title: Hippocampal volume in normal aging and traumatic brain injury.
abstract: OBJECTIVE
  To present a normative database of hippocampal and temporal horn volume and to clarify the relationship between these measures and cognitive outcome in patients with traumatic brain injury.
  
  
  METHODS
  Ninety-six healthy volunteers and 94 patients with traumatic brain injury were examined with coronal intermediate and T2-weighted MR imaging. Multispectral segmentation and volume analyses were performed. The volumetry of the hippocampus and temporal horn was characterized in the control subjects. Volumetric measures in a group of patients with traumatic brain injury who had received MR imaging 3 months or less after injury were compared with measurements in other patients in the chronic phase of recovery. The relationship between neuropsychological testing and volumetric measures was analyzed with particular emphasis on the correlation between cognitive outcome and hippocampal and temporal horn volumes.
  
  
  RESULTS
  No significant age group differences were found in the normative group from age 16 to 65. Left and right hippocampal volumes were interrelated and did not differ from each other. This was also true for the temporal horns. Hippocampal and temporal horn volumes were not significantly related. Women had larger hippocampi relative to cranial volume. Comparisons between patients with traumatic brain injury and control subjects showed significant yet modest bilateral atrophic changes in hippocampal and temporal horn enlargement in the patients with brain injury. Hippocampal and temporal horn volumes correlated significantly with each other in the group with traumatic brain injury. Cognitive outcome was modestly related to hippocampal and temporal horn volumes. However, in a specific subgroup whose images were acquired between 71 and 210 days after injury, strong correlations were noted in which temporal horn volume correlated highly with IQ and hippocampal volume correlated with verbal memory function.
  
  
  CONCLUSIONS
  Hippocampal and temporal horn volumes appear to be independent variables in healthy control subjects. Traumatic brain injury results in significant hippocampal atrophy and temporal horn enlargement. The hippocampus and temporal horn volumes were inversely correlated in the group with traumatic brain injury, suggesting a differential relationship of these structures in patients with brain injury as compared with control subjects. In the subacute phase, the volume of the temporal horn may be indicative of intellectual outcome and that of the hippocampus appears to be indicative of verbal memory function.
authors.affiliation: LDS Hospital, Salt Lake City, Utah, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Bigler
authors.forename: D D
authors.initials: DD
authors.lastname: Blatter
authors.forename: C V
authors.initials: CV
authors.lastname: Anderson
authors.forename: S C
authors.initials: SC
authors.lastname: Johnson
authors.forename: S D
authors.initials: SD
authors.lastname: Gale
authors.forename: R O
authors.initials: RO
authors.lastname: Hopkins
authors.forename: B
authors.initials: B
authors.lastname: Burnett
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001284:Atrophy; D001925:Brain Damage, Chronic / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology; D001930:Brain Injuries / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007360:Intelligence / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D012016:Reference Values; D013702:Temporal Lobe / Q000473:pathology*; D014706:Verbal Learning / Q000502:physiology