title: Increased iron levels and decreased tissue integrity in hippocampus of Alzheimer's disease detected in vivo with magnetic resonance imaging.
abstract: BACKGROUND
  Iron can catalyze damaging free radical reactions. With age, iron accumulates in brain gray matter regions and may contribute to the risk of developing age-related diseases such as Alzheimer's disease (AD). Prior MRI studies demonstrated increased iron deposits in basal ganglia regions; however, the hippocampus (Hipp), which is heavily damaged in AD, and comparator regions that are resistant to AD damage, such as thalamus (Th), have rarely been examined.
  
  
  OBJECTIVE
  To assess iron levels and evidence of tissue damage in Hipp and Th of AD subjects and healthy controls.
  
  
  METHODS
  Thirty-one AD and sixty-eight healthy control subjects participated in this study. High- and low-field strength MRI instruments were used in combination to quantify iron content of ferritin molecules (ferritin iron) using the field dependent relaxation rate increase (FDRI) method. Decreased transverse relaxation rate (R2) was used as an index of tissue damage.
  
  
  RESULTS
  Compared with healthy controls, AD subjects had increased ferritin iron in Hipp (p = 0.019) but not Th (p = 0.637), and significantly decreased R2 in Hipp (p < 0.001) but not Th (p = 0.37). In the entire sample, FDRI and R2 were negatively correlated.
  
  
  CONCLUSIONS
  The data shows that in AD, Hipp damage occurs in conjunction with ferritin iron accumulation. Prospective studies are needed to evaluate how increasing iron levels may influence the trajectory of tissue damage and cognitive and pathologic manifestations of AD.
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Erika P
authors.initials: EP
authors.lastname: Raven
authors.forename: Po H
authors.initials: PH
authors.lastname: Lu
authors.forename: Todd A
authors.initials: TA
authors.lastname: Tishler
authors.forename: Panthea
authors.initials: P
authors.lastname: Heydari
authors.forename: George
authors.initials: G
authors.lastname: Bartzokis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D005293:Ferritins / Q000032:analysis / Q000378:metabolism*; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007501:Iron / Q000032:analysis / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: D005293:Ferritins; D007501:Iron