title: Surgery and brain atrophy in cognitively normal elderly subjects and subjects diagnosed with mild cognitive impairment.
abstract: BACKGROUND
  Structural magnetic resonance imaging is used to longitudinally monitor the progression of Alzheimer disease from its presymptomatic to symptomatic phases. Using magnetic resonance imaging data from the Alzheimer's Disease Neuroimaging Initiative, we tested the hypothesis that surgery would impact brain parameters associated with progression of dementia.
  
  
  METHODS
  Brain images from the neuroimaging initiative database were used to study normal volunteer subjects and patients with mild cognitive impairment for the age group 55 to 90 inclusive. We compared changes in regional brain anatomy for three visits that defined two intervisit intervals for a surgical cohort (n = 41) and a propensity matched nonsurgical control cohort (n = 123). The first interval for the surgical cohort contained the surgical date. Regional brain volumes were determined with Freesurfer and quantitatively described with J-image software (University of California at San Francisco, San Francisco, California). Statistical analysis used Repeated Measures ANCOVA (SPSS, v.18.0; Chicago, IL).
  
  
  RESULTS
  We found that surgical patients, during the first follow-up interval (5-9 months), but not subsequently, had increased rates of atrophy for cortical gray matter and hippocampus, and lateral ventricle enlargement, as compared with nonsurgical controls. A composite score of five cognitive tests during this interval showed reduced performance for surgical patients with mild cognitive impairment.
  
  
  CONCLUSIONS
  Elderly subjects after surgery experienced an increased rate of brain atrophy during the initial evaluation interval, a time associated with enhanced risk for postoperative cognitive dysfunction. Although there was no difference in atrophy rate by diagnosis, subjects with mild cognitive impairment suffered greater subsequent cognitive effects.
authors.affiliation: Department of Anesthesiology, New York University Langone Medical Center, New York, New York 10016, USA. richard.kline@nyumc.org
authors.forename: Richard P
authors.initials: RP
authors.lastname: Kline
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Pirraglia
authors.forename: Hao
authors.initials: H
authors.lastname: Cheng
authors.forename: Susan
authors.initials: S
authors.lastname: De Santi
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Haile
authors.forename: Mony J
authors.initials: MJ
authors.lastname: de Leon
authors.forename: Alex
authors.initials: A
authors.lastname: Bekker
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D003071:Cognition / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000473:pathology* / Q000523:psychology; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000473:pathology* / Q000523:psychology