The Differential Effects of Propofol and Dexmedetomidine on Intraoperative Neuropsychological Testing During Awake Craniotomies.

BACKGROUND

This study compared the impact of propofol and dexmedetomidine sedation on intraoperative neuropsychological testing during awake craniotomy (AC) techniques.

METHODS

A retrospective cohort study was conducted, reviewing medical records of all adult patients undergoing ACs at an academic hospital from 2014 to 2022 who received picture naming intraoperatively, resulting in 60 eligible surgeries. Sedation protocols included propofol and/or dexmedetomidine, or no sedation, and neurocognitive testing was performed using the NeuroMapper software. Multiple regression analysis was used to examine changes in picture naming reaction time (RT) with propofol and dexmedetomidine doses.

RESULTS

The study found that regardless of medication used, patients were approximately 800 ms slower intraoperatively than during baseline. Regression analysis indicated that the amount of propofol sedation was not associated with changes in RT (t = 1.38; P = 0.169); however, adding dexmedetomidine was associated with an overall increase in naming latency (t = 5.96; P < 0.001), particularly at high doses of propofol (t = 3.42; P < 0.001).

CONCLUSIONS

This study provides evidence of possible differential effects of propofol and dexmedetomidine sedation on intraoperative picture naming performance during ACs. While propofol dose alone was not significantly associated with RT, the combination of propofol with dexmedetomidine was associated with longer RTs. These results suggest that anesthesiologists and neuropsychologists should be aware of the possible residual sedative effect of dexmedetomidine when combined with propofol on intraoperative picture naming performance and carefully consider sedation protocols and interpretation of data involving high doses of propofol and dexmedetomidine.