The effectiveness of istradefylline for the treatment of gait deficits and sleepiness in patients with Parkinson's disease

Purpose: Istradefylline is useful in treating the wearing-off state in Parkinson's disease (PD). We investigated the effectiveness of istradefylline (ISD) in improving arousal, sleep, and gait deficits in patients with PD. Methods: We examined 14 patients with PD treated with ISD. We assessed the patients using the Unified Parkinson's Disease Rating Scale, Parkinson's Disease Questionnaire, Timed Up-and-Go test (TUG), Freezing of Gait Questionnaire (FOG-Q), Epworth Sleepiness Scale (ESS), and Parkinson's Disease Sleep Scale (PDSS) before and 1 month after ISD use. Results: ESS scores were significantly lower 1 month after the start of ISD treatment (6.79 +/- 6.50) than before the intervention (8.14 +/- 6.15, Wilcoxon signed-rank test, p = 0.0033). PDSS scores were not significantly different 1 month after beginning the treatment (112 23 mm) when compared to those before the intervention (110 27 mm, Wilcoxon signed-rank test, p = 0.40). TUG scores were not changed after 1 month of ISD use (14.9 +/- 8.3 s) when compared to those before the intervention (21.3 +/- 30.0 s, Wilcoxon signed-rank test, p =0.59). Although these measures were not significantly affected by ISD treatment, some patients remarkably improved after the treatment. FOG-Q scores were significantly lower 1 month after the beginning of treatment (9.79 +/- 7.16) than those before the intervention (12.14 +/- 5.82, Wilcoxon signed-rank test, p = 0.030). Conclusions: ISD may improve daytime sleepiness and FOG in patients with PD.