Abstracts

Rationale: MRI-guided stereotactic laser ablation (SLA) using Visualase© (Medtronic Inc.) is becoming an accepted neurosurgical treatment for multiple applications. SLA offers a high degree of surgical precision and is minimally invasive. These factors lead to reduced hospital stays compared to more invasive procedures. Gelastic seizures secondary to hypothalamic hamartomas (HH) are particularly difficult to approach surgically. This is a retrospective review of pediatric patients who have undergone SLA for treatment of gelastic seizures. A comparison is made between patients who previously underwent surgical intervention with those who were surgically naïve.Methods: After obtaining IRB approval, a retrospective analysis was performed on 37 patients at Texas Children’s Hospital who were treated with SLA for gelastic seizures caused by HH from 2010-2015. All patients were included in final analysis had clinical follow up to assess efficacy from 2 weeks to 4 years after the procedure. Data points included age at time of surgery, gender, ethnicity, epilepsy type, number of seizures per week before/after SLA, past surgical history, adverse effects of past surgical history and adverse effects of SLA.Results: Of the 37 patients who underwent SLA, 28 (76%) were male and 9 (24%) were female. Ten (28%) patients had previous surgical intervention, including vagus nerve stimulation (3), gamma knife radiosurgery (3), craniotomy (5) and endoscopic resection (1). Overall, 27 (73%) of these patients are seizure-free at last follow-up. Five (50%) of the 10 patients with previous surgical intervention are seizure-free, compared to 22 (82%) of the 27 patients with no previous surgical intervention who are seizure-free. In most cases, patients who had SLA were discharged the morning after surgery. Serious adverse events were reported in 3 (30%) of the 10 patients who had surgery prior to SLA, which included hemiparesis, hypothyroidism, precocious puberty, memory loss and diabetes insipidus. One patient (3%) experienced a serious complication following SLA, which was a serious memory disorder. This patient had a previous temporal lobectomy. Three additional SLA patients had a mild, transient memory disorder.Conclusions: MRI-guided laser ablation appears to be at least equally as effective as traditional surgical procedures for treatment of gelastic seizures caused by HH. It appears to have fewer side effects and the vast majority of patients were discharged the next morning. SLA appears to be more effective in patients that have not undergone previous surgeries. However, half of those patients still had significant benefit.