Parkinson’s Disease is a progressive degenerative disorder of the central nervous system named after the English physician, James Parkinson, who published the first detailed description of the disease in “An Essay on the Shaking Palsy” in 1817. It is best thought of as a condition that impairs movement.
The disorder is characterized by resting tremors, muscle stiffness, slowness of movement, weakness, and loss of balance and postural reflexes. Involuntary resting tremors usually involve the hand and fingers, typically resulting in a “pill-rolling” motion. The motor symptoms of Parkinson’s Disease result from the death of dopamine-producing cells in the midbrain. What causes the gradual loss of cells producing this particular chemical messenger remains unknown.
Diagnosis is clinical and made after a thorough history and physical exam. While there is no testing that specifically identifies and confirms the presence of this disease, lab studies and nervous system imaging are often carried out to exclude other diagnoses.
Parkinson’s Disease usually begins between the ages of 40 and 70, with steady progression eventually producing severe disability. It becomes more common with aging: the disease affects one person in 1,000, and in those over 60 years of age, one in 100. About 1,000,000 people in the US suffer from this disorder. Although in most cases the cause is uncertain, in up to 20% of cases the disease might result from infection, genetic mutations, use of certain medications, exposure to specific toxins, trauma, degenerative, and/or cerebrovascular disease.
Treatment is intended to control symptoms and improve quality of life, but is not curative. The mainstay of treatment involves replacement of the neurotransmitter dopamine. The drug levodopa can produce marked improvement in up to 70% of those affected. Other medications can be used to stimulate dopamine receptors in the brain, or increase dopamine levels by blocking its metabolism. Surgical treatments are sometimes used as a primary treatment, or in cases with insufficient response to medications. Deep brain stimulation is the most common operative procedure, and involves implantation of a brain pacemaker which transmits electrical impulses to specific areas of the brain.
Unfortunately, as time passes and dopamine-producing cells continue to be lost, treatments tend to lose their effectiveness and medication-related side effects may become more troublesome. About 65% of those with Parkinson’s Disease become disabled within 5 years of diagnosis, and about 80% are disabled within 10 years of diagnosis. Potentially promising research to better manage this disease includes gene therapy, stem cell transplants, and the development of neuroprotective agents. Despite advances in treatment, the life expectancy of people with Parkinson’s Disease is reduced. Major mortality risk factors include cognitive decline, dementia, older age at onset, a more advanced disease state, and difficulty swallowing. On the other hand, a disease pattern having primarily tremor as opposed to muscle rigidity and impaired movement seems to be predictive of better survival.
A 66 year old woman who continues to actively work in the family business. She was diagnosed with Parkinson’s Disease about two years ago and currently takes a low dose of one medication to reduce a mild and occasionally bothersome tremor in her right hand. She is independent in all activities and continues to drive her car. She and her husband recently returned from a one week
cruise. This can be Table 3.
A 67 year old man who was diagnosed with Parkinson’s Disease a little over 6 years ago. He recently retired from work due to increasing difficulty moving around. He requires no assistance with activities of daily living other than some help buttoning his shirt, but now uses a cane and occasionally a walker to ambulate. His physician recently increased doses of two medications as his prior
doses no longer seemed to be as effective. This can be Table 5.
A 72 year old woman who was diagnosed with Parkinson’s Disease about 4 years ago. She has become less active in recent years and is now largely homebound. She surrendered her driver’s license last year after having three minor accidents and getting lost a few times. She is complaining of abnormal movements caused by her medications that no longer seem to be working as well
at higher doses. Her physician added an antidepressant medication during a recent hospitalization to treat pneumonia and skin breakdown on her thigh. This would be a decline.