Case 9 brain in trouble
1. What types of brain injuries are there?
Brain tumors
- A tumor, or neoplasm, is a mass of cells (not neurons) that grows independently of
the rest of the body. About 20 percent of tumors found in the human brain are
meningiomas—tumors that grow between the meninges, the three membranes that
cover the central nervous system. All meningiomas are encapsulated tumors—
tumors that grow within their own membrane. As a result, they are particularly easy to
identify on a CT scan, they can influence the function of the brain only by the pressure
they exert on surrounding tissue, and they are almost always benign tumors—tumors
that are surgically removable with little risk of further growth in the body
(encapsulated). Aside from meningiomas, most brain tumors are infiltrating.
Infiltrating tumors are those that grow diffusely through surrounding tissue. As a
result, they are usually malignant tumors;(infiltrating) that is, it is difficult to remove
or destroy them completely, and any cancerous tissue that remains after surgery
continues to grow, it is metastatic tumor (spreads). Gliomas (brain tumors that
develop from glial cells) are infiltrating, rapidly growing, and unfortunately common.
Metastaetic tumors: grow from infiltrating cells that are carried to the brain by the
bloodstream from some other part of the body.
- Surgery, radiation, chemotherapy
Cerebrovascular disorders: strokes
- Strokes are sudden-onset cerebrovascular disorders that cause brain damage. The
symptoms of a stroke depend on the area of the brain affected, but common
consequences of stroke are amnesia, aphasia (language difficulties), paralysis, and
coma. The area of dead or dying tissue produced by a stroke is called an infarct.
Surrounding the infarct is a dysfunctional area called the penumbra. The tissue in the
penumbra may recover or die in the ensuing days, depending on a variety of factors.
The primary goal of treatment following stroke is to save the penumbra. Interrupted
blood flow
- Lifestyle change is most efficient
- Cerebral haemorrhage: occurs when a cerebral blood vessel ruptures and blood seeps
into the surrounding neural tissue and damages it. Bursting aneurysms are a common
cause of intracerebral hemorrhage. An aneurysm is a pathological balloonlike dilation
that forms in the wall of an artery at a point where the elasticity of the artery wall is
defective. Internal bleeding, aneurysm bursts. Medication, brain surgery
- Cerebral ischemia: disruption of the blood supply to an area of the brain. The three
main causes of cerebral ischemia are thrombosis, embolism, and arteriosclerosis. In
thrombosis, a plug called a thrombus is formed and blocks blood flow at the site of its
formation. A thrombus may be composed of a blood clot, fat, oil, an air bubble, tumor
cells, or any combination thereof. Remove thrombus by surgery. Embolism is similar,
except that the plug, called an embolus in this case, is carried by the blood from a
larger vessel, where it was formed, to a smaller one, where it becomes lodged; in
essence, an embolus is just a thrombus that has taken a trip. In arteriosclerosis, the
walls of blood vessels thicken and the channels narrow, usually as the result of fat
deposits; this narrowing can eventually lead to complete blockage of the blood vessels.
Ischemia-induced brain damage has two important properties. First, it takes a while to
develop. Soon after a temporary cerebral ischemic episode, there usually is little or no
evidence of brain damage; however, substantial neuron loss can often be detected a
day or two later. Second, ischemia-induced brain damage does not occur equally in all
parts of the brain—particularly susceptible are neurons in certain areas of the
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