EVALUATION OF OUTCOME OF DELAYED NEUROLOGIC SEQUELAE AFTER CARBON-MONOXIDE POISONING BY TC-99M HEXAMETHYLPROPYLENE AMINE OXIME BRAIN SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY

Using brain computed tomography (CT) and single photon emission comput ed tomography (SPECT) with technetium-99m hexamethylpropylene amine ox ime (Tc-99m HM-PAO) in 13 patients with delayed neurologic sequelae af ter carbon monoxide poisoning, we tried to evaluate the clinical outco me of delayed CO sequelae. Among the 13 initial brain CTs, seven showe d low density in the cerebral white matter and one revealed hypodensit y in both globi pallidi. Of the 7 follow-up CT scans, 3 have remained unchanged, but in 4 cases more aggravating patterns with cortical atro phy without the clinical correlation were observed. There was no corre lation between the CT findings and the outcome of delayed CO sequelae. All initial SPECTs in 13 patients with delayed CO sequelae showed dif fuse patchy hypoperfusion throughout the cerebral cortex. Among the fo llow-up SPECTs in 7 patients, 6 patients showed increased cerebral per fusion with the concomitant clinical improvement, but the SPECT of a p atient in bedridden state had remained unchanged, compared with the in itial SPECT. There seemed to be good correlation between the findings of SPECT and the outcome of delayed CO sequelae. In conclusion, Tc-99m HM-PAO brain SPECT is more sensitive than CT, and may be a useful tes t in evaluating the clinical outcome of delayed neurologic sequelae af ter CO poisoning.