Detection of hippocampal atrophy in patients with temporal lobe epilepsy: a 3-Tesla MRI shape

Epilepsy Behav. 2013 Sep;28(3):489-93. doi: 10.1016/j.yebeh.2013.05.035. Epub 2013 Jul 25.

Abstract

In patients with mesial temporal lobe epilepsy (MTLE), brain MRI often detects hippocampal sclerosis (HS). Almost half of patients with MTLE do not show any hippocampal damage on visual or volumetric assessment. Here, we wished to prospectively assess 65 patients with MTLE (41 women, mean age: 39±10years, range: 21-69; right (12/65 patients) (MRI-negative) nMTLE; right (14/65 patients) (MRI-positive with HS) pMTLE; left (24/65 patients) nMTLE; and left (15/65 patients) pMTLE) using shape analysis (SA). There were significant differences among pMTLE versus nMTLE for age at seizure onset (20.2±12.8 vs. 31.8±16.7years; p=.0029), duration of epilepsy (14.6±12.7 vs. 21.3±9.6years; p=.0227), risk of refractoriness (p=.0067), frequency of antecedent febrile convulsions (FCs) (p<.001), as well as a history of epilepsy or FCs (p=.0104). All the subjects underwent the same 3-Tesla MRI protocol. Shape analysis of hippocampal formation was conducted comparing each group versus 44 matched controls. In all four subgroups, SA detected a significant atrophy in the corresponding hippocampus that coincided with the epileptogenic area. The damage was significantly more severe in patients with pMTLE (F value: 5.00) than in subgroups with nMTLE (F value: 3.50) and mainly corresponded to the CA1 subregion and subiculum. In the patients with MTLE, SA detects hippocampal damage that lateralizes with the epileptogenic area. Such damage is most prominent in the CA1 subregion and subiculum that are crucial in the pathogenesis of MTLE.

Keywords: FCs; HS; Hippocampal sclerosis; MRI; MTLE; SA; Shape analysis; febrile convulsions; hippocampal sclerosis; magnetic resonance imaging; mesial temporal lobe epilepsy; nMTLE; negative MTLE (MTLE no HS); pMTLE; positive MTLE (MTLE+HS); shape analysis.

MeSH terms

  • Adolescent
  • Adult
  • Atrophy / complications
  • Atrophy / diagnosis
  • Epilepsy, Temporal Lobe / complications
  • Epilepsy, Temporal Lobe / pathology*
  • Female
  • Hippocampus / pathology*
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged
  • Young Adult