Alzheimer's (SPECT Imaging)

Question 1

Which of the following would be most useful when trying to differentiate Alzheimer’s disease from Lewy body dementia?

Answer 1

Dat scan. The finding of temporal and parietal hypoperfusion has been found by several studies to differentiate between patient’s with Alzheimer’s from healthy older subjects (Jagust 2001).

SPECT has also been shown to be a useful method for distinguishing between Alzheimer’s disease and Lewy body dementia (Vaamonde-Gamo 2005).

The following image shows a SPECT scan of a patient with Alzheimer’s (AD) versus one with Lewy body dementia (DLB). Note how the one with DLB shows lower perfusion in occipital cortex (long arrows). In contrast, AD showed lower perfusion in medial temporal areas (short arrowheads).