Abnormal temporal lobe morphology in asymptomatic relatives of patients with hippocampal sclerosis: A replication study

Abstract

<jats:title>Summary</jats:title><jats:p>We investigated gray and white matter morphology in patients with mesial temporal lobe epilepsy with hippocampal sclerosis (<jats:styled-content style="fixed-case">mTLE</jats:styled-content>+<jats:styled-content style="fixed-case">HS</jats:styled-content>) and first‐degree asymptomatic relatives of patients with <jats:styled-content style="fixed-case">mTLE</jats:styled-content>+<jats:styled-content style="fixed-case">HS</jats:styled-content>. Using T1‐weighted <jats:styled-content style="fixed-case">magnetic resonance imaging (MRI)</jats:styled-content>, we sought to replicate previously reported findings of structural surface abnormalities of the anterior temporal lobe in asymptomatic relatives of patients with <jats:styled-content style="fixed-case">mTLE</jats:styled-content>+<jats:styled-content style="fixed-case">HS</jats:styled-content> in an independent cohort. We performed whole‐brain <jats:styled-content style="fixed-case">MRI</jats:styled-content> in 19 patients with <jats:styled-content style="fixed-case">mTLE</jats:styled-content>+<jats:styled-content style="fixed-case">HS</jats:styled-content>, 14 first‐degree asymptomatic relatives of <jats:styled-content style="fixed-case">mTLE</jats:styled-content>+<jats:styled-content style="fixed-case">HS</jats:styled-content> patients, and 32 healthy control participants. Structural alterations in patients and relatives compared to controls were assessed using automated hippocampal volumetry and cortical surface–based morphometry. We replicated previously reported cortical surface area contractions in the ipsilateral anterior temporal lobe in both patients and relatives compared to healthy controls, with asymptomatic relatives showing similar but less extensive changes than patients. These findings suggest morphologic abnormality in asymptomatic relatives of <jats:styled-content style="fixed-case">mTLE</jats:styled-content>+<jats:styled-content style="fixed-case">HS</jats:styled-content> patients, suggesting an inherited brain structure endophenotype.</jats:p>