Awake versus Asleep Motor Mapping for Maximal Safe Glioma Resection: A Single Surgeon Experience over 15 Years

Introduction: Surgical resection of peri-Rolandic gliomas carries significant motor risks, necessitating precise mapping to preserve function with maximal tumor resection. Two widely used modalities are awake and asleep mapping. Awake mapping offers direct feedback but is a stressor for patients, while asleep mapping reduces stress but lacks immediate feedback. Previous studies have shown conflicting results in outcomes between the two surgical modalities. This study compares outcomes between awake and asleep mapping in high-grade (HGG) and low-grade gliomas (LGG).

Methods: A retrospective analysis of glioma resections performed by a single surgeon from 2008 to 2024, utilizing either awake or asleep motor mapping was done. Demographics, presenting symptoms, postoperative neurological deficits lasting beyond 14 days, and survival outcomes was analyzed.

Results: Eighty-seven patients underwent mapping for peri-Rolandic tumors (39 awake, 48 asleep). The majority of these were HGG (65 HGG vs 22 LGG with a higher proportion of HGG resected asleep p= 0.0105). Median age and gender were similar (p>0.05). Persistent (>14 days) post-op neurological deficits were comparable between groups (p>0.05). Median progression-free and overall survivals for HGG were 26 and 44 months in the awake group and 12 and 33 months in the asleep group (p =0.046, 0.1333). Karnofsky Performance scale (KPS) was measured pre-and post-operatively. For the asleep group, there was a ΔKPS of 4.88 and 3.04 for the awake (p = 0.003). For LGG the ΔKPS for asleep was 2.86 compared to 10.72 for the awake group related to the seizure burden and motor deficits pre-op in LGGs (p = 0.009).

Conclusion : Awake and asleep mapping both yield favorable postoperative neurological outcomes in gliomas near motor cortex. In our cohort, both approaches are safe and effective with a possible quality of life benefit for awake procedures in low-grade gliomas. Mapping enabled comprehensive resections that increase survival without compromising function.