Serial Cerebral Perfusion Imaging in a Case with Herpes Simplex Encephalitis
To evaluate cerebral blood flow, single photon emission computed tomographies (SPECTs) were serially performed in a case with herpes simplex encephalitis (HSE). Increased accumulation of N-ispropyl-I-123-p-iodoamphetamine (I-123-IMP) and Tc - 99m - hexamethylpropyleneamine oxime (Tc - 99m - HM - PAO) were noticed in the acute phase, and continued for seven weeks after the onset of the disease. In the third week, regional cerebral blood flow (rCBF) was estimated with I-123-IMP SPECT, and rCBF showed a high value in the affected temporal and occipital lobes of 60 to 70 ml/100 g/min (normal value; 40-50 ml/100 g/min), reflecting high accumulation of the tracer. After the twelfth week, when chinical symptoms and laboratory data had improved, the increased accumulation of these tracers was converted to a decreased accumulation.