Stroke And Inner Ear: What's The Connection?

Strokes are often associated with dizziness, vertigo, and hearing problems, which can be indicative of inner ear issues. While strokes are caused by a lack of blood flow or leakage of blood into the brain, inner ear problems can also cause similar symptoms. This makes it challenging for doctors to distinguish between the two, especially in emergency rooms. However, differentiating between the two conditions is crucial as misdiagnosis can lead to improper treatment and put patients at risk of further complications.

Vertigo, dizziness and nausea can be symptoms of a stroke

Vertigo, dizziness, and nausea can be symptoms of a stroke. While these symptoms are more commonly associated with inner ear infections, they can also indicate a stroke, particularly one affecting the back of the brain.

Strokes occur when there is an injury to a blood vessel that limits blood flow to the brain. They can be ischemic (blocked blood vessels) or hemorrhagic (leakage of blood into the brain). Brainstem strokes, which affect the back of the brain, are uncommon but frequently cause dizziness. Strokes affecting the cerebellum, the area at the back of the brain that controls balance, can also cause vertigo.

It is important to distinguish between inner ear problems and strokes, as misdiagnosis can hinder recovery and leave patients vulnerable to further attacks. While basic diagnostic tools and eye-movement tests are often used, they are not always accurate. More advanced tools such as CT scans and MRIs are also sometimes necessary but can be costly and may miss strokes, especially in the first 48 hours after symptoms begin.

To help differentiate between inner ear problems and strokes, doctors can use specialised eye-tracking goggles, which record eye movements in relation to head movements. These goggles have been found to be highly accurate in detecting strokes and offer a promising option for diagnosing dizziness.

Strokes can cause balance problems

How strokes affect balance

A stroke can change the way your brain controls balance, and you may feel unsteady or uncoordinated. Strokes often cause weakness on one side of your body, making it difficult to balance. At worst, you may find it challenging to sit up safely or stand. You might also experience foot drop, where you cannot lift your toes enough to stop them from catching on the ground when you walk. This can make you feel unsteady and more prone to tripping.

Other factors affecting balance

In addition to weakness, the second main factor affecting balance after a stroke is the loss of sensation in the affected side of your body, particularly your legs. If you cannot feel your leg and foot, it becomes very difficult to know how to move. You will rely more on your vision to compensate for the lack of feeling, which takes a lot of concentration and is tiring. It also makes you less aware of your surroundings, increasing the risk of slips, trips, and falls.

Vision problems

Vision issues are common after a stroke and can include difficulty focusing, double vision, and eye movement problems. If you have hemianopia (missing part of your field of vision), you might not see obstacles in your way. Poor vision can make it harder to make quick adjustments to your posture and movements to maintain your balance, leading to bumping into things or stumbling.

Spatial neglect

Spatial neglect, or inattention, means that your brain is not processing sensory information from one side. You might not be aware of one side of your body and the space around it. People with neglect may try to move but forget to move their weak leg, causing a loss of balance.

Ataxia

People with ataxia have difficulty controlling smooth movements. Their limbs and body tend to be shaky, and arms or legs can miss their target. This condition can make it challenging to maintain balance while sitting or standing.

Vertigo

If a stroke occurs in your cerebellum or brainstem, the areas that control balance in the brain, you may experience vertigo. Vertigo is a feeling that you or the world around you are moving or spinning. It can cause dizziness and a loss of balance.

Medication side effects

Some medications commonly prescribed after a stroke, such as high blood pressure medication, can also contribute to balance issues. Additionally, withdrawal from antidepressants can cause dizziness. It is important to discuss any concerns about medication with your doctor or pharmacist.

Inner ear problems can be misdiagnosed as a stroke

Inner ear problems, such as Benign Paroxysmal Positional Vertigo (BPPV) and vestibular neuritis, can lead to vertigo and balance disturbances. These symptoms can overlap with those of a stroke, particularly when the stroke occurs in specific regions of the brain, such as the cerebellum or brainstem.

The overlap in symptoms can make it difficult for medical professionals to differentiate between inner ear problems and strokes, especially in emergency situations. As a result, it is crucial to seek immediate medical attention if you experience any symptoms indicative of a stroke, including sudden dizziness, vertigo, or balance issues, along with other stroke symptoms such as weakness on one side of the body, blurred vision, or slurred speech.

While inner ear problems can mimic stroke symptoms, it is important to note that they can also occur alongside or following a stroke. A stroke can affect the inner ear and its associated structures, leading to hearing loss, tinnitus, and vertigo. Therefore, inner ear issues should not be automatically dismissed as unrelated to a stroke but instead be carefully evaluated as part of stroke diagnosis and management.

To differentiate between inner ear problems and strokes, healthcare providers may use clinical judgment, neurological examinations, and imaging techniques such as magnetic resonance imaging (MRI) or angiography. However, even with these tools, a definitive diagnosis may be challenging due to the complex nature of the inner ear and its connections to various neurological pathways.

Eye-tracking goggles can help distinguish between strokes and inner ear infections

Dizziness, vertigo and nausea are common symptoms of both strokes and inner ear infections. However, while strokes are dangerous and require specialized treatment, inner ear problems are usually benign. For doctors, especially those working in emergency rooms, quickly and accurately distinguishing between the two is vital.

Basic diagnostic tools, such as the otoscope and simple eye-movement tests, are often inconclusive, leading many doctors to resort to expensive imaging tests such as CT scans or MRIs. However, these scans are not always effective at detecting strokes, particularly those that affect the back portions of the brain.

A new solution: eye-tracking goggles

Eye-tracking goggles, or video-oculography (VOG) goggles, have emerged as a promising tool for distinguishing between strokes and inner ear infections. These goggles are equipped with a motion sensor and a high-speed camera that records eye movements in relation to head movements.

If the eye does not react to a specific head motion with its usual reflex, this suggests that the vestibular nerve, which connects the inner ear to the brain, may be inflamed due to an infection. On the other hand, if the eye reflex remains intact, a stroke affecting the brain tissue is more likely, as strokes typically do not reach the vestibular nerve.

The use of eye-tracking goggles has been found to be highly effective in distinguishing between strokes and inner ear infections, with a small study demonstrating 100% accuracy. In addition to their diagnostic accuracy, the goggles are also cost-effective, simple to operate, and can help reduce the need for unnecessary scans, saving time and money.

Tele-Dizzy service

To address the challenge of requiring specialized expertise to interpret eye-tracking data, Johns Hopkins Hospital has introduced a "Tele-Dizzy" service. This telemedicine approach allows technicians to administer the eye-tracking goggle test, with neurologists interpreting the results remotely. This service brings subspecialty expertise to the bedside, improving the accuracy and efficiency of stroke diagnosis.

Strokes can cause weakness on one side of the body

Strokes are caused by an injury to a blood vessel that limits blood flow to the brain. They can result in partial or complete weakness on one side of the body, known as hemiparesis or hemiplegia, respectively. This occurs because the brain and spinal cord make up the central nervous system (CNS), which controls the body's movement. If there is an injury to the brain or spinal cord, the signals that command the muscles to move can be disrupted, resulting in weakness or paralysis on the side of the body opposite the injury.

About 80% of stroke survivors experience hemiparesis, which can affect the arms, hands, legs, face, neck, or trunk. People with hemiparesis can still move the affected side of the body but with limited strength. This can make everyday activities such as eating or dressing difficult and increase the risk of falls. In addition to physical therapy, there are other treatments available to help improve strength and movement on the affected side, such as electrical stimulation and cortical stimulation.

Balance problems are also a common effect of strokes. A stroke can change the way the brain controls balance, causing dizziness and unsteadiness. Vision problems, such as blurred vision, double vision, and eye movement problems, are also common after a stroke and can further impact balance. It is important to seek medical attention if you experience any symptoms of a stroke, including sudden hemiparesis, balance issues, or vision changes.

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