An 84-year-old woman was admitted to another hospital 4 days
earlier for weakness of her left arm and leg that had begun 2 days
prior to that admission. A head CT was performed and she was diagnosed
as having a stroke. Her family became concerned that “nothing
was being done.” They signed her out of that hospital and
transported her to the ED.
The CT obtained in the ED is shown in Figure 1.
- What was the patient’s likely diagnosis?
- What other tests are needed to confirm the diagnosis?
Although this patient presented with a focal neurological deficit
and the CT showed cerebral edema in the corresponding region of
the right cerebral hemisphere, the patient’s disorder was not an ischemic stroke. The subcortical
white mater has a very low attenuation, while the gray matter is
relatively normal in appearance. There is an accentuation of the gray/white matter interface, as
opposed to the loss of the gray/white interface seen with
an acute ischemic stroke (cytotoxic edema) (Figure 2, and see also
Patient 10—Noncontrast CT.
In addition, there is considerable mass
effect due to the cerebral edema, although its effect is moderated
by the patient’s underlying age-related cerebral atrophy.
The cortical sulci are effaced in comparison to the wide cortical
sulci and atrophic gyri of the opposite cerebral hemisphere. The
right lateral ventricle is compressed, although there is no midline
shift (Figure 2).
This is the typical appearance of cerebral edema associated with
tumors and abscesses and is known as peritumoral
vasogenic edema. Tumor angiogenesis
promotes the formation of immature blood vessels with abnormal permeability
that leak edema into the surrounding interstitial tissues (...