Parkinson Disease Dementia

Parkinson disease (PD) is a degenerative disorder of the brain. It mainly affects movements of the body.

• The most common symptoms are tremor (shaking or trembling) of the hands, arms, jaw, and face; rigidity (stiffness) of the trunk and limbs; slowness of movement; and loss of balance and coordination.
  
  
• Other symptoms include shuffling, speaking difficulties, (or speaking very softly), facial masking (expressionless, mask-like face), swallowing problems, and stooped posture.
  
  
• The symptoms worsen gradually.

Depression, anxiety, personality and behavior changes, sleep disturbances, and sexual problems are commonly associated with PD. In many cases, PD does not affect a person’s ability to think, reason, learn, or remember (cognitive processes).

• In some patients with PD, however, one or more cognitive processes are impaired.
  
  
• If this impairment is severe enough to interfere with the person’s ability to carry out everyday activities, it is called dementia.

About 500,000 people in the United States have PD, and about 50,000 new cases are diagnosed each year. The number of those who have cognitive symptoms is difficult to pinpoint.

• The main problem is that researchers use various definitions of cognitive impairment and dementia.
  
  
• Another problem is that PD often overlaps with other degenerative brain disorders that can cause dementia, such as Alzheimer disease and vascular disease.
  
  
• Realistic estimates suggest that at least 50% of people with PD have some mild cognitive impairment. As many as 20-40% may have more severe symptoms or dementia.

Most patients have the first symptoms of PD after the age of 60 years, but PD also affects younger people. Early-onset PD strikes people around the age of 40 years, or even earlier.

• Regardless of age at onset of the disease, dementia symptoms tend to appear later in the course of the disease.
  
  
• Dementia is relatively rare in people with onset of PD before age 50 years, even when the disease is of long duration.
  
  
• Dementia is more common in people with an older age at onset of PD.

Parkinson disease is caused by loss of neurons in a region of the brain that coordinates motor functions (movement).

• These cells produce a chemical messenger (neurotransmitter) called dopamine.
  
  
• Dopamine is involved in the control of motor movement in the brain.
  
  
• When the level of dopamine in the brain is very low, there is loss of control of movement, one of the main features of PD.

We do not know exactly why dopaminergic neurons die.

• A small number of cases of PD are hereditary (run in families), but most are not.
  
  
• Research into the genetics of PD has identified several gene abnormalities that are linked with some cases of the disease.
  
  
• For example, a gene known as SNCA (for alpha synuclein) is involved in PD. Some hereditary forms of PD are linked to mutations in this gene.
  
  
• More recently, scientists have discovered that simply having more than 2 copies of the normal SNCA gene is also linked to PD. The form of the disease linked to this abnormality has an earlier onset than typical PD, progresses more rapidly, and is more likely to lead to dementia.
  
  

Some people with PD and dementia have changes in their brain like those in people with Alzheimer disease.

Risk factors for dementia in patients with PD are as follows:

• Age 70 years or older
  
  
• Score greater than 25 on the Parkinson Disease rating scale (PDRS): This is a test that doctors use to check for progress of the disease.
  
  
• Depression, agitation, disorientation, or psychotic behavior when treated with the PD drug levodopa
  
  
• Exposure to severe psychological stress
  
  
• Cardiovascular disease
  
  
• Low socioeconomic status
  
  
• Low education level

Cognitive impairment in Parkinson disease may range from a single isolated symptom to severe dementia.

• The appearance of a single cognitive symptom does not mean that dementia will develop.
  
  
• Cognitive symptoms in PD usually appear after physical symptoms.
  
  
• Cognitive symptoms early in the disease suggest dementia with parkinsonian features, a different condition.

Cognitive symptoms in PD include the following:

• Loss of decision-making ability
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• Inflexibility in adapting to changes
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• Disorientation in familiar surroundings
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• Problems learning new material
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• Difficulty concentrating
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• Loss of short- and long-term memory
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• Difficulty putting a sequence of events in correct order
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• Problems using complex language and comprehending others’ complex language

Persons with PD, with or without dementia, respond slowly to questions and requests. They become dependent, fearful, indecisive, and passive. As the disease progresses, they become increasingly dependent on spouses or caregivers.

Major mental disorders are common in PD. Two or more of these may appear together in the same person.

• Depression – Sadness, tearfulness, lethargy, withdrawal, loss of interest in activities once enjoyed, insomnia or sleeping too much, weight gain or loss
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• Anxiety – Excessive worry or fear that disrupts everyday activities or relationships; physical signs such as restlessness or extreme fatigue, muscle tension, sleeping problems
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• Psychosis – Inability to think realistically; symptoms such as hallucinations, delusions (false beliefs not shared by others), paranoia (suspicious and feeling controlled by others), and problems thinking clearly; if severe, behavior seriously disrupted; if milder, behavior bizarre, strange, or suspicious

The combination of depression, dementia, and PD usually means a faster cognitive decline and more severe disability. Hallucinations, delusions, agitation, and manic states can occur as adverse effects of drug treatment of PD.

Any change in ability to think, reason, or concentrate; in problem solving; in memory; in use of language; in mood; or in behavior or personality in a person with Parkinson disease warrants a visit to a health care provider.

There is no definitive medical test that confirms cognitive decline or dementia in Parkinson disease. The most accurate way to measure cognitive decline is through neuropsychological testing.

• The testing involves answering questions and performing tasks that have been carefully designed for this purpose. It is carried out by a specialist in this kind of testing.
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• Neuropsychological testing addresses the individual’s appearance, mood, anxiety level, and experience of delusions or hallucinations.
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• It assesses cognitive abilities such as memory, attention, orientation to time and place, use of language, and abilities to carry out various tasks and follow instructions.
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• Reasoning, abstract thinking, and problem solving are tested.
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• Neuropsychological testing gives a more accurate diagnosis of the problems and thus can help in treatment planning.
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• The tests are repeated periodically to see how well treatment is working and check for new problems.

Imaging studies: Generally, brain scans such as CT scan and MRI are of little use in diagnosing dementia in people with PD. Positron-emission tomographic (PET) scan may help distinguish dementia from depression and similar conditions in PD.

There is no cure for dementia in Parkinson disease. Rather, the focus is on treating specific symptoms such as depression, anxiety, and psychotic behavior. A specialist in these disorders (psychiatrist) may be consulted for treatment recommendations.

|Self-Care at Home|

Protein in the diet may affect the absorption of levodopa, the major medication used to treat PD. Fluctuations in the level of levodopa may worsen some behavioral and cognitive symptoms. A low-protein diet may reduce fluctuations in dopamine levels. In some patients with these fluctuations, dietary changes can improve symptoms. However, it is important to ensure that the person is getting adequate calories and other nutrients.

People with PD should remain as active as possible. Physical therapy helps the person maintain mobility.

In general, people with PD and dementia should no longer drive. Movement problems may prevent quick reactions in hazardous driving situations. Certain medications that these persons may be taking may make them less alert. However, this should be determined on an individual basis and in compliance with the laws of your state.

|Medical Treatment|

There is no specific therapy for dementia in PD. Although cognitive symptoms initially may appear to respond to drugs that promote dopamine production, the improvement is mild and transient.

|Medications|

Various medications are used to treat the movement disorders of PD.

• These include dopamine given in the form of levodopa, medications known as dopamine agonists that act on the dopamine receptor, and medications that slow down the metabolism of dopamine. In addition, anticholinergic drugs are sometimes used.
  
  
• Unfortunately, these drugs can affect cognitive symptoms and mood disorders.
  
  
• The anticholinergic drugs, for example, help balance levels of dopamine and acetylcholine, another neurotransmitter, in the brain. These drugs can improve movement disorders but often make memory loss worse.

The dementia of PD may respond to drugs used in patients with Alzheimer’s disease.  However, these drugs, called cholinesterase inhibitors (such as donepezil [Aricept], rivastigmine [Exelon], galantamine [Reminyl]), lead to only small and temporary improvements in cognition.

Mood disorders and psychoses are usually treated with medication.

• For depression and mood disorders, various antidepressant or mood-stabilizing medications, such as tricyclic agents (such as nortriptyline [Pamelor] or desipramine [Norpramin]) or selective serotonin reuptake inhibitors (SSRIs, such as fluoxetine [Paxil] or citalopram [Celexa]) are used.
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• For agitation or psychotic symptoms, atypical antipsychotics are preferred. Clozapine [Clozaril] is often the first choice, but it may have intolerable adverse effects. Quetiapine [Seroquel] may be an alternative. Olanzapine [Zyprexa] and risperidone [Risperdal] tend to worsen motor function.

|Surgery|

Great strides have been made in surgical treatment of PD. Several different procedures are now available, and they are successful in many patients in relieving movement symptoms. Unfortunately, surgery has no effect on cognitive symptoms. In fact, most people with dementia are not candidates for surgery.

|Follow-up|

A person with Parkinson disease and dementia requires regular checkups with his or her health care provider.

• These checkups allow the health care provider to see how well treatment is working and make adjustments as necessary.
  
  
• They allow detection of new problems of cognition, mood, or behavior that could benefit from treatment.
  
  
• These visits also give the family caregiver(s) an opportunity to discuss problems in the individual’s care.

Eventually, the person with PD and dementia will become unable to care for himself or herself or even to make decisions about his or her care.

• It is best for the person to discuss future care arrangements with family members as early as possible, so that his or her wishes can be clarified and documented for the future.
  
  
• Your health care provider can advise you about legal arrangements that should be made to ensure that these wishes are observed.

|Prevention|

We know of no way of preventing dementia in PD.

|Outlook|

Persons with PD and dementia have a poorer prognosis than persons with PD without dementia. Their risk of mood disorders and other complications, as well as premature death, is higher.

|Support Groups and Counseling|

If you are a person newly diagnosed with PD, you know that your disease has changed your life drastically. Not only are you losing some of your physical abilities, but you may be starting to lose some of your mental abilities as well. You worry about how long you will be able to continue enjoying relationships with family and friends, activities you enjoy, and independence. You worry about how your family will cope with caring for you and themselves as your disease progresses. You may feel depressed, anxious, even angry and resentful. The best way to deal with these emotions is to express them in some way. For many people, talking about these feelings helps relieve them.

If you are a caregiver for a person with PD and dementia, you know that the disease tends to be more stressful for the family members than for the affected person. Caring for a person with PD and dementia can be very difficult. It affects every aspect of your life, including family relationships, work, financial status, social life, and physical and mental health. You may feel unable to cope with the demands of caring for a dependent, difficult relative. Besides the sadness of seeing the effects of your loved one’s disease, you may feel frustrated, overwhelmed, resentful, and angry. These feelings may in turn leave you feeling guilty, ashamed, and anxious. Depression is not uncommon.

Different people have different thresholds for tolerating these challenges.

• For many people with PD, talking to a close friend or family member may be helpful. For others, talking to a professional counselor or member of clergy is comforting.
  
  
• For caregivers, just “venting” or talking about the frustrations of caregiving can be enormously helpful. Others need more, but may feel uneasy about asking for the help they need. One thing is certain, though: if the caregiver is given no relief, he or she can burn out, develop his or her own mental and physical problems, and become unable to care for the person with PD.

This is why support groups were invented. Support groups are groups of people who have lived through the same difficult experiences and want to help themselves and others by sharing coping strategies. Mental health professionals strongly recommend that affected persons, to the extent they are able, and family caregivers take part in support groups.

In diseases involving dementia, it is mainly the caregivers who are helped by support groups. Support groups serve a number of different purposes for caregivers:

• The group allows the person to express his or her true feelings in an accepting, nonjudgmental atmosphere.
  
  
• The group’s shared experiences allow the caregiver to feel less alone and isolated.
  
  
• The group can offer fresh ideas for coping with specific problems.
  
  
• The group can introduce the caregiver to resources that may be able to provide some relief.
  
  
• The group can give the caregiver the strength he or she needs to ask for help.

Support groups meet in person, on the telephone, or on the Internet. To find a support group that works for you, contact the following organizations. You can also ask a trusted member of your health care team, or go on the Internet. If you do not have access to the Internet, go to the public library.

For more information about support groups, contact these agencies:

• Parkinson Alliance – (609) 688-0870 or (800) 579-8440
  
  
• American Parkinson Disease Association – (800) 223-2732
  
  
• National Parkinson Foundation – (305) 547-6666 or (800) 327-4545
  
  
• Family Caregiver Alliance, National Center on Caregiving - (800) 445-8106
  
  
• Supportpath (search on Parkinson’s disease or Caregivers)
  
  
• National Alliance for Caregiving
  
  
• Eldercare Locator Service – (800) 677-1116

American Parkinson Disease Association
1250 Hylan Boulevard, Suite 4B
Staten Island, NY 10305
(800) 223-2732
 
American Parkinson Disease Association (West Coast office)
10850 Wilshire Boulevard, Suite 730
Los Angeles, CA 90024-4319
(310) 474-5391
(800) 908-2732
 
Family Caregiver Alliance, National Center on Caregiving
(800) 445-8106
 
Michael J. Fox Foundation for Parkinson’s Research
Grand Central Station
P.O. Box 4777
New York, NY 10163
 
National Parkinson Foundation, Inc (a worldwide organization)
Bob Hope Parkinson Research Center
1501 NW 9^th Avenue
Bob Hope Road
Miami, FL 33136-1494
(305) 547-6666
(800) 327-4545
 
Parkinson Alliance
211 College Road East, 3^rd Floor
Princeton, NJ 08540
(609) 688-0870
(800) 579-8440
 
Parkinson’s Action Network (an education and lobbying group)
1000 Vermont Avenue NW, Suite 900
Washington, DC 20005
(202) 842-4101
(707) 544-1994 (California)
(800) 850-4726
 
Parkinson’s Disease Foundation
William Black Medical Building
Columbia-Presbyterian Medical Center
710 West 168^th Street
New York, NY 10032-9962
(212) 923-4700
(800) 457-6676
 
Parkinson’s Institute (a research and treatment facility)
1170 Morse Avenue
Sunnyvale, CA 94089-1605
(408) 734-2800
(800) 786-2958
 
Worldwide Education & Awareness for Movement Disorders (WE MOVE)
204 West 48^th Street
New York, NY 10024
(212) 875-8312
(800) 437-6682

|Web Links|

American Parkinson Disease Association

Michael J. Fox Foundation for Parkinson’s Research

National Institute of Neurological Disorders and Stroke, National Institutes of Health, Parkinson's Disease Information Page

National Parkinson Foundation, Inc

Parkinson Alliance

Parkinson’s Action Network

Parkinson’s Disease Foundation

Parkinson’s Institute

Worldwide Education & Awareness for Movement Disorders (WE MOVE)

Parkinson disease, Parkinson’s disease, PD, Alzheimer disease, Alzheimer’s disease, dementia, cognitive impairment, degenerative disease of the brain, degenerative disorder of the brain, dopamine, dopamine agonist, movement disorder, neurotransmitter, senility, SNCA gene, anticholinergic drugs, parkinsonism, Parkinson disease dementia, Parkinson's disease dementia

Author: Jose G Merino, MD, Staff Clinician, Section of Stroke Diagnostics and Therapeutics, National Institute on Neurological Disorders and Stroke, National Institutes of Health.

Coauthor(s): Jose Luchsinger, MD, MPH, Assistant Professor, Department of Internal Medicine, Columbia University College of Physicians and Surgeons; Zhigao Huang, MD, PhD, Assistant Professor, Director of Parkinson Center, Department of Neurology, University of Florida Health Science Center Jacksonville.

Editors: Nestor Galvez-Jimenez, MD, Program Director of Movement Disorders, Director of Neurology Residency Training Program, Department of Neurology, Division of Medicine, Cleveland Clinic Florida; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Helmi L Lutsep, MD, Associate Director, Oregon Stroke Center; Associate Professor, Department of Neurology, Oregon Health and Science University.