Asleep-awake-asleep versus hypnosis for low-grade glioma surgery: long term follow-up outcome.

BACKGROUND: Hypnosis-aided craniotomy is a safe alternative to standard asleep-awake-asleep (AAA) surgery in glioma surgery. The impact of these two anesthetic methods on tumor prognosis has never been assessed. OBJECTIVE: This study aimed to evaluate the possible impact of the type of sedation (i.e., hypnosedation vs. standard sedation) on postoperative outcomes in awake surgery for gliomas. METHODS: Adult patients who underwent awake surgery for a diffuse glioma, excluding glioblastomas, between May 2011 and December 2019 at the authors' institution were included in the analysis. Pearson Chi-square, Fisher exact, and Mann-Whitney U tests were used for inferential analyses. RESULTS: Sixty-one (61) patients were included, thirty-one were female (50.8 %), and the mean age was 41.8 years (SD = 11.88). Most patients had IDH mutated tumors (n = 51; 83.6%). Twenty-six patients (42.6%) were hypnosedated while 35 (57.4%) received standard AAA procedure. The overall median follow-up time was 48 months (range: 10 months-120 months). Our results did not identify any significant difference between both techniques in terms of extent of resection (sub-total resection >95% rates were 11.48% vs. 8.20%, OR = 2.2, 95% CI = 0.62-8.44; P = 0.34) and of overall survival (87.5% of patients in the AAA surgery group reach 9 years OS vs. 79% in the hypnosis cohort, cHR = 0.85, 95% CI = 0.12-6.04; P = 0.87). CONCLUSION: Hypnosis for awake craniotomy is rarely proposed although it is a suitable alternative to standard sedation in awake craniotomy for LGGs, with similar results in terms of extent of resection or survival.

Hypnosis for Awake Surgery of Low-grade Gliomas: Description of the Method and Psychological Assessment.

BACKGROUND: Awake craniotomy with intraoperative electric stimulation is a reliable method for extensive removal of low-grade gliomas while preserving the functional integrity of eloquent surrounding brain structures. Although fully awake procedures have been proposed, asleep-awake-asleep remains the standard technique. Anesthetic contraindications are the only limitation of this method, which is therefore not reliable for older patients with high-grade gliomas. OBJECTIVE: To describe and assess a novel method for awake craniotomy based on hypnosis. METHODS: We proposed a novel hypnosedation procedure to patients undergoing awake surgery for low-grade gliomas in our institution between May 2011 and April 2015. Surgical data were retrospectively recorded. The subjective experience of hypnosis was assessed by 3 standardized questionnaires: the Cohen Perceived Stress Scale, the Posttraumatic Stress Disorder Checklist Scale, the Peritraumatic Dissociative Experience Questionnaire, and a fourth questionnaire designed specifically for this study. RESULTS: Twenty-eight questionnaires were retrieved from 43 procedures performed on 37 patients. The Peritraumatic Dissociative Experience Questionnaire revealed a dissociation state in 17 cases. The Perceived Stress Scale was pathological in 8 patients. Two patients in this group stated that they would not accept a second hypnosedation procedure. The Posttraumatic Stress Disorder Checklist Scale revealed 1 case of posttraumatic stress disorder. Burr hole and bone flap procedures were the most frequently reported unpleasant events during opening (15 of 52 events). CONCLUSION: The main findings of our study are the effectiveness of the technique, which in all cases allowed resection of the tumor up to functional boundaries, and the positive psychological impact of the technique in most of the patients.

New insights into the neural network mediating reading processes provided by cortico-subcortical electrical mapping.

OBJECTIVES: To ascertain the neural network mediating reading using intraoperative electrostimulation. EXPERIMENTAL DESIGN: A cortical and axonal intraoperative electrical mapping of reading processes was achieved in seven patients who underwent awake surgery for a left occipitotemporal glioma. We performed resection cavity overlapping and superimposition with a diffusion tensor imaging-based white matter atlas. We assessed the relationship between the location of resection cavities and the occurrence of reading impairments of regular, irregular, and pseudowords. PRINCIPAL OBSERVATIONS: Intraoperative stimulation of the left posterior inferior temporal cortex (ITCp) elicited reading disturbances. Subcortical stimulation at the anterior portion of the visual word form area (VWFA) induced addressed phonology (irregular words reading) disturbances. Subcortical stimulation of the connection between VWFA and the posterior segment of the arcuate fascicle (AFp) induced both addressed and assembled phonology (irregular and pseudowords reading) disturbances. Postoperative assessment showed that resection of the posterior portion of the inferior longitudinal fascicle (ILFp), connecting the visual cortex to VWFA, induced long-term and global reading impairment. Resection of the terminations of left AFp in the ITCp-induced irregular and pseudowords reading disturbances with no impairment of regular words reading. Resection of the anterior portion of ILF did not induce reading impairment. CONCLUSIONS: Our data support an inner posterior-to-anterior hierarchical coding of letter strings in the VWFA and a crucial role of the left ILFp to provide visual inputs to the VWFA. Furthermore, we suggest that the AFp is involved in an interactive feedback system between visual and nonvisual information, recruited when reading irregular and pseudowords.