People with idiopathic Parkinson's disease may develop several symptoms over time, but they typically develop the primary symptoms bradykinesia, tremor, rigidity, and parkinsonian gait. Most people with Parkinson's do not develop all of the symptoms associated with the disease.

The disease may progress quickly or gradually over years. Many people become profoundly disabled and others function relatively well.

Symptoms may vary from day to day or even moment to moment. There is no clear reason for the fluctuation of symptoms. Variance may be attributable to the disease process or to antiparkinson medications.

Primary Symptoms
Bradykinesia is slowness in voluntary movement. It produces difficulty initiating movement as well as difficulty completing movement once it is in progress. The delayed transmission of signals from the brain to the skeletal muscles, due to diminished dopamine, produces bradykinesia.

Tremors in the hands, fingers, forearm, or foot tend to occur when the limb is at rest but not when performing tasks. Tremor may occur in the mouth and chin as well.

Rigidity, or stiff muscles, may produce muscle pain and an expressionless, mask-like face. Rigidity tends to increase during movement.

Poor balance is due to the impairment or loss of the reflexes that adjust posture in order to maintain balance. Falls are common in people with Parkinson's.

Parkinsonian gait is the distinctive unsteady walk associated with Parkinson's disease. There is a tendency to lean unnaturally backward or forward, and to develop a stooped, head-down, shoulders-drooped stance. Arm swing is diminished or absent and people with Parkinson's tend to take small shuffling steps (called festination). Someone with Parkinson's may have trouble starting to walk, appear to be falling forward as they walk, freeze in mid-stride, and have difficulty making a turn.

Secondary Symptoms
The progressive loss of voluntary and involuntary muscle control produces a number of secondary symptoms associated with Parkinson's. Most patients do not experience all of them, and symptoms vary in intensity from person to person. Some secondary symptoms of Parkinson's disease include the following:

• Constipation
• Difficulty swallowing (dysphagia) saliva and food that collects in the mouth or back of the throat may cause choking, coughing, or drooling
• Excessive salivation (hypersalivation)
• Excessive sweating (hyperhidrosis)
• Loss of bladder and/or bowel control (incontinence)
• Loss of intellectual capacity (dementia) late in the disease
• Psychosocial: anxiety, depression, isolation
• Scaling, dry skin on the face and scalp (seborrhea)
• Slow response to questions (bradyphrenia)
• Small, cramped handwriting (micrographia)
• Soft, whispery voice (hypophonia)

Diagnosis
Diagnosis is based on symptoms and ruling out other disorders that produce similar symptoms.

A patient must have two or more of the primary symptoms, one of which is a resting tremor or bradykinesia. In many cases, this diagnosis is made after observing that symptoms have developed and become established over a period of time.

After a thorough neurological exam and medical history, the neurologist may order computerized tomography (CT scan) or magnetic resonance imaging (MRI scan) to meet the other criterion for a diagnosis of Parkinson's disease: ruling out disorders (e.g., brain tumor, stroke) that produce parkinsonian symptoms. Some examples follow:

• Medications antipsychotics (e.g., Haldol) and anti-emetics (e.g., Compazine)
• Multiple strokes
• Hydrocephalus
• Progressive supranuclear palsy degeneration of midbrain structures
• Shy-Drager syndrome atrophy of central and sympathetic nervous systems
• Wilson's disease copper excretion causes degeneration of the liver and basal ganglia