Diagnostic Accuracy of Somatosensory-Evoked Potential Changes for Predicting Postoperative Neurological Deficits Following Brain Tumor Surgery.

BACKGROUND

Intraoperative neuromonitoring is widely used during brain tumor surgery to reduce the risk of neurological injury. Somatosensory evoked potentials (SSEPs) are frequently employed to monitor functional integrity of sensory pathways and assist with localization of the central sulcus. However, the diagnostic accuracy of SSEP changes alone in predicting postoperative neurological deficits during brain tumor resection remains incompletely characterized.

METHODS

This retrospective study included 511 patients who underwent craniotomy with SSEP monitoring between 2019 and 2023. Postoperative neurological outcomes were assessed through clinical chart review. Diagnostic accuracy metrics, including sensitivity, specificity, positive predictive value (PPV), and diagnostic odds ratio (DOR) were calculated. Subgroup analysis compared reversible versus irreversible SSEP changes.

RESULTS

SSEP changes demonstrated high specificity (95%) but low sensitivity (16%) for predicting postoperative neurological deficits. Irreversible SSEP changes had significantly higher PPV than reversible changes (72% vs. 47%, P = 0.048). Notably, SSEP changes were associated not only with sensory deficits but also with motor (DOR = 6.1) and language (DOR = 2.6) deficits. Tumor characteristics, including location, size, and eloquence, were comparable across groups.

CONCLUSIONS

Intraoperative SSEP changes demonstrate high specificity but limited sensitivity for predicting postoperative neurological deficits following brain tumor surgery. Irreversible SSEP changes appear to have greater prognostic value than reversible changes. These findings suggest that SSEP deterioration may reflect broader peri-Rolandic cortical dysfunction and may provide useful adjunctive information for intraoperative risk assessment and stratification when interpreted alongside other monitoring modalities and clinical context.