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Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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The three key signs of Parkinson's disease are tremor (shaking) at rest, rigidity, and slowness in the initiation of movement (called bradykinesia). Of these features, two are required to make the diagnosis. Postural instability is the fourth key sign, but it happens late in the disease, usually after having PD 8 years or more.

• Tremor at rest
• Tremor usually begins in one arm and may start and stop.
• As with most tremors, it worsens when under stress and improves during rest or sleep.
• After several months to a few years, both arms may become affected, but the initial asymmetry (one-sidedness) is often maintained.
• PD tremor may also involve the tongue, lips, or chin.
• The characteristic PD tremor is present and most prominent with the limb at rest.
• The tremor may appear as a pill-rolling motion of the hand or a simple oscillation of the hand or arm.
• Rigidity
• Rigidity refers to an increase in resistance to someone else moving the patient's joint.
• The resistance can be either smooth ("lead-pipe") or start and stop ("cog wheeling"). (Cog wheeling is thought to be a tremor rather than rigidity.)
• Having someone else flex and extend the patient's relaxed wrists tests for rigidity.
• Rigidity can be made more obvious with voluntary movement in the opposite limb.
• Bradykinesia
• Bradykinesia refers to slowness of movement but also includes a lessening of unplanned movements and decreased size of movement.
• Bradykinesia is also expressed as micrographia (small handwriting), hypomimia (decreased facial expression), decreased blink rate, and hypophonia (soft speech).
• Postural instability
• Postural instability refers to imbalance and loss of reflexes used to keep a person upright.
• This symptom is an important milestone, because it is not easy to treat and a common source of disability in late disease.
• Other symptoms
• People may experience freezing when starting to walk (start-hesitation), during turning, or crossing a threshold such as going through a doorway.
• Flexed postures of the neck, trunk, and limbs may occur.
• Altered mental status generally occurs late in PD and affects 15% to 30% of people with PD.
• Short-term memory and visual-spatial function may be impaired.
• The onset of PD is typically unilateral, with the most common initial finding being an asymmetric rest tremor in one arm. About 20% of people first experience clumsiness in one hand.
• Over time, PD patients will notice symptoms related to progressive bradykinesia, rigidity, and problems with walking (called gait disturbances).
• The initial symptoms of PD may be nonspecific and include fatigue and depression.
• Some people experience a subtle decrease in dexterity and may notice a lack of coordination with activities such as golf, dressing, or climbing stairs.
• Some people complain of aching or tightness in the calf or shoulder region.
• The first affected arm may not swing fully when walking, and the foot on the same side may scrape the floor.
• Over time, posture becomes progressively flexed and the gait becomes shorter, leading to a shuffling gait.
• Decreased swallowing may lead to excess saliva and ultimately drooling.
• Symptoms of problems with the involuntary nervous system are common and may include constipation, sweating abnormalities, and sexual dysfunction.
• Sleep disturbances are also common.

Symptoms are usually progressive in their severity over time. However, not every symptom described may be apparent in each individual PD patient. However, the older the age of initial onset of PD, usually the more rapid development of motor and cognitive decline symptoms.

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