In Childhood Epilepsy, Scalp Spike Ripples Predict Seizure Risk Better Than Spikes
NEW YORK (Reuters Health) – In children with epilepsy, recorded scalp spike ripples are better than spikes at predicting seizure risk, according to new findings.
Spike ripples, or short bursts of high-frequency oscillations co-occurring with epileptiform discharges, are easier to detect than ripples alone and have greater pathological significance, researchers explain in Brain, online March 25.
“This biomarker outperforms analysis of spikes alone in categorizing seizure risk,” Dr. Catherine J. Chu of Massachusetts General Hospital and Harvard University in Boston and colleagues conclude. “These data provide evidence that spike ripples are a specific non-invasive biomarker for seizure risk in benign epilepsy with centrotemporal spikes (BECTS).”
The team prospectively evaluated spike ripples in scalp electroencephalography (EEG) recordings from 21 children between 5 and 17 years of age with BECTS and 13 healthy controls between 9 and 14 years of age, at one medical center. Children without both a history of focal motor or generalized seizures and an EEG showing sleep-activated centrotemporal spikes were excluded from the study.
The healthy controls had no history of seizure or known neurological disorder. Children with BECTS and healthy controls with a history of autism spectrum disorder, intellectual disability, or other unrelated neurological disease were excluded, while those with attention disorders and mild learning difficulties were included.
The research team compared the rate of spike ripples between children with epilepsy and healthy controls; as well as between 10 children with active epilepsy (within one year of seizure) and 13 (including two patients with BECTS who returned after at least 12 months for repeat testing) who were seizure-free for more than one year, using semi-automated and automated detection methods.
The spike-ripple rate was higher in children with active epilepsy compared to healthy controls (P=0.0018) or in children with epilepsy who were seizure-free while on or off medication (P=0.0018). Among epilepsy patients with spike ripples, each seizure-free month lowered the odds of a spike ripple by a factor of 0.66 (P=0.021).
Comparing the presence of at least one spike ripple vs. a classic spike event to identify a group, the researchers found similar sensitivity (100% for both) and negative predictive value, but they found significantly greater specificity (85% vs. 31%) and positive predictive value (83% vs. 53%) of spike ripples.
Dr. Ahmed T. Abdelmoity, director of the division of child neurology at Children’s Mercy Kansas City in Missouri, told Reuters Health by email, “BECTS sometimes poses a challenge in the neurology clinic as most patients have a benign course and will not require treatment; however about 10% to 15% will require treatment and sometimes might develop a drug-resistant form of epilepsy.”
Dr. Abdelmoity, who was not involved in the study, noted that “accuracy in predicting patients who might require treatment through EEG and initiating treatment earlier are important, to help prevent seizures and reduce family anxiety.”
“These findings bring clarity, with the knowledge that patients with BECTS can have different outcomes,” he added. “They also explain some of the neurophysiology of those outcomes.”
The researchers recommend further related studies to investigate using this biomarker to guide medication and predict seizure risk.
The study did not have commercial funding, and the authors declared no conflicts of interest. They did not respond to requests for comment.
Reuters Health Information © 2019
Cite this: In Childhood Epilepsy, Scalp Spike Ripples Predict Seizure Risk Better Than Spikes – Medscape – Apr 18, 2019.