ELECTROENCEPHALOGRAPHIC MAPPING AND TC-99M HMPAO SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY IN CARBON-MONOXIDE POISONING

Study objective: To investigate whether topographic analysis of EEG ma pping and technetium-99m (Tc-99m) hexamethylpropylenamine oxide (HMPAO ) brain single-photon emission computed tomography (SPECT) can detect cerebral anomalies in the acute phase of carbon monoxide poisoning. De sign: Twelve patients aged 18 to 55 years with severe carbon monoxide poisoning and no history of neurologic disorder were evaluated. Either nasal (5 patients) or hyperbaric (7 patients) oxygen therapy was admi nistered. Criteria for hyperbaric oxygen therapy were blood CO of more than 20%, loss of consciousness, pregnancy, or signs of cardiac injur y. After oxygen treatment, all patients had a blood CO value of 0% and no patient had persistent acute signs of toxicity. Patients then were investigated by confentional EEG, EEG mapping, and Tc-99m HMPAO brain SPECT. These procedures were performed on the day of admission. Parti cipants: After nasal (5 patients) or hyperbaric (7 patients) oxygen th erapy was administered, 12 adults with severe carbon monoxide poisonin g were evaluated. Al studies were performed on the day of admission. M easurements: Conventional EEG, EEG mapping, and Tc-99m) HMPAO brain SP ECT. Results: While classic EEG was normal in 9 of 12 patients and sho wed diffuse anomalies in 3, EEG mapping and Tc-99m HMPAO brain SPECT d emonstrated unilateral or bilateral regional anomalies in 8 of 12 pati ents. Anomalies were localized in temporo-parieto-occipital areas, the watershed areas of the major cerebral arteries, or in temporal cortex . Conclusion: These preliminary results suggest that EEG mapping and T c-99m HMPAO brain SPECT can be complementary tools to diagnose early r egional cerebral anomalies in carbon monoxide-poisoned patients.