Table 1

Characteristics of the study population

MemantinePlaceboMann-Whitney test p value
Number of patients1312
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 score3 [2.5–3]3 [2.5–3]p=0.83
L-dopa dose (mg) for ‘on-L-dopa’ assessments200 [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 score28 [26–28.2]28 [26–28.2]p=0.79
Mattis dementia rating scale score137 [130–139]136 [132–139]p=0.85
Drowsiness on the Epworth sleepiness scale8 [4–9]9 [5–10]p=0.53
Montgomery-Asberg depression rating scale8 [6–16]8.5 [3–14]p=0.69
Patients with subthalamic nucleus stimulationn=8 of 13n=8 of 12
Stimulation duration (years)8 [7.25–9]7.5 [5.5–8.25]p=0.44
Total electrical energy delivered per second85 [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