Diagnosis of Parkinson’s Disease

There are no lab tests to definitively diagnose Parkinson’s disease. Your doctor will ask about your medical history and do a thorough physical exam.

A neurological exam will include a range of tests to evaluate your strength, coordination, balance, and other aspects, such as:

• Muscle tone
• Rapid alternating movements
• Gait, posture
• Postural stability
• Quickness and precision of movement
• Observation of a tremor (during rest or activity)

A mini-mental status test may be done. Activities of daily living may also be evaluated, such as dressing, cutting and eating food, swallowing, hygiene, walking, and falls.

There are four symptoms that are considered "hallmarks" of Parkinson’s disease. These symptoms include:

• Tremor while at rest
• Rigidity
• Slowness of movement (bradykinesia)
• Postural instability

Sometimes, not all of these hallmark symptoms are present. If that is the case, your doctor may examine you every few months to check on your symptoms.

Other symptoms of Parkinson’s disease include:

• Blank facial expression
• Decreased eye blinking
• Stooped posture
• Depression
• Sleep disturbances
• Shuffling gait
• Difficulty with initiating movement
• Difficulty rising from a sitting position
• Difficulties with activities of daily living
• Voice changes
• Swallowing and drooling difficulties
• Changes in handwriting
• Loss of smell

If your doctor has questions about the cause of your symptoms, you may be given tests to try to eliminate the possibility of other disorders. These tests may include:

• Blood tests
• Urine tests
• CT scans
• MRI scans

Your doctor may also give you a trial of levodopa, a medicine that increases the amount of dopamine your brain produces. A positive response to this medicine may help to confirm the diagnosis.

Your doctor may also have imaging tests done, such as:

• PET scan —You will be given an injection of a substance that will make the pictures of your brain clearer. You will lie on a table, which will slowly move you through a ring-shaped scanner. This test may take about 30 minutes or longer.
• SPECT scan—You will be given an injection of a substance that will make the pictures of your brain clearer. You will lie on a table, and a camera-like object will slowly rotate around you. This test may take about 90 minutes or longer. Your doctor may choose to use a specific type of scan, called DATscan, to evaluate your condition.