Go Back Brain/18. More than one of above/Metabolic, Endocrine, Toxic/18.5 Carbon Monoxide Poisoning/ Go to Index

49 y.o. comatose female found down…adjacent to a coal heater.

Findings:

Restricted diffusion within the frontal and parietal cortex / subcortical white matter.

Restricted diffusion depicted within bilateral caudate, basal ganglia, putamen, and corticospinal tracts.

DDx for Anoxic-Ischemic Encephalopathy:

Cardiac arrhythmia

Myocardial infarction

Drug overdose

Respiratory failure

Sepsis

Environmental toxins

Carbon Monoxide Poisoning

Formation of carboxyhemoglobin in the blood results in hypoxia-anoxia.

The direct toxic effect of carbon monoxide on mitochondria interferes with oxidative phosphorylation.

Thus… anoxic-ischemic encephalopathy, usually bilateral.

Clinical suspicion usually confirmed by the presence of elevated carboxyhemoglobin the blood.

Carbon Monoxide Poisoning

CT: Bilateral globus pallidus hypodensity described.

MRI: Hyper or hypointensity within the globus pallidus bilaterally. Abnormal signal can be demonstrated in the cortex, subcortical white matter, hippocampi, and basal ganglia.

Carbon Monoxide Poisoning

A delayed encephalopathy occurs in ~3% of patients. At 2-3 weeks after the initial insult, additional MRI findings have been described. They include: hyperintensity in the corpus callosum, subcortical U fibers, and the capsules. T2 hypointensity in the thalamus and putamen are also described.

Carbon Monoxide Poisoning

Often, regions which initially demonstrate restricted diffusion normalize.