Verbal memory deficits associated with fornix atrophy in carbon monoxide poisoning

J Int Neuropsychol Soc. 2001 Jul;7(5):640-6. doi: 10.1017/s1355617701005112.


Magnetic resonance (MR) images and neuropsychological testing data of 69 carbon monoxide (CO) poisoned patients were prospectively obtained within 1 day of CO poisoning, two weeks and six months. CO patients' Day 1 cross-sectional fornix surface area measurements, corrected for head size by using a fornix-to-brain ratio (FBR), were compared to normal age and gender-matched controls. Additionally, a within-subjects analysis was performed comparing the mean areas between CO patients' Day 1, 2 weeks and 6-month FBR. The FBR was correlated with patients' neuropsychological data. There were no significant differences between CO patients' Day 1 fornix measurements compared to normal control subjects. However, significant atrophic changes in the fornix of CO poisoned patients occurred at two weeks with no progressive atrophy at 6 months. By 6 months, CO patients showed significant decline on tests of verbal memory (when practice effects were taken into account), whereas visual memory, processing speed and attention/concentration did not decline. This study indicates that CO results in brain damage and cognitive impairments in the absence of lesions and other neuroanatomic markers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Amnesia / diagnosis*
  • Amnesia / physiopathology
  • Atrophy
  • Brain Damage, Chronic / diagnosis*
  • Brain Damage, Chronic / physiopathology
  • Carbon Monoxide Poisoning / diagnosis*
  • Carbon Monoxide Poisoning / physiopathology
  • Female
  • Follow-Up Studies
  • Fornix, Brain / pathology*
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Mental Recall / physiology
  • Middle Aged
  • Neuropsychological Tests*
  • Prospective Studies
  • Verbal Learning / physiology*