Friday, November 2, 2007


I am studying Parkinson's by analyzing electroencephalogram (EEG) data. This post will describe what this data is.

EEG data is collected by placing many electrodes onto a person's scalp. These electrodes will then generate data (data which are typicall called "brain waves" though this an incorrect description!) by comparing the voltage they detect to a common or ground electrode. Every electrode compares its readings against the same ground electrode. This data is then collected over time to create a voltage vs. time graph of a person's brain activity.

Each line in an EEG graph represents the potential difference of the neurons under the electrode compared to the ground electrode. Thus, if the neurons are firing fast and often under an electrode, that electrode channel will exhibit a high frequency because the potential difference of those neurons is fluctuating very quickly.

This data can then be used to understand how the brains electrical activity changes depending on the task the brain is trying to accomplish. For instance, when a person is trying to manipulate an object with their hand, the electrodes over their motor cortex will display electrical activity.

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

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

Medgineer's Corner

Welcome to the Medgineer's Corner,

This blog will highlight some of the interesting problems I come across while intersecting my interests in medicine and engineering, describe programming problems I face at a world famous software company, and question social customs we see in our society today.