The following discussion is for general informational purposes only and is not meant to provide the reader with specific medical advice. Please consult with your personal physician, or with a neurologist, for specific advice, guidance and information regarding your particular circumstances.
In 1817 a British doctor, Dr. James Parkinson, published a paper on what he called "shaking palsy". He described the common symptoms of shaking/trembling hands. Parkinson's disease was named after Dr. Parkinson since he first described the disease. More than 500,000 people in the United States are affected by Parkinson's diease.
Parkinson's Disease (PD) is caused by a lack of production of dopamine in an area of the brain known as the substantia nigra, located deep in the base of the brain. There is a delicate balance between the effect of acetylcholine (a neurotransmitter that carries messages along the nerves) and dopamine. Acetylcholine inhibits motor activity, while dopamine facilitates motor activity. If dopamine is decreased, then the effect of acetylcholine is enhanced and motor activity becomes slower.
There are many processes which can cause a lack of dopamine. The process can be degenerative, viral, toxic, or traumatic in etiology. Strokes in the area of the substantia nigra can also produce a decrease in dopamine levels. PD is chronic and usually worsens over time.
Parkinson's disease can begin at any age. Most people experience their first symptoms in their 40s or 50s. The four major symptoms are: rigidity (stiffness in arms, legs and neck), resting tremor (shakiness of hands), bradykinesia (slowness in initiating movement which may contribute to decreased facial expression, change in speech, shuffling gait, smaller-lettered handwriting, trouble with fine finger movements) and loss of postural reflexes (poor balance and coordination).
Secondary symptoms can include: depression, emotional changes, memory and sleep problems, changes in speech patterns, urinary or bowel difficulties, low blood pressure upon standing or problems chewing or swallowing. Patients can experience difficulty rising from the chair, and have trouble walking. Their feet may feel like they are sticking to the ground when they are trying to walk.
Disease progression varies among individuals. For some progression is slow, over 20-30 years, while others may progress more rapidly.
Diagnosis is made from a complete medical history and physical exam. Laboratory tests and a CT scan or MRI of the brain are done to exclude other potential causes.
Medications to replace dopamine (levadopa) can provide dramatic relief from Parkinsonian symptoms. There are new therapies available aimed at mimicking the action of dopamine and these medications are known as dopamine agonists. In some cases, the use of levadopa can be delayed if Parkinson's patients are given dopamine agonists early during diagnosis. This is important as many people can become resistant to levadopa after prolonged use or at high doses.