Abstract
This was a study to evaluate the posterior cingulate sign in differential diagnosis between Alzheimer’s and frontotemporal disease. The impending availability of effective treatment for Alzheimer’s disease makes this differential diagnosis important. Methods: Images of 20 patients with clinically confirmed or autopsy-proven (10 patients) Alzheimer’s disease and 20 patients with clinically confirmed or autopsy-proven (7 patients) frontotemporal disease were compared with the consolidated images of 20 elderly healthy control subjects. The 99mTc-hexamethylpropyleneamine oxime SPECT data on brain blood flow from each patient were compared with the consolidated control image using statistical parametric mapping. Results: Sixteen of 20 patients with Alzheimer’s disease showed the posterior cingulate sign in the form of significant blood flow reductions; 1 of 20 patients with frontotemporal disease showed the posterior cingulate sign. That patient’s illness has evolved into Alzheimer’s disease. The remaining 19 patients were negative for the posterior cingulate sign. Conclusion: When present, the posterior cingulate sign indicates the presence of Alzheimer’s disease; it is apparently absent in frontotemporal disease, thus serving as a differential diagnostic sign. It was absent in 3 patients with proven tangle-predominant Alzheimer’s disease.
Footnotes
Received Sep. 30, 2003; revision accepted Dec. 12, 2003.
For correspondence or reprints contact: Frederick J. Bonte, MD, Nuclear Medicine Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9061.
E-mail: Frederick.Bonte{at}UTSouthwestern.edu.
