Age-Based Characteristics of West Syndrome in Patients with Mitochondrial Disease

Choi, Young Ha; Baek, Min Seong; Na, Ji Hoon; Kang, Hoon Chul; Lee, Joon Soo; Kim, Heung Dong; Lee, Young Mock

Abstract

PURPOSE
West syndrome is a severe form of age-specific epilepsy that typically affects infants younger than 2 years of age with mitochondrial disease. We aimed to examine age-specific characteristics of the syndrome in these patients.
METHODS
We retrospectively analyzed 54 patients with West syndrome diagnosed with mitochondrial disease between March 2006 and March 2016. We compared treatment strategies and diagnostic and clinical variables between patients with early-onset ( < 6 months of age) and late-onset (â‰¥6 months of age) seizures.
RESULTS
Seizure was the first symptom in 30 (90.9%) and 13 (65%) patients of the early-onset and late-onset groups, respectively (P=0.046). Delayed development was observed in 3 (9.1%) and 7 (35%) patients of the early-onset and late-onset groups, respectively (P=0.023). Lactate levels were normal in 17 patients (55%) of the early-onset group and 5 (25%) of the late-onset group (P=0.036), while initial brain magnetic resonance imaging (MRI) findings were normal in 23 (67.6%) and 8 (40%) patients of the early-onset and late-onset groups, respectively. Final MRI findings were abnormal in 32 patients (94.1%) of the early-onset group and 18 (90%) of the late-onset group (P=0.036). Although ketogenic diets reduced seizure frequency in both groups, the difference was not significant.
CONCLUSION
There is no significant difference in epilepsy-related variables when patients are divided based on a cut-off age of 6 months. However, differences in the first symptom at onset and MRI findings were observed. Although lactate levels were not of significant diagnostic value in the early-onset group, they may be in the late-onset group.