Breakthrough Research in Pediatric Epilepsy

MRI-guided stereotactic laser ablation (SLA) is at least as effective as and less harmful than typical surgical procedures for treating galactic seizures caused by hypothalamic hamartomas (HH), according to research¹ presented at the 69^th Annual Meeting of the American Epilepsy Society (AES 2015).

“SLA seems minimally invasive and precise,” said Shawn Reddy, a medical student at Baylor University. “For our HH patients, SLA is an efficacious treatment for gelastic seizures.”

“Most patients,” he continued, “were minimal or no side effects from SLA.”

This study is particularly important because of the difficulty in surgically treating gelastic seizures due to HH.

For the study, the results of 37 SLA procedures performed at Texas Children’s Hospital were reviewed for efficacy and safety data. The patients were then split into 2 groups, those who previously had surgery (eg, gamma knife radiosurgery) and those who did not. “Twenty-nine of them [total patients] are currently seizure free at last clinical follow-up,” said Reddy. Additionally, of the 10 patients who previously had surgery, 8 were seizure free at last clinical follow-up.

Only one serious adverse event was noted by the researchers, and this patient had a temporal lobectomy less than 3 months before the SLA procedure.

“Finally,” Reddy concluded, “the majority of patients were discharged from the hospital the next morning.”

Other research² at AES 2015 demonstrated that the use of whole-exome sequencing (WES) in initial diagnostic workup increases diagnostic yield in early onset epilepsy.

“We feel our study supports the clinical utility of using WES upfront for this cohort of patients based on diagnostic yield, the yield of those with specific treatment implications,” stated Michelle Demos, MD, of BC Children’s Hospital in Canada.

“Having a genetic diagnosis can have a significant clinical impact,” said Demos. “If you identify a disorder that has treatment implications, this is important.” However, access to genetic testing on a clinical basis is low.

The patient group for this study, done by Demos and colleagues, consisted of 50 children who had a diagnosis of epilepsy of unknown cause at 5 years old or younger. Depending on how old the diagnosis was at the time of the study, patients were either placed in a prospective (epilepsy < 6 months) or retrospective (epilepsy > 6 months) group.

Demos and colleagues made a definite or likely diagnosis in 32% of the patients and a potential or possible diagnosis in 22%. Further, 16% of the yields had treatment implications. Some of the identifications even occurred for patients who already underwent other genetic testing, such as chromosome microarray or specific gene testing.

This study also demonstrated that time to diagnosis from enrolling was quick. “It was under two months,” said Demos, “and obviously a lot faster when performed up front with their epilepsy diagnosis.”

“Having a genetic diagnosis does provide opportunity for the potential of a therapeutic indication, even if it’s not known, perhaps for the future,” she concluded.

Moving forward, this group will do an economic analysis of doing WES up front compared to other diagnostic testing.

The AES 2015 Annual Meeting was held December 4-8 in Philadelphia.

Session: Pediatric Epilepsy Highlights Section, Dec. 7, 2015.

References:

1. Reddy S, et al. Safety and efficacy of stereotactic laser ablation of hypothalamic hamartomas. Abstract No 2.305, 2015. American Epilepsy Society Annual Meeting, www.aesnet.org.

2. Demos M, et al. Targeted analysis of whole exome sequencing in early onset epilepsy. Abstract No 1.311, 2015. American Epilepsy Society Annual Meeting, www.aesnet.org.