Table II.
Accelerometric data.
| ET (20 pts) | DT (20 pts) | PD-T (20 pts) | p value (Kruskal-Wallis test) | ET vs DT (p value) | ET vs PD-T (p value) | DT vs PD-T (p value) | |
|---|---|---|---|---|---|---|---|
| Tremor frequency (Hz)* | 10.6 ± 2.5 | 6.1 ± 2.4 | 5.4 ± 0.8 | <0.001 | <0.001 | <0.001 | 0.12 |
| Peak dispersion (Hz)* | 2.0 ± 0.2 | 4.2 ± 1.1 | 2.7 ± 0.5 | <0.001 | <0.001 | <0.001 | <0.001 |
| Spectral coherence (%)* | 89.7 ± 12.7 | 44.0 ± 16.9 | 75.8 ± 20.9 | <0.001 | <0.001 | <0.001 | <0.001 |
| Unilateral tremor | 8/20 | 6/20 | 16/20 | 0.004 | 0.51 | 0.01 | 0.001 |
| Resting tremor amplitude > action tremor amplitude | 0/20 | 4/20 | 14/20 | <0.001 | 0.35 | <0.001 | 0.001 |
Legend: pts=patients; ET=essential tremor; DT=dystonic tremor; PD-T= parkinsonian tremor.
*
Tremor frequency, peak dispersion and spectral coherence refer to postural tremor for patients with ET and DT and to resting tremor for patients with PD-T.