Abstracts

Rationale: The purpose of this sduty is to validate the effectiveness of stereotactic radiofrequency thermocoagulation (SRT) for hypothalamic hamartoma (HH).Methods: The clinical records of 120 patients (80 males and 40 females) with HHs who underwent SRT between 1997 and 2014 were retrospectively reviewed. In this series, all patients underwent a single surgical procedure of SRT in our hospital. Our SRT is based on the MRI-guided stereotactic planning for the target localization which was determined using the reconstructed multi-dimensional image planning software of the Surgiplan workstation (Leksell Surgiplan®). We set multiple coagulated lesions and trajectories to disconnect the plane between the HH and the attaching hypothalamus, not but in the whole volume of the HH.Results: The age at first SRT was 1-50 years (median; 9 years). 34 patients underwent previous treatment at other institute. All patients had gelastic seizures (GSs). 103 patients also had various types of seizures other than GS (non-GSs). The maximum diameter of HH was 4.5-80 mm (median; 15mm). Some of these patients also had mental retardation (n=60; 50%), behavioral disorder (n=60; 50%), and precocious puberty (n=40; 33%). A total of 165 SRTs were performed. 36 patients required re-SRTs targeting the recurrence of GS (2 SRTs, n=30; 3 SRTs, n=3; 4 SRTs, n=3). There was no mortality and severe morbidity after SRT. There were various transient complications including Horner’s syndrome (n=104; 63%), hyperphagia (n=46; 28%), hyponatremia (n=43; 26%), high fever (n=40; 24%), short memory disturbance (n=13; 8%), asymptomatic intracranial hemorrhage (n=4; 3%), and prolonged disturbance of consciousness (n=1; 1%, completely recovered 3 months after SRT). Repeat SRTs had an equal prevalence of transient complications to first SRT. Among 113 patients who had at least 6 months follow-up period, 94 patients (84%) achieved GS freedom after first SRT (n=72; 64%), 2nd SRT (n=19; 17%), 3rd SRT (n=1; 1%), and 4th SRT (n=2; 2%), respectively. 77 (75%) of 102 patients with non-GSs achieved non-GS freedom. Overall seizure freedom was achieved in 76 patients (65%). 23 patients became free from anti-epileptic drugs. Residual non-GSs did not improve on repeat SRT especially in patients with longer history of GS. Behavioral disorder and intellectual problems also improved in patients with seizure freedom. There were some patients with postoperative hormonal disorder including delayed PP after SRT (n=12; 12%), weight gain without hyperphagia (n=9; 7.5%), and pituitary disfunction (n=2; 2%).Conclusions: SRT achieved excellent seizure outcome with minimum invasiveness. Repeat SRT was also effective for residual GS, whereas ineffective for residual non-GS. SRT should be applied for HH at early epilepsy stage.