Aneurysmal subarachnoid hemorrhage (aSAH) is a
sudden, life-threatening bleeding on the surface
of the brain.
Symptoms of aSAH include a severe headache,
confusion and numbness in the body, among
other warning signs described in the following
sections. Anyone who experiences these
symptoms or recognizes them in others should
call an ambulance immediately. Once in hospital,
people with an aSAH will undergo surgery to stop
the bleeding and prevent fatal re-bleeding.
Between a few days to two weeks into their
recovery, about a third of patients with aSAH
experience a worsening of their neurological
condition due to delayed cerebral vasospasm – a
constriction, or tightening, of arteries in the brain.
Cerebral vasospasm restricts blood flow to the
brain and may subsequently lead to the death
of blood-starved brain tissue, a consequence
known medically as cerebral infarction and
accompanied by poor long-term outcomes.
Even when people make a good physical recovery,
there is a high rate of lasting cognitive problems.
Unfortunately, there is currently no way to
predict which aSAH patients will have cerebral
vasospasm, although some risk factors have been
Currently, an invasive approach is used to treat
cerebral vasospasm. This is associated with
medical risks and often requires repeated
procedures. Research into effective medical
treatments is ongoing to improve the outlook for
people with aSAH and cerebral vasospasm.
About this eBook
This eBook has been developed by Idorsia Pharmaceuticals Ltd as a resource to improve understanding of cerebral vasospasm occurring after aneurysmal subarachnoid hemorrhage. It provides a useful summary of current information about the causes, signs and management of cerebral vasospasm. It highlights the impact it can have on the individual and those around them. It also outlines the strategies people caring for those affected by cerebral vasospasm can use to manage their condition as effectively as possible.
The book is intended for the use of a general audience.
Understanding aSAH and cerebral vasospasm
What is aSAH?
aSAH is classified as a type of stroke. Why does
this type of bleeding on the brain occur, what is
its impact on the brain and how is it treated?
Unlike other types of brain hemorrhage,
which can be caused by severe head injuries,
aSAH is specifically caused by the rupture of
an aneurysm – a weak, bulging spot on the wall
of a brain artery – which allows blood to escape
and accumulate in the space around the brain.
While it’s not fully understood why some people
develop aneurysms, there are certain factors
such as genetics, high blood pressure and smoking,
that increase the risk of an aneurysm developing
and of it rupturing.
Any bleeding on the brain is very dangerous as the
blood pools together and places pressure on the
surrounding brain tissue. This, coupled with the
interrupted blood supply due to the burst blood
vessel, reduces much-needed blood flow to the
brain and can cause severe damage.
What is cerebral vasospasm and what causes it?
Cerebral vasospasm is the physical narrowing of
a blood vessel in the brain which restricts or cuts
off blood flow to the affected area.
While the exact causes of cerebral vasospasm
are not fully understood, there are various
physiological and biochemical reactions that may
be triggered by aSAH – a bleed on the brain – that
lead to the release of substances that constrict
It is thought that cerebral vasospasm is caused by the release of ‘vasoactive mediators’ after a bleed on the brain; biochemical ‘triggers’ that cause blood vessels to contract.
Endothelin is one of the most powerful, long-acting vasoactive mediators that causes blood vessels to contract.
Patients with cerebral vasospasm show high levels of endothelin in their cerebral spinal fluid.
Greater understanding of the role that endothelin may play in causing cerebral vasospasm has led to new treatments that block its negative effect being researched as a potential way to prevent or reverse vasospasm in the future.
Evidence of cerebral vasospasm can often be
seen on an angiogram (a special x-ray of blood
vessels) in people who have had an aSAH, even
when there are no apparent clinical symptoms.
This means that there has been some narrowing
of the blood vessels, but not enough to cause
neurological deterioration. About 70% of
aSAH patients show angiographic evidence of
cerebral vasospasm, but only a third have clinical
manifestations. There is no way to predict which
patients will be affected.
Signs and symptoms of cerebral vasospasm
Given the recovery period needed for
aSAH, especially for patients who are
kept anesthetized in the early stages,
symptoms of cerebral vasospasm can be
hard to spot, but may be most noticeable
by a sudden change in the patient’s
consciousness or new symptoms such as
paralysis in certain parts of the body.
What is the outlook for people with aSAH and cerebral vasospasm?
Those that survive aSAH will typically require rehabilitation. While some will recover well enough to live independently, many will face long-term symptoms such as physical or cognitive (‘thinking’) disabilities that require the support of a caregiver.
Disabilities are typically more severe in those that go on to experience cerebral vasospasm after aSAH. Cerebral vasospasm is one of the leading secondary causes of disability and death in those that experience aSAH.
Where does aSAH occur in the brain?
An aneurysmal subarachnoid hemorrhage (aSAH) is a sudden,
life-threatening bleeding that occurs between two layers of
the protective membranes surrounding the brain; the so-called
How is aSAH diagnosed and treated?
In addition to more ‘typical’ stroke-like symptoms,
such as slurred speech, weakness on one side of the
body and loss of consciousness, a hallmark symptom of
aSAH is a sudden, intense and agonizing headache,
which is often described by patients as a ‘thunderclap’
or ‘gunshot’ or ‘the worst headache of their life’.
Anyone experiencing or noticing someone else showing
these symptoms should seek urgent medical assistance.
Once admitted to hospital, a number of tests may be
conducted to confirm a diagnosis of aSAH, primarily
a computed tomography (CT) scan to identify blood in
the subarachnoid space. Other tests such as a lumbar
puncture, a magnetic resonance imaging (MRI) scan,
an angiogram (an X-Ray of blood vessels) and a neurologic
examination, may be used to detect changes in the brain
that may not be visible on a CT scan.
What happens when vasospasm occurs?
Cerebral vasospasm involves an abnormally strong contraction of the smooth
muscle cells located in the wall of one or more blood vessel(s) in the brain.
This contraction narrows the blood vessel, limiting the amount of blood that can flow through it and decreasing the amount of blood reaching the part of the brain that the vessel supplies blood to.
How long and how much of the brain is deprived of blood will determine the extent of the short- or long-term damage caused to the individual.
Symptoms of cerebral vasospasm
Diagnosis and management of cerebral vasospasm
To limit the damage caused by cerebral vasospasm, it is important that it is identified and treated as quickly as possible.
Physical examination: to check for symptoms suggestive of cerebral vasospasm in people who have had a recent aSAH.
Cerebral angiography: to examine blood vessels in the brain using an x-ray machine, after injecting dye through them.
As noted previously, evidence of cerebral vasospasm can often be seen on an angiogram even when there are no apparent clinical symptoms. This means that there has been some narrowing of the blood vessels, but not enough to cause neurological deterioration. About 70% of aSAH patients show angiographic evidence of cerebral vasospasm, but only a third has clinical manifestations.
Other tests, such as Transcranial Doppler (TCD), a type of scan using ultrasound waves to measure blood velocity through the brain's blood vessels, may also be used to detect vasospasm.
In terms of prevention, the calcium channel antagonist or ‘blocker’ nimodipine may be beneficial in reducing the consequences of low blood supply to the brain in people who have had aSAH.
Cerebral vasospasm is typically treated with hemodynamic therapy. This involves inducing high blood pressure while keeping a healthy amount of fluid in the body’s circulatory system in the patient in an attempt to force a blood supply to the brain region affected by the vasospasm.
If this is not effective, some invasive methods such as balloon angioplasty, where a small balloon is inserted into the constricted blood vessel and inflated to forcibly open the vessel, may be performed.
For those vessels not accessible to angioplasty, local injection of a vasodilator into the affected vessels is sometimes attempted. This is also an invasive procedure.
While these approaches are generally accepted for the treatment of severe cerebral vasospasm, evidence about their effectiveness is limited and they are labor intensive, can cause serious side effects and are associated with a risk of further brain damage. Many hospitals are not able to perform these procedures.
Research is ongoing to develop new treatment options for cerebral vasospasm in the future.
Depending on the extent of the damage caused by the aSAH and/or cerebral vasospasm, many people will need rehabilitation training and therapy. This usually starts in hospital and even once home, it’s common for people to regularly visit the hospital for rehabilitation appointments.
Rehabilitation training and therapy is usually delivered by a team of different types of specialists, including a neurologist to oversee the program, nurse specialists, physiotherapists, occupational therapists and speech and language therapists, to help the individual relearn any basic skills that aSAH and/or cerebral vasospasm may have impaired.
Long-term impact of aSAH and cerebral vasospasm
Death to an area of brain tissue due to inadequate blood supply caused by cerebral vasospasm can have a lasting physical, social and emotional impact, affecting all aspects of someone’s life and the lives of their caregivers, family and friends.
Many people who experience aSAH and cerebral vasospasm are left with long-lasting damage to their memory, the speed at which they process information, their ability to analyze and understand shapes and spaces and their energy levels, all of which can affect someone’s capacity to work.
One study of aSAH patients treated over the course of a decade showed that of those previously in full or part-time employment, almost half were unemployed at follow-up a year later.
If someone is not working, or if a family member needs to take time off to care for that person, this can have a financial impact on the individual and the wider family.
The family dynamic can change dramatically depending on the needs and abilities of the person recovering from aSAH and cerebral vasospasm.
Friends and family may find it difficult to cope with the changes that cerebral vasospasm brings and be unsure how best to help in terms of both practical and emotional support.
It is normal for family members that take on the role of the caregiver to feel overwhelmed or resentful at times and/or guilty for harboring these feelings. It is important to remember that friends and family will go through their own ‘grieving’ process too. Sometimes it can be easier to speak to a stranger than a friend in these circumstances and there are often support networks for caregivers available within patient associations who share similar experiences.
Coming to terms with the sudden and unexpected mental or physical limitations following aSAH and cerebral vasospasm can be very difficult for the patient and their family and friends.
Being less able to do the same mental or physical tasks as before the event can impact self-worth, reduce confidence and lead to depression.
Rehabilitation and recovery can be a long and frustrating process and can put a strain on family life and change the family dynamic.
It’s important to remember that emotions are likely to change and most people will experience one or more of the so-called ‘five stages of grief’: denial, anger and frustration, depression/ withdrawal, bargaining, acceptance.
In order to reach the stage of acceptance, patients and their families will need to adjust their expectations and set new goals and objectives. It can be helpful to simply take one day at a time.
Rehabilitation and recovery can be a long process, so it is important for those who were negatively affected by aSAH and cerebral vasospasm (experiencing brain-tissue death as a result) to be realistic in their expectations of to what extent they will be able to relearn old skills or return to independence.
The level of support for people and families affected by complications after aSAH, or stroke more broadly, of which cerebral vasospasm is one, varies greatly from country to country. Local associations and healthcare professionals can often be a good source of information about benefits, grants, social services and other resources available.
Many people find it helpful to become as informed about the condition as they can be. This can help them to feel more in control and manage expectations, as well as make note of any points to discuss with healthcare professionals at the next appointment.
Patient support organizations are a good source of information and support on a variety of topics such as rehabilitation, psychological services, home adaptations, benefits and social services.
Some people find it helpful to attend support group meetings or to join online forums. Communicating with other people in a similar situation can help to avoid feelings of isolation.
Examples of organizations that offer this kind of support include:
Brain Aneurysm Foundation (www.bafound.org): US-based organization with global reach, linking patients, families and the medical community in brain-aneurysm awareness, education, support, advocacy, and research funding
Joe Niekro Foundation (www.joeniekrofoundation.com), Organization providing patient services and education across the US and Canada, as well as funding research and engaging with international communities
This resource has been developed by Idorsia Pharmaceuticals Ltd in order to provide an environment to deliver a better understanding of aSAH and cerebral vasospasm and to pool information regarding the condition, the diagnosis procedure, available treatments and the impact it can have on the lives of those affected. The resource is for use by a general audience.
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