Intraoperative hyperventilation vs remifentanil during electrocorticography for epilepsy surgery - a case report

Area of Science:

• Neuroscience
• Epileptology
• Surgical Neurology

Background:

• Intraoperative electroencephalography (EEG) traditionally detects irritative zones via interictal spikes.
• Identifying the seizure onset zone (SOZ) offers superior localization but is hindered by waiting for spontaneous seizures.
• Seizure precipitants are used, but provoked seizures may differ from spontaneous ones.

Observation:

• This study explored using hyperventilation and remifentanil as intraoperative seizure precipitants.
• Recordings were made from subdural and intraventricular electrodes in a patient with temporal lobe epilepsy.
• Two distinct ictal onset zones were identified in response to each provocation method.

Findings:

• Hyperventilation-induced and remifentanil-induced focal seizures originated from different brain regions in the same patient.
• Resection of both identified SOZs resulted in the patient remaining seizure-free for one year.
• This marks the first report of hyperventilation as an intraoperative seizure precipitant in human focal epilepsy.

Implications:

• Provocation methods can reveal distinct SOZs, enhancing surgical localization for epilepsy.
• This technique may improve surgical outcomes and reduce recurrence rates in focal epilepsy.
• Further research into seizure provocation could refine intraoperative strategies for epilepsy surgery.