A Retrospective Analysis of Anaesthetic Management for Epilepsy Surgery with Intraoperative Neuromonitoring

A Retrospective Analysis of Anaesthetic Management for Epilepsy Surgery with

Intraoperative Neuromonitoring

Introduction:

Approximately 65 million people are affected with epilepsy worldwide3.

Prevalence of epilepsy in India has been reported as 4.3 per 1000 population1. Approximately 30-35% of patients develop drug resistant epilepsy (DRE)2.

Drug resistant epilepsy has been defined by International League against Epilepsy (ILAE) task force as failure to respond to two tolerated, appropriately chosen and adequately tried anti-epileptic drugs (AEDs)4. Various modalities are available for surgically remediable lesions provided there is concordance between different investigation modalities. The surgical management and neurological complications in patients undergoing epilepsy surgery is documented in the literature, but anaesthetic course and perioperative complications are less well-described. Anaesthesia management varies with the type of surgical technique selected and hence poses additional challenges. To address the anaesthetic and preoperative challenges faced we seek to investigate the data of patients with DRE who underwent epilepsy surgery at our institute.

Aims and objectives:

• To assess the anaesthetic techniques used and any possible impact they may have upon neuromonitoring
• To assess complications occurring in perioperative period.

Justification:

There have been many advances in surgery for drug resistant epilepsy which demands appropriate changes in anaesthetic management as well.

With newer guidelines still emerging for epilepsy surgery, we would like to conduct retrospective analysis of our anaesthetic and surgical date which will help us in formulating newer protocols on department level and provide better preoperative care leading to favourable outcomes.

Methodology:

Design of study:

This study will be a retrospective comparative study

Study duration:

From Jan 2020 to July 2025

Selection of cases:

After obtaining approval from institutional ethic committee, the study will be conducted at Superspeciality hospital, NSCB Medical College, Jabalpur

All patients who meet our inclusion criteria will be enrolled.

Inclusion criteria:

• Patients who have undergone surgery for drug resistant epilepsy

Exclusion criteria:

• Appropriate records and documentation not available

Method of study:

This study will be conducted at Superspeciality hospital, NSCB Medical College, Jabalpur after approval of institutional ethics committee and review board. This retrospective comparative study will enrol all patients with appropriate documentation who have undergone surgery for drug resistant epilepsy between January 2020 to April 2022. Drug resistant epilepsy will be defined as patients refractory to two or more antiepileptic drugs in adequate doses for at least two years.

Demographic data like age, sex, weight, height and data related to illness, age of onset of seizures, duration of epilepsy, investigations done and  relevant history. Intraoperative data to be collected; type and duration of surgery, anaesthetic technique and duration used, use of supplementary scalp blocks, neuromonitoring used, complications and recovery from anaesthesia. Postoperative data to be collected; immediate complications like postoperative nausea and vommiting (PONV), secures, ventilation and use of AEDs perioperatively. Long term outcome will be assessed using Engel rating scale as free of disabling seizure (Engel class I), rare disabling seizure (Engel II), worthwhile improvement (Engel III), or no worthwhile improvement (Engel class IV).[5]

Statistical analysis:

Data will be collected using GraphPad Prism version 10.4.2 (633) for windows software. Mean, standard deviation (SD) and confidence intervals (CI) will be calculated in the three groups for measurable demographic data like age and weight. Inter-group and intra-group hemodynamic parameters at different time points will be assessed with repeated measure ANOVA (analysis of variance) test. Categorical data will be assessed with chi-square test.

Results and conclusions:

Results and conclusions will be drawn at the end of the study.