title: Seizure frequency and lateralization affect progression of atrophy in temporal lobe epilepsy.
abstract: BACKGROUND
  It is unclear which factors lead to progressive neuronal damage in mesial temporal lobe epilepsy (MTLE). The objective of this study was to evaluate whether progressive hippocampal and extrahippocampal atrophy occur in patients with MTLE and whether this atrophy is related to seizures.
  
  
  METHODS
  We performed 2 MRI scans in 33 patients with clinical and electroencephalographic diagnosis of MTLE and in 24 healthy controls. MRI was performed in a 2-T scanner, and a T1-weighted gradient-echo sequence with 1 mm thickness was used for voxel-based morphometry analysis. Follow-up images were obtained at least 7 months after the first baseline MRI. Comparisons between the patient's follow-up and baseline MRIs, and between patients and controls, were performed. A corrected p value of 0.05 was set as the threshold for the statistical analysis.
  
  
  RESULTS
  Follow-up MRI was performed after a median interval of 39 months (range 7-85 months). Three patients were seizure-free between the first and second MRIs. We observed progressive white and gray matter atrophy (p < 0.05) in patients with MTLE. This progression was more intense in patients with left MTLE compared with right MTLE. A higher frequency of seizures and a longer duration of epilepsy were associated with progression of gray and white matter atrophy in patients with MTLE.
  
  
  CONCLUSIONS
  The progression of white and gray matter atrophy in patients with mesial temporal lobe epilepsy (MTLE) was more intense in patients with left MTLE and was associated with poorer seizure control and a longer duration of epilepsy.
authors.affiliation: Department of Neurology, University of Campinas-UNICAMP, SP, Brazil, ClnAPCe Program, MRC-UNICAMP, SP, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Coan
authors.forename: S
authors.initials: S
authors.lastname: Appenzeller
authors.forename: L
authors.initials: L
authors.lastname: Bonilha
authors.forename: L M
authors.initials: LM
authors.lastname: Li
authors.forename: F
authors.initials: F
authors.lastname: Cendes
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D013702:Temporal Lobe / Q000473:pathology*