensory-motor impairment characterized by the Upper-Extremity Fugl-Meyer (UEFM) were assessed for NU with a modified version of the Actual Amount of Use Test (AAUT), which measures the disparity between amount of use in spontaneous versus forced conditions. Participants were also assessed with measures of limb apraxia, spatial neglect, attention/arousal, and self-efficacy. Using stepwise multiple regression, we determined which variables predicted AAUT NU scores. Results. Scores on the UEFM as well as attention/arousal predicted the degree of NU (P < .05). Attention/arousal predicted NU above and beyond UEFM (P < .05). Conclusions. The results are consistent with the importance of attention and engagement necessary to fully incorporate the paretic limb into daily activities. Larger-scale studies that include additional behavioral (eg, sensation, proprioception, spasticity, pain, mental health, motivation) and neuroanatomical measures (eg, lesion volume and white matter connectivity) will be important for future investigations.