A stroke occurs when blood supply to the brain is interrupted. The way a stroke affects the brain depends on which part of the brain suffers damage, and to what degree.
Sitting just above the spinal cord, the brain stem controls your breathing, heartbeat, and blood pressure. It also controls your speech, swallowing, hearing, and eye movements.
Impulses sent by other parts of the brain travel through the brain stem on their way to various body parts. We’re dependent on brain stem function for survival. A brain stem stroke threatens vital bodily functions, making it a life-threatening condition.
The most common type of stroke is an ischemic stroke, which is caused by a blood clot. A clot can form in an artery that supplies blood to the brain. A clot that forms elsewhere can travel through the blood vessels until it becomes trapped in one that supplies blood to the brain. When blood can’t get to a section of the brain, the brain tissue in that area dies off because it’s not receiving oxygen.
Aside from blood clots, an arterial dissection can also cause an ischemic stroke. An arterial dissection is a tear in an artery that supplies blood to the brain. As a result of the tear, blood can accumulate within the arterial vessel wall and cause obstruction of blood flow. This pressure can also lead the wall to burst, rupture, or leak.
The other type of stroke is called a hemorrhagic stroke. This is when a week blood vessel bursts, causing blood to pool and pressure to build in the brain.
Symptoms of stroke depend on which area of the brain is affected. A stroke in the brain stem can interfere with vital functions such as breathing and heartbeat. Other functions that we perform without thinking, such as eye movements and swallowing can also be altered. Brain stem stroke can also impair your speech and hearing, and cause vertigo.
All of the signals from your brain move through the brain stem to reach the different parts of your body. Nerve cells that come from various sections of the brain carry these signals right through the brain stem to the spinal cord.
When blood flow in the brain stem is interrupted, such as with stroke, those brain signals are also disrupted. In turn, the different parts of the body that these signals control will also be affected. This is why some people experience numbness on one or both sides of the body, or paralysis in their arms or legs.
A brain stem stroke can cause you to lose your sense of smell and taste.
About 1 percent of people who have had a stroke experience psychosis in the form of hallucinations or delusions. Hallucinations involve seeing or hearing something that isn’t there. Delusions are a strong belief in something that isn’t true.
Other rare complications include coma and locked-in syndrome. Locked-in syndrome is a condition in which your entire body, except for the eye muscles, is paralyzed. People are able to think and communicate through eye movements, such as blinking.
Anybody can have a stroke, but your risk increases with age. A family history of stroke or mini-stroke, also called a transient ischemic attack, increases your risk. People over age 65 account for two-thirds of all strokes.
Males and people of African-American, Hispanic, or Asian/Pacific Islander descent are also at higher risk. However, women are more likely to die from stroke than men.
Other conditions that increase your risk of stroke include:
- high blood pressure
- high cholesterol
- cardiovascular disease
- certain blood disorders
- autoimmune diseases
Lifestyle risk factors
Some factors that increase your risk of stroke are beyond your control. But many lifestyle choices that can increase your likelihood of having a stroke are not. These include the use of long-term hormone replacement therapies and birth control pills. Women over the age of 35 who also smoke are at a particularly high risk.
Behaviors that increase your risk of stroke include:
- physical inactivity
- alcohol abuse
- drug use, such as cocaine, heroin, and amphetamines
A brain stem stroke is a life-threatening medical emergency. If you have symptoms that indicate a stroke, your doctor will likely order imaging tests such as MRI scan, CT scan, Doppler ultrasound, or angiogram. Heart function testing may include electrocardiogram and echocardiogram. Additional diagnostic procedures may include blood tests, as well as kidney and liver function testing.
In the event of ischemic stroke, the first line of treatment is to dissolve or remove the blood clot. If a stroke is diagnosed quickly enough, a clot-busting medications can be given. If possible, a catheter can be used to remove the clot in a procedure called an embolectomy. In some cases, angioplasty and stenting are used to widen an artery and keep it open.
For a hemorrhagic stroke, the bleeding must be stopped. A clip or coil is sometimes placed on the aneurysm to stop the bleeding. Medication to reduce clotting also may be required.
In the meantime, your medical team may need to take additional measures to keep your heart and lungs functioning.
A brain stem stroke can result in serious long-term problems. Medication and ongoing therapy may be necessary. Physical therapy can help people regain large motor skills and occupational therapy can help with everyday tasks. Speech therapy can help you regain control over how you speak and swallow.
Some survivors of brain stem stroke are left with severe disabilities. In these cases, psychological counseling can help them adjust.
Despite the risks that you can’t avoid, there are things you can do to decrease your chances of stroke. Some general guidelines to follow include:
- Eat a low-fat and low-sodium diet rich in fruits, vegetables, and fish.
- Exercise regularly.
- Don’t smoke.
- Don’t abuse alcohol or drugs.
If you’re obese or have high blood pressure, diabetes, high cholesterol, or a type of chronic illness, follow your doctor’s recommendations for keeping them under control.