Impact of awake mapping on extent of resection and neurological outcomes of Low-grade gliomas: a systematic review and Meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of non-randomized comparative studies
PubMed 41398134 · doi:10.1007/s10143-025-03998-w
What was done
A systematic review and meta-analysis evaluated studies comparing awake surgery with intraoperative electrical mapping (AwS) against surgery under general anesthesia (GA) in adults with low-grade gliomas (LGGs). Literature searches were conducted in PubMed, Embase, and Scopus. Quality was assessed using the ROBINS-I tool for non-randomized studies. Binary outcomes were measured as risk ratios (RR) and continuous variables as standardized mean differences (SMD) with 95% confidence intervals (CI).
What was found
Across 10 included studies totaling 735 patients (401 AwS, 334 GA), preoperative tumor volume on MRI did not differ significantly between groups (SMD: -0.14; 95% CI: -0.31 to 0.03; p = 0.11). Mean volumetric extent of resection was also comparable (SMD: 0.79; 95% CI: -0.24 to 1.81; p = 0.13). No statistically significant differences were observed in early motor deficits (RR: 0.50; 95% CI: 0.16 to 1.51; p = 0.23) or overall early neurological outcomes (RR: 0.67; 95% CI: 0.23 to 1.93; p = 0.46). However, late neurological outcomes, including motor and language deficits, were significantly improved in the AwS group (RR: 0.27; 95% CI: 0.13 to 0.54; p = 0.0002).
Why it matters
These findings suggest that awake brain mapping preserves long-term functional status without sacrificing tumor resection volume in patients undergoing surgery for low-grade gliomas.
Limits
All included studies were non-randomized, introducing risk of selection bias and confounding by indication. The total cohort size across 10 studies is modest (735 patients), and the abstract does not report long-term oncological endpoints such as progression-free or overall survival.
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- supports During brain tumor resections in eloquent areas such as the left hemisphere, awake craniotomy with intraoperative speech testing is used to identify functional boundaries and prevent speech deficits.