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CHAPTER 4 - IMAGES OF STROKES
Select a chapter from the list
Strokes are one of the leading causes of death in the U.S. They are caused by either a
blood clot that chokes off blood supply to an area of the brain or by a blood vessel
breaking. Cigarette smoking is one of the most significant risk factors for strokes. On
SPECT, strokes are demonstrated by areas of significant decreased or absent activity.
SPECT is often helpful in the evaluation and management of cerebral vascular disease.
After an acute stroke' early SPECT depicts the area of ischemia with greater accuracy
than either computed tomography or magnetic resonance imaging. When the perfusion defect
is large' the likelihood of hemorrhagic complications or herniation increases.
Reperfusion of an arterial territory after thrombolysis can be documented more
conveniently with SPECT than with angiography. SPECT before and after the injection of
acetazolamide has been used to assess the vascular reserve in patients with severe
stenosis of the proximal vessels of the cerebrovascular tree. Here are several
examples.
Left Frontal Stroke
Ellen, 63, was suddenly paralyzed on the right side of her body. Unable to even speak, she
was in a panic and her family was extremely concerned. As drastic as these symptoms were,
two hours after the event, her CAT scan was still normal. Suspecting a stroke, the
emergency room physician ordered a brain SPECT study that showed a hole of activity in her
left frontal lobe caused by a clot that had choked off the blood supply to this part of
the brain. From this information, it was clear that a stroke had occurred and her doctors
were able to take measures to limit the extent of the damage. Ellen was a smoker.
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Left Frontal Stroke
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Right Side Strokes
Bill, 48 year old male with left frontal lobe stroke, affecting speech, mood and
temperament. Although Bill was not a cigarette smoker, he had over 10 years of moderate
marijuana smoking.
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Two Right Sided Strokes
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Nancy was a 59-year-old woman suffering from severe depression that had been nonresponsive
to treatment. Upon admission to a psychiatric hospital a SPECT study was done to evaluate
her condition. Since she had not experienced any symptoms that would point to this, I was
surprised to see that she had had two large strokes. Nearly immediately her non-responsive
depression had made more sense to me. Sixty percent of the people who have frontal lobe
strokes experience severe depression within a year. As a result of the SPECT study, I
sought immediate consultation with a neurologist who evaluated her for the possible causes
of the stroke, such as plaques in the arteries of the neck or abnormal heart rhythms. He
felt the stroke had come from a blood clot and placed her on blood thinning medication to
prevent further strokes. Nancy was a smoker.
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