Lennox-Gastaut Syndrome in Mitochondrial Disease

PURPOSE: Previous studies have shown that neurologic symptoms are dominant in patients with mitochondrial diseases, and most of these patients have seizure-related disorders. The epileptic classification of these patients as Lennox-Gastaut syndrome (LGS) is as high as 25%. This study aimed to investigate the clinical manifestations, diagnoses, treatments, and epilepsy in LGS, which is associated with mitochondrial disease. MATERIALS AND METHODS: A retrospective study was conducted on 372 patients who were diagnosed with mitochondrial disease between 2006 and 2016. Of these 372 patients, 40 patients diagnosed with LGS were selected, and they were classified into two groups based on the history of West syndrome. Patient characteristics were reviewed, and associations between clinical factors and outcomes after the treatment were analyzed. RESULTS: The proportion of individuals with mitochondrial disease with LGS with a history of West syndrome was 32.5%. Among the patients with mitochondrial disease with LGS, neonatal seizure (p=0.029), seizure as the first symptom (p=0.018), and generalized paroxysmal fast activity frequency on electroencephalogram (p=0.018) in the group with a history of West syndrome were statistically significantly high. The first symptom onset (0.6±0.4 yrs vs. 1.6±0.9 yrs, p=0.003) and first seizure onset (0.9±0.7 yrs vs. 3.9±3.1 yrs, p<0.001) were significantly faster in patients with a history of West syndrome. CONCLUSION: Close monitoring of the medical condition and early intervention might improve the prognosis of individuals with mitochondrial disease with LGS and a history of West syndrome.