Abstracts

Investigational studies established the pivotal role of mammillary bodies [quot]MB[quot] and mammillothalamic tracts [quot]MTT[quot] in mnemonic function integrity. In addition, other animal studies highlighted the noteworthy anticonvulsive effect achieved by lesioning the same structures. Here we document our preliminary experience pertaining to the safety and tolerability of bilateral deep brain stimulation of MB and MTT in patients with refractory epilepsy [quot]RE[quot]. Three males (41-43 years) with RE were enrolled in a prospective, randomized, double-blind study. Neither medication nor vagus nerve stimulation [quot]VNS[quot] were capable to achieve a satisfactory seizure control. VNS was turned off six weeks before electrodes implantation without changing the medication. At different phases of the study, EEG-video, PET-FDG scan and neuropsychological examinations (verbal and visual memory), were performed for all patients. During the pre-randomization period, after electrodes implantation and before randomization, several brief intermittent stimulation trials (maximal range 130 Hz, 200 [micro]s, 0.3 to 3.5V) were performed for each target separately and unilaterally. Up to now, no transient or permanent related-surgery complications were recorded in any patient. No deterioration of the cardiovascular and respiratory parameters were identified. No impairment of verbal and visual mnemonic function was observed during or after the pre-randomization period. As our study still remains double-blinded, the outcomes upon seizures[rsquo] frequency and severity are still pending evaluation. However, No seizures[rsquo] aggravation was observed and all patients were satisfied after surgery. Based on our early-stage experience, it seems that electrodes[rsquo] implantation and intermittent brief electrical stimulations in MB and MTT are safe and well-tolerated in humans. These remarkable findings may encourage us to enroll more patients in this study. The potential anticonvulsive efficacy of this procedure will be analyzed at the end of the double-blind period. (Supported by Medtronic gives electrodes and stimulators.)