Abstracts

Rationale: Some patients with epilepsy associated to autoimmune encephalitis develop drug resistant epilepsy and could be potential surgical candidates. However results of resective surgery in this context are not well known. We report the results of a retrospective multicenter study including patients with drug resistant epilepsy associated to antineuronal antibodies who underwent epilepsy surgery. Our objective was to describe the surgical outcome and find out if this correlates with the type of antibodies.Methods: 11 patients (6 male, 5 female) were included in the study. Mean age was 38 years; mean age at seizure onset was 26 years.Results: An acute phase of the disease could be identified in 8/12 patients. Detected antibodies were: antiMa2 (2 patients), antiGAD (5, titers not available for review), anti Hu (1 ), anti VGKC (antigen not specified: 2, one associated to anti GAD), antiLG1 (1) and antiCASPR2 (1). Antibodies were detected in serum in all patients and in CSF in 2. Associated diseases included testicular tumor (3 patients, 2 antiMa2 and 1 antiHu), type I diabetes mellitus (2 antiGAD patients, one also with celiac and thyroid disease). Five patients received corticosteroids and immunoglobulins during the acute phase of the disease. In 5 patients diagnosis was made after review of pathology. Mean time from seizure onset to presurgical evaluation was 4.5 years. Mean number of previously tried AED was 3.6. Seizure frequency was high (daily in 6 patients). MRI showed abnormal findings in most patients (unilateral MTS: 3 patients, bilateral MTS: 1, unilateral mesial temporal structures enlargement with hyperintensity: 4). All patients had focal seizures with temporal lobe semiology. Interictal EEG showed unilateral temporal interictal epileptiform discharges in 8 patients and bilateral in 3. EEG seizures were recorded from one temporal lobe in 8 patients and from both temporal lobes, independently, in 3. Memory deficit was bilateral in 4 patients and unilateral in 4. Surgical procedures included: anteriomesial temporal resection (8), selective amygdalohyppocampectomy (1), focal resection of the temporal pole (1) and radiofrequency thermocoagulation of mesial structures (1). Pathology showed inflammatory infiltrates in 8/10 patients. Seven patients had at least 3 year follow up: Engel class IV 2 patients, class III 3 (2 seizure recurrence after being class I), clase I 2. Two patients had one year follow up, both Engel class II. Two patients had only 6 month follow up: Engel class I 1 , Engel class IV 1. 5 patients with class I and II outcome at last follow up included a variety of antineuronal antibodies (LG1 1, VGKC associated to anti GAD 1, anti Hu 1, anti Ma2 1, anti GAD 1). 2/3 patients with class IV outcome had bilateral independent seizures recorded.Conclusions: Surgical treatment may improve seizure frequency in some patients with drug resistant epilepsy associated to antineuronal antibodies. The small number of cases and the different approches strongly suggest the need for guidelines to better classify these patients and international registries to study outcomes in larger populations.