Intracranial Aneurysms Overview

Questions and Answers

Which characteristic is unique to fusiform aneurysms compared to saccular aneurysms?

They have a defined orifice or neck.

They are berry-like in shape.

They exhibit circumferential dilation of the artery. (correct)

They account for the majority of intracranial aneurysms.

What condition is primarily associated with fusiform aneurysms?

Diabetes mellitus

Traumatic injury

Hypertension

Atherosclerosis (correct)

Which statement regarding dissecting aneurysms is accurate?

They are formed by blood leaking through a tear in an artery. (correct)

They have well-defined necks facilitating blood flow.

They typically result from congenital malformations.

They are the most common type of intracranial aneurysm.

How do saccular aneurysms typically impact morbidity and mortality?

They account for the majority of cases leading to aSAH. Signup and view all the answers

What is a characteristic feature of dolichoectasia?

Marked elongation and tortuosity of the vessel. Signup and view all the answers

Which imaging technique best demonstrates the dimensions of an aneurysm prior to treatment?

Digital subtraction angiography Signup and view all the answers

What critical information about the flow in fusiform aneurysms differentiates them from saccular aneurysms?

Inflow and outflow are longitudinally separate. Signup and view all the answers

What is the significance of a narrow neck in saccular aneurysms?

It can determine the treatment approach. Signup and view all the answers

What potential consequence can arise from a dissecting aneurysm?

Stenosis or narrowing of the vessel lumen. Signup and view all the answers

What feature primarily defines a saccular aneurysm?

It resembles a berry and has a specific neck size. Signup and view all the answers

Study Notes

Intracranial Aneurysms Overview

Intracranial aneurysms are bulges in arterial walls within the brain, posing significant health risks.
Aneurysms can lead to subarachnoid hemorrhage (aSAH), causing severe morbidity and mortality.

Saccular Aneurysm

Most frequent type of intracranial aneurysm, accounting for about 90% of cases.
Characterized by rounded, berry-like outpouchings from first and second-order branches in the circle of Willis.
May feature narrow or wide necks; their morphology influences treatment approaches.
Principal contributors to morbidity and mortality associated with aSAH.

Fusiform Aneurysm

Defined by circumferential dilation of an arterial segment without a distinct neck.
Inflow and outflow routes of blood are longitudinally separate within these aneurysms.
Highly associated with atherosclerosis, which leads to destruction of the tunica media and arterial stretching.
Conditions causing vessel damage can also result in fusiform aneurysms.
When accompanied by elongation and tortuosity of the artery, it is termed dolichoectasia.

Dissecting Aneurysm

Arise from dissection of an arterial wall where blood penetrates through a tear.
Can lead to stenosis (narrowing) or outward displacement, classifying them as dissecting aneurysms.

Imaging Examples

Subarachnoid Hemorrhage Case:
- CT shows extensive subarachnoid hemorrhage (Fisher grade 3).
- 3D CT angiography identifies a saccular aneurysm from the left internal carotid artery.
- Digital subtraction angiography reveals the aneurysm size (4.7 mm height, 3.2 mm width) before treatment.
- Post-treatment imaging shows complete obliteration of the aneurysm using platinum coils.
Dolichoectasia Case:
- CT imaging indicates an enlarged basilar artery causing significant mass effect on the pons.
- Digital subtraction angiography of the left vertebral artery demonstrates dolichoectasia affecting the involved vessels.

Description

This quiz explores the different types of intracranial aneurysms, with a focus on saccular and fusiform aneurysms. Learn about their characteristics, prevalence, and implications in subarachnoid hemorrhage. Test your knowledge on the morphological aspects of these significant medical conditions.