Bell’s Palsy vs Stroke: What’s the Difference?

Both stroke and Bell’s palsy are conditions that affect the neurological system (brain, spinal cord, and nerves). These two conditions can sometimes be difficult to tell apart. But Bell’s palsy and stroke are two different medical conditions. Please continue reading to find out the difference between Bell’s palsy vs stroke.

What is the main cause of Bell's palsy?

Bell’s palsy was first described by a Scottish surgeon, Sir Charles Bell, as a condition that affects the facial nerves and facial muscles. This condition is associated with unilateral temporary facial paralysis (sudden weakness on one side of the face that is temporary). Approximately 40,000 people are diagnosed with Bell’s palsy in the US each year.

It is unclear what exactly is the direct cause of Bell’s palsy. Experts think the most common cause is an inflammation of the seventh cranial nerve (facial nerve) or facial nerve damage from a viral infection, which leads to temporary paralysis.

What is the main cause of a stroke?

According to the CDC and American Stroke Association, stroke impacts nearly 800,000 people in the US each year. The leading causes of stroke are high blood pressure, high cholesterol, diabetes, obesity, and smoking.

Close to 90% of all strokes are ischemic strokes. An ischemic stroke is a brain injury that occurs when the blood supply to a part of the brain is reduced or blocked, for example, by a blood clot. This results in a lack of oxygen and the death of brain cells within minutes.

The other type of stroke is a hemorrhagic stroke which occurs due to a ruptured blood vessel and bleeding into the brain.

A transient ischemic attack (TIA) occurs due to a temporary clot in a blood vessel. TIAs last for a few minutes and occur due to a temporary interruption in the blood supply to a part of the brain.

A stroke is a medical emergency. Early diagnosis and treatment are essential to limit the damage and save a person’s life.

How to tell the difference between Bell's palsy and a stroke?

Bell’s palsy and stroke can both cause facial weakness. However, there are some key differences between Bell’s palsy and stroke signs.

Bell’s palsy symptoms

Symptoms of Bell’s palsy include central facial weakness and lower facial weakness. Other symptoms include trouble smiling with an uneven or lopsided smile, a flat nasolabial fold, difficulty closing the eye on the affected side, excessive tearing from the eye, changes in taste, mouth dryness, ringing in one or both ears, and extreme sensitivity to sound. The symptoms usually improve gradually over a period of several weeks to months. A Bell’s palsy patient will usually recover fully in about 6 months.

Stroke symptoms

Symptoms of a transient ischemic attack may include dizziness; numbness and weakness on one side of the body, including the face, arm, and leg; confusion; difficulty talking (slurred speech); problems with walking, balance, and coordination; and difficulty seeing out of one eye.

Ischemic stroke symptoms may include speech difficulty (trouble speaking or finding words), difficulty understanding others, numbness or weakness in the face, arm, or leg (this is often one-sided), trouble walking, vision problems (difficulty seeing out of one eye, double vision, or eyes gazing in one direction), severe headache, vomiting, and dizziness.

When a weakened blood vessel ruptures and causes a hemorrhagic stroke, the symptoms depend on the part of the brain affected, for example, the brain stem or the thalamus. Symptoms may include severe headache, vomiting, sudden difficulty speaking, loss of sensation, weakness, paralysis, seizures, loss of consciousness, and coma.

An easy way to recognize stroke symptoms is to remember the acronym BE FAST:

B: Balance problems
E: Eyes (vision loss)
F: Face (drooping or uneven smile)
A: Arm (weakness)
S: Speech problems
T: Time is of the essence in a stroke

Is Bell's palsy the same as a mini-stroke?

No, Bell’s palsy is not the same as a mini-stroke (transient ischemic attack or TIA). Bell’s palsy occurs due to an inflammation of the facial nerve. A TIA occurs due to a temporary interruption in blood flow to a part of the brain. However, Bell’s palsy can mimic stroke. The two conditions can be difficult to tell apart because they can both cause weakness on one side of the face.

Can Bell's palsy turn into a stroke?

Bell’s palsy cannot turn into a stroke. However, studies have shown that Bell’s palsy patients have a two times higher risk of suffering a stroke. Therefore, if you have had Bell’s palsy, it is worth discussing stroke prevention measures with your healthcare provider. It’s also important to keep all your follow-up appointments during recovery from Bell’s palsy.

What is the treatment for Bell's palsy vs stroke?

Healthcare providers can make a definitive diagnosis of Bell’s palsy by performing a neurologic exam, testing the facial nerve, and doing electromyographic studies on the facial muscles. Treatment for Bell’s palsy may consist of corticosteroids to reduce inflammation or antiviral medications if deemed necessary.

Diagnosis of a stroke is made by checking vital signs and performing blood tests as well as imaging studies such as CT scan, MRI scan, carotid ultrasound, and cerebral angiogram in the emergency department.

Treatment for a stroke depends on the situation. For an ischemic stroke, treatment may include emergency intravenous clot-dissolving medication, emergency endovascular surgery to deliver medication directly at the site of the blood clot or surgically remove the clot, and other procedures like carotid endarterectomy or angioplasty and stents. A hemorrhagic stroke may be treated with medication to lower intracranial pressure (pressure inside the brain) and surgical procedures to remove blood from the brain, surgical clipping to clamp an affected blood vessel and stop blood flow, endovascular embolization (coiling to block blood flow into an aneurysm), and other procedures.

Bell's palsy or stroke: How to tell the difference?

Symptoms of Bell’s palsy are limited to the face. If you suspect a stroke, seek immediate medical attention. Watch out for other focal neurologic deficits that extend beyond the face, such as difficulty walking, problems with balance and coordination, and difficulty understanding what others are saying. Err on the side of caution and seek emergency medical care if you are not sure whether it is Bell’s palsy or stroke. Remember, people who have had a previous stroke are at risk of future stroke.

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