Definition

Parkinson's disease (PD) is a progressive movement disorder that causes:

• Muscle rigidity
• Tremor at rest
• Slowing down of movements (bradykinesia)
• Difficulty moving and gait instability

It is caused by a loss of nerve cells in the brain. This includes loss in an area called the substantia nigra . The loss decreases the amount of dopamine in the brain. Low dopamine results in PD symptoms.

Substantia Nigra—Yellow Section

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Causes

Factors that cause the loss may be from the genes, 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.

Secondary PD has similar symptoms but is caused by several factors such as:

• Antipsychotic drugs, such as haloperidol]]> (Haldol), ]]>fluphenazine]]> (Prolixin), ]]>trifluoperazine]]> (Stelazine), and ]]>chlorpromazine]]> (Thorazine)
• Cardiovascular drugs such as some calcium channel blockers and antiarrhythmic drugs
• ]]>Carbon monoxide poisoning]]>
• Manganese poisoning
• ]]>Hydrocephalus]]>
• ]]>Brain tumors]]>
• ]]>Stroke]]>
• ]]>Encephalitis]]>
• ]]>Meningitis]]>
• Intravenous drug abuse of MPTP (a type of neurotoxin)
• ]]>Reserpine]]> (medicine to treat schizophrenia and high blood pressure)
• Insecticide exposure
• ]]>Trauma]]>
• ]]>AIDS]]>

Risk Factors

Factors that increase the chance of PD include:

• Age: 50 or older
• History of polio]]>
• Gender: men (slightly more likely to develop PD)
• Family members with PD
• Nonsmokers
• Exposure to toxins, drugs, or conditions listed above
• ]]>High cholesterol]]>
• ]]>Melanoma]]> skin cancer

Symptoms

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

Symptoms include:

• "Pill-rolling" tremor in the hands
• Tremors are present at rest, improve with movement, and are absent during sleep
• Stiffness and rigidity of muscles, usually beginning on one side of the body
• Difficulty and shuffling when walking
• Short steps
• Slowness of purposeful movements
• Trouble performing usual tasks, due to shaking in hands
• Trouble speaking (often speaking with a low volume)
• Flat, monotonous voice
• Stuttering
• Shaky, spidery, or small handwriting
• Poor balance
• Difficulty with rising from a sitting position
• “Freezing”
• Anxiety]]>
• Seborrhea (a skin problem that causes a red rash and white scales)
• Loss of smell
• Urinary symptoms (frequency and urgency)
• Bowel movement symptoms (straining, constipation)
• Tendency to fall
• Stooped posture
• Increasingly mask-like face, with little variation in expression
• Trouble chewing and swallowing
• Drooling and excessive salivation
• ]]>Depression]]>
• ]]>Dementia]]>
• Hallucinations
• Difficulty thinking, problems with memory
• Decreased sense of smell
• Sleep problems such as REM-behavior disorder

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
• CT scan]]> —a type of x-ray that uses a computer to make pictures of structures inside the head
• ]]>MRI scan]]> —a test that uses magnetic waves to make pictures of structures inside the head
• ]]>PET scan]]> —a scan that makes images that show the amount of activity in the brain

Treatment

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

If you are diagnosed with PD, follow your doctor's instructions .

Prevention

There are no guidelines for preventing PD.