We present the case of a 63-year-old man complaining of subjective memory loss (he works as a veterinary physician and had a good performance at neuropsychological tests).
The patient underwent an 18F-FDG PET-CT scan which showed a decrease in glucidic metabolism in parietal and occipital lobes, more prominent on the left side (white arrow). The hypometabolism was confirmed also by SPM analysis (green arrow). Four months later, a PET-CT with 18F-florbetapir was performed, showing a diffuse loss of contrast between white and gray matter and, more interestingly, focal areas of increased tracer uptake in frontal and parieto-occipital cortex of the left hemisphere (red arrow).
Most longitudinal studies have shown that patients with subjective memory problems or Subjective Cognitive Decline (SCD) have an increased risk of future cognitive decline or dementia [1,2].
Studies on patients with SCD who underwent annual cognitive assessments show that they are almost three times as likely to be diagnosed with mild cognitive decline or dementia. Interestingly, the first complaints of memory decline occurred on an average of six years before mild cognitive impairment (condition that sometimes, but not always, progresses to dementia) was diagnosed, and about nine years before dementia was diagnosed. Moreover, in case of SCD there is a higher chance of changes in brains on imaging scans, specifically higher levels of beta-amyloid protein [2,3].
Figure 1: PET-CT with FDG shows a decrease in glucidic metabolism in parietal and occipital lobes, more prominent on the left side (white arrow). The hypometabolism was confirmed also by SPM analysis (green arrow). PET-CT with 18F-florbetapir shows a diffuse loss of contrast between white and gray matter and, more interestingly, focal areas of increased tracer uptake in frontal and parieto-occipital cortex of the left hemisphere.