# Neurocognitive Outcomes After Extracranial Surgery and General Anesthesia in Patients with a History of Mild-to-Moderate Traumatic Brain Injury: Systemic Review and Meta-Analysis

## TL;DR

This study finds that surgeries under general anesthesia may worsen cognitive outcomes in people with a history of mild-to-moderate traumatic brain injury.

## Contribution

The study is the first to meta-analyze the impact of extracranial surgeries and GA on neurocognitive outcomes in mild-to-moderate TBI patients.

## Key findings

- TBI patients who had surgeries under GA performed worse on cognitive tests like TMT-A and TMT-B.
- There was no significant difference in hospital or ICU length of stay or functional recovery outcomes.
- More research is needed due to the limited number of studies included in the meta-analysis.

## Abstract

This study investigated whether individuals with mild-to-moderate traumatic brain injury (TBI) are at increased risk of neurocognitive deficits following surgeries that do not involve the brain under general anesthesia (GA). We have systematically reviewed and meta-analyzed observational studies, finding that TBI patients who underwent these surgeries performed worse on cognitive tests compared to those who did not undergo GA surgeries. However, the length of hospital stays, and overall recovery were not affected. Since only a few studies were deemed eligible for this meta-analysis, more research is needed to understand the full impact of these surgeries on TBI patients.

Accelerated neurocognitive decline associated with surgeries under general anesthesia (GA), a phenomenon referred to as postoperative neurocognitive disorder (PND), is a significant public health concern. It not only poses inherent risks but may also contribute to the development of other neurodegenerative disorders. We systematically searched five databases for studies examining cognitive function in patients with mild-to-moderate TBI with (participant) or without (control) subsequent extracranial surgeries/GA. A random effects model was applied to calculate mean differences (MDs) and 95% confidence intervals (CIs). Five outcomes were analyzed post hoc: trail-making tests A and B (TMT-A/B), Glasgow Outcome Scale–Extended (GOSE), and length of stay (LOS) in intensive care units (ICUs) and hospitals. Five studies met the criteria for our meta-analysis. Patients with a history of mild-to-moderate TBI who underwent extracranial surgeries/GA exhibited worse outcomes in TMT-A [MD = 2.04; CI 0.38–3.70; p = 0.016] and TMT-B [MD = 16.59; CI 9.58–23.60; p < 0.001]. Differences in the ICU and hospital LOS and GOSE between the study groups were insignificant. Our results suggest that extracranial surgeries/GA may worsen neurocognitive outcomes without affecting functional recovery in mild-to-moderate TBI patients. Given the limited number of studies identified and the high incidence of TBI, more research on PND in TBI patients is warranted.