Table 1.
Participant characteristics at time of first scan
| Control | aAD | lvPPA | PCA | fvAD | P-value | |
|---|---|---|---|---|---|---|
| n | 37 (85) | 17 (40) | 25 (66) | 20 (48) | 12 (27) | |
| Male, n (%) | 16 (43.2) | 6 (35.3) | 9 (36.0) | 7 (35.0) | 7 (58.3) | 0.672 |
| Education | 16.0 [16.0, 18.0] | 16.0 [14.0, 18.0] | 16.0 [14.0, 19.0] | 16.0 [12.0, 16.0] | 16.0 [13.5, 18.0] | 0.421 |
| Age at MRI, years | 61.9 [57.9, 65.6] | 59.4 [53.5, 70.3] | 58.5 [56.9, 64.5] | 58.0 [55.1, 61.4] | 63.9 [59.7, 69.5] | 0.137 |
| Inter-scan interval, years | 1.2 [0.9, 1.7] | 1.2 [0.9, 1.5] | 1.1 [0.9, 1.3] | 1.0 [0.9, 1.2] | 1.0 [0.7, 1.1] | 0.162 |
| Disease duration, years | – | 3.0 [1.9, 4.0] | 2.7 [1.7, 3.9] | 2.2 [1.3, 4.0] | 2.2 [1.8, 5.2] | 0.747 |
| MMSE, 0–30 | 29.0 [28.0, 30.0] (20) | 23.0 [20.0, 25.0] (17) | 25.0 [23.0, 28.0] (25) | 24.5 [18.8, 25.2] (20) | 23.0 [17.0, 26.0] (12) | <0.001 |
| Recognition memory, discrimination, 0–1 | 1.0 [0.9, 1.0] (7) | 0.6 [0.5, 0.7] (10) | 0.8 [0.8, 1.0] (25) | 0.7 [0.6, 0.9] (19) | 0.6 [0.6, 0.8] (12) | <0.001 |
| Speech, 0–4 | 4.0 [4.0, 4.0] (3) | 2.5 [2.5, 3.0] (9) | 2.5 [2.0, 3.0] (19) | 3.0 [3.0, 4.0] (15) | 3.5 [2.2, 4.0] (11) | 0.004 |
| Letter fluency, number of words/60 s | 19.0 [17.5, 20.5] (7) | 9.0 [5.0, 13.0] (13) | 8.5 [5.2, 10.8] (22) | 10.0 [6.5, 15.5] (19) | 6.5 [3.0, 11.0] (12) | 0.001 |
| Forward digit span, length correct | 7.0 [7.0, 8.0] (11) | 5.0 [3.0, 6.0] (9) | 5.0 [4.0, 5.0] (25) | 6.0 [5.0, 7.0] (20) | 5.0 [4.0, 6.0] (12) | 0.005 |
| Rey figure copy, 0–12 | 12.0 [12.0, 12.0] (3) | 11.0 [4.0, 12.0] (9) | 12.0 [11.0, 12.0] (19) | 2.5 [0.0, 8.8] (12) | 9.5 [4.5, 11.0] (10) | 0.001 |
| Judgement of line orientation, 0–6 | 6.0 [6.0, 6.0] (3) | 3.0 [0.8, 5.0] (8) | 5.0 [4.0, 6.0] (19) | 2.0 [0.0, 4.0] (13) | 4.0 [3.0, 5.0] (9) | 0.004 |
| Social behaviour, 0–18 | 17.0 [17.0, 17.0] (3) | 17.5 [16.8, 18.0] (8) | 18.0 [17.0, 18.0] (19) | 17.0 [16.0, 18.0] (15) | 13.0 [11.1, 16.5] (11) | 0.004 |
| Oral trail-making test, 0–6 | 6.0 [5.5, 6.0] (3) | 0.0 [0.0, 3.0] (5) | 2.0 [0.2, 3.0] (10) | 0.5 [0.0, 2.8] (10) | 2.0 [0.2, 3.8] (6) | 0.051 |
| Reverse digit span, length correct | 6.0 [4.5, 6.0] (11) | 3.0 [3.0, 3.0] (9) | 3.0 [3.0, 4.0] (25) | 3.0 [2.0, 3.0] (19) | 3.0 [2.0, 3.2] (12) | <0.001 |
Data are presented as median [IQR] for all continuous variables. Education, age at MRI, interscan interval, and disease duration are expressed in years. Sample sizes (n) indicate number of unique individuals per group; total number of scans per group is given in parentheses. For each cognitive score, numbers in parentheses indicate the number of observations per group. P-values reflect the results of a chi-squared test for sex and Kruskal-Wallis tests for all other variables.
aAD= amnestic Alzheimer’s disease; fvAD = frontal-variant Alzheimer’s disease; naAD = non-amnestic Alzheimer’s disease.