Cholinergic Augmentation in Frequently Falling Subjects With Parkinson's Disease

The purpose of this study is to find out if a medication that increases levels of a brain chemical called acetylcholine will improve balance and reduce falls in patients with parkinson's disease who have the problem of very poor balance and are frequently falling or nearly falling on a daily basis. Donepezil, a drug approved for the treatment of Alzheimer's dementia, will reduce falls in subjects with Parkinson's disease and balance impairment.

This trial is a double-blinded cross-over design comparing donepezil with placebo in 40 subjects with idiopathic Parkinson's disease who report frequent falls or near falls (>2/week). The purpose of this study is to find out if a medication that increases levels of a brain chemical called acetylcholine will improve balance and reduce falls in patients with parkinson's disease who have the problem of very poor balance and are frequently falling or nearly falling on a daily basis. Donepezil, a drug approved for the treatment of Alzheimer's dementia, will reduce falls in subjects with Parkinson's disease and balance impairment.

The primary outcomes were fall frequency determined using daily event recording by the subjects onto postcards which accumulated data for six weeks per phase. Falls were defined as landing on the floor. Fall frequency is the number of reported falls divided by the number of days reported. Postcards were mailed back to the investigator weekly.

The secondary outcome was near fall frequency determined using daily event recording by the subjects onto postcards which accumulated data for six weeks per phase. Near falls were defined as a fall that did not land on the floor (for example grabbing a handrail or a table). Near fall frequency is the number of reported near falls divided by the number of days reported. Postcards were mailed back to the investigator weekly.

Inclusion Criteria: Age over 21 Diagnosis of Parkinson's disease Treated with dopaminergic medication for at least 1 year Exclusion Criteria: Must be ambulatory (can use walker or cane) No obvious remediable cause of falls Falls are on basis of non-CNS etiologies (cardiogenic, orthopedic, peripheral neuropathy, etc) Dementia present (MMSE < 25) Not taking cholinergic or anticholinergic medications 10 days prior to screening visit No Warfarin use