View Full Version : Parkinson's Disease
11-27-1998, 11:35 PM
To Gregory and my fellow pre-meds,
Do any of you guys know much about Parkinson's disease? I recently heard that Michael J. Fox and Janet Reno suffer from it. It is especially surprising to hear how Michael J. Fox has it since he is only 37. I've read that a drug called L-Dopa is effective in treating Parkinson's but that the effects of the drug wear off with continued use and patients occasionally have to go on "drug fasts" in order to keep their bodies responsive to it. I'd appreciate it if anybody could tell me more about it. I once thought about specializing in Neurology, but then I realize that science/medicine knows little about the brain and often there is little a neurologist can do for their patients at present because of our lack of understanding of how the brain works.
Unfortuately Parkinson's disease is very common with approx 1-2/1000 cases in the general population
and 1/100 in the elderly. The basic etiology is unknown but the symptoms are caused by a loss of nerve
cells in the substantia nigra and locus coeruleus. The symptoms include resting tremor, rigidity,
bradykinesia and problems with gait (Parkinson's shuffle). There is no cure but there are several
therapies available to help ease symptoms. In addition to Levodopa, there are anticholinergic drugs,
dopamine agonists, Amantadine, diet therapy, and lots of others in the experimental stages. Because
it is so common, you'll learn all about it in freshman neurology and biochem.
11-28-1998, 11:05 AM
Edgar, something else interesting about the disease is that, according to my studies in biomedical aging, it may be the exact opposite of schizophrenia. Schizophrenia has an early onset and is characterized by an excess of dopamine in the substantia nigra. Whereas Parkinson's has a late onset and is characterized by a deficit of dopamine. Thus, consider the treatments for the two: For schizophrenia, you want a drug that involves the uptake of dopamine and for Parkinson's you want to produce more dopamine. The treatment of one disease produces the symptoms of the other. Thus, the schizophrenic patient may exhibit tremors and gait disorders whereas the Parkinson's patient may eventually suffer from hallucinations.
And as Deb stated it is very common. I know a Parkinson's sufferer quite well -- my grandfather. Fortunately, his progression has been quite slow.
That's all I can offer from my limited knowledge base. Perhaps some of the medical students could offer more.
11-28-1998, 01:37 PM
Gregory and Deb,
On Friday I am going to be giving an oral presentation on transposable elements and their relation to human diseases. Transposable elements are literally "jumping genes", mobile DNA fragments that randomly insert into human somatic and germ-line cells and sometimes inactivate other important genes in the human genome. One of the papers I will be presenting states that "TEs" may be a causation factor for Huntington's Disease. HD is a late-onset disease that is autosomal dominant and usually occurs in older people, who don't know they have it until they've passed the gene onto their children. Anyways, HD symptoms also involve loss of coordinated movement, and I was wondering if the symptoms for Huntington's Disease, Parkinson's, and Alzheimer's Disease are similar. Deb, how is a physician able to diagnose the differences between these diseases if the symptoms are so similar?
11-28-1998, 01:42 PM
Gregory and Deb,
I am also surprised how common Parkinson's Disease is in the US population. Gregory, I've visited nursing homes twice in my life and noticed that some geriatric patients are slightly demented. Could this be caused by the treatment for Parkinson's. Perhaps their medication makes them have schizophrenic symptoms? Once I met a patient who was paranoid I was from the FBI and was going to bust her because I was taking notes of what she was telling me about her experiences during the Depression in the US.
Although there will always be misleading presentations, Parkinson's,
Huntington's and Alzheimers are usually fairly easy to differentiate.
Alzheimer's patients usually present with memory loss or some level
of dementia. Huntington's patients usually present with chorea
and Parkinson's patients often initially present with resting tremor.
While dementia can occur in all three, if other neuro symptoms are
absent it is probably Alzheimers. However, the differential diagnosis
(with dementia as the chief complaint) would include (in addition to
the aforementioned three): vascular dementia, Pick's disease, Diffuse
Lewy Body disease, normal pressure hydrocephalus, progressive supranuclear
palsy, frontotemporal dementia, cortical basal dementia, and primary
progressive aphasia. As you can see, a neuro consult is usually the best
way to proceed with this type of patient. (my reference is Harrison's...
"Principles of Internal Medicine")
Hope this infor helps.