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ex-Member
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Join Date: Sep 2006
Posts: 110
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ex-Member
Join Date: Sep 2006
Posts: 110
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bbb
Quote:
Originally Posted by reverett123
There is one point about the BBB theory that poses a problem: If the increased permeability is the cause of our problem, why is damage limited to the substantia nigra? The same question in another form might be why is the BBB just leaking in the area of the SN? In other words why would the damage be localized there?
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Also, the brain consists of dozens of cell types, each one of which deals with a different function, and whose deficiency or damage would lead to a different medical disorder. If a deficiency of the blood brain barrier had a primary effect in Parkinson's Disease then somebody would simultaneously suffer from dozens of neurological disorders. The selective insufficient function in Parkinson's Disease shows that there is a specific insufficient function of the dopaminergic neurons rather than dozens of cell types.
most people don't come in to contact with sufficient quantities of toxins in order to cause Parkinson's Diseae. For example, carbon monoxide, the most widespread of the toxins would have to cause a coma for it to cause Parkinson's Disease. The general tendency in Parkinson's Disease is a very gradual decline. If this were due to toxicity this would only be explained by persistent exposure over many years or even decades to a known toxic cause of Parkinson' Disease. However, if exposure does occur it is usually sporadic rather than persistent.
The study that claims that there is a defective blood brain barrier in Parkinson's Disease used only five subjects. Due to the small number of subjects and the low level of increased permeability found, statistically it would not be considered as significant. Although it used five subjects as controls, there is no indication that these were age controlled. So all that they may have shown is that there is a tendency for the blood brain barrier to deteriorate with age, which is something that was already known. Also, if the blood brain barrier deteriorated with age and thereby made Parkinson's Disease more likely, why is it that amongst the oldest of people - those between 110 and 120 years old - Parkinson's Disease is virtually unknown.
Last edited by Curious; 09-04-2007 at 10:58 AM.
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