The Dosing and Timing of Peri-operative Electrical Stimulation of Nerve following Nerve Repair in Peripheral Nerve Injury: A Scoping Review

Background: Peripheral nerve injuries often have incomplete functional recovery after neurorrhaphy. Peri-operative electrical stimulation is a promising adjunct, but optimal dosing and timing remain unclear. Objective: Map dosing parameters (frequency, amplitude, pulse width, session duration), timing strategies (pre-conditioning, intraoperative, postoperative), and reported outcomes of peri-operative electrical stimulation used with peripheral nerve repair. Methods: Following PRISMA-ScR guidance, we searched PubMed, Embase, Web of Science, Scopus, and Google Scholar (January 2000–May 2025). Empirical animal and human studies reporting ES around nerve repair were included. Data were charted on stimulation parameters, repair context, outcomes, and safety. Narrative synthesis was used. Of 1242 records, 55 studies were included (28 animal experiments, 6 RCTs, 5 clinical series, 7 mechanistic studies, 9 reviews). Results: Evidence clusters around three timings. (1) Pre-conditioning ES shows strong mechanistic and functional benefits in rodents but lacks clinical testing. (2) Intraoperative single-session ES—most commonly 20 Hz for ~ 60 min—consistently accelerates axonal regeneration in animals and improved sensory and motor outcomes in human trials. (3) Postoperative repeated Electrical stimulation yields mixed results, with one RCT in severe cubital tunnel syndrome showing functional and electrophysiologic gains. Reported parameters vary, animal work typically uses microampere currents and microsecond pulses, and human studies use milliampere currents and longer pulses scaled to nerve size. Safety reporting is limited but favorable. Heterogeneity and incomplete parameter reporting impede direct comparison and clinical standardization. Conclusions: The most translatable regimen is brief intraoperative low-frequency Electrical Stimulation (≈20 Hz, ~ 60 min) delivered at repair. Priority gaps include head-to-head trials of timing strategies, human dose–response curves (amplitude and pulse width vs. nerve caliber), standardized outcome frameworks, and long-term safety and cost-effectiveness.