Somatosensory evoked potential monitoring for position-related brachial plexus injury during cerebellopontine angle tumor resection: A retrospective cohort study.

ObjectiveTo evaluate the utility of intraoperative somatosensory evoked potential monitoring for detecting position-related brachial plexus injury during cerebellopontine angle tumor resection, identify independent risk factors, and assess the effectiveness of somatosensory evoked potential-guided interventions.MethodsThis retrospective cohort study included 45 patients who underwent cerebellopontine angle microsurgery in the lateral or semilateral position. Median nerve somatosensory evoked potentials were continuously monitored. Patients were stratified according to somatosensory evoked potential changes. Clinical characteristics, surgical variables, and protective positioning measures were compared. Cox regression was performed to identify independent risk factors.ResultsSomatosensory evoked potential alterations occurred in 14 patients (31.1%). Following repositioning, 13 patients recovered intraoperatively; 9 patients returned to baseline within 46-110 min (mean, 64 ± 20.5 min) and 4 patients within 2 h. Changes in latency and threshold across time points were statistically significant (p<0.01 and p<0.0001, respectively). One patient without somatosensory evoked potential recovery developed mild, transient symptoms that resolved within 5 weeks. Independent risk factors included age ≥60 years (hazard ration = 2.78), body mass index ≥25 kg/m (hazard ration = 3.02), operative time ≥5 h (hazard ration = 3.65), intraoperative temperature <36.5°C (hazard ration = 2.31), and absence of protective positioning (hazard ration = 3.87) (all p<0.05).ConclusionsOur findings suggest that routine somatosensory evoked potential monitoring during lateral decubitus cerebellopontine angle tumor resection may help mitigate brachial plexus injury and improve surgical safety.