ACUTE ENCEPHALOPATHY WITH BILATERAL THALAMOTEGMENTAL INVOLVEMENT IN INFANTS AND CHILDREN - IMAGING AND PATHOLOGY FINDINGS

PURPOSE: To investigate the imaging and pathologic characteristics of acute encephalopathy with bilateral thalamotegmental involvement in in fants and children. METHODS: Five Japanese children ranging in age fro m 11 to 29 months were studied. We performed CT imaging in all patient s, 10 MR examinations in four patients, and an autopsy in one patient. RESULTS: The encephalopathy affected the thalami, brain stem tegmenta , and cerebral and cerebellar white matter, The brain of the autopsied case showed fresh necrosis and brain edema without inflammatory cell infiltration, Petechiae and congestion were demonstrated mainly in the thalamus. CT and MR images showed symmetric focal lesions in the same areas in the early phase, These lesions became more demarcated and sm aller in the intermediate phase. The ventricles and cortical sulci enl arged. MR images demonstrated T1 shortening in the thalami. The progno sis was generally poor; one patient died, three patients were left wit h severe sequelae, and only one patient improved. CONCLUSIONS: The enc ephalopathy might be a postviral or postinfectious brain disorder, T1 shortening in the thalami indicated the presence of petechiae.