Intracerebral Hemorrhage: Bleeding Inside the Brain
All strokes damage the brain by disrupting circulation, but
strokes come in multiple varieties. Because different parts of
the brain are specialized to perform specific functions,
symptoms produced by strokes vary according to what part of the
brain was injured. In one patient the symptom might be weakness
on one side of the body. In another it might be a partial loss
of vision. In still another, a loss of speech. And symptoms can
vary in intensity from mild to severe according to how large the
area of damage is and whether it occurred in a pivotal location.
Strokes can also vary according to another fundamental
difference -- whether they involve a blocked blood vessel or a
hemorrhage. Most strokes are due to the former in which
brain-tissue damaged by lack of circulation is called an
infarction. But 10-15% of strokes involve bleeding from ruptured
blood vessels within the brain tissue, and while it's bad enough
to have an infarction, hemorrhagic strokes (intracerebral
hemorrhages) can be even more devastating.
One prominent figure with spontaneous intracerebral hemorrhage
is Ariel Sharon, whose hemorrhagic stroke occurred while he was
still prime minister of Israel. Although some patients with
intracerebral hemorrhage recover to a point of being able to
enjoy other people and regain some independence in functioning,
Sharon's poor clinical outcome is all too common in patients
with this disease.
The additional problem with hemorrhagic strokes is that the new
deposit of blood occupies space -- sometimes a lot of it -- and
there is only so much space within the skull (braincase) to go
around. The fresh hemorrhage crowds and distorts the
brain-tissue next to it, and additionally subjects the rest of
the brain to increased pressure that can itself be damaging.
Because of these distortions and pressure-changes, a patient
with intracerebral hemorrhage often shows a decreased level of
consciousness or even coma.
Another kind of spontaneous bleed within the braincase is
subarachnoid hemorrhage, often caused by ruptured aneurysms
outside the brain but inside the braincase. While this, too, is
a very serious condition, it is not the focus of this particular
essay, and spontaneous intracerebral hemorrhages are not caused
by aneurysms of this kind. Yet another kind of bleed that can be
confused with (primary) intracerebral hemorrhage is secondary
hemorrhage. This occurs in some patients who started out with
infarctions of the brain but who had subsequent bleeding from
fragile blood-vessels around the infarction's edges. This kind
of bleed is not quite as serious as that which occurs when the
bleed is primary (the initial event).
How are intracerebral hemorrhages diagnosed? Since the 1970s
when computed tomographic (CT) scans were introduced, this
imaging technique has been the most effective and sensitive
tool. A fresh hemorrhage within brain tissue is dramatically
evident on CT scans. And unlike infarctions that can take a day
or two to show up on CT scans, hemorrhages are already visible
at the earliest moment a scan can be made.
Although surgical removal of blood-clots from the surface of the
brain -- called subdural and epidural hematomas -- can be
life-saving and function-sparing, surgery for a bleed (hematoma
or blood-clot) within the brain tissue itself is another story.
Some studies comparing outcome between operated and unoperated
patients with intracerebral hemorrhage showed improved outcome,
on average, for operated patients, while still others showed
worsened outcome. Operated or unoperated, patients had high
rates of death and disability.
Because of the limited prospects for meaningful improvement,
surgery for intracerebral hemorrhage is often an act of
desperation. One crusty old clinician was blunt about the
direness of the situation, saying, "Show me a patient with
intracerebral hemorrhage whose life was saved by surgery, and
I'll show you a patient you wish you hadn't operated on." His
point was that survivors of this operation usually show severe
impairments.
However, one form of hemorrhage within brain tissue is probably
a special case, and that is hemorrhage within the cerebellum,
located within the bony braincase just above the nape of the
neck. Surgical extraction of blood clots occurring within the
cerebellum prevents excessive pressure on the nearby brainstem
that handles a lot of basic and necessary functions, like
breathing.
Administration of cortisol-type steroids is a nonsurgical
treatment that has been studied in a scientific way, comparing
treated patients to untreated patients with the same condition.
The steroids didn't help. Decreasing the patients' blood
pressures by administering medication has likewise been studied,
but with the same outcome -- no benefit. However, in a
preliminary study one nonsurgical treatment showed promise.
Intravenous administration of activated factor VII (a natural
component of the blood-clotting system) reduced expansion of the
intracerebral blood-clot, death and disability when given within
four hours of the initial hemorrhage. A larger study is underway
to see if this benefit holds up under further analysis.
Otherwise, what can be done acutely for this condition?
Individualizing treatment seems rational, even if unproved. For
example, if the patient had a bleed while taking a blood-thinner
(as was the case with Ariel Sharon) then it makes sense to stop
the blood-thinner or reverse its effects. Supportive management,
like administering intravenous fluids to prevent dehydration,
monitoring for irregular heartbeats and protecting the patient's
airway also make sense. If the patient can't consume food in the
usual way, feeding through tubes or intravenous lines can be
considered, though this decision can be postponed until the
patient's prospects are more apparent.
Who is at risk for intracerebral hemorrhage? Neurologists at
Malmo University Hospital in Malmo, Sweden, compared 147
patients with intracerebral hemorrhage with 1029 similar but
stroke-free patients in order to determine risk factors. They
found that hypertension (high blood pressure), diabetes,
elevated triglyceride levels in the bloodstream, history of
psychiatric problems, smoking and (surprisingly) short stature
were more frequent in patients with intracerebral hemorrhage.
However, when it comes to modifiable risk-factors (those that
one can do something about) a variety of studies indicate that
hypertension is the single most important factor. Thus,
treatment of hypertension, when present, is probably the single
most effective thing that one can do in order to prevent this
disease.
(C) 2006 by Gary Cordingley