Table 2.
Sample characteristics.
| Parkinson’s disease (N = 63) |
Essential tremor (N = 53) |
P value | Effect size | |
|---|---|---|---|---|
| Demographics | ||||
| Age | ||||
| Mean (sd) | 66.1 (9.6) | 67.3 (10.3) | .51 | 0.12 |
| Range | 41–82 | 28–81 | ||
| Education (years) | ||||
| Mean (sd) | 14.6 (2.9) | 13.6 (2.2) | .04 | 0.39 |
| Range | 7–20 | 10–18 | ||
| Gender (n, m/f) | 48/15 | 34/19 | .16 | 0.13 |
| Ethnicity | n (%) | n (%) | 0.19 | |
| Caucasian | 58 (92.1) | 53 (100%) | ||
| Native American | 2 (3.2) | |||
| Asian American | 1 (1.6) | |||
| Hispanic | 1 (1.6) | |||
| Mixed ethnicity | 1 (1.6) | |||
| Disease duration (years) | ||||
| Mean (sd) | 8.3 (3.8) | 30.8 (17.4) | <.001 | 1.86 |
| Range | 2–20 | 4–70 | ||
| UPDRS-III ON (n = 53) | ||||
| Mean (sd) | 19.9 (10.7) | |||
| Range | 4–59 | |||
| FTMCRS – Total (n = 20) | ||||
| Mean (sd) | 53.5 (14.9) | |||
| Range | 34–97 | |||
| Dopaminergic Medications | n = 61 | |||
| Motor medications | n = 35 | |||
| General cognitive functioning | ||||
| TOPF (z-score) | ||||
| Mean (sd) | 0.2 (0.9) | 0.0 (0.8) | .22 | 0.23 |
| Composites (Z-scores) | ||||
| Attention and processing speed | ||||
| Mean (sd) | −0.1 (0.6) | −0.4 (0.5) | .00 | 0.54 |
| Executive functioning | ||||
| Mean (sd) | −0.7 (0.9) | −0.2 (0.5) | .32 | 0.69 |
| Language | ||||
| Mean (sd) | 0.2 (0.8) | 0.2 (0.8) | .94 | 0.00 |
| Learning and memory | ||||
| Mean (sd) | −0.0 (0.8) | −0.0 (0.7) | .85 | 0.00 |
| Visuospatial/perceptual | ||||
| Mean (sd) | 0.2 (0.8) | 0.2 (0.8) | .93 | 0.00 |
| Mood | ||||
| BDI-II | ||||
| Mean (n/sd) | 7.5 (n = 62/5.6) | 7.3(n = 50/6.3) | .87 | 0.03 |
| Range | 0–30 | 0–31 | ||
| GDS | ||||
| Mean (n/sd) | 6.0 (n = 1/−) | 1.0 (n = 2/1.4) | .21 | |
| Range | – | 0–2 | ||
| BAI | ||||
| Mean (n/sd) | 10.1 (n = 61/6.3) | 9.4 (n = 49/6.1) | .54 | 0.11 |
| Range | 0–29 | 0–25 | ||
| GAI | ||||
| Mean (n/sd) | 6.0 (n = 1/−) | 0.5 (n = 2/0.7) | .09 | |
| Range | – | 0–1 |
Note. n=number; sd = standard deviation; UPDRS = Unified Parkinson’s Disease Rating Scale (Goetz et al., 2008); FTM = Fahn-Tolosa-Marin Clinical Rating Scale (Fahn et al., 1988); TOPF = Test of Premorbid Functioning (Pearson Assessment, 2009); BDI-II = Beck Depression Inventory (Beck et al., 1996); GDS = Geriatric Depression Scale (Yesavage et al., 1982); BAI = Beck Anxiety Inventory (Beck & Steer, 1988); GAI = Geriatric Anxiety Inventory (Pachana et al., 2007).
For a normative sample, a Z-score mean is 0 and standard deviation (SD) is 1.
Effect size = Cohen’s d for continuous variables, Cramer’s V for categorical variables.
Signifiant levels are bolded.