Intraoperative Tonic-Clonic Seizure Under General Anesthesia Captured by Electroencephalography: A Case Report

Intraoperative Seizure Under General Anesthesia Not Detected by EEG: A Case Report

Intraoperative seizures under general anesthesia are infrequent. However, seizure activity under general anesthesia confirmed by contemporaneous EEG has been reported. We describe the case of a 39-year-old female undergoing right frontal brain tumor resection who experienced an intraoperative seizure. Intraoperative neuromonitoring was utilized and included four channels of EEG, somatosensory evoked potentials (SSEP), and transcranial motor evoked potentials (MEP). During this operation, characteristic motor manifestations of a seizure occurred. However, the EEG did not demonstrate seizure activity due to limitations in EEG lead placement. Post-operatively in the ICU, motor manifestations of seizure activity continued, and subsequent EEG recordings demonstrated classic seizure activity. Due to the previous hemicraniectomy, corkscrew EEG electrodes were not placed over the right skull defect, thereby failing to detect the intraoperative seizure. Anesthesiologists should be aware that limitations with EEG electrode placement can fail to detect intraoperative seizures, and treatment to extinguish the seizure should proceed in an emergent fashion.

Two cases of anesthetics-induced epileptic seizures: a case report and literature review

Background

Anesthetics like propofol have been reported to be capable of controlling status epilepticus. However, we have observed during daily clinical work that some anesthetics can induce epileptic seizures. Therefore, this study aims to explore the relationships between anesthetics and epilepsy.

Case presentation

We collect and report two cases of anesthetics-induced epileptic seizures, in order to arouse attention towards this critical phenomenon. We also summarize the current research progress on this topic, analyze associations between anesthetics and epilepsy, and discuss the mechanisms underlying the associations. Two females, seizure-free for more than 3 years, presented with anesthetics-induced epileptic seizures and controlled by administration of Midazolam and Diazepam. By literature review, we included six studies which found that the occurrence of epileptic seizures has no relationship with the age/sex of patients, the surgery procedure, nor the type of anesthesia. It is closely related to the decreased blood concentration of antiepileptic drugs (AEDs) and the inadequate preoperative preparation.

Conclusions

Unnecessary surgery should be avoided for patients with epilepsy, and anesthetists should make careful selections on anesthetics and prepare adequately for surgery.

A case report of several intraoperative convulsions while using the Narcotrend monitor: Significance and predictive use

INTRODUCTION

Intraoperative seizures under general anesthesia are rare and our observation is the first to demonstrate a distinct electroencephalogram (EEG) pattern on the Narcotrend monitor.

PATIENT CONCERNS

We present the case of a 30-year-old man undergoing craniotomy for glioblastoma resection under general anesthesia who suffered tonic-clonic seizures captured in a specific pattern by the intraoperative EEG.

DIAGNOSES

Our depth of anesthesia monitor recorded, before the seizure, a widening of the beta-wave performance in a distinct "triangular-shaped" pattern. This pattern was repeated before the second seizure. The patient had no previous history of seizures and following surgery no further seizures were recorded.

INTERVENTIONS

A spectrogram analysis showed a distinct increase in mean absolute beta power immediately prior to the first seizure. The EEG immediately prior to the second seizure was characterized by broadband noise. Both seizures were characterized by increased mean absolute delta, theta, and beta power.

OUTCOMES

The increase in EEG beta activity seen before the tonic-clonic movements may represent cortical irritability secondary to surgical manipulation, induced by electrical stimulation, reflecting progressive brain over-arousal. The attentive analysis of the relative beta power may have helped forecast the occurrence of the second seizure.

LESSONS

We report the use of a simple, inexpensive, and portable EEG-based monitoring device to assist seizure detection and decision making.