Brain Stem Stroke
Written by Ada’s Medical Knowledge Team
What is brain stem stroke?
A brain stem stroke occurs when there is a blockage obstructing the flow of blood to the brain stem ‒ the base of the brain that is connected to the spinal cord. A brain stem stroke can be due to either:
- A blood clot or other obstruction in the blood vessels, known as an ischemic stroke
- Blood coming out of a blood vessel, known as a hemorrhagic stroke
Ischemic strokes are overall far more common than hemorrhagic strokes. Around one in ten ischemic strokes takes place in the brain stem.
- Face. The face becomes weak or droopy, with the effect usually more visible on one side
- Arm. One arm becomes numb or weak, and there may be difficulty raising it
- Speech. Speaking becomes difficult, and the affected person’s voice becomes slurred
- Time to call. If any of the above is noticed, the emergency services should be called immediately.
The brain stem and the blood vessels that supply it play a vital role in the following bodily functions:[^3][^4]
- Heart rate
Any of the above can be affected by a brain stem stroke. Vertigo, the feeling that the body is moving even if it is not, is by no means an indication on its own that anything is severely wrong. However, vertigo can sometimes be caused by a brain stem stroke. Therefore, if a doctor discovers that a person experienced vertigo during a stroke, then it can be one indication that it was a stroke affecting the brainstem, especially in conjunction with other typical symptoms being present.
A number of other health conditions, particularly high blood pressure, increase the risk of stroke.[^5] Strokes also become more likely as a person gets older or engages in certain behaviours, like smoking. The best means for lowering the risk of stroke is to live a healthy life with a good diet, not smoking and getting plenty of exercise or movement.
The brain stem is vital for many bodily functions, including:[^4]
- Body movement
- Processing sights and sounds
- Eye movement
- Blood pressure
Any of the above could be affected by a brain stem stroke.
The specific symptoms depend on the part of the brainstem affected and whether the stroke is ischemic or hemorrhagic. The three parts of the brainstem are:
- The midbrain
- The pons
- The medulla
These are supplied by multiple arteries, some of which split up to carry blood to the left and right sides of the brain.
Ischemic brain stem stroke symptoms
Vertigo and dizziness. A brain stem stroke can cause a person to feel like they have lost a sense of where their body is in space. Vertigo is the feeling that the body is moving when a person is actually standing or sitting still. This sensation may also lead to a feeling of nausea and subsequently lead to vomiting.
Changes to hearing. Some ischemic brain stem strokes can lead to the perception of sounds when none are present, otherwise known as tinnitus. The person affected may also become more sensitive to certain sounds or frequencies, a condition known as hyperacusis.
Changes to eye movements. One or both of the person’s eyes may move in an unusual way during and after a brain stem stroke. The eyes may involuntarily move from side to side or up and down. One eye may stay off-centre, or the eyelid may appear droopy. The affected person’s pupils may become smaller. The ways the eyes are affected by a brain stem stroke can cause the vertigo and dizziness described above and may also lead to double vision.
Loss of coordination of muscle control Medically known as ataxia, this is when the affected person is unable to control their muscles properly. This can lead them to lose balance or fall to the floor.
Loss of ability to speak. Otherwise known as dysarthria, a person affected by brain stem stroke may find it difficult to speak in the way that they usually do. Speech may be slurry, or the person may not be able to talk at all. Other parts of the throat, mouth or tongue may be affected by a brain stem stroke causing difficulties in swallowing, for example.
Loss of body feeling. A person affected by brain stem stroke might find it harder to feel pain or changes in temperature. This sensation may only affect certain parts of the body, such as the face, arms, chest or tongue. They may also perceive sensations in incorrect places, like when the foot is touched, it may feel like the leg is touched.
Unusual breathing patterns. A person may find it difficult to breathe as they usually would. Doctors may need to take action to help the person breathe during treatment.
Locked-in syndrome is a rare condition that usually happens when there is damage to the part of the brain stem called the pons, e.g. through a stroke. One of the reasons the pons is important is, because it transmits information between the brain and the spinal cord. Locked-in syndrome occurs when all of these signals that are important in controlling muscle movement in the body are disrupted. The parts of the brainstem that control facial movement and speaking are also affected during locked-in syndrome:
- A person is quadriplegic, which means they have little or no ability to move their arms, legs or torso
- They are unable to speak
- They remain conscious and able to perceive the world
A person affected by this syndrome generally can only move their eyes and blink after the stroke has taken place. Their ability to breathe and swallow may also be affected.
Symptoms of brain stem hemorrhages
A hemorrhagic stroke in the blood vessels supplying the brain stem is much rarer than an ischemic stroke. However, when bleeding does occur in this part of the brain, then the consequences are usually severe, and there is a high risk of the person not surviving the stroke.
The following symptoms are all common outcomes of a brain stem hemorrhage:
- An inability to see straight with eyes moving out of their normal position
- Weakness in both the arms and the legs
- Difficulty breathing, eating or swallowing
- Loss of consciousness and coma
Brain stem strokes are caused by the blood supply to part of the brain stem getting cut off, either due to a blockage in the blood vessels (ischemic stroke) or due to bleeding in the blood vessels supplying the brain stem (hemorrhagic stroke).
Ischemic stroke causes
Small vessel disease. This is an umbrella term describing a number of abnormal changes to the small arteries and veins in the brain. This can lead to effects including tiny bleeds or small blockages that reduce blood flow. This continued damage to the blood vessels increases the risk of a stroke occurring. An MRI or CT brain scan is usually necessary to detect small vessel disease. The most common cause of small vessel disease is high blood pressure (hypertension.
Artery dissection. A more common cause of stroke in patients aged under 45, artery dissection is when the inner lining of an artery becomes torn causing blood to build up. This can lead to a blood clot that blocks the artery and causes ischemic stroke. Artery dissection can also cause an aneurysm, which is when part of the artery wall becomes weakened and bulges outwards. If this bulged-out structure does not hold, and blood begins to escape, then this can lead to hemorrhagic stroke.
Hemorrhagic stroke causes
In a hemorrhagic stroke, damage is caused by bleeding in or around the brain. The resulting collection of blood coming out of the bleed begins to put pressure upon and damages the brain tissue surrounding the bleeding site. This initial injury can lead to further swelling and inflammation within the brain, putting it under more pressure.
Although a big part of the brain injury from a hemorrhagic stroke occurs because of the initial bleed, continued bleeding and the later swelling can lead to even more complications. That is why it is so important to get a stroke treated as quickly as possible.
High blood pressure often shows no specific symptoms, unless it is suddenly rising and/or very severe; this means that many people affected by high blood pressure will not be aware that they have it.
High-blood pressure is made more likely by living an unhealthy lifestyle. This is also true of several other risk factors for stroke, including:[^5]
- Following a balanced and varied diet, rich in vegetables and fruits, high in unprocessed, whole foods
- Stopping smoking or chewing tobacco products
- Getting enough exercise or generally plenty of movement
- Drinking less alcohol
- Not taking stimulant drugs such as cocaine, amphetamines and crystal meth
- Atrial fibrillation, an abnormal heart rhythm
- Vasculitis, which is when blood vessels inside the brain become swollen and inflamed due to infection or to conditions affecting the immune system
- Old age. Most strokes happen to those aged over 65
- Certain inherited conditions that weaken the blood vessels, such as autosomal dominant polycystic kidney disease (ADPKD) and fibromuscular dysplasia
- Brain infection, such as encephalitis
- Cerebral amyloid angiopathy, a buildup of proteins on the walls of the arteries in the brain
- Brain tumors
- Arteriovenous malformations, an abnormal connection between blood vessels
- Oral contraceptives (birth control pills)
- Postmenopausal hormone therapy
Good to know: There is an ongoing debate whether spinal manipulation as performed by chiropractors could increase the risk of stroke, particularly at the base of the brain. The research on this topic is continually evolving, and it is impossible to say with any certainty how close the link is. However, there is likely to be some connection between brain stem stroke and spinal manipulation.
Anyone displaying signs of stroke should immediately be taken to a hospital emergency room for diagnosis. This will usually begin with a physical examination and a review of a person’s medical history. Brain scans are needed to confirm whether the person is affected by a stroke and, if so, what type of stroke it is.
A brain scan can help determine:
- If a stroke has taken place
- Whether the stroke is hemorrhagic or ischemic
- The damage that has been caused to the brain thus far
It can also help detect any potential brain abnormalities that may have contributed to or caused the stroke.
Given the risk of ongoing damage from an untreated stroke, a brain scan must be carried out promptly after the affected person reaches a hospital.
A ct scan is generally one of the first tests made after a suspected stroke, because it is much quicker than an MRI scan. CT scans use X-Ray technology.
A magnetic resonance imaging (MRI) scan uses radio waves and a strong magnetic field to build a detailed image of the interior of the body. An MRI scan usually provides a more detailed picture than a CT scan, so could be beneficial given injuries in the brain stem can be very small.
Stroke, angiography and contrast dye
In the early stages of a brain stem stroke, the blockage or bleed in the brain stem may be too hard to detect by a standard CT scan. In this case, a doctor may insert a small amount of dye in the blood before performing the scan.
In both a computed tomography angiogram (CTA scan) and a magnetic resonance angiogram (MRA), the dye is usually injected through an intravenous drip in the arm. It can also be injected into a vein on the back of the hand or via a thin tube, known as a catheter, through another blood vessel.
Brain stem strokes are a medical emergency, and a person affected by one will need to be taken to a hospital to be treated immediately. After this initial treatment, rehabilitation and other forms of aftercare may be needed.
Emergency treatment of brain stem stroke
The immediate treatment of a brain stem stroke depends on:
- The type of stroke
- The severity of symptoms
- The parts of the brain stem involved
The first step is generally to stabilize the person affected, making sure that they can breathe and taking any lifesaving measures necessary
If a brain stem stroke is caused by a blood clot, then medication can be given that can break down the clot and allow blood to flow normally through the blood vessel again. This process is known as thrombolysis and should be administered within a few hours of symptoms starting to show.
Acute endovascular therapy
In some cases, the doctor may choose to apply the clot-dissolving medication directly to the blood clot to aid removal. This is achieved by inserting a catheter into the affected person’s groin and maneuvering it up to the affected blood vessel supplying the affected brain stem area.
Hemorrhagic brain stem stroke treatment
If the stroke becomes hemorrhagic, then the aim of hospital treatment will be to stop the bleeding and reduce any pressure on the brain. This generally includes a mixed treatment approach, including surgery and medications.
Breathing assistance and other measures
After a brain stem stroke, the person affected may need assistance with breathing. This may involve the insertion of a tube down a person’s windpipe to deliver air to the lungs or simply a mask that delivers air through the nostrils.
Swallowing and other involuntary functions might be affected by the stroke. For example, the affected person may be at higher risk of aspiration pneumonia, which is when fluids or solid particles, such as food, go into the windpipe or lungs.
Brain stem stroke rehabilitation and aftercare
Following a brain stem stroke a person’s physical abilities are often restricted. The amount to which the person is affected can vary from a feeling of numbness or weakness to total paralysis of the body (locked-in syndrome). This can lead to several potential problems including:
- Deep vein thrombosis, potentially dangerous blood clots which are more likely to form if the person is not moving around for long periods
- Unhealthy nutrition, because of difficulty swallowing or chewing
- Aspiration pneumonia, a type of pneumonia caused by food or drinks being accidentally inhaled into the lungs
- Skin problems, due to increased pressure on the skin caused by the lack of movement
- Falls and other accidents related to a sudden loss of balance and/or physical weakness
- Breathing issues
Most of these can be managed with good nursing care and the help of a physical therapist to assist with how the problems can be avoided, once the person is discharged from hospital and after possibly further in- and/or outpatient rehabilitation.
- Wheelchair usage, if necessary
- Eye movement problems
An occupational therapist will assist a person affected by stroke in regaining the ability to complete tasks necessary for living day to day, such as:
- Getting dressed
- Washing the body
- Getting around
This therapy will often involve a person’s family or people they are close with. An occupational therapist can assist with accessing further help, such as a wheelchair or devices that make getting in and out of a bath easier.
Difficulties in speaking and swallowing after a stroke
A person may have difficulty speaking or swallowing after a stroke in the brain stem. An inability to speak can cause frustration and make it difficult for the affected person to communicate their needs. An inability to swallow can lead to difficulty eating and getting the right nutrition, as well as some other conditions such as aspiration pneumonia.
Emotional difficulties after stroke
After a stroke, many people experience emotional problems, feel fearful of living with future complications or long-term disability and may feel a loss of confidence in accomplishing everyday tasks or social activities.
- Low, depressed mood and mood swings
- Clinical depression
- Crying or laughing easily, sometimes with no apparent reason or in socially inappropriate situations
- Feeling angry a lot more than previously
- The feeling that the person’s personality has changed
- Developing generalized anxiety disorder
- Developing post traumatic stress disorder
- Denial about the consequences of the stroke and needing help in day-to-day tasks
Emotional difficulties tend to improve with time and treatment, and there are various treatment options available to help and support someone experiencing them, including:
- Support groups such as those the registered with the National Stroke Association
- Talking therapies, such as psychotherapy
- Medications, such as antidepressants
Q: What is the prognosis for a brain stem stroke?
A: Following a brain stem stroke, long-term disability or a person not surviving the stroke are a serious risk. A medical professional will be able to give guidance and support regarding a person’s long-term prognosis, but it is often hard to predict the outcome accurately and, in the end, people may fare worse or much better than previously estimated.
Q: What is the survival rate for brain stem stroke?
A: It is difficult to give an accurate figure for the survival rate of brain stem stroke as a whole. This is because it depends so greatly on where in the brainstem the stroke takes place, whether the stroke is hemorrhagic or ischemic and several other factors.
For example, in a study of patients at a New England medical center, the majority affected by posterior circulation stroke survived. However, another study shows that an ischemic stroke in the basilar artery, which supplies the pons part of the brain stem, carries a high mortality risk.
Q: Are there any brain stem stroke recovery stories?
A: Yes. While rehabilitation and recovery after a stroke are difficult, there are numerous cases of survivors recovering the majority of their motor and cognitive functions after one has taken place. Support groups, such as those the registered with the National Stroke Association, often offer opportunities to meet other stroke survivors. Healthtalk.org includes a number of recovery stories by people of all ages.
Other names for brain stem stroke
- Brain stem infarct
"Hemorrhagic stroke.” Harvard Medical School. January, 2013. Accessed: 21 September, 2018. [^3] “[Brain Stem Stroke])http://www.strokeassociation.org/STROKEORG/AboutStroke/EffectsofStroke/Brain-Stem-Stroke_UCM_310771_Article.jsp#.XBz8BM_7R25).” Stroke Association. October, 2016. Accessed: 21 December, 2018. [^4] “The Structure And Function Of The Human Brain .” Northern Brain Injury Association. 2018. Accessed: 21 December, 2018. [^5] “Stroke (Cerebrovascular accident).” , 2018. Accessed 21 December, 2018. ↩ ↩
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“Mechanism and Therapy of Brain Edema after Intracerebral Hemorrhage Cerebrovascular Diseases. July, 2016. Accessed: 29 November, 2018. ↩
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