Table 3.
Externally-paced tapping: mean (95% CI) difference between controls and each patient group, with and without adjustment for age and gender.
| Estimate (95% CI) | bvFTD (N=20) | svPPA (N=11) | naPPA (N=4) | AD (N=8) | |
|---|---|---|---|---|---|
| Clock variance (ms2) | Unadjusted | 13,000 (3974, 31,331) | −3615 (−8273, −48) | 24,307 (−6768, 95,512) | 1853 (−3253, 6341) |
| Adjusted | 13,039 (1925, 30,692) | −2723 (−9133, 3382) | 25,349 (−8713, 99,028) | 2717 (−5721, 9926) | |
| Motor variance (ms2) | Unadjusted | −2716 (−6794, 31) | −888 (−3942, 2375) | −40 (−18,838, 29,831) | −1614 (−4699, 382) |
| Adjusted | −2500 (−7260, 1569) | −1138 (−4942, 2429) | −428 (−21,022, 28,325) | −1714 (−6136, 1449) | |
| Mean IRI (ms) | Unadjusted | −2 (−16, 18) | 4 (0, 8) | −78 (−238, 3) | 3 (−3, 11) |
| Adjusted | 0 (−21, 21) | 6 (0, 19) | −77 (−237, 12) | 6 (−3, 21) | |
| Drift (ms) | Unadjusted | −9 (−66, 28) | −14 (−35, 3) | −105 (−343, 4) | −13 (−57, 8) |
| Adjusted | −15 (−86, 29) | −18 (−43, 5) | −106 (−364, 6) | −21 (−69, 11) | |
| Absolute drift (ms) | Unadjusted | 34 (10, 82) | −10 (−22, 3) | 80 (−4, 294) | 1 (−13, 26) |
| Adjusted | 38 (5, 99) | −7 (−24, 10) | 82 (−6, 309) | 6 (−16, 36) |
A positive effect is indicative of greater variance (clock and motor variance) or slower time (IRI and drift metrics) relative to controls. Effects in bold indicate statistically significant mean differences between the patient group and controls, p<0.05.
IRI=inter-response interval, i.e. mean speed of tapping across the whole task; drift=difference between first and last tap; absolute drift=the modulus of drift.
Abbreviations: CI, confidence interval; bvFTD, behavioural variant frontotemporal dementia; naPPA, progressive non-fluent aphasia; svPPA, semantic variant primary progressive aphasia, AD, Alzheimer׳s disease.