Table 1
Demographic, clinical, and neuropsychological characteristics of Healthy Controls (HC) and Essential Tremor (ET) patients. Data are reported as mean ± standard deviation for continuous variables and as counts for categorical variables.
| HC (24) | ET (26) | P-VALUE | |
|---|---|---|---|
| Age | 63.8 ± 6.87 | 65.3 ± 10.2 | 0.547a |
| Sex (F/M) | 13/11 | 9/17 | 0.16b |
| Education | 10.9 ± 4.44 | 10.2 ± 3.98 | 0.571a |
| Familiarity (no/yes) | N.A. | 13/9 | N.A. |
| Disease_duration | N.A. | 12.7 ± 16.6 | N.A. |
| FTM-Scale | N.A. | 9.85 ± 4.18 | N.A. |
| MMSE* | 27.6 ± 2.08 [24.7–30] | 27.5 ± 1.34 [25.7–30] | 0.83a |
| COWAT* | 29.2 ± 7.61 [17.8–47.6] | 26.8 ± 5.84 [17.5–41.5] | 0.223a |
| MCST- CA* | 5.79 ± 0.721 [3.0–6.0] | 5.37 ± 1.3 [3.0–8.7] | 0.162a |
| MCST- PE* | 0.875 ± 1.61 [0.0–6.4] | 1.32 ± 2.04 [0.0–6.4] | 0.392a |
| RAVLT_I* | 43.5 ± 5.84 [29.7–56.1] | 40.8 ± 9.13 [28.9–57.3] | 0.217a |
| RAVLT_D* | 8.85 ± 2.31 [5.2–15.0] | 7.55 ± 2.25 [4.7–12.8] | 0.05a |
| Digit_span_F* | 5.77 ± 0.875 [4.0–7.2] | 5.06 ± 0.719 [3.5–6.25] | 0.003a |
| Digit_span_B* | 3.79 ± 0.588 [345] | 3.35 ± 0.797 [2345] | 0.029a |
| FAB* | 16 ± 1.46 [13.5–18.0] | 15.1 ± 1.74 [13.5–18.0] | 0.054a |
| TOKEN* | 31.4 ± 1.37 [29.25–33.75] | 30.9 ± 2.16 [26.25–33.75] | 0.388a |
| JLO-V* | 24.5 ± 3.78 [2021222324252627282930] | 23.8 ± 4.43 [2021222324252627282930] | 0.578a |
| BECK_II | 6.39 ± 4.57 | 7.19 ± 3.89 | 0.547a |
| HAMA | 6.39 ± 3.83 | 6.85 ± 2.87 | 0.571a |
[i] a ANOVA.
b Chi square.
In bold significant at Bonferroni’s correction 0.0033. N.A. Not Applicable.
Abbreviations: ET = Essential Tremor; HC = Healthy controls; FTM-Scale: Fahn-Tolosa-Marin tremor scale; BDI-II = Beck Depression Inventory II; HAMA = Hamilton Anxiety Rating Scale.
Neuropsychological test with possible score range [min-max]: MMSE = Mini Mental State Examination [0–30]; COWAT: Controlled Oral Word Association Test [0 – (no maximus limit)]; MCST-CA = Modified Card Sorting Test-Categories Achieved [0–6]; MCST-PE = Modified Card Sorting Test-Perseverative Errors [0 – (no maximus limit)]; RAVLT-I = Rey Auditory-Verbal Learning Test Immediate Recall [0–75]; RAVLT-D = Rey Auditory-Verbal Learning Test-Delayed Recall [0–15]; Digit_span_F = Digit Span Forward [0–9]; Digit_span_B = Digit Span Backward [0–8]; FAB = Frontal Assessment Battery [0–18]; TOKEN = Token Test [0–36]; JLO-V = Judgment of Line Orientation [0–30]. *Values are reported as mean ± standard deviation [range of observed score as min-max].
Table 2
Demographic, clinical, and neuropsychological characteristics of the two ET clusters and healthy controls (HC). Data are reported as mean ± standard deviation for continuous variables and as counts for categorical variables.
| CLUSTER 1 ET (14) | CLUSTER 2 ET (12) | HC (24) | P-VALUE | POST-HOC | |
|---|---|---|---|---|---|
| Age | 64.8 ± 9.99 | 65.8 ± 10.8 | 63.8 ± 6.87 | 0.823a | N.A. |
| Sex (F/M) | 6/8 | 3/9 | 13/11 | 0.25c | N.A. |
| Education | 10 ± 3.92 | 10.4 ± 4.21 | 10.9 ± 4.44 | 0.823a | N.A. |
| Familiarity (no/yes) | 5/6 | 8/3 | N.A. | 0.19d | N.A. |
| Disease_duration | 15.2 ± 19.4 | 10.1 ± 4.97 | N.A. | 0.408b | N.A. |
| FTM-Scale | 9.83 ± 12.9 | 9.50 ± 3.21 | N.A. | 0.695b | N.A. |
| MMSE* | 27.6 ± 1.51 [25.7–30.0] | 27.4 ± 1.17 [26.0–30.0] | 27.6 ± 2.08 [24.7–30.0] | 0.887a | N.A. |
| COWAT* | 27.1 ± 7.14 [18.5–41.5] | 26.5 ± 4.14 [17.5–32.4] | 29.2 ± 7.61 [17.8–47.6] | 0.393a | N.A. |
| MCST- CA* | 5.41 ± 1.6 [3.0–8.7] | 5.33 ± 0.888 [4.0–6.0] | 5.79 ± 0.721 [3.0–6.0] | 0.281a | N.A. |
| MCST- PE* | 1.7 ± 2.4 [0.0–6.4] | 0.883 ± 1.52 [0.0–3.7] | 0.875 ± 1.61 [0.0–6.4] | 0.513a | N.A. |
| RAVLT_I* | 48.1 ± 5.38 [40.9–57.3] | 32.3 ± 2.68 [28.9–37.6] | 43.5 ± 5.84 [29.7–56.1] | <.0001a | C1 > C2 C1 > HC HC > C2 |
| RAVLT_D* | 8.82 ± 2 [6.2–12.8] | 6.06 ± 1.51 [4.7–8.6] | 8.85 ± 2.31 [5.2–15.0] | 0.0002a | C1 > C2 C1 = HC HC > C2 |
| Digit_span_F* | 5.14 ± 0.719 [4.0–6.25] | 4.96 ± 0.737 [3.5–6.0] | 5.77 ± 0.875 [4.0–7.2] | 0.015a | C1 = C2 C1 = HC HC > C2 |
| Digit_span_B* | 3.43 ± 0.938 [2345] | 3.25 ± 0.622 [234] | 3.79 ± 0.588 [345] | 0.054a | N.A. |
| FAB* | 15 ± 2.02 [13.5–18.0] | 15.2 ± 1.44 [13.5–17.30] | 16 ± 1.46 [13.5–18.0] | 0.175a | N.A. |
| TOKEN* | 30.4 ± 2.18 [26.25–33.0] | 31.6 ± 2.02 [28.0–33.75] | 31.4 ± 1.37 [29.25–33.75] | 0.272a | N.A. |
| JLO* | 22.8 ± 5.45 [2021222324252627282930] | 25.1 ± 2.26 [2223242526272829] | 24.5 ± 3.78 [2021222324252627282930] | 0.372a | N.A. |
| BECK_II | 6.57 ± 3.99 | 7.92 ± 3.8 | 6.39 ± 4.57 | 0.554a | N.A. |
| HAMA | 6.71 ± 3.31 | 7 ± 2.37 | 6.39 ± 3.83 | 0.85a | N.A. |
[i] a ANOVA across three groups.
b ANOVA between clusters.
c Chi square across three groups.
d Chi square between clusters.
N.A. Not Applicable. In bold results significant at the post hoc.
Abbreviations: ET = Essential Tremor; HC = Healthy controls; FTM-Scale: Fahn-Tolosa-Marin tremor scale; BDI-II = Beck Depression Inventory II; HAMA = Hamilton Anxiety Rating Scale.
Neuropsychological test with possible score range [min-max]: MMSE = Mini Mental State Examination [0–30]; COWAT: Controlled Oral Word Association Test [0 – (no maximus limit)]; MCST-CA = Modified Card Sorting Test-Categories Achieved [0–6]; MCST-PE = Modified Card Sorting Test-Perseverative Errors [0 – (no maximus limit)]; RAVLT-I = Rey Auditory-Verbal Learning Test Immediate Recall [0–75]; RAVLT-D = Rey Auditory-Verbal Learning Test-Delayed Recall [0–15]; Digit_span_F = Digit Span Forward [0–9]; Digit_span_B = Digit Span Backward [0–8]; FAB = Frontal Assessment Battery [0–18]; TOKEN = Token Test [0–36]; JLO-V = Judgment of Line Orientation [0–30]. *Values are reported as mean ± standard deviation [range of observed score as min-max].
Figure 1
Violin plots. Violin plots showing the distribution of scores for the three cognitive variables that showed statistically significant differences in post-hoc comparisons between groups: RAVLT Immediate Recall (RAVLT_I), RAVLT Delayed Recall (RAVLT_D), and Digit Span Forward. The plots compare performance across ET Cluster 1 (C1), ET Cluster 2 (C2), and healthy controls (HC).