Objective To injvestigate the cerebral blood flow of patients with early syphilis Methods 99 Tc m ECD as brain perfusion imaging agent was used in single photon emission computed tomography (SPECT) for 32 patients with early syphilis and 15 controls Visual analyses were made on every BSPECT image Results The 32 patients with early syphilis had general, patchy hypoperfusion of cerebral blood flow Fourteen of the 32 patients had 48 episodes of marked patchy hypoperfusion of rCBF The responsible areas of hypoperfusion in a patchy distribution involved the left frontal lobe (6 episodes), right frontal lobe (3), left parietal lobe (7), right parietal lobe (6), left temporal lobe (11), right temporal lobe (5), left occipital lobe (3), left basal ganglia (3), cerebellum (1), and nerve nuceus (1) No abnormality was found in the control group Conclusions Cerebral blood flow abnormalities exist in patients with early syphilis General patchy hypoperfusion on SPECT imaging is common Objective To investigate the cerebral blood flow of patients with early syphilis Methods 99 Tc m ECD as brain perfusion imaging agent was used in single photon emission computed tomography (SPECT) for 32 patients with early syphilis and 15 controls Visual analyzes were made on every BSPECT image Results The 32 patients with early syphilis had general, patchy hypoperfusion of cerebral blood flow Fourteen of the 32 patients had 48 episodes of marked patchy hypoperfusion of rCBF The responsible areas of hypoperfusion in a patchy distribution involved the left frontal lobe (6 episodes), right left lobe (3), left parietal lobe (3), left parietal lobe (7), right parietal lobe (6), left temporal lobe 1), and nerve nuceus (1) No abnormality was found in the control group Conclusions Cerebral blood flow abnormalities in patients with early syphilis General patchy hypoperfusion on SPECT imagin g is common