Relationship between comprehensive geriatric assessment and amyloid PET in older persons with MCI

Abstract Background. The association between amyloid deposition and cognitive, behavioral and physical performance in mild cognitive impairment (MCI) due to Alzheimer's disease (AD) has been poorly investigated, especially in older persons. Methods. We studied the in vivo correlation between the amyloid deposition at Positron Emission Tomography (amyloid-PET) and the presence of memory loss, reduced executive function, physical performance and neuropsychiatric symptoms in older persons with MCI due to AD. Amyloid-PET was performed with 18F-flutemetamol and quantitavely analyzed. Results. We evaluated 48 subjects, including 21 men and 27 women older than 65 years old. We performed in each patient a comprehensive geriatric assessment including MMSE, Clock Drawing Test, ADL, IADL, NPI, SPPB and Hand Grip strength. Then, each patient underwent amyloid-PET. The mean scores obtained at the MMSE by the subjects under examination was 24.97 ± 3.90 with a median NPI of 4. PET scan revealed brain amyloid deposition in 21 persons. Participants with positive amyloid scans exhibited a higher prevalence of pathological clock drawing test (p=0.0009). We did not find a significant association between MMSE score and beta amyloid plaque burden. When amyloid deposition was present, we observed that the deposition was diffuse, involving cortex in a widespread manner, as showed by alterations of CDT. Conclusion. Our findings support the recent hypothesis that amyloid deposition could be associated with multiple cerebral dysfunction, such as executive dysfunction and other cognitive impairment.