Cingulate island sign

The cingulate island sign is a highly specific radiological sign described in dementia with Lewy bodies.

It refers to the pattern of metabolism seen on FDG-PET in patients with dementia with Lewy bodies 1-3. On FDG-PET, there is occipital hypometabolism with relative sparing of the posterior cingulate cortex, thus creating the appearance of an 'island' of normal metabolism in the posterior cingulate region 1-3. The same pattern can also be appreciated in SPECT, whereby the posterior cingulate region has relatively normal perfusion while there is surrounding occipital hypoperfusion 2,3

The cingulate island sign has been described as a useful radiological differentiator between dementia with Lewy bodies, which has the sign, and Alzheimer disease, in which the sign is not present 1-3. However, it has been found that as dementia with Lewy bodies progresses over time, the sign disappears, likely due to concomitant Alzheimer disease 3.

Article information

rID: 70534
Section: Signs
Tag: cases, cases
Synonyms or Alternate Spellings:

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