Tuesday, October 30, 2007

Parkinson's Disease

During my last year as an undergrad, I began to see the potential in mixing my interests in engineering and medicine. I was doing research with a neurologist who was studying Parkinson's disease.

Parkinson's disease is a neurological disorder that has a much higher prevelance in the elderly. Parkinson's is the 2nd most common illness amongst seniors, behind cancer, and it is projected to become the most common illness within 20 years.

Parkinson's affects the central nervous system and causes movement disorders, such as; Bradykinesia (a slowness in movement), tremors (predominantely in the limbs), and a shuffling gait. Parkinson's disease can also cause slurred speech and cognitive dysfunctions.

The primary symptoms of Parkinson's Disease are caused by a lack of dopamine production in the brain. Dopamine is a neurotransmitter, which is a chemical that neurons in the brain use to communicate to each other. The brain does not produce enough dopamine and it does not function properly, causing the symptoms.

I know what you're all thinking (if you're smart that is), "If we inject patients with dopamine, they'll be cured!".....Damn, maybe YOU should be a medgineer!?

The problem with injecting patients with dopamine is that it is not safe to inject ANYthing into the brain. Injecting dopamine into the circulatory system will not help either because it cannot cross the blood brain barrier.

The current treatment for Parkinson's is to give patients L-Dopa, which is a precursor to dopamine. That means that the body can take L-Dopa and convert it, through a series of chemical reactions, into dopamine.

However, there are (of course) problems with this treatment...

1) It is very difficult for doctor's to perscribe the "perfect" dose of L-Dopa. If they do not perscribe enough, the patient's symptoms linger. If they perscribe too much, they patient will make too much dopamine and they will have dyskinesias (spasmatic type movements). Also, too much dopamine can result in a lack of inhibition and lead to social problems (this is why some Parkinson's patients become gamblers).

2) After a while, either less of the L-Dopa converts into dopamine or the dopamine receptors in the brain stop working and the dosage has to increase. This continuously happens until the L-Dopa becomes ineffective.

More info on Parkinson's Disease can be found at http://en.wikipedia.org/wiki/Parkinson

Next time I'll post about the research I'm currently working on.

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