Supporting People Living With Parkinson Disease in Central and South Texas
Parkinson's disease (PD) is a chronic, progressive, degenerative disorder of the central nervous system affecting more than 1.5 million people in the United States, or approximately 1 in 100 people over age 60. Clinically, the disease is characterized by a decrease in spontaneous movements, difficulty in walking, postural instability, rigidity, and tremor, as well as many other non-movement related symptoms. Parkinson's disease results from degeneration of neurons in a region of the brain called the substantia nigra, resulting in decreased availability of the neurotransmitter dopamine.
The English doctor James Parkinson first described Parkinson’s disease in 1817. Building from Dr. Parkinson’s initial insights, we now know Parkinson's as a disorder of the central nervous system resulting from degradation and cell death of substantia nigra cells. Substantia nigra cells produce dopamine, a chemical called a neurotransmitter responsible for carrying nerve signals within the brain for coordination of movement. Loss of dopamine causes neurons to function abnormally, impairing body movement. Parkinson's is classified as a movement disorder; other diseases in this class include essential tremor, dystonia, torticollis, and Tourette’s syndrome.
Although the average age of onset is about 63, the disease can occur in younger people; there are documented cases of PD in people as young as their teens. Typically, first onset of symptoms before age 50 is called “young-onset” or “early-onset” Parkinson’s disease. The disease occurs with similar frequency in both men and women, and occurs in people of all ethnic backgrounds and races.
There is no definitive test, or biomarker, for Parkinson's; it is usually diagnosed by exclusion, or “ruling things out.” The rate of misdiagnosis can be relatively high, especially for young-onset cases or when a non-specialist makes the diagnosis. The number of people living with the disease is not known with certainty, but some estimates indicate that over six million people worldwide have Parkinson's.
What are the symptoms of Parkinson's disease?
People are generally most familiar with the movement-oriented, or “motor” symptoms of Parkinson's disease, as they are the most evident external evidence of the disease. These symptoms, which are also called the "cardinal" symptoms of PD, can be remembered by using the acronym “TRAP”:
(T)remor – usually a resting tremor, often in the hands, arms, legs, torso, or lips and face. The tremor tends to be relatively slow, about 4-6 cycles per second, and often shows a “pill-rolling” movement in the hands and fingers.
(R)igidity – muscular stiffness and tightness, often displaying a “start and stop” jerky motion called “cogwheel rigidity” when a limb is manually moved.
(A)kinesia or bradykinesia – lack of movement or extreme slowness in movement.
(P)ostural instability – limping, shuffling gait, or balance problems, often resulting in falls.
Lack of facial expression is also a common characteristic resulting from the four cardinal symptoms.
Also important are the non-movement symptoms of PD, sometimes called "non-motor" or "dopamine non-responsive" symptoms. These common symptoms can have a major impact on people with PD. For example, cognitive impairment, ranging from mild memory difficulties to dementia, and mood disorders, such as depression and anxiety, occur frequently, particularly in people with Parkinson’s (PWPs) with later onset. Also common are sleep difficulties, loss of sense of smell, constipation, speech and swallowing problems, unexplained pain, drooling, and low blood pressure when standing.
Not all PWPs experience the same symptoms, have the same rate of progression, or respond to treatment the same way. Each case tends to be different.