This course explains what occurs to the exact location of your stroke. I would have appreciated knowing this but my doctor told me nothing about my stroke or recovery. I worried about my brain rotting from the damage. The picture from there is rather gruesome, which probably resembles my brain right now.
http://neuropathology-web.org/chapter2/chapter2bCerebralinfarcts.html
In the first day or so, the infarct appears
as a poorly demarcated area of
softening.
CT Imaging at this stage may be negative,
especially in brain stem infarcts. MRI is much more
sensitive. At the peak of edema, the infarct appears
hypodense and bright on T2
MRI images. The infarcted
tissue becomes sharply demarcated and softens progressively.
From the second week onward, it begins to
disintegrate and
is gradually replaced by a cavity. The size and location
of infarcts follows the anatomy of vascular territories.
Microscopical examination in the first
24 to 48 hours reveals
anoxic neurons, pallor
of staining and vacuolization of the white matter due to unraveling of myelin,
and axonal swellings. During the
first week, there is a transient inflammatory reaction, especially
around blood vessels and in the meninges, due to release of arachidonic
and other fatty acids. As the core of the infarct disintegrates, endothelial
cells from the periphery proliferate, and capillaries grow into the dead
tissue.
Neovascularization (which accounts for contrast enhancement)
peaks at 2 weeks. Monocytes from the blood stream enter the infarct through
damaged vessels. They ingest the products of degradation of neurons and myelin
and are transformed into
lipid-laden macrophages. Macrophage reaction
appears early and peaks at 3-4 weeks. Astrocytes from the surrounding
undamaged brain proliferate and form a
glial scar around the infarct.
This is completed in approximately 2 months. After that, the infarct remains
unchanged. With maturation of new capillaries and glial scar formation,
the blood brain barrier is once again sealed. Neurons do not regenerate.
So, some brain tissue is lost forever.
|
Old MCA infarct. A collapsed cavity. |
No comments:
Post a Comment