"Silent Stroke" can lead to PD
 

My thanks to Olsen for drawing my attention to this in another thread.

Dr Pinteaux, of Manchester University, said:
"Our work identifying that a silent stroke can lead to Parkinson's disease shows it is more important than ever to ensure stroke patients have swift access to anti-inflammatory medication. These drugs could potentially either delay or stop the onset of Parkinson's disease." [1]

There's a history of strokes and heart disease in my family, but none, as far as I'm aware, apart from me, of PD.

[1] "Silent Stroke can cause Parkinson's Disease"
Medical News Today, 20 Dec 2012
http://www.medicalnewstoday.com/articles/254301.php

John

This post reports research into the effect of series of small strokes. These are often smaller than mini-strokes (TIAs). They can be too small to be detected in scans (they may only be visible under the microscope at autopsy). They can go unnoticed. They "silently" kill doperminergic neurones.

In an article in Science Daily [1] reporting on brain autopsies of a group of old people:

"Microscopic lesions or infarcts -- too small to be detected using brain imaging -- were in 30 percent of the brains of people who had no diagnosed brain disease or stroke. ... Two-thirds of the people had at least one blood vessel abnormality, suggesting a possible link between the blocked vessels and the familiar signs of aging. ... Although Parkinson's disease occurs in only 5 percent of older people, at least half of people 85 and older have mild symptoms associated with the disease."

Any hypothesized etiology of PD must explain why, for most people, there was no obvious start to the disease, why the progression is slow, and why the progression is usually not linked to a series of known adverse events. These requirements are met by the microscopic stroke theory.

However, the microscopic stroke theory does not obviously explain the preferential death of substantia nigra neurons found in PwP.

Recent work at the University of Manchester [2] goes some way to filling this gap:

"The team induced a mild stroke similar to a silent stroke in the striatum area of the brain in mice. They found there was inflammation and brain damage in the striatum following the stroke, which they had expected. What the researchers didn’t expect was the impact on another area of the brain, the substantia nigra. When they analysed the substantia nigra they recorded a rapid loss of Substance P (a key chemical involved in its functions) as well as inflammation.

The team then analysed changes in the brain six days after the mild stroke and found neurodegeneration in the substantia nigra. Dopaminergic neurones had been killed."

Reference

[1] "Signs of Aging May Be Linked to Undetected Blocked Brain Blood Vessels"
Science News, Sep. 1, 2011
http://www.sciencedaily.com/releases...0901163918.htm

[2] "Silent stroke can cause Parkinson’s disease"
University of Manchester, 18 Dec, 2012.
http://www.manchester.ac.uk/aboutus/...splay/?id=9267

John