Carbon Monoxide Brain Toxicity: Clinical, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, and Neuropsychological Effects in 9 People

Carbon monoxide (CO) exposure is a common cause of toxic brain damage, whereby effects range from transient neurological dysfunction to coma and death. A spectrum of severity of magnetic resonance imaging (MRI) findings after CO brain toxicity, including globus pallidus and white matter lesions, is well documented. Reports of MR spectroscopy (MRS) findings re main sparse. This article reports 9 people exposed to CO because of an apartment house's faulty gas heater. Four, with transient loss of consciousness after chronic moderate level CO exposure, suffered intellectual impairment without MRI abnormalities. The MRS of 1 individual demonstrated decreased n-acetyl aspartase in the basal ganglia, bilaterally. Of 5 exposed to high levels for about 12 hours, 1 died prior to clinical and/or MRI evaluation. One who suffered coma recovered but was lost to evaluation. Three, who were unconscious for hours to days, exhibited T2 MRI white matter signal abnormalities. MRS showed decreased basal ganglia n-acetyl aspartase in 2. One of these suffers a Parkinsonian syndrome. All 3 are intellectually impaired. This study demonstrates that although MRI and MRS are useful markers of CO-induced brain damage, they are not always sensitive to resultant intellectual dysfunction.