title: Volumetric changes in amygdala and entorhinal cortex and their relation to memory impairment in patients with medial temporal lobe epilepsy with visually normal MR imaging findings.
abstract: OBJECTIVE
  To explore the relation between parahippocampal structures, such as the amygdala and the entorhinal cortex (EC), with verbal and nonverbal memory in patients with medial temporal lobe epilepsy (MTLE) with visually normal MR imaging findings by volumetric measurements using magnetic resonance imaging (MRI).
  
  
  METHODS
  Thirty-six consecutive patients with MTLE presenting a non-sclerotic hippocampus though visual inspection were assessed by MRI to measure the volumes of the hippocampus, amygdale and EC, and by using the clinical memory scale (CMS), a test battery for verbal and nonverbal memory, where summation of all CMS subscale scores equals the memory quotient (MQ). The correlations between MRI volumetric data (Z scores or asymmetry indexes (AI; (L-R)/(L+R)), "L" and "R" refer to the left and right volumes of each structure, respectively), clinical variables and memory scale scores were analyzed using a principal component regression model.
  
  
  RESULTS
  Volumetric MRI revealed significant differences between the volumes of the hippocampus, EC, and right amygdala, but no differences in the volume of the left amygdala between the controls and the patients group. The patients group performed significantly worse in MQ (p < 0.01), the associate memory test (p < 0.01), directed memory test (p < 0.05), and the nonsense graphical recognition test (p < 0.05) compared to the control group. The asymmetry of the amygdala negatively correlated to verbal paired associates' recall and nonsense graphical recognition. The direct memory was positively related to the volume of the EC.
  
  
  CONCLUSIONS
  The volumetric asymmetry of the amygdala contributes to either verbal or nonverbal memory impairment in MTLE patients. Verbal memory may correlate with the volume of the EC.
authors.affiliation: Department of Neurology, Guang Zhou Women and Children's Medical Center, China. Electronic address: pengbingwei2@foxmail.com.
authors.forename: Bingwei
authors.initials: B
authors.lastname: Peng
authors.affiliation: Department of Neurology, Peking Union Medical College Hospital, China. Electronic address: wuliwen@pumch.cn.
authors.forename: Liwen
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Neurology, Peking Union Medical College Hospital, China. Electronic address: zhanglh04036@163.com.
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Peking Union Medical College Hospital, China. Electronic address: ccscc2012@126.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000473:pathology*; D018728:Entorhinal Cortex / Q000473:pathology*; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000473:pathology* / Q000523:psychology*; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000473:pathology* / Q000523:psychology*; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests; D021641:Recognition, Psychology; D055815:Young Adult
keywords: MRI; Medial temporal lobe epilepsy; Memory impairment; Verbal and nonverbal memory; Volumetric analysis