Magnetic resonance imaging findings after acute carbon monoxide poisoning.

Carbon monoxide (CO) is the most common toxic gas. It is odourless, colourless, inflammable, and highly toxic. CO is released during incomplete combustion of carboncontaining substances. This gas is the most frequent cause of death by accidental poisoning, as well as being responsible for a significant percentage of suicides. Prevalence of death by CO poisoning increases during the winter due to absent or deficient ventilation of domestic heaters and the higher incidence of depression during the winter months. CO causes adverse effects by binding to haemoglobin. Once inhaled, it passes into the bloodstream. The affinity of CO for the haem groups is 250 to 300 times that of oxygen, causing it to bind tightly (although not irreversibly) to haemoglobin to form carboxyhaemoglobin. This leads to decreased blood oxygen content which mainly affects the CNS and myocardium. Toxicity depends on the exposure time and amount inhaled, and it may be either acute or chronic. Initial symptoms range from nonspecific signs such as headache, dizziness, nausea, vomiting, and confusion, to events including loss of consciousness, coma, and death. Morbidity after CO poisoning includes neurological sequelae, mainly cognitive impairment, parkinsonism, and psychiatric symptoms. We present the case of a 38-year-old man with a personal history of paranoid