CT, MR, and SPECT findings in a general paresis.

CNS changes in a case with general paresis were investigated by X-ray computed tomography (CT), Magnetic resonance (MR), and single photon emission computed tomography (SPECT). CT and MR showed a mild degree of diffuse cortical atrophy and the dilatation of lateral ventricles with no signs of ischemic lesions or inflammations. On the other hand, SPECT using 123I-N-isopropyl-p-iodoamphetamine (123I-IMP demonstrated marked reduction of the cerebral blood flow especially in the bilateral frontal and temporal cortices. Moreover, the reduction of the blood flow was significantly improved after the antisyphilitic therapy, correlated with the improvement of the mental disorders. These observations suggested that the SPECT is a useful method to evaluate the brain dysfunctions, and to assess the effect of antisyphilitic therapy in the patients with general paresis.