Abstracts

Rationale: Autism spectrum disorder (ASD) and epilepsy commonly co-occur. Resective and non-resective surgeries can be effective treatments for patients with drug resistant epilepsy. However, past research in patients with ASD and epilepsy has yielded mixed results in regard to seizure outcomes following epilepsy surgery. We performed a systematic review focused on outcomes of epilepsy surgery in patients with ASD.

Methods: We adhered to the PRISMA standards. Using relevant search terms, MEDLINE, Embase, and PsycInfo were queried from inception to December 2021. Two authors independently screened titles and abstracts of each study for eligibility. Studies were included if they reported change in seizure frequency or Engel classification following epilepsy surgery in at least one person with ASD. Quality assessment of studies was conducted using an NIH assessment tool. Through use of this tool, the quality of each study was characterized as good, fair or poor. Reviewers also rated the rigor by which each study measured non-seizure related outcomes following epilepsy surgery. Relevant non-seizure related outcomes included changes in behavior, psychosocial functioning, symptoms of ASD and neuropsychological profile. Studies that used extensive standardized testing both before and after surgery to assess multiple relevant outcomes were rated as excellent. Those that used only subjective reporting, or non-standardized clinical assessments were considered adequate. Studies that failed to assess non-seizure related outcomes either before or after surgery were considered inadequate.

Results: A total of 593 abstracts were identified, of which 78 were selected for full text review. Thirty-seven studies reporting on 293 patients were included. A total of 131 patients underwent resective surgery, 144 underwent neuromodulation, and 18 underwent other palliative procedures (corpus corpus callosotomy or multiple subpial transection). The distribution of seizure outcomes for all procedures was as follows: 79 (26.96%) Engel I or seizure free, 87 (29.69%) Engel II/III or >80% reduction in seizure frequency without seizure freedom, 127 (43.34%) Engel IV or  < 80% reduction in seizure frequency. Overall study quality was considered good in 10 studies and fair in 27. No study was determined to be of poor quality. With regard to non-seizure related outcomes, the quality of reporting on these outcomes was rated as excellent in 9 studies, adequate in 18 studies, and inadequate in 10 studies.

Conclusions: Based on past work, there is potential for properly selected patients with ASD and epilepsy to experience a significant reduction in seizure frequency or seizure freedom following resective and non-resective epilepsy surgery. The majority of studies did not use standardized, objective measures to assess non-seizure related outcomes. There is a need for more large prospective studies that rigorously assess seizure and non-seizure related outcomes following epilepsy surgery in persons with ASD.

Funding: None