Characteristics of the study population
| Memantine | Placebo | Mann-Whitney test p value | |
|---|---|---|---|
| Number of patients | 13 | 12 | |
| Age at study entry (median [Q25-Q75]) (minimum–maximum) | 66 [62–72] (59–81) | 64 [60–73] (46–78) | p=0.68 |
| Disease duration (years) (minimum–maximum) | 15 [12–23] (5–29) | 13.5 [10–16.3] (5–25) | p=0.27 |
| Hoehn and Yahr score | 3 [2.5–3] | 3 [2.5–3] | p=0.83 |
| L-dopa dose (mg) for ‘on-L-dopa’ assessments | 200 [100–200] | 200 [100–200] | p=0.89 |
| L-dopa equivalent daily dose (mg) | 1000 [700–1400] | 1075 [700–1200] | p=0.93 |
| Mini mental scale examination score | 28 [26–28.2] | 28 [26–28.2] | p=0.79 |
| Mattis dementia rating scale score | 137 [130–139] | 136 [132–139] | p=0.85 |
| Drowsiness on the Epworth sleepiness scale | 8 [4–9] | 9 [5–10] | p=0.53 |
| Montgomery-Asberg depression rating scale | 8 [6–16] | 8.5 [3–14] | p=0.69 |
| Patients with subthalamic nucleus stimulation | n=8 of 13 | n=8 of 12 | |
| Stimulation duration (years) | 8 [7.25–9] | 7.5 [5.5–8.25] | p=0.44 |
| Total electrical energy delivered per second | 85 [70–131] | 95 [74–126] | p=0.41 |
The parameters are expressed as the median value [1st quartile–3rd quartile]. The groups were similar at baseline. The total electrical energy delivered (TEED) was calculated as (V2*frequency* pulse width)/2