CHAPTER 5 Nervous System^225
Cerebral Aneurysm
WHAT WENT WRONG?
A cerebral aneurysm is a balloon-like out-pouching caused by a congenital or
developed weakness in a cerebral artery. Trauma, infection, or vessel wall lesions
due to atherosclerosis can all lead to the development of an aneurysm. Increased
pressure within the vessel lumen may cause the aneurysm to rupture, causing sig-
nificant intracranial bleeding.
PROGNOSIS
Patients are often asymptomatic with the aneurysm, until the time of the rupture.
Some patients have the aneurysm identified on a radiological study as an inciden-
tal finding. The decision can then be made to monitor or treat the aneurysm. If an
arterial aneurysm ruptures without warning, the patient will have significant bleed-
ing—a hemorrhagic stroke. The blood may need to be evacuated from the intracra-
nial area to relieve pressure. The rupture of the aneurysm may be fatal, or the patient
may have long-term disability following the event.
HALLMARK SIGNS AND SYMPTOMS
- Asymptomatic until rupture
- Very bad headache due to hemorrhage and increased intracranial pressure
- Decreased level of consciousness due to increased intracranial pressure from
blood accumulating within the brain
INTERPRETING TEST RESULTS
- Angiogram highlights the aneurysm due to structural abnormality.
- CT scan shows the aneurysm unless it is very small.
- Digital subtraction angiography shows the detail of the vasculature—abnor-
mal structure.
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