Type of biomarker | Index used | Patients with a clinical diagnosis of probable Alzheimer's disease | |||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | ||
Aβ deposition | Florbetapir neocortical SUVr | 1.46 | 1.54 | 1.86 | 1.20 | 1.48 | 1.81 | 0.87 | 1.80 | 1.92 | 1.71 | 1.41 | 1.77 | 1.56 | 1.28 | 1.29 | 1.83 | 1.72 | 0.89 | 1.59 | 1.68 | 1.45 | 1.76 |
Neuronal degeneration | Atrophy W-score | 3.36 | 1.82 | 5.71 | 1.33 | 3.52 | 4.77 | 6.11 | 3.24 | 2.37 | 2.07 | 1.36 | 2.51 | 0.13 | 1.08 | 2.84 | 1.91 | 4.25 | 2.01 | 1.72 | 2.85 | 3.80 | 1.38 |
Hypometabolism W-score | 1.39 | 4.44 | 4.88 | 1.75 | 5.51 | 5.83 | 1.96 | 3.26 | 3.26 | 4.33 | 2.97 | 4.42 | 1.73 | 1.89 | 3.05 | 5.52 | 4.83 | 2.30 | 2.40 | 4.84 | 1.62 | 4.30 | |
Presence of both biomarkers? | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | Yes | Yes |
Amyloid load was assessed through neocortical florbetapir SUVr and considered as positive over 1.1 (for more details, see Materials and Methods). Alzheimer's disease type neuronal degeneration was considered using two indexes: (1) atrophy in the hippocampus, amygdala, and lateral temporal lobe and (2) hypometabolism in the angular gyrus, precuneus, and posterior cingulate. Both indexes are expressed in W-scores (i.e., age-adjusted Z-scores) compared with the control group. Patients were selected for additional analysis if they had a florbetapir-positive PET scan together with at least one neurodegeneration degeneration W-score > 1.65. Indexes considered as positive are bolded. This condition was fulfilled for all patients, except for patients 7 and 18 that were consequently excluded from additional analyses.