Cyclic Neuromuscular Electrical Stimulation as a Priming Intervention in Acute Stroke: A Narrative Review of Rationale and Clinical Perspectives.

The acute phase of stroke is characterized by heightened neuroplasticity; however, rehabilitation interventions are often limited because of impaired voluntary motor control and systemic instability. Severe cases may miss the opportunity for recovery before adequate physiological readiness is achieved. Cyclic neuromuscular electrical stimulation (NMES) is a noninvasive modality that induces muscle activity and sensory input independently of volitional effort. Besides suppressing muscle atrophy, NMES can potentially activate the central nervous system. This narrative review aimed to investigate the neurophysiological mechanisms and clinical applicability of cyclic NMES in patients with acute stroke, focusing on its strategic value and current challenges. NMES in the acute phase showed modest improvements in muscle strength, spasticity, and walking ability. However, inconsistencies in patient selection, stimulation parameters, and outcome measures remain major barriers to its application. Successful clinical integration requires redefining NMES as a "priming stimulus," with an emphasis on comfort, responsiveness, and continuity. Developing semi-standardized, strategically guided protocols is necessary. Cyclic NMES can be a preparatory intervention during the critical "window of neuroplasticity" in acute stroke rehabilitation, offering potential benefits that extend beyond conventional adjunctive therapies. Further studies focusing on stratified patient selection and neurophysiologically informed outcome measures are needed to enhance evidence-based application.