What is hemiplegia?
Hemiplegia is paralysis that affects only one side of your body. This symptom is often a key indicator of severe or life-threatening conditions like a stroke, but can also happen with conditions and circumstances that aren’t as dangerous.
Hemiplegia is paralysis, which means you can’t move or control the muscles in the affected body part. That can cause muscles that are completely limp. It can also cause spastic hemiplegia, a type of paralysis where muscles contract uncontrollably. Hemiplegia affects either the right side of your body (right hemiplegia) or the left side of your body (left hemiplegia), with your spine (backbone) being the dividing line between the two halves.
Hemiplegia may affect your face, arm and leg on one side of your body in various ways: The paralysis may not be present, or not be as severe in all of these three body areas. There are even some rare conditions that cause hemiplegia to come and go, affecting one or both sides of the body as it does.
Depending on how and why it happens, hemiplegia may be treatable. In some cases, no treatment is necessary, while others need immediate medical care to reverse the cause of the hemiplegia.
IMPORTANT: Hemiplegia is a key sign of a stroke, which is a life-threatening medical emergency. To recognize the symptoms of a stroke, remember to think FAST:
- F is for face. Ask the person to smile. Look for a droop on one or both sides of their face, which is a sign of paralysis (facial hemiplegia) or muscle weakness.
- A is for arm. A person having a stroke often has muscle weakness or paralysis on one side. Ask them to raise their arms. If they have new one-sided weakness or paralysis, one arm will stay higher while the other will sag and drop downward, or won’t raise up at all.
- S is for speech. Strokes often cause a person to lose their ability to speak. They might slur their speech or have trouble choosing the right words.
- T is for time. Time is critical, so don’t wait to get help! If possible, look at your watch or a clock and remember when symptoms start. Telling a healthcare provider about when the symptoms started can help them know what treatment options are best.
What are the most common causes of hemiplegia?
Hemiplegia happens because of problems that affect your central nervous system (CNS). The two parts that make up your central nervous system are your brain and spinal cord. To understand how conditions cause hemiplegia, it helps to know a little bit about how your CNS works.
Anatomy of the central nervous system
A key part of how your CNS works involves a concept known as “decussation.” This term comes from “decussis,” the Latin word for the Roman numeral “X.” Decussation means that nerves on opposite sides cross over each other (like an X) and switch sides. The place that happens is in your brainstem, just above where your skull and spine connect.
Decussation is why conditions on one side of your brain often affect the opposite side of your body. Healthcare providers call this “contralateral hemiplegia,” which means “opposite side paralysis.” When you have hemiplegia on the same side, the term is “ipsilateral hemiplegia.”
The only exceptions to decussation happen when the affected nerves don’t pass through the area of the brainstem where the nerve fibers switch sides. Because of this, hemiplegia happens differently depending on where in your CNS the problem starts.
Conditions that cause hemiplegia
There are dozens of conditions and circumstances that can cause hemiplegia. Some of the most common causes include:
- Strokes or transient ischemic attacks (TIAs).
- Aneurysms and hemorrhages inside of your brain.
- Concussions and traumatic brain injuries (TBIs).
- Spinal cord injuries.
- Injuries you experience during birth or very early childhood, causing conditions like hemiplegic cerebral palsy.
- Congenital conditions (which you have when you’re born) such as alternating hemiplegia of childhood.
- Facial paralysis conditions like Bell’s palsy.
- Seizures and epilepsy.
- Bleeding in between your brain and its outer layers (subdural hematomas or subarachnoid hemorrhages) or between your skull and your brain’s outer membrane (epidural hematomas).
- Brain tumors (including cancers).
- Nervous system diseases, especially autoimmune and inflammatory conditions, such as multiple sclerosis or progressive multifocal leukoencephalopathy (PML).
- Infections that affect your nervous system, like encephalitis, meningitis or Ramsay Hunt syndrome.
- Migraine headaches (when these involve hemiplegia, they’re known as hemiplegic migraines).
Care and Treatment
How is hemiplegia treated?
The treatments for hemiplegia depend on the underlying cause. Some of these conditions are treatable or even curable. Others may get better on their own. Unfortunately, many of these conditions cause permanent damage to parts of your nervous system, such as spinal cord or traumatic brain injuries. In these cases, the hemiplegia won’t go away, although it may improve to some degree.
Because there are so many different ways to treat hemiplegia that a healthcare provider is the best person to tell you more about the possible treatments in your situation. They can give you information that considers your specific condition, circumstances, health history and more.
What can I do at home to treat hemiplegia?
Hemiplegia is a key symptom of stroke, which is a life-threatening medical emergency. Because of that, you shouldn’t try to self-diagnose or self-treat it.
An exception to this is a condition where hemiplegia can happen temporarily, like migraines, or if you have permanent hemiplegia from another nonlife-threatening cause. In either of these cases, talk to your healthcare provider about your condition and its symptoms. They can tell you when hemiplegia is a sign that you need to seek medical attention immediately.
How can hemiplegia be prevented?
Hemiplegia often happens unpredictably. Because of that, there’s no way to prevent it entirely. However, you can reduce your risk of it by avoiding conditions or circumstances that can cause hemiplegia. Some steps you can take include:
- Eat a balanced diet and maintain a weight that’s healthy for you. Many conditions related to your circulatory and heart health, especially stroke, can cause brain damage that leads to hemiplegia. Preventing stroke and similar conditions is a key way to reduce your risk of developing hemiplegia.
- Manage your health conditions. Chronic conditions like Type 2 diabetes, high blood pressure and epilepsy can raise your risk for conditions or injuries that could cause hemiplegia. Managing these conditions is essential to lowering your risk of developing this symptom. Managing conditions that can cause incremental damage to your brain or spinal cord over time, such as multiple sclerosis, is also crucial.
- Don’t ignore infections. Infections, especially ones that affect your eyes and ears, can cause hemiplegia if they spread to your brain. Getting prompt treatment for infections — and then following treatment guidelines as closely as possible — can reduce your risk of this happening.
- Wear safety equipment. Protective gear, especially helmets and safety restraints (such as seat belts), can help you avoid head, neck and back injuries that could lead to hemiplegia.
Are rehabilitation and exercise useful to treat hemiplegia?
When hemiplegia isn’t temporary, healthcare providers often recommend rehabilitation in addition to other treatments. Rehabilitation can take place in a hospital (inpatient rehabilitation), clinic or office (outpatient rehabilitation), or at home. Rehabilitation generally includes:
- Physical therapy: Focused on leg function, standing, walking and balance.
- Occupational therapy: Focused on arm/hand function and other activities of daily life.
- Prescription of equipment, to enhance safety and the ability to function inside and outside of your home.
- Managing symptoms associated with hemiplegia, such as spasticity and depression.
- Guidance and resources to address the consequences of hemiplegia, for example, returning to work or applying for disability benefits.
There’s ample evidence that exercise helps optimize health and the ability to function after hemiplegia. Exercising may be more challenging with hemiplegia. This is why rehabilitation therapists usually develop exercise programs adapted to a person’s needs and abilities.
When to Call the Doctor
When should I see a doctor or healthcare provider?
Hemiplegia is almost always a reason to see a healthcare provider as soon as possible. The only exception is if you know you have a condition that causes hemiplegia (such as hemiplegic migraines) and your healthcare provider advises you on how to monitor and react to this symptom.
Frequently Asked Questions
What’s the difference between hemiplegia and hemiparesis?
Hemiplegia and hemiparesis are similar in that they describe weakness on one side of your body, and they’re caused by the same conditions and injuries. Generally, hemiplegia refers to complete paralysis, while hemiparesis refers to partial weakness.
A note from Cleveland Clinic
Hemiplegia is a symptom that causes paralysis on one side — left or right — of your body. Because it’s a key symptom of a stroke, hemiplegia is almost always a reason to seek immediate medical care (unless you have a diagnosed condition that causes hemiplegia and your healthcare provider tells you that emergency care isn’t necessary).
Hemiplegia can often be frightening or alarming, especially if it happens unexpectedly. However, the most common cause of hemiplegia, stroke, is often reversible if a person gets medical care immediately. Many other causes of hemiplegia are also treatable or reversible, so it’s important not to delay medical care if you have it.
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