A preoperative exam can help determine whether patients with focal epilepsy are good candidates for surgical resection, but it can also help predict the outcome of an additional invasive exam, according to a study published in JAMA Neurology.
Using MRI, EEG, and clinical features, the “5-SENSE” score can predict whether patients with epilepsy will benefit from a more invasive examination with stereotactic depth electrodes (SEEG). Using this score could reduce the number of patients who undergo an unsuccessful evaluation, according to Stephen Schuele, MD, MPH, director of epilepsy and neurophysiology in the Ken and Ruth Davee Department of Neurology and co-author of the study.
The 5-SENSE score can be used to help make a more informed decision with the individual patient when an invasive exam will be beneficial. “
Stephen Schuele, MD, MPH, Professor of Physical Medicine and Rehabilitation
For many patients with focal drug-resistant epilepsy, surgery is the only curative option. During this procedure, the epileptogenic zone – the area of the brain that causes seizures – is removed. This means that the procedure is usually reserved for patients whose seizures originate in non-critical areas of the brain, with the exception of regions that are responsible for language, memory or vision, for example.
The definition of an epileptogenic zone is the primary goal of the preoperative evaluation. This zone can be identified in about 70 percent of patients with non-invasive video EEG and imaging, but the remaining 30 percent require more invasive EEG evaluation with electrodes placed in the brain. Deciding who would benefit from this invasive screening is challenging, according to Schuele.
“Up to 30 percent of patients who do an invasive stereo-EEG exam cannot identify a resectable focus and go through the procedure, and the associated risks and costs, without improved seizure control,” said Schuele.
This is where the 5-SENSE score comes in: the score includes information obtained during non-invasive exams, including the presence of a focal lesion on the MRI, the lack of certain activity on the EEG of the scalp, and other clinical factors.
In the study, researchers evaluated 128 patients undergoing an invasive SEEG using the 5-SENSE test at nine centers around the world. The study found that 76 percent of patients whose 5-SENSE score indicated they would not have a resectable epileptogenic zone got the same result after invasive EEG.
These results show that the 5-SENSE score can be used to predict which patients the invasive evaluation is unlikely to identify a focal seizure zone.
“I think we should offer more personalized advice to patients who have decided to have epilepsy surgery,” said Schuele. “The 5-SENSE-Score can give a patient a specific number to decide whether the chance and the risk are worthwhile.”
Source:
Journal reference:
Astner-Rohracher, A., et al. (2021) Development and validation of the 5-SENSE score to predict the focality of the zone with the onset of seizures, as assessed by stereoelectroencephalography. JAMA neurology. doi.org/10.1001/jamaneurol.2021.4405.
