Pediatric emergency medicine trisk 4003 4003

Current Evidence. Cavernous malformations (CMs), also known as
cavernous angiomas or cavernomas, are compact lesions comprised of
sinusoidal vascular channels lined by a single layer of endothelium that
lacks the full complement of mature vessel wall components. Between the
vascular channels in the core of the lesion, there is loose connective tissue
stroma without intervening brain parenchyma. The prevalence of CMs has
been estimated to be between 0.4% and 0.9% of the population and 8% and
15% of all vascular malformations. They present with headache, seizure,
focal neurologic deficit, or as an incidental radiographic finding.
The majority of CMs are located supratentorially, typically in the white
matter of the cerebral hemispheres. The infratentorial CMs are located in
the cerebellum, pons, midbrain, and medulla. Less frequent locations of
CMs are the lateral and third ventricles, cranial nerves, and optic chiasm.
Acute hemorrhage from a chiasmal CM is a rare cause of permanent visual
loss. Of the extracerebral locations, the cavernous sinus, the orbits, and the
spinal cord are the most common.
Diagnostic Imaging. CT is more sensitive at detecting CMs, but its
specificity is low since most appear simply as high-density lesions (acute
hemorrhage) with little or no contrast enhancement. This is in contrast to
the high sensitivity and specificity of MRI for CMs. The MRI appearance
of CMs has been categorized into four types: a hyperintense core on T1and T2-weighted images representing subacute hemorrhage (Type I); a
“classic” picture of mixed-signal, reticulated core surrounded by a lowsignal rim (Type II); an iso- or hypointense lesion on T1 and markedly
hypointense lesion with hypointense rim on T2, which corresponds to
chronic hemorrhage (Type III); and punctate, poorly visualized hypointense
foci, which can be visualized only on gradient echo MRI, representing tiny
CM or telangiectasia (Type IV).
Management. With most asymptomatic CMs, particularly when the
diagnosis is relatively clear by MRI characteristics, the right approach for
the patient is conservative management with close follow-up. Type I and II
CMs are composed of acute or subacute hemorrhage and are more likely to
rebleed and may warrant closer follow-up. In contrast to a bleeding episode

from an AVM, a bleeding episode from a CM is rarely life threatening.
However, there is more controversy with symptomatic CMs which
hemorrhage in deep, difficult-to-access surgical locations.