Internal bleeding can occur in any part of the brain. Blood may accumulate in the brain tissues itself, or in the space between the brain and the membranes covering it. The bleeding may be isolated to part of one hemisphere (lobar intracerebral hemorrhage) or it may occur in other brain structures, such as the thalamus, basal ganglia, pons, or cerebellum (deep intracerebral hemorrhage).
An intracerebral hemorrhage can be caused by a traumatic brain injury or abnormalities of the blood vessels (aneurysm or angioma). When it is not caused by one of these conditions, it is most commonly associated with high blood pressure (hypertensive intracerebral hemorrhage). In some cases, no cause can be found.
Blood irritates the brain tissues, causing swelling (cerebral edema). It can collect into a mass called a hematoma. Either swelling or a hematoma will increase pressure on brain tissues and can rapidly destroy them. Symptoms vary depending on the location of the bleed and the amount of brain tissue affected. The symptoms usually develop suddenly, without warning, often during activity. They may occasionally develop in a stepwise, episodic manner or they may get progressively worse. Other factors that raise the risk of intracerebral hemorrhage include the following: Premature infants (born earlier than 35 weeks gestation) will sometimes have bleeding into the ventricles (fluid-filled spaces) in the brain. This type of bleed is called intra-ventricular hemorrhage (IVH). This occurs in the first day or so of life and is usually not preventable. The outcome is variable, depending on the severity of bleed and ranges from no apparent damage to severe disability. Diagnosis is by ultrasound and usually done in an intensive care nursery.
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