Clinical outcome and magnetic resonance imaging of carbon monoxide intoxication. A long-term follow-up study

Ital J Neurol Sci. 1999 Jun;20(3):171-8. doi: 10.1007/s100720050028.


The clinical and neuroradiological outcome of carbon monoxide (CO) intoxication was evaluated prospectively in 30 patients over a follow-up period of 3 years. Among the patients studied, 22 had been acutely exposed to CO while 8 were chronically exposed. One month after CO poisoning, 12 of the 22 patients with acute intoxication showed magnetic resonance imaging (MRI) abnormalities: 6 also had neurological sequelae and 6 were asymptomatic. The remaining 10 patients showed neither MRI abnormalities nor neurological sequelae. During the 3-year follow-up, 4 of the patients with both MRI abnormalities and neurological sequelae improved in both clinical features and MRI findings. One of the 6 asymptomatic patients with MRI abnormalities developed a progressive cognitive impairment 2 months after acute intoxication, with a concomitant severe worsening of the MRI lesions. Among the 10 patients with neither MRI abnormalities nor neurological sequelae, only 1 developed neurological sequelae after a clear period of 4 months. In the group of patients who experienced chronic CO intoxication, only 1 presented with a neuropsychiatric syndrome which improved at follow-up. Brain MRI showed white matter lesions which remained unchanged at control scan after 1 year. In conclusion, we observed that some patients with severe CO poisoning and neurological sequelae may fully regain normal functions after approximately 1 year. The presence of MRI lesions 1 month after CO poisoning did not accurately predict the subsequent outcome. The observation of a clear period longer than the usual 2-40 day interval in 2 patients should be considered for careful planning of follow-up and for prognosis in CO-poisoned patients.

MeSH terms

  • Acute Disease
  • Adolescent
  • Adult
  • Aged
  • Brain / pathology*
  • Carbon Monoxide Poisoning / complications
  • Carbon Monoxide Poisoning / diagnosis*
  • Carbon Monoxide Poisoning / physiopathology
  • Child
  • Chronic Disease
  • Cognition Disorders / etiology
  • Female
  • Follow-Up Studies
  • Humans
  • Longitudinal Studies
  • Magnetic Resonance Imaging*
  • Male
  • Mental Disorders / etiology
  • Middle Aged
  • Nervous System Diseases / etiology
  • Recovery of Function