rTMS to Improve Cognition in Parkinson's

Inclusion Criteria: * Veterans who seek services at Hines VA Hospital or Jesse Brown VA Medical Center * Diagnosis of PD or atypical parkinsonism as determined by a neurologist * Meet criteria for having mild cognitive impairment * Receiving stable (i.e., no changes in medication and medication dose) medication and who are expected to remain on stable medication for the duration of the RCT * Speak and read English * 50 years or older Exclusion Criteria: * Dementia * Failure to demonstrate decision making capacity * History of deep brain stimulation surgery * Severe depression * Resting head tremor * Dyskinesia that will interfere with collecting imaging data * Has congestive heart failure * Implanted cardiac pacemaker or defibrillator * Cochlear implant, nerve stimulator, or intracranial metal clips * Implanted medical pump * Increased intracranial pressure * History of claustrophobia * Metal in eyes/face, shrapnel/bullet remnants in brain * Participants at potential increased risk of seizure including those who have the following: * history (or family history) of seizure or epilepsy * history of stroke, head injury, or unexplained seizures * presence of other neurological disease that may be associated with an altered seizure threshold * such as CVA, cerebral aneurysm, dementia, increased intracranial pressure * Concurrent medication use such as tricyclic antidepressants, neuroleptic medications, any other drug known to lower seizure threshold * Secondary conditions that may significantly alter electrolyte balance or lower seizure threshold * No quantifiable motor threshold such that rTMS dosage cannot be accurately deter-mined