Abstract TMP40: Secondary Motor Nerve Deficit Correlates With Poorer Outcome in Acute Stroke Patients

Abstract

Introduction: Anterograde degeneration after stroke leads to secondary injury of peripheral motor nerves. It remains unclear whether this secondary dysfunction affects functional improvement and whether early electrophysiological parameters could possibly predict rehabilitative outcome. Methods: A total of 43 adult patients of middle cerebral artery infarction (MCAI) within 2 weeks after onset was prospectively recruited from January 2016 to December 2017. Ten healthy subjects were recruited as control. All the subjects were investigated by electromyography to record and analyze electrophysiological parameters on admission. All the patients were evaluated by NIHSS, BI, mRS, Fugl-Meyer assessment (FMA) and Alberta Stroke Program Early CT score on admission, then by BI, mRS and FMA in the 6-month follow-up. Multiple regression analysis was used to screen the possible predictive factor for neurological outcome. Results: Twenty-six patients were with massive MCAI and 17 patients with subcortical MCAI. The compound muscle action potential (CMAP) amplitude of median, ulnar, tibial and common peroneal nerves, and motor unit number estimation in abductor of pollicis brevis were significant decreased in the hemiplegic limbs than those in the unaffected limbs and in the healthy controls, and further diminished in massive MCAI compared to those in subcortical MCAI. Fibrillation potentials / positive sharp waves in abductor digiti minimi and tibialis anterior were found in majority of patients, and were more frequently detected in massive MCAI, confirming the motor axonal deficit. CMAP amplitude of the affected ulnar nerves was significantly decreased in patients with unfavorable outcome (mRS>3) 3 and 6 months after attack, shown as an independent predictor for poorer outcome. In addition, the affected ulnar CMAP ≥10.45mV was associated with more than 50% decrement of mRS 6 months post stroke, with sensitivity and specificity of nearly 80%. Conclusions: The data indicated that secondary peripheral motor deficit occurred within 2 weeks after stroke, correlated with severity of the disease. Relatively low CMAP amplitude of hemiplegic ulnar nerve could serve as an independent factor to predict poorer outcome and worse recovery in the 6-month follow-up.