Resection of Gliomas with and without Neuropsychological Support during Awake Craniotomy-Effects on Surgery and Clinical Outcome

Abstract

Background: During awake craniotomy for tumor resection, a neuropsychologist (NP) is regarded as a highly valuable partner for neurosurgeons. However, some centers do not routinely involve an NP, and data to support the high influence of the NP on the perioperative course of patients are mostly lacking.

Objective: The aim of this study was to investigate whether there is a difference in clinical outcomes between patients who underwent awake craniotomy with and without the attendance of an NP.

Methods: Our analysis included 61 patients, all operated on for resection of a presumably language-eloquent glioma during an awake procedure. Of these 61 cases, 47 surgeries were done with neuropsychological support (NP group), whereas 14 surgeries were performed without an NP (non-NP group) due to a language barrier between the NP and the patient. For these patients, neuropsychological assessment was provided by a bilingual resident.

Results: Both groups were highly comparable regarding age, gender, preoperative language function, and tumor grades (glioma WHO grades 1-4). Gross total resection (GTR) was achieved more frequently in the NP group (NP vs. non-NP: 61.7 vs. 28.6%, P = 0.04), which also had shorter durations of surgery (NP vs. non-NP: 240.7 ± 45.7 vs. 286.6 ± 54.8 min, P < 0.01). Furthermore, the rate of unexpected tumor residuals (estimation of the intraoperative extent of resection vs. postoperative imaging) was lower in the NP group (NP vs. non-NP: 19.1 vs. 42.9%, P = 0.09), but no difference was observed in terms of permanent surgery-related language deterioration (NP vs. non-NP: 6.4 vs. 14.3%, P = 0.48).

Conclusion: We need professional neuropsychological evaluation during awake craniotomies for removal of presumably language-eloquent gliomas. Although these procedures are routinely carried out with an NP, this is one of the first studies to provide data supporting the NP's crucial role. Despite the small group size, our study shows statistically significant results, with higher rates of GTR and shorter durations of surgery among patients of the NP group. Moreover, our data emphasize the common problem of language barriers between the surgical and neuropsychological team and patients requiring awake tumor resection.

Keywords: awake surgery; brain tumor; direct electrical stimulation; interdisciplinary teamwork; intraoperative testing; neuropsychologist.

Figure 1

Duration of surgery. Boxplot of duration of surgery for the neuropsychologist (NP) and the non-NP group with median, minimum, and maximum whiskers and quartile-boxes. There was a statistically significant difference in the duration of surgery between both groups (P < 0.01).

Figure 2

Residual tumor. Bar chart of gross total resection (GTR, in %) for the neuropsychologist (NP) and non-NP group. GTR was achieved in 61.7% of patients in the NP group and 28.6% of patients in the non-NP group according to magnetic resonance imaging (MRI) performed after surgery (P = 0.04).

Figure 3

Surgery-related language deterioration. Bar chart comparing surgery-related language worsening between the neuropsychologist (NP) and non-NP group. In the NP group, 53.2% of patients showed no new surgery-related deficits, whereas transient deficits occurred in 40.4% of the patients and permanent deficits occurred in 6.4% of the patients. In the non-NP group, no new surgery-related deficits were documented for 57.1% of patients, whereas 28.6% of the patients were diagnosed with transient deficits and the remaining 14.3% of the patients suffered from permanent deficits. Regarding surgery-related permanent deficits, there was no statistically significant difference between groups (P = 0.48).