Abstracts

Rationale: Patients with chromosome 15q duplication syndrome (Dup15q) are at higher risk for developmental delay, epilepsy of variable severity and sudden unexpected death in epilepsy. It is common for children with Dup15q to be diagnosed with treatment resistant epilepsy. Vagus nerve stimulation (VNS) is approved for use in patients with treatment resistant epilepsy but its efficacy has not been studied in individuals with any chromosomal duplication.Methods: A detailed electronic survey was conducted through the Dup15q Alliance containing comprehensive questions regarding demographics, seizure control and anticonvulsant medication use prior to and after VNS placement in a 2 year time frame.Results: 17 patients responded (10 females) with mean age of 19 years (range 7-39). 11 individuals have isodicentric duplication (68%) and 6 (32%) have interstitial or edge duplications of the chromosome 15. The age of seizure onset ranged from 4 months to 13 years with a mean of 4.8 years and a median of 6 years. 11/17 (68%) have generalized seizures, 4/17 (23%) have generalized and focal seizures and 1/17 has focal seizures. 15 patients have Lennox-Gastaut Syndrome. Prior to VNS placement: Our cohort was on mean of 3 anticonvulsant medications (range 1-5). 3 patients had <1 seizure daily, 5 had 2-10 seizures daily and 9 had >10 seizures per day. 4/17 patients (24%) had history of status epilepticus and 3/17 (17%) were using rescue antiepileptic medication more than twice per month. After the VNS placement: Our cohort was on a mean of 2.8 anticonvulsant medications (range 1-5). 9/17 patients (55%) had >50% seizure reduction of their predominant seizure type and 8/17 (45%) had <50% seizure reduction. 1/17 patients (6%) had status epilepticus. 1/17 (6%) was using rescue antiepileptic medication more than twice per month. 11/17 (65%) used the magnet, 7 of which reported moderate to dramatic reduction on the seizure duration.5/17 reported mild or no reduction. Complications occurred in 2/17 (12%) patients. One reported site infection after the placement that required hospitalization and one reported dysphagia that resolved with change in the parameters. Overall in a scale of 1-10 (1 - no benefit, 10 - most effective treatment) for the patient’s epilepsy, 9/17 (58%) scored higher than 5, 5/17 (29%) higher than 7 and only 3/17 (17%) reported no benefit. At least 8 patients opted to replace the generator battery.Conclusions: This is the first report of VNS efficacy and safety on patients with treatment resistant epilepsy due to chromosome 15 duplication or any other chromosomal duplication. VNS was safe and well tolerated and even though our sample size was small, the results were robust with a positive trend on seizure reduction, frequency of status epilepticus and patient satisfaction. Further studies are needed to determine the efficacy of VNS use within our cohort. Based on our review VNS should be considered in patients with epilepsy that failed medical treatment.