VNS Implantation, Dietary Therapies Reduce Seizures in Children With TSC, DRE

Robyn Whitney, MD

Data from a retrospective chart review suggest dietary therapies and vagal nerve stimulation (VNS) were effective in reducing seizures in children with tuberous sclerosis complex (TSC) and drug refractory epilepsy (DRE) who were ineligible for epilepsy surgery.

Investigators, including Robyn Whitney, MD, division of pediatric neurology, department of pediatrics, McMaster Children’s Hospital, McMaster University, Ontario, Canada, assessed seizure outcomes and adverse effects (AEs) in 20 children, 15 of whom (75%) were treated with dietary therapies, including the classic ketogenic diet (n = 10), the medium chain triglyceride diet (n = 4), and the modified Atkins diet (n = 1), Patients had a median age of 4.2 years (interquartile range, 2.5-11.7) at initiation, and 10 out of 15 children had persistently good ketone levels.

According to data presented at the American Epilepsy Society (AES) Annual Meeting, December 3-7, 2021, in Chicago and virtually, after a median follow-up duration of 23 months, a total of 7 children (47%) had a greater than 50% reduction in seizure frequency when treated with dietary therapy. Following a median of 17 months (range, 1-108 months) participants discontinued the diet, 3 due to AEs, 3 due to ineffectiveness, 2 due to improved seizure control, and 3 due to other reasons. The most common AEs related to diet were constipation in 7 participants (47%) and vomiting in 5 participants (33%). 

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Children who underwent VNS had a median age of implantation of 12 years, and 5 of the 9 who initiated VNS were referred to the treatment following failed or discontinuation of dietary therapy. VNS therapy was well-tolerated, and 6 of 9 patients treated with VNS had a 50% or greater reduction in seizures after a median follow-up period of 37 months. Seven of 9 patients had a response to the magnet, 4 reporting aborted seizures, 2 reporting reduced seizure duration, and 1 reporting reduced seizure severity. 

Patients had a median age at seizure onset of 5 months (range, 2 days – 2.5 years), and all had daily seizures when beginning dietary therapy or at the time of VNS implantation. The most common seizure type was focal seizures, and investigators observed TSC2 variants in 11 of 15 patients (73%). 

The retrospective review included children who were treated with dietary therapy or VNS therapy at 2 academic centers in Ontario, Canada between 2010 and 2020. Investigators noted the small number of studies investigating the effectiveness of dietary therapies and VNS in treating TSC, and the resultant need for a systematic review and meta-analysis of the existing data to determine the effect. 

Robyn Blackford, RD, LDN, registered dietician, Ann & Robert H. Lurie Children’s Hospital of Chicago, recently spoke with NeurologyLive® on the importance of understanding different dietary approaches to help control seizures, specifically the ketogenic diet. 

“For that classic, ketogenic diet, everything is weighed on a gram scale,” Blackford said. “You know every calorie, every protein, carbohydrate, fat, etc., down to the 100th of the gram. That way, we make sure patients stay in the correct amount of ketosis and everything is measured.”

Blackford further shared her thoughts on the commonly used dietary therapies, which patients benefit from certain approaches, and how much room patients are allotted to go outside their normal regimen. She also discussed how ketosis is achieved and whether mixing diets can have a positive or negative impact on a patient’s outcomes. Watch what she had to say in the video below. 

For more coverage of AES 2021, click here.

REFERENCE

Parbhoo K, Abushama A, Robyn Whitney, et al. Ketogenic diet or vagal nerve stimulation in children with tuberous sclerosis complex and drug-refractory epilepsy. Presented at AES 2021; December 3-7, 2021; Chicago, IL and Virtual. Abstract 1.222.