Table 2.
Clinical examination data for ET and PD patients.
| ET patients (n = 50) | PD patients (n = 50) | Significance | |
|---|---|---|---|
| (A) Straight-arm extensiona | |||
| Overall (all joints) | 1.08 ± 0.68 | 0.61 ± 0.57 | MW = 3.59, p < 0.001 |
| Shoulder | |||
| Flexion-extension | 0.00 ± 0.00 | 0.20 ± 0.10 | MW = 2.42, p = 0.16 |
| Adduction-abduction | 0.00 ± 0.00 | 0.20 ± 0.10 | MW = 2.42, p = 0.16 |
| Elbow | 0.04 ± 0.20 | 0.06 ± 0.29 | MW = 0.44, p = 0.66 |
| Wrist | |||
| Flexion-extension | 0.75 ± 0.76 | 0.17 ± 0.40 | MW = 4.35, p < 0.001 |
| Adduction-abduction | 0.01 ± 0.07 | 0.05 ± 0.18 | MW = 1.38, p = 0.17 |
| Pronation-supination | 0.25 ± 0.53 | 0.15 ± 0.46 | MW = 1.07, p = 0.29 |
| MCP joint | |||
| Flexion-extension | 0.51 ± 0.51 | 0.35 ± 0.37 | MW = 1.47, p = 0.14 |
| Adduction-abduction | 0.06 ± 0.19 | 0.10 ± 0.23 | MW = 1.12, p = 0.26 |
| Phalanges | 0.00 ± 0.00 | 0.02 ± 0.10 | MW = 1.42, p = 0.16 |
| Thumb | |||
| Flexion-extension | 0.12 ± 0.34 | 0.09 ± 0.24 | MW = 0.69, p = 0.49 |
| Adduction-abduction | 0.09 ± 0.28 | 0.09 ± 0.24 | MW = 0.27, p = 0.79 |
| Opposition | 0.03 ± 0.21 | 0.06 ± 0.30 | MW = 1.01 p = 0.32 |
| Thumb interphalangeal | 0.00 ± 0.00 | 0.02 ± 0.10 | MW = 1.42, p = 0.16 |
| Re-emergent tremorb | 0 (0%) | 1 (2%) | χ2 = 1.01, p = 0.32 |
| (B) Winged arm extensiona | |||
| Overall (all joints) | 1.16 ± 0.64 | 0.55 ± 0.60 | MW = 4.60, p < 0.001 |
| Shoulder | |||
| Flexion-extension | 0.00 ± 0.00 | 0.01 ± 0.07 | MW = 1.00, p = 0.32 |
| Adduction-abduction | 0.00 ± 0.00 | 0.01 ± 0.07 | MW = 1.00, p = 0.32 |
| Elbow | 0.24 ± 0.76 | 0.08 ± 0.23 | MW = 0.12, p = 0.90 |
| Wrist | |||
| Flexion-extension | 0.74 ± 0.52 | 0.17 ± 0.42 | MW = 5.74, p < 0.001 |
| Adduction-abduction | 0.01 ± 0.07 | 0.01 ± 0.07 | MW = 0.00, p = 1.00 |
| Pronation-supination | 0.15 ± 0.39 | 0.12 ± 0.40 | MW = 0.59, p = 0.56 |
| MCP joint | |||
| Flexion-extension | 0.34 ± 0.47 | 0.39 ± 0.46 | MW = 0.71, p = 0.48 |
| Adduction-abduction | 0.02 ± 0.14 | 0.07 ± 0.25 | MW = 1.65, p = 0.10 |
| Phalanges | 0.00 ± 0.00 | 0.01 ± 0.07 | MW = 1.00, p = 0.32 |
| Thumb | |||
| Flexion-extension | 0.17 ± 0.36 | 0.02 ± 0.10 | MW = 2.72, p = 0.01 |
| Adduction-abduction | 0.02 ± 0.10 | 0.03 ± 0.12 | MW = 0.46, p = 0.65 |
| Opposition | 0.00 ± 0.00 | 0.01 ± 0.07 | MW = 1.00, p = 0.32 |
| Thumb interphalangeal | 0.00 ± 0.00 | 0.02 ± 0.10 | MW = 1.42, p = 0.16 |
| Re-emergent tremorb | 0 (0%) | 2 (4%) | χ2 = 2.04, p = 0.15 |
| (C) Isolated proximal tremor prevalencec,d,e | |||
| Liberal definition | 10 (20%) | 1 (2%) | χ2 = 6.54, p = 0.01 |
| Conservative definition | 19 (38%) | 3 (6%) | χ2 = 13.11, p < 0.001 |
| Isolated distal tremor prevalencec,d,f | |||
| Liberal definition | 2 (4%) | 25 (50%) | χ2 = 24.56; p < 0.001 |
| Conservative definition | 1 (2%) | 19 (38%) | χ2 = 18.06; p < 0.001 |
| Proximal – distal postural tremord, g | 0.47 ± 1.35 | −0.37 ± 0.81 | MW = 4.73; p < 0.001 |
| Wrist – MCP postural tremorh | 0.42 ± 0.83 | −0.25 ± 0.52 | MW = 4.76; p < 0.001 |
| Wrist flexion/extension tremor – wrist pronation/supinationi | 0.73 ± 0.93 | 0.07 ± 0.44 | MW = 4.81; p < 0.001 |
| Isolated postural thumb tremorc,j | |||
| Liberal definition | 0 (0%) | 0 (0%) | χ2 = 0.00, p = 1.00 |
| Conservative definition | 0 (0%) | 2 (4%) | χ2 = 2.04; p = 0.15 |
MW = Mann–Whitney test.
χ2 = Chi-square test.
aWHIGET tremor scores are shown for the more severely affected limb.
bDefined as an overall tremor score of 1 or higher that emerges 1 or more seconds after initiation of arm extension.
cDefined liberally as a WHIGET score ≥ 0.5, and conservatively as a WHIGET score ≥ 1.
dThe shoulder, elbow, and wrist were considered proximal, while the MCP joints and the phalanges (including the thumb joints) were considered distal.
ePresence of proximal postural tremor in the absence of distal postural tremor.
fPresence of distal postural tremor in the absence of proximal postural tremor.
gCalculated as follows. The highest WHIGET postural tremor score in each joint (regardless of direction, hand, or postural position) was summed separately for proximal vs. distal joints. The difference of these two sums was designated as “proximal – distal postural tremor.”
hCalculated as follows. The highest WHIGET postural tremor score in the wrist (regardless of direction, hand, or postural position) was determined. The highest WHIGET postural tremor score in the MCP joint was also determined. The difference of these two values was designated as “wrist–MCP postural tremor.”
iTo assess this, we used the highest WHIGET tremor scores, and calculated difference between wrist flexion-extension postural tremor and wrist pronation-supination postural tremor (wrist flexion/extension tremor – wrist pronation/supination tremor).
jPresence of postural thumb tremor in the absence of all other postural tremor.