In 2003, I became aware of a tremor in my left hand. In 2004, after tests to eliminate other possible explanations (like a brain tumor), I was officially diagnosed with Parkinson's Disease. Since then I have learned a great deal about PD. I am an amateur in this field but have one small advantage over the experts: I know what it feels like to have PD. Most doctors have to depend on patient reports when evaluating symptoms. I've got the inside dope. That said, most of what follows is my reading of expert opinion and scientific studies on PD.
In the middle of the brain is a pea-sized area called the substantia nigra. It is composed mainly of a particular kind of neuron which has the task of manufacturing and regulating the release of dopamine, a messenger chemical. We start life with three times as many of these neurons as we need to do the job. If more than two thirds of these neurons either die or take sick leave, we start showing a variety of symptoms like tremors, poor balance, and slowness of movement.
The condition caused by loss of dopaminergic neurons is called Parkinson's Disease (PD). During an autopsy, it is possible to say with certainty that the deceased person did, or did not, have PD (though he probably died from other causes). During life, there is no single definitive test. The symptoms of PD vary according to individual body chemistry. And the symptoms also vary somewhat depending on what caused the neuron depletion in the first place. Added to that, there are poisons, diseases, physical head injuries and brain tumors which can produce some of the same symptoms. Part of the diagnosis process is to eliminate all of the known possible explanations of symptoms. When all that is left is PD, voila. The final test is to treat with PD medication — if that works it must be PD.
Some day there will be a test which will detect neuron depletion before we get into a deficit situation. This will be of great benefit because there are things that can be done to slow PD progress.
Most people with PD have Idiopathic PD. Idiopathic just means we don't know what caused the PD. When that cause or group of causes is better understood, we should be able to prevent many cases of PD. And there may be some hints about how to slow the progress of PD in those who already have it.
In the articles below, I comment on a few of the scientific experiments. These articles are background material for a trial I will be doing in the summer of 2006 — I will be growing fava and mucuna beans which contain levodopa. In the fall of 2006, I will report here on my experiments with these beans.
Subjects covered (the first is complete, the others coming soon):
Feedback: allan@cogeco.ca