Abstracts

Rationale: To determine the prevalence of and risk factors for various peri-ictal autonomic changes in focal seizures of temporal or frontotemporal onset. Methods: Children admitted to the pediatric epilepsy monitoring unit (PEMU) at Mayo Clinic Rochester were identified from a database. Those with focal seizures of temporal or frontotemporal onset and a captured clinical seizure with EEG correlate were studied. Various signs and symptoms of autonomic dysfunction were evaluated and the frequency of each was determined. Age, gender, antiepileptic drug (AED) polytherapy, number of generalized tonic-clonic seizures over the last year, lateralization, MRI abnormality, and etiology were evaluated as potential risk factors for peri-ictal autonomic dysfunction. Results: Tachycardia, oxygen desaturation, and salivation were the most frequently found autonomic changes (Table 1). Older children tended to have tachycardia more so than younger children (mean age with tachycardia 12.3 years vs. 6.6 years without, p <.001) as well as a larger number of different autonomic changes (Table 2, p = .0012). Report of at least one generalized tonic clonic seizure in the last year was not associated with differences in autonomic changes. Two of three children (66.7%) with a genetic etiology for their seizures had desaturations with focal seizures compared to 9 of 45 children (20with another etiology (p = .063). Those with a right sided epileptic focus had a higher number of different autonomic changes than those with a left sided focus (mean 2.57 vs 1.50, p = .043), as well as more salivation with focal seizures (23.8% vs 3.8%, p = .042). Oxygen desaturation (29.4% vs 7.3 %, p = .095), tachycardia (55.9% vs 28.6%, p = .085), and salivation (17.7% vs 0%, p = .093) tended to be seen more often in children, and cough less often (8.8% vs 28.6%, p=.078), with AED polytherapy than those with either no therapy or monotherapy. Children with an MRI abnormality had more tachycardia (60% vs 29.4%, p= .044), oxygen desaturations (33.3% vs 5.8%, p= .0327), salivation (20% vs 0%, p= .048), and number of different autonomic changes (median 2.5 vs 1.0, p= .031). Conclusions: Oxygen desaturation and tachycardia were the most frequently encountered autonomic derangements peri-ictally. Older age was significantly associated with tachycardia in focal seizures and a larger number of different autonomic changes. An abnormality on MRI was significantly associated with tachycardia, oxygen desaturation, salivation, and a larger number of different autonomic changes in focal seizures. There was a trend toward genetic etiology being associated with more oxygen desaturation. Right sided epileptic focus was significantly associated with salivation and a larger number of different autonomic changes. There was a nonsignificant trend towards AED polytherapy being associated with more oxygen desaturation, tachycardia, and salivation, and less cough.