rTMS to Improve Cognition in Parkinson's

This study is investigating whether repetitive transcranial magnetic stimulation (rTMS) — a non-invasive brain stimulation technique that uses magnetic pulses on the scalp — can improve thinking and memory problems in veterans who have Parkinson's disease or a related condition. **You may be eligible if...** - You are a veteran who receives care at Hines VA Hospital or Jesse Brown VA Medical Center - You have been diagnosed with Parkinson's disease or a related condition by a neurologist - You have been diagnosed with mild thinking or memory problems (mild cognitive impairment) - You are on a stable medication regimen (no changes planned) - You speak and read English - You are 50 years old or older **You may NOT be eligible if...** - You have been diagnosed with dementia - You have had deep brain stimulation surgery - You have a pacemaker, defibrillator, cochlear implant, nerve stimulator, or metal in your head - You have severe depression or severe tremors that interfere with testing - You have a history of seizures or epilepsy - You have claustrophobia or cannot undergo MRI scanning - You have significant heart failure Talk to your doctor to see if this trial is right for you.