Abstracts

Rationale: MTLE (medial temporal sclerosis) refers to a specific subset of patients with seizures originating in the medial temporal lobe structures. The most common pathologic substrate of MTLE is HS(hippocampal sclerosis), which strongly suggests that MTLE with HS represents a subtype of a greater syndrome of MTLE. The onset of seizure after the age of 20(late onset MTLE with HS) is not uncommon in MTLE with HS, which suggests MTLE with HS might be also not homogenous clinical feature. This study tried to reveal the clinical characteristics between conventional MTLE with HS and late-onset MTLE with HS. Methods: One hundred nine patients of unilateral MTLT with HS were analyzed to compare the clinical profiles, which included demographic data, antecedent etiology, neurological deficits, clinical characteristics of seizure (prevalence of 2' generalized tonic-clonic seizure, clustering nature, nocturnal preponderance, clinical features of temporal lobe seizure), and prognosis. Additional lesions except HS on MRI and central nervous system infection related-MTLE were excluded. Results: Thirty over 119 patients (25.2%) has seizure onset after the age of 21. The mean age at the onset was 11.3 years (range;1-20) in conventional group and 32.5 years (range; 21-65) in late-onset group. Febrile convulsion, aura, and automatism were statistically significantly higher in conventional group and nocturnal dominancy was higher in late-onset group. The proportion of patients who were seizure-free or aura-only for at least 24 months at follow-up was higher in group late-onset group with statistically significance, which was 43.3% in late-onset group compared to 19.3% in conventional group. Conclusions: This results showed the clinical characteristics between 2 groups were clearly different in febrile convulsion, semiology, and prognosis. In considering of the age onset of seizure, this study suggested MTLE with HS did not have homogenous clinical feature, even though a subset with of a syndrome of MTLE.