Neurology Today Conference Reporter: CNS Annual Meeting

Tuesday, October 10, 2017

Stopping AEDs? Why 24-Hour EEG Monitoring for Seizure Activity May Be Enough

BY JAMIE TALAN

KANSAS CITY, MO—There is little extra benefit in doing electroencephalography (EEG) monitoring for possible seizure activity in young patients with epilepsy for more than 24 hours, a new study suggests.

Reporting the findings here at the Child Neurology Society annual meeting last week, Sanjeev V. Kothare, MD, FAAN, director of child neurology at the Steven and Alexandra Cohen Children's Medical Center of New York and professor of pediatrics and neurology at Hofstra Northwell School of Medicine, said that the goal of the study was to determine if long-term EEG monitoring (ambulatory or video EEG) was adding enough benefit compared to routine monitoring when identifying patients at higher risk for seizure recurrence when stopping their antiepileptic drugs (AEDs).

Many neurologists order prolonged EEG monitoring (up to 72 hours) to determine if they can detect possible seizure activity before deciding to wean their patients off the AEDs, Dr. Kothare told the Neurology Today Conference Reporter.

The neurologists reviewed the medical charts of 101 epilepsy patients — 48 boys and 53 girls between ages of two and 19. They had different types of seizure disorders and had not had a seizure in at least one year. Their physicians wanted to wean them from their medications. Nineteen had a routine EEG (about 24 hours), 50 were monitored for 72 hours, and 32 patients had both EEG studies prior to medication withdrawal.​

The researchers reviewed medical records from follow-up exams from between six months and 89 months. The overall relapse rate was 22 percent, and AEDs were started in 26 patients. They found that 21 percent of the patients with 24-hour monitoring had relapsed as had 18 percent of those who had undergone 72-hour monitoring and 28 percent of those who had both types of monitoring before stopping their medication.

"Twenty-four hours is good enough [for EEG monitoring]," Dr. Kothare said. "If we didn't pick up anything within the first 24 hours we really don't find much more on longer monitoring."

Commenting on the study, Solomon L. Moshé, MD, FAAN, professor of neurology, neuroscience and pediatrics and director of clinical neurophysiology at the Albert Einstein College of Medicine, said: "The study provides additional information about the use of EEG in predicting seizure recurrence when one considers discontinuing medications. The information that the short EEG monitoring may be as informative as prolonged monitoring allows us to use either approach based on the patient's needs, including the etiology of their seizures."

"It depends on what you are looking for," he said. "Sometimes a short observation period is good enough, but sometimes you need to capture the full events to make a decision about stopping medications," Dr. Moshé added.

LINK UP FOR RELATED INFORMATION:​

Bettini L, Croquelois A, Maeder-Ingvar M, Rossetti AO. Diagnostic yield of short-term video-EEG monitoring for epilepsy and PNESs: A European assessment. Epilepsy Behav 2014;39:55-58.