Detecting regional cerebral blood flow changes in Alzheimer's patients after milameline treatment: activation or baseline SPECT?

UNLABELLED The purpose of this study was to evaluate the effectiveness of activation versus baseline SPECT in detecting the regional cerebral blood flow (rCBF) changes in Alzheimer's disease (AD) patients after milameline (CI979/RU35926) treatment. METHODS Ten patients with AD who took part in a milameline drug trial were examined by (99m)Tc-hexamethylpropyleneamine oxime SPECT before and after the medication. A split-dose technique was used for the acquisition of baseline and activation images within a single session. Two patients were unable to complete the activation challenges. rCBF changes were assessed using the statistical parametric mapping program. Both increased and decreased contrasts were used to test rCBF changes on activation and baseline images, respectively. rCBF changes caused by activation were also examined before and after milameline treatment. RESULTS Decreased rCBFs were observed at the temporal cortex on both sides of the brain and at the left parietal cortex on the activation SPECT images after milameline, whereas no statistically significant rCBF change was found on the baseline SPECT images. Memory stress caused not only increased rCBF in many areas of the brain, including the parietotemporal cortex, but also decreased rCBF at the splenium of the corpus callosum. CONCLUSION Cognitive activation scans are more effective than baseline scans in detecting rCBF changes in AD patients after milameline.