Abstracts

Rationale: Mitochondrial (mt) disorders can cause epilepsy, including specific syndromes such as MERRF and MELAS. However, the effects of epilepsy and antiepileptic drugs (AEDs) on mt function are unclear. The objective of this study was to retrospectively assess the incidence of mt respiratory complex (RC) dysfunction in children with epilepsyMethods: The following clinical data were gathered: age, gender, presence of chronic static encephalopathy (CSE), epilepsy type, AEDs' number, and epilepsy control. Buccal swabs were used to determine RC-I activity by immunocapture and RC-IV and citrate synthase (CS) activities using microspectrophotometry. RC activity values were normalized relative to CS activity, and expressed as ratios (I/CS and IV/CS). Results: A total of 58 children, 24 M, 34 F, ages 1-21 years were studied: 33 (57%) had CSE; 27 (46.6%) generalized and 29 (50%) focal epilepsy; AEDs mean number was 1.4 (range 0-3); 41 (70.7%) children had well controlled epilepsy. The frequency of abnormal I/CS and/or IV/CS was significantly higher in patients with CSE (60.6% vs. 20%, p=0.002). A significant increased frequency of abnormal I/CS (41.2% vs. 14.6%, p=0.027) was seen in patients with uncontrolled epilepsy. Epilepsy type and AEDs' number did not have an effect on the frequency of RCs dysfunction.Conclusions: Experimental investigations have found that epilepsy decreases mt RC, damages mt, and activates oxidative stress, perpetuating the epileptogenic cycle of high-energy-demand neurons. Our clinical study supports these findings, demonstrating that epilepsy is associated with mt dysfunction, which is worse in patients with underlying CSE or uncontrolled epilepsy.