Seizure prediction ‘milestone’ achieved
medwireNews: Pioneering research shows that intracranial electroencephalographic monitoring is feasible in patients with drug-resistant epilepsy.
Overall, 15 patients with between two and 12 disabling partial-onset seizures per month received surgically implanted seizure advisory systems designed to collect data and assess whether the patient is at low, moderate, or high risk for a seizure.
As reported in TheLancet Neurology, two patients required surgery after 4 months due to migration or seroma, and a third patient experienced infection after 7 months. The patient who experienced migration subsequently had the device removed due to a site reaction.
Four months of adequate data was successfully collected for 11 patients, allowing creation of an algorithm to predict when they were at high likelihood for seizure.
In the advisory phase of the study, the high-risk algorithms were between 54% and 100% sensitive for prediction of seizures. And data collection for five patients allowed low-advisory likelihoods that gave negative predictive values of between 98% and 100%.
Although there was no significant impact on the effectiveness of clinical measures taken during the advisory phase, the researchers note that some patients reported lifestyle benefits, such as choosing to swim while having a low likelihood for seizure.
"Our small proof-of-concept study shows that seizure prediction is possible and could lead to new therapeutic strategies and more independence for individuals with epilepsy," say Mark Cook (St Vincent's Hospital, Melbourne, Victoria, Australia) and co-authors.
Of concern, the researchers found a significant discrepancy between patients' seizure diaries and the data collected by their devices. The two types of record significantly correlated in just five cases, with most patients significantly underestimating the number of seizures.
"Our findings have pronounced implications for trials of new epilepsy treatments, which often rely on patient-reported events as the primary efficacy endpoint," the researchers observe.
In an accompanying comment, Christian Elger and Florian Mormann, from the University of Bonn Medical Centre in Germany, praise the researchers for achieving the "major milestone" of demonstrating seizure prediction.
Acknowledging that "uncertainty in seizure counting has been ignored by much of the epilepsy community," they hope that the findings "will increase awareness of this crucial problem and open up a new research avenue for EEG [electroencephalography] -based, automated seizure-documentation devices that could eventually replace seizure diaries."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lynda Williams, Senior medwireNews Reporter