Abstract
BACKGROUND: Seizures are a common but often overlooked manifestation of MELAS. This study aimed to describe the characteristics of seizures in MELAS and to analyze the clinical, electroencephalographic, imaging, and biochemical factors associated with drug-resistant epilepsy. METHODS: A single-center retrospective study was conducted to investigate the clinical characteristics of seizures in MELAS patients. The study collected data on clinical features, muscle biopsy results, genetic testing, seizure symptoms, electroencephalography (EEG), neuroimaging findings, cerebrospinal fluid and blood biochemistry, and the modified Rankin Scale (mRS). We also investigated the correlation between seizure frequency and mRS scores. In addition, we analyzed the risk factors for drug-resistant epilepsy in MELAS. RESULTS: A total of 37 patients with confirmed MELAS (24 males and 13 females) were included in the study. All patients experienced seizures, with an onset age ranging from 14 to 53 years and a mean of 32 years. These MELAS patients experienced a variety of seizure types, with generalized seizures being the most common. EEG findings revealed background rhythm abnormalities in all patients, and epileptiform discharges were observed in 37.8% of patients during the interictal phase. Status epilepticus (OR 16.499; 95% CI, 1.615-168.557; P = 0.018) and elevated resting serum lactate levels (OR 8.594; 95% CI, 1.342-59.733; P = 0.024) were identified as independent risk factors for drug-resistant epilepsy. In addition, changes in the seizure frequency at the last follow-up compared to baseline were positively correlated with the mRS score. (r = 0.533, p < 0.001). CONCLUSION: Status epilepticus and elevated resting serum lactate levels were predictive of the development of drug-resistant epilepsy in MELAS. Poor seizure control was significantly associated with increased clinical disability. Early identification of high-risk patients for drug-resistant epilepsy could facilitate the development of more effective treatment plans.