Gait and balance problems are a significant source of disability in patients with Parkinson
disease. Physical therapy remains one of the main treatments. On the other hand some
medications, such as methyphenidate and atomoxetine, have been tried with promising results.
The outcomes in gait and balance in Parkinson disease after a combination of physical therapy
and the medications mentioned above have not been explored yet. The investigators want to
evaluate whether the addition of medication, either low dose of methylphenidate or
atomoxetine, to physical therapy will achieve improvement in gait and balance in Parkinson
disease more than physical therapy alone. The investigators propose a pilot, single center,
rater blind, prospective randomized trial. 2-arm-parallel group, intention-to-treat analysis.