The correct answer is C.
In a recent randomized controlled trial of patients with stable PD, 60 were randomized to 200 mg caffeine (about the amount in two cups of coffee) twice daily and 61 to placebo for six months. Results showed that motor symptoms did not improve with caffeine compared to placebo (difference in mean MDS-UPDRS-III score: -0.48 points, 95% CI -3.21, 2.25).2 Results from an earlier, six-week study by the same group showed that caffeine may improve motor symptoms of PD.3 Together, the results suggest a short-term benefit for caffeine that may not be sustained over longer term followup. The results also suggest that epidemiological links between caffeine consumption and decreased risk of PD may not be explained by a beneficial impact of caffeine on motor symptoms of PD.
Question 3 (Answer on Next Page >)
1. Noyce AJ, Bestwick JP, Silveira-Moriyama L, et al. Meta-analysis of early nonmotor features and risk factors for Parkinson disease. Ann Neurol. 2012;72:893-901.
2. Postuma RB, Anang J, Pelletier A, et al. Caffeine as symptomatic treatment for Parkinson disease (Café-PD): A randomized trial. Neurology. 2017;89:1795-1803.
3. Postuma RB, Anang AE, Munhoz RP, et al. Caffeine for treatment of Parkinson disease: a randomized controlled trial. Neurology. 2012;79:651-658.