| −6 months preoperative | 6 months postoperative | 18 months | 36 months | 54 months | 66 months | ||
| UHDRS motor score | S1 | 54 | 35 | 21 | 10 | 9 | 8 |
| S2 | 48 | 47 | 43 | 42 | 58 | – | |
| C | 30.7 (12.1) | – | 39.3 (17.5) | 48.4 (21.3) | – | – | |
| UHDRS behavioural scale | S1 | 33 | 22 | 8 | 6 | – | – |
| S2 | 10 | 8 | 8 | 8 | – | – | |
| UHDRS independence scale* | S1 | 60 | 70 | 80 | 80–90 | 80 | 90 |
| S2 | 70–80 | 70–80 | 70–80 | – | 60 | – | |
| C | 98 (4.5) | – | 85 (5.4) | 82 (13.0) | – | – | |
| Total functional capacity* | S1 | 4 | 5 | 8 | 8 | 11 | 13 |
| S2 | 8 | 7 | 7 | 7 | 5 | – | |
| C | 10.2 (2.5) | – | 8.5 (2.0) | 8.8 (1.6) | – | – | |
| Hand tapping (mean total No for both hands)* | S1 | 80 | 110 | 114 | – | 170 | 162 |
| S2 | 110 | 125 | 130 | – | Unable to do – | Sore wrist | |
| C | 76 (17) | – | 63 (17) | 66 (15) | – | – | |
| Walking test (s) | S1 | 27.0 | 20.0 | 17.2 | – | 15.6 | 15.2 |
| S2 | 32.0 | 27.0 | 25.6 | – | Wheelchair bound | ||
| C | 16.5 (3.1) | – | 19.0 (2.7) | 19.0 (1.6) | – | – | |
| MMSE* | S1 | 26 | 27 | 27 | 28 | 26 | 30 |
| S2 | 28 | 30 | 30 | 30 | 24 | – | |
| C | 28.3 (0.6) | – | 26.7 (0.6) | 27.6 (0.8) | – | – | |
| Verbal fluency (FAS)* | S1 | 25 | 26 | 26 | – | 36 | 34 |
| S2 | 25 | – | – | – | 14 | – | |
| C | 26.7 (4.2) | – | 27.4 (4.3) | 23.4 (6.2) | – | – | |
| Stroop (colour/word/interference)* | S1 | 55/45/45 | 45/55/45 | – | – | 54/90/45 | 54/78/38 |
| S2 | 49/70/31 | 55/90/46 | – | – | 49/60/25 | – | |
| C | 71.1/46.4/27 | – | 65.7/40.6/26.9 | 57.2/41.6/24 | – | – | |
| Reitan trail making test A and B (s) | S1 | A:88; B:209 | A:61 | – | – | A:35; B:79 | A:62; B:124 |
| S2 | – | – | – | – | – | – | |
| C | A:73.6 (9.2); | – | A:77 (8.6); | A:83.3 (12); | – | – | |
| B:163 (21.7) | B:235.7 (40.2) | B:259.4 (50) | |||||
| BDI | S1 | 29 | 27 | 12 | – | 9 | 2 |
| S2 | 4 | 4 | 4 | 4 | – | – |
Control values = mean (SD). Control values were inserted where available.
*Tests where higher scores indicate better performances.
BDI, Beck Depression Inventory; C, Huntington’s disease controls; FAS, fluency of words beginning with F, A and S; L, left; MMSE, Mini-Mental State Examination; R, right; S1, subject No 1; S2, subject No 2; UHDRS, Unified Huntington’s Disease Rating Scale; –, not determined.