One (good) disease leads to another

Not at all a good disease, just a play on words. I am speaking about Parkinson's Disease today as a popular press headline caught my attention. The news story got much of the study correct, except that is states the research as "confirming" a link between Parkinson's and Melanoma. In fact, the study supports the link, and it supports previous research, but in the actual journal submission, the researchers do make a note about caution when interpreting the results which implies anything but a confirmation. The warning has to do with the data that was reviewed in that it wasn't all collected in the same manner.

Still, let me share a few things in case you are unawares. Parkinson's Disease is often associated with tremors and gait disturbance and is more complicated than a similar condition called essential tremor (ET is a progressive neurological disorder as well). Parkinson's is chronic and does worsen over time, i.e is progressive, but it is also degenerative in that the symptoms become disabling. In PD the patient may also have problems with thinking and speech.

Parkinson's disease does not have a definitive cause and is often considered idiopathic - meaning there is not clear cause! It does involve a lack of the neurotransmitter dopamine - it just isn't known exactly why the cells that produce dopamine die off in these persons. The most common treatment is with a drug called levodopa which the body turns into dopamine. Dopamine helps with movement, thinking, emotions and feelings of pleasure.

For some time, there has been concern about a higher than normal incidence of the most serious skin cancer, melanoma , in patients with PD. (other skin cancer types are basal cell and squamous cell) There has been previous research of the issue with two theories. One is that for some reasons PD patients are just more prone to it (making me think maybe dopamine is a protective factor?) or the medicine to treat it was itself putting the patient at risk.

The study from the University of Nebraska Medical Center found the four fold increase of melanoma with PD persons as compared to similar non PD persons and did not think it was from levodopa. I found a better report in a medical magazine and will link it here.

However, in educating myself about this condition and seeing that the levodopa was considered suspect at some point, I want to use that as a teaching point. If you find yourself needing a prescription medication and it has one of those warnings about avoiding sunlight - you might want to take that a little more seriously.