Withdrawing amantadine in dyskinetic patients with Parkinson disease: The AMANDYSK trial

I applaud the authors of the AMANDYSK trial1 and agree that their placebo-controlled withdrawal design supports the antidyskinetic effect of amantadine for l-dopa-induced dyskinesias. This design emulates clinical practice, where a drug is routinely tapered and stopped if the benefit is unclear. However, the authors' deductions on the measured nonmotor symptoms are dubious. They couched their interpretation as a …