Does Parkinson’s disease progress to Alzheimer’s disease or dementia?

Alzheimer’s disease and Parkinson’s disease are both common in the elderly, especially in those over 85.

Parkinson’s disease is a degenerative neurological disorder which results from nerve cells in the brain not producing enough of the chemical dopamine that regulates movement in the human body.

The disease develops gradually, most often starting on one side with a slight tremor in one hand, for example.

As Parkinson’s progresses, the trembling may spread to other parts of the body, and the person may experience additional symptoms, such as muscle stiffness, slowing of movement and deterioration in balance and coordination.

Those with Parkinson’s with normal cognition are at a very high risk of developing mild cognitive impairment or dementia over time, according to a study released by Neurology Today.

The study reported about half of the those with Parkinson’s disease who had normal cognition at a baseline evaluation developed cognitive impairment within six years, and all these cases were projected to progress to dementia within five years.

In summary, the transition from normal cognition to cognitive impairment, which includes dementia, is a frequent and rapid occurrence among established Parkinson’s patients.

Further, for those with the disease who go on to develop dementia, there is usually at least a 10- to 15-year lag between the individual’s diagnosis of Parkinson’s and the onset of dementia. And, those who do develop dementia may develop Alzheimer’s dementia as well.

Contact Dana Territo, the Memory Whisperer, Director of Services at Alzheimer’s Services of the Capital Area, (225) 334-7494,, or visit the organization at 3772 North Blvd., Baton Rouge.