Alz Res Therapy: How does the cognitive trajectory of patients with focal amyloid deposits change?

The accumulation of ß-amyloid (Aß) in Alzheimer's disease (AD) can be detected by positron emission tomography (PET) imaging
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Although typical AD patients show diffuse Aß deposition, most people with normal cognition have no Aß deposition in amyloid PET, but a considerable number of people have focal Aß deposition (cognitive accessibility [CU] is 13.

However, there is evidence to support the view that localized Aß deposition is different from diffuse Aß deposition
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Dealing with patients with focal Aß deposits on PET scans is a challenge

In a previous cross-sectional study, Si Eun Kim of Sungkyunkwan University School of Medicine in South Korea and others found that patients with focal Aß deposition involving larger areas or striatum have poor cognitive function
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Although there are studies using the standardized uptake value ratio (SUVR) to focus on the regional Aß burden, no previous studies have focused on the longitudinal trajectory of focal Aß deposition based on visual scores

In this way, they used the 18F-fluorouracil PET visual score to assess Aß deposition and followed the patients for a 2-year annual neuropsychological test
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And compared the cognitive development trajectory of patients with focal Aß deposition and patients without Aß deposition or diffuse Aß deposition

The core hypothesis is that the decline in cognitive ability will be affected by the baseline cognitive level, the degree and location of Aβ deposition in the lesion
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They interviewed 240 participants from 9 referral centers in South Korea (112 cognitively barrier-free [CU], 78 amnestic mild cognitive impairment [aMCI] and 50 Alzheimer’s disease (AD) Patients with dementia [ADD]) underwent a 2-year follow-up
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Participants underwent neuropsychological testing and 18F-fluorouracil (FMM) positron emission tomography (PET) evaluation

Visually inspect 10 areas (frontal lobe, anterior/posterior cingulate gyrus (PPC), lateral temporal lobe, parietal lobe, and striatum in each hemisphere) in the FMM scan, and divide the participants into three groups
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No FMM, Focal-FMM (FMM ingestion of 1-9 areas) and Diffuse-FMM

Finally, a mixed effect model was used to study the speed of cognitive decline in the Focal-FMM group compared with the No- or Diffuse-FMM group, according to the cognitive level, degree and location of Aß involvement
.

Forty-five of 240 people (18.
8%) are classified as Focal-FMM

The cognitive decline of the Focal-FMM group was faster than that of the No-FMM group (especially in the CU and aMCI stage), and slower than the Diffuse-FMM group (especially in the CU stage)
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In the Focal-FMM group, participants with higher FMM intake (7-9 areas) had faster cognitive decline than participants with lower intake (1-3 or 4-6 areas)
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When PPC, striatum, and frontal cortex were ingested, the Focal-FMM group had a faster cognitive decline compared with the No-FMM group
.

The important significance of this study lies in the discovery that when predicting the cognitive decline of patients with focal Aβ deposition, the patient's cognitive level, the degree and location of focal involvement are all important
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