Table 3.
Summary of performance on cognitive assessments at baseline, and after 12 months and 24 months of follow-up
| Assessment | Controls |
Premanifest HD |
Early HD |
||||||
| Baseline | 12 months | 24 months | Baseline | 12 months | 24 months | Baseline | 12 months | 24 months | |
| SDMT (number correct)* | |||||||||
| Mean (SD) | 52.41 (9.41) | 54.50 (9.00) | 54.37 (9.86) | 51.46 (10.29) | 52.51 (10.28) | 52.03 (10.88) | 33.86 (10.11) | 32.25 (10.79) | 31.01 (11.23) |
| N | 116 | 116 | 110 | 116 | 116 | 111 | 116 | 113 | 109 |
| Stroop Word Reading (number correct)* | |||||||||
| Mean (SD) | 106.09 (16.47) | 107.85 (15.99) | 107.27 (16.03) | 99.76 (16.16) | 101.57 (16.94) | 99.46 (15.58) | 78.36 (19.56) | 75.56 (20.37) | 71.97 (22.11) |
| N | 116 | 116 | 110 | 116 | 116 | 111 | 116 | 113 | 111 |
| Trails A completion time (s)† | |||||||||
| Mean (SD) | 27.72 (10.29) | 24.92 (8.46) | 26.16 (10.76) | 28.58 (9.90) | 27.47 (10.56) | 26.96 (8.79) | 50.19 (23.52) | 50.67 (24.39) | 54.41 (32.13) |
| N | 116 | 116 | 110 | 116 | 116 | 111 | 116 | 113 | 111 |
| Trails B completion time (s)† | |||||||||
| Mean (SD) | 61.03 (25.74) | 60.32 (32.58) | 57.18 (24.35) | 66.86 (28.48) | 63.83 (28.69) | 66.45 (31.61) | 139.62 (74.94) | 139.15 (70.70) | 143.2 (78.97) |
| N | 116 | 116 | 110 | 116 | 116 | 111 | 115 | 113 | 110 |
| Paced Tapping 3 Hz precision (1/SD of ITI in 1/ms)† | |||||||||
| Mean (SD) | 0.025 (0.011) | 0.027 (0.010) | 0.027 (0.011) | 0.020 (0.008) | 0.022 (0.009) | 0.020 (0.008) | 0.010 (0.007) | 0.010 (0.007) | 0.009 (0.006) |
| N | 116 | 114 | 110 | 116 | 116 | 111 | 112 | 110 | 104 |
| Paced Tapping 1.8 Hz precision (1/SD of ITI in 1/ms)|† | |||||||||
| Mean (SD) | 0.022 (0.008) | 0.023 (0.008) | 0.023 (0.007) | 0.018 (0.007) | 0.019 (0.007) | 0.018 (0.006) | 0.009 (0.006) | 0.010 (0.005) | 0.009 (0.006) |
| N | 116 | 115 | 110 | 116 | 117 | 111 | 112 | 110 | 104 |
| Serial 2 s with tapping (correct subtractions)* | |||||||||
| Mean (SD) | 9.44 (2.45) | 9.50 (2.57) | 10.22 (2.93) | 8.22 (2.71) | 8.12 (2.80) | 8.69 (2.90) | 5.94 (2.29) | 5.58 (2.58) | 6.16 (2.64) |
| N | 115 | 116 | 109 | 117 | 117 | 111 | 107 | 105 | 98 |
| Spot the Change set size 5 (k)* | |||||||||
| Mean (SD) | 3.09 (1.11) | 3.09 (1.23) | 3.34 (1.12) | 2.84 (1.32) | 2.91 (1.18) | 2.87 (1.09) | 1.65 (1.27) | 1.38 (1.51) | 1.44 (1.44) |
| N | 114 | 115 | 110 | 116 | 115 | 111 | 107 | 106 | 104 |
| Negative Emotion Recognition (number correct)* | |||||||||
| Mean (SD) | 26.02 (5.01) | 26.90 (5.21) | 27.30 (5.88) | 23.48 (5.71) | 24.70 (5.66) | 24.67 (6.26) | 16.42 (6.46) | 16.33 (6.80) | 15.71 (7.22) |
| N | 110 | 115 | 110 | 111 | 116 | 111 | 105 | 110 | 105 |
| UPSIT (number correct out of 20)* | |||||||||
| Mean (SD) | 17.16 (2.21) | 16.99 (1.98) | 17.13 (2.29) | 16.58 (2.56) | 16.70 (2.21) | 16.50 (2.26) | 13.51 (3.26) | 12.65 (3.28) | 12.59 (3.66) |
| N | 116 | 116 | 107 | 117 | 116 | 111 | 116 | 113 | 108 |
| Circle Tracing direct annulus length (log cm)* | |||||||||
| Mean (SD) | 6.84 (0.36) | 7.05 (0.31) | 7.18 (0.28) | 6.73 (0.37) | 6.94 (0.35) | 7.05 (0.31) | 6.38 (0.41) | 6.54 (0.41) | 6.50 (0.45) |
| N | 115 | 115 | 109 | 116 | 116 | 111 | 112 | 112 | 106 |
| Circle Tracing indirect annulus length (log cm)* | |||||||||
| Mean (SD) | 5.59 (0.41) | 6.03 (0.40) | 6.16 (0.43) | 5.56 (0.43) | 5.90 (0.39) | 6.03 (0.38) | 5.14 (0.48) | 5.38 (0.52) | 5.38 (0.49) |
| N | 115 | 116 | 109 | 116 | 116 | 111 | 112 | 112 | 106 |
*
Higher values mean better performance.
†
lower values mean better performance.
HD, Huntington's disease; ITI, inter-trial interval; SDMT, Symbol Digit Modalities Test; UPSIT, the University of Pennsylvania Smell Identification Test.