Hallucinations/Delusions

• Visual: Hallucinations in people with PD are usually visual. Common hallucinations include seeing animals or people, such as a furry creature running by or a deceased loved one sitting in the room.
• Auditory: Hearing voices or sounds that are not real is less common but is reported by a small percentage of people with PD.
• Olfactory: Smelling an odor that is not related to an actual source is rare in PD.
• Tactile: Feeling something imaginary, like bugs crawling on your skin, is rare in PD.
• Gustatory: Sensing a bitter or abnormal taste in your mouth that has no source is rare in PD.

• Hallucinations are most often a side effect of medication and are not necessarily a sign of a decline in cognitive abilities. Most hallucinations experienced by people with PD are fleeting and non-threatening. However, in some cases hallucinations may become threatening or bothersome.
• Although hallucinations can affect anyone taking medication to manage PD symptoms, they are more common in people who have problems with thinking or memory, or when under medical stress.
• Visual hallucinations are more likely to occur in low light or low visibility situations. To reduce risk, increase lighting in particularly dark areas, such as hallways.
• Hallucinations may occur in the peripheral vision (out of the corner of the eye), in the form of a flash of light, people or small animals such as cats or dogs. Images often disappear when the person looks more closely.
• Sometimes people with PD have presence hallucinations — the feeling that someone is in the room with them or standing behind them.
• Some people are aware that hallucinations are occurring. This is called “retaining insight.” With insight, you might be able to create coping mechanisms. However, some people find them incredibly real, or may lose insight as the disease progresses.

It is important for people with PD to talk about hallucinations with their family and care team — these are manageable and can be troublesome if not treated. Discuss all possible symptoms with your doctor, no matter how minor, rare or bizarre you may think they are.

• Good lighting and stimulating activities in the evening can help keep hallucinations at bay.
• While a hallucination is occurring, care partners can help their loved one by reassuring them that they will be safe and validating their partner’s experience. For example, say, “I’ll take the cat outside” instead of arguing that there is no cat.

Some examples of delusions and their impact in PD include:

• Jealousy
  • Belief: Your partner is being unfaithful.
  • Behavior: Paranoia, agitation, suspiciousness, aggression
• Persecutory
  • Belief: You are being attacked, harassed, cheated or conspired against.
  • Behavior: Paranoia, suspiciousness, agitation, aggression, defiance, social withdrawal
• Somatic
  • Belief: Your body functions in an abnormal manner. You develop an unusual obsession with your body or health.
  • Behavior: Anxiety, agitation, reports of abnormal or unusual symptoms, extreme concern regarding symptoms, frequent visits with the clinician

• Delusions are less common in PD than visual hallucinations. They affect about 8% of people with PD.
• Compared to hallucinations, delusions tend to be more complicated, present a greater risk for behavioral disturbances and safety concerns, are typically more difficult to treat and represent a more obvious deterioration or decline in one’s condition.
• Delusions can begin as generalized confusion at night. Over time, confusion can develop into clear delusions and behavioral disturbances during the day.
• Paranoia can lead to medication noncompliance — a person refusing to take medications, believing they are poisonous or deadly.
• Delusions can be associated with dementia. As a result, people with delusions are often confused and extremely difficult to manage. In these cases, many caregivers require outside assistance.

All forms of delusions can be seen with PD, although delusions of jealousy and persecution (like paranoia) are most widely reported and represent a greater challenge for treatment. These delusions can lead to aggression, which can pose a serious safety risk to the person with PD, family members and care partners.

Many PD medications can lead to symptoms of psychosis:

• Classic PD medications like carbidopa-levodopa (Sinemet) and dopamine agonists are designed to increase dopamine levels, improving motor symptoms. However, by boosting the dopamine supply, these medications can inadvertently cause serious emotional and behavioral changes.
• Other medications used to treat PD can also cause these symptoms by lowering levels of acetylcholine, shifting its balance with dopamine. These medications include amantadine and anticholinergics (Artane and Cogentin). In addition to the prescription drugs, anticholinergics are typically the main ingredient in over-the-counter sleep aids and many allergy medications.

Dementia is a term used to describe a group of symptoms associated with a decline in memory and thinking. It is commonly associated with Alzheimer's disease, but people with PD can also develop it.

• Hallucinations and delusions can result from the basic chemical and physical changes that occur in the brain, regardless of other factors such as PD medications. This is most commonly seen in cases of PD with dementia.
• If psychosis and dementia occur early in the disease process, doctors may consider a diagnosis of Lewy body Dementia (LBD).

Delirium is a reversible change in a person's level of attention and concentration.

• Delirium usually develops over a short period of time (hours to days) and resolves following treatment of the underlying condition.
• Signs of delirium include altered consciousness or awareness, disorganized thinking, unusual behavior and hallucinations.
• Because there are so many symptoms, delirium can be confused with other conditions, such as dementia or drug-induced psychosis.
• To diagnose delirium, a person’s level of concentration or attention must go through a change.
• People with Parkinson's have a higher risk of delirium when admitted to the hospital, due to the new settings for the procedure or surgery, which may be unrelated to their PD.

Common causes of delirium include:

• Infection, such as urinary tract infection or pneumonia
• Imbalance of sodium, potassium, calcium or other electrolytes
• Stroke
• Heart disease
• Liver disease
• Fever
• Vitamin B12 deficiency
• Head injury
• Sensory changes, such as hearing loss and vision changes

In addition to medical conditions and changes, many commonly used drugs and chemicals can also cause delirium:

• Anticholinergic medications: diphenhydramine hydrochloride (Benadryl^®), trihexyphenidyl (Artane^®), benztropine (Cogentin^®), ranitidine (Zantac^®) and oxybutynin (Ditropan^®)
• Narcotics containing codeine or morphine
• Antibiotics
• Nonsteroidal anti-inflammatory drugs (NSAIDS) including Aleve^®, Motrin^® and Advil ^®
• Insulin
• Sedatives
• Steroids
• Anti-seizure medications
• Alcohol
• Recreational drugs

Pimavanserin (Nuplazid®) was approved by the U.S. Food and Drug Administration (FDA) in 2016 specifically for the treatment of Parkinson's disease psychosis.

• Unlike other antipsychotics, it does not block dopamine. It is a selective serotonin inverse agonist, meaning it targets serotonin receptors.

Clozapine (Clozaril®) has been studied and proven effective in improving hallucinations and delusions in PD. However, due to a rare, yet serious side effect known as agranulocytosis ― a reduction in white blood cells that interferes with the body's ability to fight infection ― there is a tendency use this medication only if quetiapine is not tolerated or effective.

• Anyone who takes clozapine is required to get weekly blood tests for the first six months, and every two weeks thereafter, to monitor white blood cell levels.

Quetiapine (Seroquel®) has fewer side effects, but there is limited evidence for its efficacy in people with Parkinson’s.

• It is most often prescribed to be taken just before going to bed because it may be mildly sedating.