What is Cerebral Aneurysm?
What is a cerebral aneurysm and how many types are there?
An unruptured cerebral or intracranial aneurysm (UIA) is a focal (abnormal) dilation of an artery in the brain which is caused by a weakening of the vessel wall. Aneurysms differ in location site, size and morphology.
How does an intracranial aneurysm (IA) manifest itself? Can headaches be a symptom?
A sudden, heavy headache, a type of headache which has not been experienced before is the leading symptom of subarachnoidal hemorrhage by rupture of an IA. Rupture of an IA may also cause focal neurological deficits by intracranial hemorrhage and even sudden death caused by vasospams and global brain ischemia.
Unruptured intracranial aneursma (UIA) rarely manifest themselves by progressive headaches. Most headaches are considered to be incidental symptoms in patients with UIA. Availability and quality of brain imaging resulted in an increasing detection rate of UIA in European populations.
UIA may get symptomatic by space-occupaying effects, particularly cranial nerve deficits may occur which are associated with visual disturbances, double vision or speaking problems. UIA may also get symptomatic when causing an ischemic stroke in the territory of the artery which harbours the UIA.
How are brain aneurysms usually detected?
Unruptured cerebral aneurysms are mainly detected by brain imaging (magnetic resonance tomography (MRT) together with MR-angiography).
Who is at risk of having a unruptured intracranial aneurysm (UIA)
There are risk factors for the formation, the growth and the rupture of an IA. Hypertension, cigarette smoking and alcohol consumption (particularly the sudden intake of high quantities) are risk factors. The chance of finding an unruptured IA is increased (app. 10%) if two or more first-degree relatives are affected. In the general population the prevalence of UIA is about 3.2 % in people without comorbidity and the age of 50 years.
What is the therapeutic management of aneurysms without hemorrhage?
When detecting an UIA a first question which has to be addressed is whether the finding is incidental or whether symptoms have been caused by the UIA. If symptoms caused the detection of an UIA endovascular or microsurgical teratment will have to be considered. If an UIA was incidentally detected the following suggestions can be made:
(1) Adjust lifestyle: no cigarette smoking, avoid alcohol or at least reduce the consumption of aclohol (> 150 mg alcohol/ week which is about two 0,75 l bottles of wine/ week increases the risk of growth and rupture of IA), check for arterial hypertension and start treatment if blood pressure is elevated.
(2) Consult experts: The risk of rupture of the IA has to be weighted against the risk associated with an endovascular or microsurgical treatment. On average, there is a five-year rupture risk of app. 3% and an app. 4% risk with intervention. The individual risks depend on the location and the size of the IA. Thus, decision has to be individualized.
(3) Follow up: Growing aneurysms are 12 times more likely to rupture than stable ones. Thus, there is a need of observation.
There are some key factors which will be considered when discussing endovascular or microsurgical treatment: age of the patient, risk factors (hypertension, smoking, alcohol consumption, family history of IA and subarachnoidal bleeding), maximum diameter of the IA, morphology, location (which artery harbours the IA), evidence of growth of IA, symptoms caused by IA.
What about large aneurysms?
Large aneurysms may get symptomatic because of their space-occupaying effects. The risk of rupture increases with the maximum diameter of the aneurysm.
What progess has been made in the treatment of aneurysms in recent years?
New techniques available for endovascular therapy increased the rates of successful aneurysm occlusion within the last years.
How do patients recover after a ruptured aneurysm? Will their life be the same as before?
In general, approximately 25% of patients will have a complete restitution of health (without any symptoms and signs). 25% will have some minor symptoms but will be able to live the same life as before without any restrictions. App. 10% will have some disabilities but will be able to life independently. App. 10% will live in a dependent state and app. 20% of patients will die.
How can aneursyms get complicated, what are the risks of not treating the on time?
UIA may get complicated by space occupaying effects but the most severe complication is the rupture of aneurysms with bleeding into the subarachnoidal space, which is the space covering the brain (subarachnoid hemorrhage, SAH).
What other risks are there?
Rare complications are ischemic stroke which is caused by the formation of a thrombus in the UIA.
Are there any generally accepted factors that are conductive to aneurysm formation and rupture?
Risk factors are: Hypertension, smoking and alcohol, particularly the sudden intake of large amounts of alcohol. There is a higher risk of formation and rupture of an IA if the person had already suffered a bleeding caused by another IA. If two or more first-degree relatives are affected the chance of finding an UIA is increased to 10%. People with polycystic kidney disease have also a high risk of IA formation.
How impartant is lifstyle? Is there a genetic predisposition to a aneurysms?
Lifestyle is important: Stopp smoking, detect and treat high blood pressure, stopp or reduce alcohol intake to a minimum.
There is a genetic background: If two or more first-degree relatives are affected the chance of finding an UIA is increased to 10%.
Does everybody stress impact us in this respect?
The relation between stress and formation, growth and rupture of an IA is not clearly shown. Chronic stress may cause sleep deficits, may increase blood pressure and the risk of imfection. Thus, indirectly stress may be a risk.
Can we talk about prevention? Current guidelines recommend screeing for brain aneurysms if two or more first-degree relatives in a family are known to have a brain aneurysm.
As stated above: Lifestyle is important.
If two or more fisrt-degress relatives in a family are known to have IA then screening is recommended.