title: Amygdala Volumetry in Patients with Temporal Lobe Epilepsy and Normal Magnetic Resonance Imaging.
abstract: BACKGROUND
  It has been suggested that the pathophysiology of temporal lobe epilepsy may relate to abnormalities in various brain structures, including the amygdala. Patients with mesial temporal lobe epilepsy (MTLE) without MRI abnormalities (MTLE-NMRI) represent a challenge for diagnosis of the underlying abnormality and for presurgical evaluation. To date, however, only few studies have used quantitative structural Magnetic Resonance Imaging-based techniques to examine amygdalar pathology in these patients.
  
  
  METHODS
  Based on clinical examination, 24-hour video EEG recordings and MRI findings, 50 patients with EEG lateralized TLE and normal structural Magnetic Resonance Imaging results were included in this study. Volumetric magnetic resonance imaging (MRI) studies of the amygdalas and hippocampi were conducted in 50 non-epileptic controls (age 7-79 years) and 50 patients with MTLE with normal MRI on a 1.5-Tesla scanner. Visual assessment and amygdalar volumetry were performed on oblique coronal T2W and T1W MP-RAGE images respectively. The T2 relaxation times were measured using the 16-echo Carr-Purcell-Meiboom-Gill sequence (TE, 22-352). Volumetric data were normalized for variation in head size between individuals. Results were assessed by SSPS statistic program.
  
  
  RESULTS
  Individual manual volumetric analysis confirmed statistically significant amygdala enlargement (AE) in eight (16%) patients. Overall, among all patients with AE and a defined epileptic focus, 7 had predominant increased volume ipsilateral to the epileptic focus. The T2 relaxometry demonstrated no hyperintense signal of the amygdala in any patient with significant AE.
  
  
  CONCLUSIONS
  This paper presented AE in a few patients with TLE and normal MRI. These findings support the hypothesis that there might be a subgroup of patients with MTLE-NMRI in which the enlarged amygdala could be related to the epileptogenic process.
authors.affiliation: Department of Radiology, Guru Gobind Singh Medical College and Hospital, Baba Farid University of Health Sciences, Faridkot, India.
authors.forename: Paramdeep
authors.initials: P
authors.lastname: Singh
authors.affiliation: Department of Medicine, Guru Gobind Singh Medical College and Hospital, Baba Farid University of Health Sciences, Faridkot, India.
authors.forename: Rupinderjeet
authors.initials: R
authors.lastname: Kaur
authors.affiliation: Department of Radiology, Dayanand Medical College and Hospital, Ludhiana, India.
authors.forename: Kavita
authors.initials: K
authors.lastname: Saggar
authors.affiliation: Department of Neurology, Dayanand Medical College and Hospital, Ludhiana, India.
authors.forename: Gagandeep
authors.initials: G
authors.lastname: Singh
authors.affiliation: Department of Radiology, Guru Gobind Singh Medical College and Hospital, Baba Farid University of Health Sciences, Faridkot, India.
authors.forename: Simmi
authors.initials: S
authors.lastname: Aggarwal
keywords: Amygdala; Epilepsy, Temporal Lobe; Neuroimaging