[Can magnetic resonance imaging of the brain in the acute phase of carbon monoxide intoxication forecast delayed encephalopathy?].

We examined the usefulness of Magnetic Resonance Imaging (MRI) test in the acute phase of carbon monoxide intoxication for forecasting delayed encephalopathy (DE). [Case 1] 26-year-old female. COHb 12%. Takotsubo (Ampulla) cardiomyopathy was supervened. Pallidal disorder was recognized in MRI test in the early stage. Although Prophylactic HBO was performed, DE began. 36 days later, disorder was recognized in large area, such as, in cerebral white matter and callosum, and abnormality was found in WMS-R and MMSE. Since HBO was performed, DE subsided. In MRI test, on the other hand, high signal range in cerebral white matter and callosum were gradually decreased and WMS-R and MMSE were improved. [Case 2] 19-year-old female. COHb 9.4%. The state was considered to be mild but pallidal disorder was found in MRI test at the beginning. DE did not start, then the part of pallidal disorder was narrowed. WMS-R and MMSE showed slightly low level. [Case 3] 19-year-old female. COHb 7.3%. The state was considered to be mild and there was no abnormal findings in MRI test in the early stage. DE did not start. [Case 4] 48-year-old male. COHb 48.9%. Rhabdomylosis was supervened, then ischemic change in a left radiate crown was recognized in the early MRI test. Since the third day, disorientation and restlessness had been developed, so that the patient was transferred to psychiatric department, though it was still difficult to distinguish the case from DE. Although the case is relatively mild, pallidal disorder is recognized in the early MRI test. Pallidal disorder alone can cause memory disorder and cognitive impairment. Even if pallidal disorder alone is recognized in the early MRI test, white matter disorder is developed with time, and then DE begins. If there are no typical carbon monoxide intoxication findings, some cases can be suspected as DE. It is useful to perform serial MRI test in order to prepare for delayed encephalopathy in carbon monoxide intoxication.