Memory one month after acute carbon monoxide intoxication: a prospective study
- 1Department of Internal Medicine and Clinical Toxicology, Fernand Widal-Lariboisiére Hospital, 75475 Paris Cedex 10, France
- 2Department of Medical and Toxicological Intensive Care, Fernand Widal-Lariboisiére Hospital; University Paris 7–Institut National de la Santé et de la Recherche Médicale (INSERM U26) 75475 Paris Cedex 10, France
- 3Emergency Medical Services, Paris Fire Department, 55 boulevard de Port Royal, 75013 Paris, France
- Correspondence to: Pr S Dally, Department of Internal Medicine and Clinical Toxicology, Fernand Widal Hospital, 75475 Paris Cedex 10; dally{at}ext.jussieu.fr.
- Accepted 20 June 2002
Abstract
Background: Serious delayed neuropsychological sequelae may complicate carbon monoxide intoxication. The existence of minor manifestations, especially memory disturbances, is not well documented.
Aims: To study several memory functions after carbon monoxide intoxication.
Methods: In a prospective study, 32 poisoned patients without risk factors for cognitive disturbances were compared to 32 paired control subjects one month after acute carbon monoxide intoxication (blood carbon monoxide concentration at least 1.0 mmol/l), who had been treated with standard conventional therapy. Psychometric tests included Buschke’s verbal memory testing, verbal digit span, Corsi’s visuospatial span, reaction times, Stroop’s colours decoding test, and verbal fluency test.
Results: (1) Memory functions in poisoned subjects were not worse than in the control group and were even better in some areas: learning, word recall, and quality of learning by Buschke’s verbal memory testing. Attention was also better in the patients, in whom visual reaction time was shorter than in controls. (2) Results of several memory functions—quality of learning and immediate visual memory—were positively correlated with the initial carbon monoxide level.
Conclusions: In a highly selected subset of patients devoid of risk factors for memory impairment, memory, objectively evaluated by psychometric testing, was not worse one month after carbon monoxide intoxication in patients undergoing standard treatment than in paired control subjects.
