When most people hear the word dementia, they think of Alzheimer’s disease. Although Alzheimer’s is one of the most common types of dementia, it is not the only type. The second most likely kind of dementia is caused by a buildup of proteins in the brain, known as Lewy bodies. When Lewy bodies accumulate, they can lead to symptoms of hallucinations and other cognitive and nervous system problems. People living with Parkinson’s disease (PD) are more susceptible to Lewy body dementia (LBD) compared to the general population. They may experience mild or severe cognitive symptoms that typically progress over time. Living with a rapid eye movement (REM) sleep behavior disorder is also a risk factor for acquiring LBD.

Here is what you should know about LBD if you or a loved one has PD.

Making Sense of the Science

PD and LBD often occur simultaneously, leading some members of the medical community to consider Parkinson’s as part of a group of similar diseases that fall under the umbrella of Lewy body disorders. Technically, Lewy bodies are clumps of alpha-synuclein proteins that can accumulate in various parts of the brain and brain stem.

The location of Lewy bodies determines how they may affect the body, for example:

• Brain cortex — Planning, multitasking, navigation, memory problems, anxiety, agitation, and delusions
• Brain stem — Constipation, depression, sleep problems, fluctuations in blood pressure, and body temperature
• Substantia nigra (midbrain, top of the brain stem) — Movement symptoms, including resting tremors, shuffling walk, and slowness

Dementia with Lewy bodies (DLB) can also happen in people without PD who have cognitive issues but no dysfunction in body movement. Although it often goes underdiagnosed, scientists estimate that about 1.4 million Americans have some form of LBD. Similar to Parkinson’s, people with LBD have low levels of the neurotransmitters dopamine and acetylcholine. Risk factors for LBD include being male, over age 60, and having a family history of PD or LBD.

The difference between DLB and PD dementia is the order in which symptoms appear. If dementia (including visual hallucinations, mood changes, and REM sleep disturbances) happens first, the diagnosis will be DLB. However, if motor symptoms appear before signs of dementia, the condition may be more accurately called PD dementia. Either way, the effects of Lewy bodies on neurotransmitters in the brain are likely the underlying cause of hallucinations.

Common Types of Hallucinations

About 20 percent to 40 percent of people with PD have experienced hallucinations (seeing or hearing things that are not there) or delusions (believing something that is not true, like a conspiracy). Fortunately, not all hallucinations are scary or disturbing. Sometimes, they can be hardly noticeable, like for one member who wrote, “I have infrequent hallucinations that are shadows in my peripheral vision. They startle me. But I can live with them if they don’t get worse.”

Lewy bodies can cause visual hallucinations of strange shapes, animals, or people. In addition, you may smell, hear, or feel things that are not there. For example, one member said, “About a year ago, I could smell bacon cooking. We do not have bacon in the house. It finally went away.”

Hallucinations may even be pleasant, like for one member who described her first experience. “In my living room, I saw a little boy covered in fur. It lasted a good eight seconds, vivid and defined. I wasn’t startled, just curious. I absolutely believed it was real until it vanished. My neurologist asked, “Did it frighten you?” and I replied, “No, in fact, I wish the little furry boy would return!’”

Hallucinations are a sign of potential worsening symptoms of Parkinson’s and should not be encouraged, even if they seem like a positive experience. Let your doctor know right away if you start to see or hear things that are not there.

Possible Treatment Options

In some cases, treating a new onset of hallucinations or delusions can be as simple as addressing an underlying infection or adjusting your medication. New hallucinations or delusions that come on rapidly (over the course of hours to days) are called delirium. Delirium is due to another underlying medical reason and includes infections, electrolyte problems, a recent hospital stay, and medication. Delirium is not the same thing as hallucinations or delusions from dementia. Ruling out an alternative cause, especially one that may be easily treatable, is always the first step.

Treating hallucinations from LBD is often not needed if the person living with them is not bothered or agitated, assuming their safety (and others’ safety) are not at risk. In LBD, hallucinations do not usually cause distress to the person.

There is no cure for LBD, but certain medications can help manage the symptoms. Unfortunately, treating PD and hallucinations from LBD can be tricky. Multiple members have reported hallucinations as a side effect of Parkinson’s medication. “I had hallucinations years ago with Amantadine, but my doctor reduced the dosage, and they stopped.” Another member said, “I don’t like the racing nervousness side effect and hallucinations I get with levodopa.” Although levodopa significantly reduces motor control issues, it can also exacerbate hallucinations. Many antipsychotic medications have the opposite effect, preventing hallucinations while increasing movement problems.

Some forms of antipsychotics are more promising than others for people with motor and cognitive issues. Doctors may prescribe quetiapine (Seroquel) or clozapine (Clozaril) to help treat hallucinations but minimize any effects on motor control. These medications can have serious side effects, so caution is warranted. Additionally, quetiapine and clozapine are not FDA approved for the use of hallucinations or delusions from PD. They are sometimes prescribed off-label. Efficacy for these medications is mixed. Pimavanserin (Nuplazid), a newer medication that influences serotonin rather than dopamine, offers hope for those with hallucinations and motor issues.

Recognizing and Responding to Hallucinations

Loved ones and caregivers play a crucial role in responding to hallucinations. If something strange happens or if you suspect you may be hallucinating, it is important to have a quick and easy way to contact a family member or trusted neighbor for help.

One member wrote, “I have hallucinations, but they’re usually not disturbing. The other day, I had a scary one about mosquitoes in my room, hundreds of them. I called my son, and he came home to check on me. My wife held my hand and laid down with me. It gave me a panic attack, but finally, I calmed down.”

Avoid arguing or trying to correct someone who is having a hallucination. Instead, stay calm and provide reassurance. It can be upsetting to watch a loved one hallucinate, but hallucinations do not always need to be a cause for alarm. If the doctor is already aware of the problem, and the individual with Parkinson’s does not become overly distressed, simply changing the subject can be the best way to avoid confusion and frustration.

You can provide a distraction or try to direct the person’s attention back to you. There is no need to play along with the hallucination, but it is OK to acknowledge that the other person is seeing or experiencing something. Covering mirrors, minimizing background noises, and avoiding lights that cast shadows can make the environment less confusing for someone who hallucinates.

In addition, people living with Parkinson’s and LBD often have trouble getting a good night’s sleep, which can exacerbate hallucinations and other cognitive issues. Caregivers should plan for stimulating daytime activities, including exposure to sunshine and a consistent bedtime routine to promote healthy sleep and quality of life. Support groups are available to help caregivers manage daily life with a loved one who is living with LBD.

Talk With Others Who Understand

MyParkinsonsTeam is the social network for people with Parkinson’s disease and their loved ones. On MyParkinsonsTeam, more than 85,000 members come together to ask questions, give advice, and share their stories with others who understand life with PD.

If you have experienced hallucinations, or care for someone who has, please share your story in the comments below, or start a conversation by posting on MyParkinsonsTeam.