Abstracts

Rationale: Epilepsy occurs in about one-third of all people with severe intellectual disability and about one-sixth of those with mild intellectual disability. The treatment of epilepsy syndromes (e.g. LGS, chromosomal disorder with epilepsy, brain malformations, epileptic encephalopathies ) remains difficult in this group of patients, freedom of seizures is rarely achieved. Polypharmacotherapy and side effects are frequent, sometimes surgical management is possible, callosotomy is a palliative surgical treatment of last choice. Therefore our study aimed to evaluate vagal nerve stimulation (VNS) as non-pharmacological and non-resective treatment-option in this group of patients. Methods: We investigated prospectively 42 adult patients with epilepsy and mental retardation before and after implantation of VNS with respect to seizures (drop attacks, status epilepticus), psychiatric comorbidity (depression, interictal dysphoric disorder/IDD, psychosis) and quality of life. Patients were monitored at least 6 months before implantation, follow up lasted at least 12 months (in- and outpatient based). Results were determined during the last 3 months of follow up. Results: 26 patients (61%) responded with a reduction of total seizure frequency of more than 50% (10 patients / 23 %: >75%). 13 of 31 patients (42 %) had a reduction of severe drop attacks of more than 50%. The magnet could be used successfully for interrupting auras / series in 23 patients (42%). 7 of 12 patients (58%) had significant benefit with respect to depression /IDD. In patients with non-affective disorders (psychosis) no effects were seen. Significant side effects did not occur. VNS was valued as very good in self-rating, by families and caregivers in 38 of 42 cases (90%). Conclusions: Our results support the indication of VNS particularly in this group of patients. Effects are long lasting and worthwhile not only on seizures, but as well on comorbidity with affective disorders. Tolerability was good, side effects were easy to handle. VNS can considerably improve the quality of life.