Differential diagnosis between Alzheimer's and frontotemporal disease by the posterior cingulate sign.
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 (99m)Tc-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.


CONCLUSIONS
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.
Bonte
Frederick J
FJ
Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75290-9061, USA. Frederick.Bonte@UTSouthwestern.edu
Harris
Thomas S
TS
Roney
Celeste A
CA
Hynan
Linda S
LS
D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology; D003704:Dementia / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005625:Frontal Lobe / Q000000981:diagnostic imaging; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging*; D006801:Humans; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D019690:Technetium Tc 99m Exametazime; D013702:Temporal Lobe / Q000000981:diagnostic imaging; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime