title: Longitudinal analysis of hippocampal T2 relaxometry in FMTLE.
abstract: OBJECTIVE
  To investigate the degree of T2 relaxometry changes over time in groups of patients with familial mesial temporal lobe epilepsy (FMTLE) and asymptomatic relatives.
  
  
  METHODS
  We conducted both cross-sectional and longitudinal analyses of T2 relaxometry with Aftervoxel, an in-house software for medical image visualization. The cross-sectional study included 35 subjects (26 with FMTLE and 9 asymptomatic relatives) and 40 controls; the longitudinal study was composed of 30 subjects (21 with FMTLE and 9 asymptomatic relatives; the mean time interval of MRIs was 4.4 ± 1.5 years) and 16 controls. To increase the size of our groups of patients and relatives, we combined data acquired in 2 scanners (2T and 3T) and obtained z-scores using their respective controls. General linear model on SPSS21® was used for statistical analysis.
  
  
  RESULTS
  In the cross-sectional analysis, elevated T2 relaxometry was identified for subjects with seizures and intermediate values for asymptomatic relatives compared to controls. Subjects with MRI signs of hippocampal sclerosis presented elevated T2 relaxometry in the ipsilateral hippocampus, while patients and asymptomatic relatives with normal MRI presented elevated T2 values in the right hippocampus. The longitudinal analysis revealed a significant increase in T2 relaxometry for the ipsilateral hippocampus exclusively in patients with seizures.
  
  
  CONCLUSIONS
  The longitudinal increase of T2 signal in patients with seizures suggests the existence of an interaction between ongoing seizures and the underlying pathology, causing progressive damage to the hippocampus. The identification of elevated T2 relaxometry in asymptomatic relatives and in patients with normal MRI suggests that genetic factors may be involved in the development of some mild hippocampal abnormalities in FMTLE.
authors.affiliation: Laboratory of Neuroimaging, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil; Faculty of Medical Sciences, UNICAMP (University of Campinas), Campinas, SP, Brazil.
authors.forename: Luciana Akemi Yasuda
authors.initials: LA
authors.lastname: Suemitsu
authors.affiliation: Laboratory of Neuroimaging, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil; Department of Neurology, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil.
authors.forename: Clarissa Lin
authors.initials: CL
authors.lastname: Yasuda
authors.affiliation: Laboratory of Neuroimaging, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil; Department of Neurology, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil.
authors.forename: Marcia Elisabete
authors.initials: ME
authors.lastname: Morita
authors.affiliation: Laboratory of Neuroimaging, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil; Institute of Physics "Gleb Wataghin", University of Campinas, Campinas, SP, Brazil.
authors.forename: Guilherme Coco
authors.initials: GC
authors.lastname: Beltramini
authors.affiliation: Laboratory of Neuroimaging, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil; Department of Neurology, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Coan
authors.affiliation: Laboratory of Neuroimaging, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil.
authors.forename: Felipe
authors.initials: F
authors.lastname: Bergo
authors.affiliation: Department of Medical Genetics, University of Campinas, Campinas, SP, Brazil.
authors.forename: Iscia
authors.initials: I
authors.lastname: Lopes-Cendes
authors.affiliation: Laboratory of Neuroimaging, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil; Department of Neurology, FCM, UNICAMP (University of Campinas), Campinas, SP, Brazil. Electronic address: fcendes@unicamp.br.
authors.forename: Fernando
authors.initials: F
authors.lastname: Cendes
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000151:congenital* / Q000473:pathology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis
keywords: Familial mesial temporal lobe epilepsy; Longitudinal analysis; Magnetic resonance imaging; T2 relaxometry