title: Amygdala enlargement: Temporal lobe epilepsy subtype or nonspecific finding?
abstract: Amygdala enlargement (AE) is observed in patients with temporal lobe epilepsy (TLE), which has led to the suggestion that it represents a distinct TLE subtype; however, it is unclear whether AE is found at similar rates in other epilepsy syndromes or in healthy controls, which would limit its value as a marker for focal epileptogenicity.
  
  
  
  We compared rates of AE, defined quantitatively from high-resolution T1-weighted MRI, in a large multi-site sample of 136 patients with nonlesional localization related epilepsy (LRE), including TLE and extratemporal (exTLE) focal epilepsy, 34 patients with idiopathic generalized epilepsy (IGE), and 233 healthy controls (HCs).
  
  
  
  AE was found in all groups including HCs; however, the rate of AE was higher in LRE (18.4%) than in IGE (5.9%) and HCs (6.4%). Patients with unilateral LRE were further evaluated to compare rates of concordant ipsilateral AE in TLE and exTLE, with the hypothesis that rates of ipsilateral AE would be higher in TLE. Although ipsilateral AE was higher in TLE (19.4%) than exTLE (10.5%), this difference was not significant. Furthermore, among the 25 patients with unilateral LRE and AE, 13 (52%) had either bilateral AE or AE contralateral to seizure onset.
  
  
  
  Results suggest that AE, as defined with MRI volumetry, may represent an associated feature of nonlesional localization related epilepsy with limited seizure onset localization value.
authors.affiliation: New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY, 10016, United States. Electronic address: anr086@ucsd.edu.
authors.forename: Anny
authors.initials: A
authors.lastname: Reyes
authors.affiliation: New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY, 10016, United States; New York University School of Medicine, Department of Radiology, New York, NY,10016, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: Thesen
authors.affiliation: New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY, 10016, United States.
authors.forename: Ruben
authors.initials: R
authors.lastname: Kuzniecky
authors.affiliation: New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY, 10016, United States.
authors.forename: Orrin
authors.initials: O
authors.lastname: Devinsky
authors.affiliation: University of California San Diego, Center for Multimodal Imaging and Genetics (CMIG), San Diego, CA 92093, United States.
authors.forename: Carrie R
authors.initials: CR
authors.lastname: McDonald
authors.affiliation: The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, 3084, Australia.
authors.forename: Graeme D
authors.initials: GD
authors.lastname: Jackson
authors.affiliation: The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, 3084, Australia; Austin Health, Department of Neurology, Melbourne, Victoria, Australia.
authors.forename: David N
authors.initials: DN
authors.lastname: Vaughan
authors.affiliation: New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY, 10016, United States; St. Georges University School of Medicine, Department of Behavioral Sciences, St. Georges, Grenada.
authors.forename: Karen
authors.initials: K
authors.lastname: Blackmon
mesh_terms: D000328:Adult; D000679:Amygdala / Q000473:pathology* / Q000503:physiopathology; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology
keywords: MRI; Morphometry; Nonlesional epilepsy; Temporal lobe epilepsy