Table 2.
Sample characteristics.
|
N = 304 Parkinson's disease patients 88% caucasian |
Mean | Standard deviation | Range |
|---|---|---|---|
| Age (years) | 64.7 | 10 | 30–90 |
| Years of education | 15.0 | 3 | 7–20 |
| Years with symptoms | 9.7 | 6 | 1–33 |
| UPDRS motor score, on medication | 26.3 | 10 | 7–54 |
| Percent tremor predominant | 82 | ||
| Levodopa equivalency dose | 771 | 532 | 0–2950 |
| Dementia Rating Scale-II total score | 137.2 | 5 | 119–148 |
| Neurocognitive domain Z-scores* | |||
| Executive composite score | −0.6 | 0.9 | −2.9–1.9 |
| Verbal memory composite score | −0.4 | 1.1 | −3.7–1.8 |
| Processing speed composite score | −0.7 | 0.9 | −3.2–1.9 |
| Language composite score | 0.2 | 1.2 | −4.0–3.2 |
| Working memory composite score | 0.2 | 0.8 | −1.9–2.7 |
| Mild cognitive impairment (MCI) subtypes | |||
| Percent amnestic single-domain MCI | 0.3 | ||
| Percent multidomain amnestic MCI | 30.2 | ||
| Percent nonamnestic MCI | 16.7 | ||
| Percent cognitively intact | 52.8 |
*Z-scores based on normative data from test manuals and published norms: normative mean = 0, standard deviation = 1; mild cognitive impairment was based on Movement Disorder Society criteria and utilized a 1.5 SD below the mean cut value. [25] UPDRS: Unified Parkinson's Disease Rating Scale.