December 12th, 2017
A 45-year-old woman experienced long-term, chronic exposure to carbon monoxide in the restaurant kitchen where she was employed as a cook.After returning to the restaurant after 5 days off work, she noticed that her symptoms returned immediately; she then aired out the room and called the gas company.Approximately 6 hours after a leak was detected, the patient went to the hospital, where her carboxyhemoglobin was found to be within normal limits and results of a neurologic examination were described as normal. Based on her symptoms, the patient believed she had been exposed to CO for at least 1 year before the leak was discovered. Initially, she experienced flu-like symptoms, which eventually resolved.At the time of her first neuropsychological evaluation (17 months after the exposure was identified), her persisting complaints included difficulties in reading, writing, speaking and word retrieval. The test results were consistent with secondary frontal lobe dysfunction associated with subcortical disorders such as those seen after CO exposure. Results of a subsequent neuropsychological examination (29 months post exposure) showed slight improvement in performance, but her performance was still consistent with mildfrontal/subcortical dysfunction.Although the initial screening of a brain magnetic resonance image (MRI) performed 15 months after the exposure was interpreted as being within normallimits, two subsequent blind reviews of the same scans identified multiple bilateral lesions in the basal ganglia, which were consistent with chronic CO exposure. We present this case as an example of the utility of MRI and neuropsychological examinations in detecting central nervous system dysfunction secondary to CO exposure. Key words:carbon monoxide, neuropsychology, toxicant-induced encephalopathy, neuroimaging, MRI, neurobehavioral methods. Environ Health Perspect110:1051–1055 (2002).[Online 6 September 2002]http://ehpnet1.niehs.nih.gov/docs/2002/110p1051-1055devine/abstract.html Reproduced with permission from Environmental Health Perspectives