Can someone be diagnosed with Parkinson's and Alzheimer's?

Dtflex, I wonder how they know that the psychotic behavior and halucinations are not Lewy Body? Since Lewy Bodies cause those symtoms and Parkinson's patients have LBs in their brains, how could they tell that these particular psychotic behaviors are caused by something else? (I'm not arguing here, I just truly am curious.) And I wonder if this observation is based on autopsy-confirmed cases? Does that mean that in 30% of the Parkinson's brains that have been studied there are other pathologies in addition to the Lewy Bodies?

This is certainly a huge challenge to diagnose!

According to mom's geriatric psychiatrist there are about 30% of Parkinson's patients that develop psychotic behavior such as halucinations and cognitive impairment that is not Lewey Bodies Dementia. We tried mom on Seroquel but it did not have any beneficial effects and only increased some of the Parkinson symptoms such as "freezing". She is on the 9.5mg Excelon patch which is helpful.

My mother-in-law was diagnosed with Lewy Body Dementia. The doctor explained it, in layman's terms, to my father-in-law as a combination of Alz and Parkinson's. It took three years to get to this diagnosis and she lived three more years afterwards.

My heart goes out to you. It is a long and difficult journey. God bless your FIL and you and your family.

Lilliput, you say "Although there is a form of Alz. that some PD patients develop." I wonder if you are thinking of Lewy Body Dementia? That is not a form of Alz. Both Alz and LBD are forms of dementia. I know that a lot of people kind of use Alz to mean dementia, but it is just a specific kind of dementia.

Heidi, this is an oversimplication, but as I understand it, people with Parkinson's Disease (PD) have clumps of protein in their brains. This was first identified by Dr. Lewy doing post mortem studies about a century ago. People with Alzheimer's Disease (AD) have tangles in their brains. (By the way, Lewy and Alzheimer worked at the same research center at the same time.)

The "Lewy Bodies" can cause not only the familiar physical symptoms of PD, but cognitive problems as well. If someone with PD develops dementia, particularly with certain characteristics, he is usually diagnosed with having Parkinson's Disease with Dementia (PDD).

The Lewy Body clumps don't always start out by causing PD symptoms. Sometimes dementia (with particular characteristics) comes first, and the Parkinson symptoms may appear much later or only very mildly. Such people are said to have Dementia.with Lewy Bodies.

Both caused by the clumps in the brain named for Lewy, PDD and DLB are basically the same pathology just differentiated by which symptoms came first and are strongest. Together both diseases are called Lewy Body Dementia (LBD).

Brain autopsies often reveal both clumps and tangles -- evidence of both LBD and AD.

So you are right; it is very difficult to accurately diagnose different types of dementia. It can be important to get an early diagnosis by someone who has experience and expertise in this field. For examples, some drugs developed for AD are even more effective for LBD. Some drugs that are OK when given to an AD patient can cause permanent damage or death to someone with LBD.

I would ask the psychiatrist why she or he came up with AD instead of the more expected PDD. Does your FIL have characteristics that fit the AD profile better? (And don't be surprised if the doctor just doesn't know much about LBD -- that is unfortunately not uncommon, even among specialists.)

You might want to do a little research on the Lewy Body Dementia Association web site, particularly on the subject of the characteristics of LBD that distinguish it from other forms of dementia.

Best of luck to you and your family. Whatever the specific kind of dementia, it is a heartbreaking disease.

That may follow under "Lewy Body Dementia" a combo of dementia and parkinsons. Googel it.

Though there is no actual Alzheimer's test at this time, doctors can diagnose it by eliminating other causes of their problems. Here is a good article on Alzheimer's testing. There is also lots of information on Alzheimer's warning signs.

The problem with both PD and Alz. is that there is no definitive "test." Most doctors do a visual exam and rely on the information from the patient and his or her family.
There are some drugs that treat both, most have varying results and some carry serious side effects. Each patient is different.
PD and Alz are different illnesses. Your father could have both. PD effects mainly motor skills. Alz. effects cognitive abilities. Although there is a form of Alz. that some PD patients develop.