Definition

Parkinson's disease (PD) is a progressive movement disorder. PD is characterized by:

    
  • Slowing down of movements (bradykinesia)
  • Tremor at rest
  • Muscle rigidity
  • Loss of reflexes that maintain posture and equilibrium
  • Part of the Brain Affected by PD—Yellow Section

    Substansia Nigra

    Copyright © Nucleus Medical Media, Inc.

    Causes

    PD is caused by a loss of certain nerve cells in the brain. The loss of these cells causes a decrease in the amount of a brain chemical called dopamine. Low dopamine levels cause PD symptoms.

    The brain cells may be lost because of genetic defects, the environment, or some combination of the two. A small amount of people with PD have an early-onset form. This type is caused by an inherited gene defect.

    Risk Factors

    PD is more common in men and in people aged 50 years and older. Other factors that increase your chance of PD include:

        
  • Family members with PD
  • Nonsmokers
  • Exposure to toxins, such as insecticides, carbon monoxide, or manganese
  • Certain medications, such as antipsychotics, antiseizures, antiemetics, or cardiovascular medications
  • Certain health conditions, such as:     
  • Polio
  • High cholesterol
  • Melanoma
  • Hydrocephalus
  • Brain tumors
  • Stroke
  • Encephalitis
  • Meningitis
  • HIV infection
  • IV drug use
  • Symptoms

    Symptoms of PD begin mildly. They will worsen over time.

    PD may cause:

        
  • Problems with dexterity
  • Difficulty with activities of daily living
  • Fatigue
  • Stiffness and rigidity of muscles, usually beginning on one side of the body
  • Tremors are present at rest, improve with movement, and are absent during sleep
  • Slowness of purposeful movements
  • Neuropsychiatric symptoms, such as:     
  • Depression
  • Anxiety
  • Dementia
  • Hallucinations
  • Difficulty and shuffling when walking
  • Poor balance
  • Tendency to fall
  • Loss of smell
  • Sleep problems
  • Flat, monotonous voice
  • Stuttering
  • Trouble speaking (often speaking with a low volume)
  • Increasingly mask-like face, with little variation in expression
  • Drooling and excessive salivation
  • Shaky, spidery, or small handwriting
  • Seborrhea (a skin problem that causes a red rash and white scales)
  • Trouble chewing and swallowing
  • Urinary symptoms (frequency and urgency)
  • Bowel movement symptoms (straining, constipation)
  • Diagnosis

    The doctor will ask about your symptoms and medical history. A physical exam will be done. There are no tests to definitively diagnose PD. The doctor will ask many questions. This will help to rule out other causes of your symptoms.

    Tests to rule out other conditions may include:

        
  • Blood tests
  • Urine tests
  • Imaging tests take pictures of internal bodily structures. This can be done with:

        
  • MRI scan
  • CT scan
  • SPECT scan
  • Treatment

    Currently, there are no treatments to cure PD. There are also no proven treatments to slow or stop its progression. Some medications may help to improve symptoms. Over time, the side effects of the medication may become troublesome. The medications may also lose their effectiveness.

    Medications

    Medications that may be used to treat PD include:

        
  • Levodopa-carbidopa
  • Dopamine agonists
  • Monoamine oxidase inhibitors
  • Anticholinergics
  • COMT inhibitors
  • Antivirals
  • Depression or hallucinations may also occur with PD and its treatment. Medications may be prescribed to attempt to treat these conditions. The drugs may include:

        
  • Selective serotonin reuptake inhibitors (SSRIs)
  • Tricyclic antidepressants
  • Antipsychotics
  • Hip fractures are common in those with PD. Bisphosphonates are medications that may help reduce this risk.

    Constipation, drooling, and lightheadedness when standing are common and may improve with medications or other treatments.

    Surgery

    Different brain operations are available, and many more are being researched including:

        
  • Deep brain stimulation (DBS)—implanting a device to stimulate certain parts of the brain; can decrease tremor and rigidity
  • Thalamotomy and pallidotomy—destroying certain areas of the brain to improve tremor when medication does not work (not as common as deep brain stimulation)
  • Nerve-cell transplants (research only)—to increase amount of dopamine made in the brain
  • Physical Therapy

    Therapy can improve muscle tone, strength, and balance. It includes exercises and stretches. There is also evidence that tai chi may be beneficial.

    Psychological Support

    Consider joining a support group with other people with PD. It will help to learn how others are learning to live with the challenges of PD.

    Prevention

    There are no current guidelines to prevent PD.