Table 2. Motor function in SMA type 2 and 3 patients.
| SMA type 2 | SMA type 3 | Overall | |||
|---|---|---|---|---|---|
| Non-sitter | Sitter | Non-Ambulant | Ambulant | ||
| MFM-20 score 1 | n = 3 | n = 21 | n = 0 | n = 8 | n = 32 |
| D1 (standing position and transfers)** | 4.2 a (0-.) | 4.2 a (2.1–8.3) | - | 56.2 b (43.7–68.7) | 4.2 (4.2–36.4) |
| D2 (axial and proximal motor function)** | 29.2 a (25.0-.) | 75.0 a (64.6–83.3) | - | 95.8 b (89.6–99.0) | 83.3 (63.5–91.7) |
| D3 (distal motor function)* | 66.7 a (50.0-.) | 83.3 a, b (70.8–95.8) | - | 100 b (93.7–100) | 83.3 (66.7–100) |
| Total** | 26.7 a (20.0-.) | 48.3 a (40.8–54.2) | - | 80.8 b (73.3–85.8) | 51.7 (40.4–63.7) |
| MFM-32 score 2 | n = 15 | n = 11 | n = 9 | n = 11 | n = 46 |
| D1 (standing position and transfers)** | 2.6 a (0–2.6) | 2.6 a, b (2.6–2.6) | 10.2 b, c (6.4–11.5) | 66.7 c (51.3–79.5) | 3.8 (2.6–31.4) |
| D2 (axial and proximal motor function)** | 38.9 a (27.8–44.4) | 63.9 a, b (52.8–80.6) | 91.7 b, c (88.9–97.2) | 97.2 c (91.7–100) | 76.4 (41.0–94.4) |
| D3 (distal motor function)** | 71.4 a (66.7–90.5) | 80.9 a, b (66.7–90.5) | 95.2 b, c (90.5–95.2) | 100 c (95.2–100) | 90.5 (70.2–95.2) |
| Total** | 28.1 a (23.9–35.4) | 42.7 a, b (35.4–48.9) | 60.4 b, c (57.8–60.9) | 84.4 c (70.1–90.6) | 48.4 (35.1–67.4) |
| Brooke 3 ** □ | n = 16 | n = 26 | n = 9 | n = 15 | n = 66 |
| 1 (n) | 0 a | 3 a | 6 b | 13 b | 22 |
| 2 (n) | 2 | 9 | 2 | 2 | 15 |
| 3 (n) | 8 a | 9 a, b | 1 a, b | 0 b | 18 |
| 4 (n) | 5 | 4 | 0 | 0 | 9 |
| 5 (n) | 1 | 1 | 0 | 0 | 2 |
| Moviplate 4 | n = 13 | n = 9 | n = 9 | n = 10 | n = 41 |
| Dominant side** | 47 a (38–58) | 42 a (27–46) | 71 b (62–78) | 69 b (62–79) | 54 (41–71) |
| Non-dominant side** | 46 a (24–50) | 40 a (32–50) | 60 b (55–65) | 65 b (51–70) | 50 (40–64) |
| Active-Seated 5 | n = 9 | n = 5 | n = 8 | n = 6 | n = 28 |
| Predicted FRV (%)** | 7.1 a (3.8–16.0) | 9.5 a, b (7.1–18.4) | 65.1 b, c (42.4–82.9) | 76.0 c (57.2–108.0) | 32.5 (7.4–66.1) |
| Home-monitoring by ActiMyo® 6 | n = 8 | n = 5 | n = 13 | ||
| Activity time (%) | 46.9 (40.3–50.9) | 59.4 (48.4–75.2) | 48.1 (43.9–57.2) | ||
| ||Ω||–median (°/s) * | 14.7 (13.7–17.1) | 18.1 (16.1–23.8) | 15.3 (14.4–19.1) | ||
| ||Ω|| - 95th percentile (°/s) | 111.2 (101.6–133.5) | 136.9 (125.5–159.2) | 115.4 (109.4–143.1) | ||
| ||A||–median (m/s2) | 0.040 (0.032–0.050) | 0.048 (0.040–0.057) | 0.040 (0.037–0.052) | ||
| ||A|| - 95th percentile (m/s2) | 0.244 (0.194–0.285) | 0.286 (0.220–0.333) | 0.245 (0.205–0.304) | ||
| vA–median (m/s2) | 0.015 (0.013–0.022) | 0.019 (0.017–0.023) | 0.018 (0.014–0.022) | ||
| vA - 95th percentile (m/s2) | 0.134 (0.111–0.177) | 0.156 (0.131–0.197) | 0.145 (0.122–0.181) | ||
| P–median (W/kg) | 0.053 (0.049–0.061) | 0.075 (0.055–0.095) | 0.059 (0.050–0.074) | ||
| P - 95th percentile (W/kg) | 0.680 (0.551–0.777) | 0.877 (0.623–1.051) | 0.722 (0.579–0.906) | ||
Abbreviations: MFM: Motor Function Measure; FRV: Functional reaching volume; ||Ω||: norm of the angular velocity of the wrist; ||A||: norm of the acceleration of the wrist; vA: vertical acceleration of the wrist; P: power.
Values are median (IQR) and overall population size is n = 78 unless otherwise indicated
1 Thirty-two patients performed the MFM-20 scale; 1 sitter and 2 non-sitter patients with SMA type 2 aged 2 to 3 years old could not perform the MFM-20 due to lack of cooperation
2 Forty-six patients performed the MFM-32 scale
3 The Brooke level could not be evaluated in thirteen patients (3 non-sitter and 8 sitter patients with SMA type 2 and 4 ambulant patients)
4 Two non-sitter patients with SMA type 2 could not perform the Moviplate test due to a technical issue
5 Nine patients could not perform the Active-Seated test due to technical issues (n = 8) and patient compliance issue (n = 1 refused to perform the test because of fatigue). Six results were excluded from the analysis since these tests were performed under different conditions (with a second version of the software, including a calibration and performance of the test without any table)
6 In the initial protocol, the ActiMyo® device was only proposed to non-ambulant patients with SMA type 2 aged over 6 years old. During the study this eligible population was broadened to patients with SMA type 3, including ambulant patients. Results presented here correspond to data recorded in thirteen patients with SMA type 2 who have been home using every day as part the trial. Measured parameters were averaged on a 180-hour period spread over two weeks.
* p ≤ 0.05
** p ≤ 0.001
□ Application conditions of the Chi-square test not fully verified (theoretical effectives ≤ 5, too small effectives)
a, b, c Subscript letters represent Post-hoc tests results. In a row, a same subscript letter indicates subset of categories (non-sitter SMA type 2, sitter SMA type 2, non-ambulant SMA type 3 and ambulant SMA type 3) which do not differ significantly from each other at level 0.05.