What is Central Vertigo?
Central vertigo is a condition where a person experiences sensations of movement or spinning, even when they’re not moving. This is caused by issues in the parts of the central nervous system that control balance. Patients usually describe the feeling as dizziness accompanied by illusions of motion, making it different from feeling faint or woozy, which is often due to a decrease in blood flow to the brain.
Our body controls balance through a complex system. This system includes small structures in our inner ear called the saccule, utricle, and semicircular canals. Tiny sensory hair cells within these structures send signals about our body’s position to our brain via the eighth cranial nerve (also known as the vestibulocochlear nerve). The brain receives these signals in an area known as the vestibular nuclei, which is divided into four different parts and is responsible for helping us keep our balance and maintain our gaze when our body position changes.
In simple terms, the whole system helps us keep our vision steady and maintain our body posture. It’s like a reflex that gets activated when we change our head and body position. This process also involves other parts of the brain, like the medial vestibular nucleus and the nucleus prepositus hypoglossi.
Any damage to the balancing structures or their connecting nerves, particularly those linked with the cerebellum (a part of the brain that controls balance and coordination), can result in symptoms of vertigo and related signs of irregular eye movement.
What Causes Central Vertigo?
Peripheral vertigo is a condition that happens because of issues in the system that helps control balance, extending from the inner ear to a certain part of the nerve that carries signals from the ear to the brain. This type of vertigo is responsible for over 90% of all vertigo incidents.
Central vertigo happens when there’s a problem like injury or dysfunction in parts of the brain that are related to balance and coordination. This kind of vertigo is usually caused by limited blood supply to certain areas of the brain and is more common in older adults who have risk factors for blood vessel disease. In younger individuals, a common reason for central vertigo is an condition like multiple sclerosis which damages the protective coating that surrounds nerve fibers.
There’s another kind of central vertigo called Migrainous vertigo or vestibular migraine. This type affects 1% to 3% of people generally. It’s easier to recognize when a patient suffers from repeated vertigo along with typical migraine headaches. But, the diagnosis can prove tricky when a patient only experiences repeated long-lasting vertigo.
It’s also worth noting that medications can cause vertigo as well, especially some common antiseizure drugs like phenytoin, phenobarbital, and carbamazepine. Other drugs that can cause damage to the ear (ototoxic), such as certain antibiotics like aminoglycoside or macrolide and cisplatin, a cancer treatment drug, can also trigger vertigo. Other less usual causes of vertigo include infections, injuries, and tumors in the back part of the brain.
Risk Factors and Frequency for Central Vertigo
In the United States, about 800,000 people have a stroke each year. The majority of these, approximately 85%, are ischemic strokes, strokes caused by a clot blocking blood flow to the brain. Out of those, 20% impact the back part of the brain. The most common type of stroke in this area is called lateral medullary syndrome, or Wallenberg syndrome. This happens when blood flow to certain arteries in the brain gets blocked. The most common symptom of this type of stroke is a certain kind of dizziness called central vertigo.
Stroke is more common in men than in women, with men experiencing it about twice as often. Central vertigo can also happen because of a condition known as multiple sclerosis. This condition affects around 10 to 80 out of every 100,000 people in the United States each year, and is three times more common in women.
Migraine headaches, another condition that can cause vertigo, affect about 12% of adults. They occur in 6% of men and 18% of women. Vertigo is a fairly common symptom of migraines, but the exact number of people who experience it isn’t known, because doctors may not all diagnose this symptom the same way. Vertigo is more often diagnosed by ear, nose, and throat doctors than by those who practice general internal medicine. When it comes to migraines, people usually have spells of vertigo that last for a few hours and don’t have any problems with their ears, nose, or throat. They also don’t show any specific signs or symptoms of nerve or brain conditions. Tests that create images of the brain are usually normal. Diagnosis for vertigo due to migraines often happens when other reasons for the vertigo have been ruled out.
Signs and Symptoms of Central Vertigo
Vertigo is a sensation of feeling off balance, like you’re spinning or that the world around you is spinning. It often presents as an emergency situation. Though most cases of vertigo are caused by relatively harmless conditions like benign paroxysmal positional vertigo, acute vestibular neuritis, Meniere disease etc., there could be severe underlying causes such as brainstem ischemia or infarction, making it very important to identify the root cause of vertigo in a clinical setting.
When a patient comes in with vertigo, doctors need to obtain a detailed medical history. They look for information on the onset of vertigo, its duration, relation to the patient’s posture, and any accompanying symptoms like hearing impairments, headaches, fever, skin rash, recurrence of episodes etc. They also look into the patient’s exposure to illness, vascular risk factors, medication and dosage, and any symptoms related to the brainstem, such as weakness, numbness, blurry vision or difficulty speaking.
Episodes of vertigo are commonly seen in people who suffer from migraines and they often face symptoms like hearing disturbances, nausea, vomiting, and a heightened sensitivity to motion sickness. Before diagnosing such cases as vestibular migraines, doctors need to rule out other possible causes of vertigo.
Physical examination plays a critical part in finding out the root cause of vertigo. It usually involves checking vital signs, looking for skin rashes, listening for any irregularity in neck sounds, evaluating the heart’s condition to rule out arrhythmia, and performing the Dix-Hallpike maneuver to exclude benign positional vertigo or features of central vertigo. It’s important to investigate any signs pointing towards central vertigo, which are often subtle and require sharp clinical acumen to detect.
A specific bedside test, called the HINTS test (which stands for Head Impulse, Nystagmus, and Skew deviation), is used to differentiate between peripheral vertigo and central vertigo. This test is only valid if the patient is experiencing continuous vertigo at the time the test is performed.
Understanding the vestibulo-ocular reflex is crucial for interpreting the results of the HINTS test. The reflex, stemming from the semicircular canals, involves the vestibular division of the eighth cranial nerve and the vestibular nuclei, which work together to help us keep our eyes steady during head movements, aiding in activities like talking or walking. Stimulation to the right peripheral vestibular apparatus (as occurs when turning the head to the right), results in an opposite movement of the eyes to the left. Under conditions of peripheral vestibular dysfunction, this reflex is disturbed. However, the reflex remains normal in the presence of a central vestibular lesion.
Throughout the test, the patient is asked to maintain eye contact with the doctor’s nose while the doctor quickly turns the patient’s head about 30 degrees to the side. The doctor then observes for corrective eye movements or “catch-up saccades”. If such saccades are noted then the test is regarded as positive, indicating a peripheral cause of vertigo, which is generally not as severe.
The type of nystagmus (or involuntary eye movement) also helps differentiate between peripheral and central vertigo. In peripheral vertigo, the nystagmus is always uni-directional, often involving a spinning movement, regardless of the direction of the patient’s gaze. However, in central vertigo, the pattern of nystagmus is more complex and can change with the direction of the gaze. Any vertical nystagmus is a sign of central vertigo. Lastly, the HINTS test checks for “skew deviation” – when one eye is higher than the other, another sign of central vertigo.
- Peripheral Vertigo:
- Intense symptoms
- Torsional, unidirectional nystagmus
- Normal exam apart from nystagmus
- Eyes open during visual suppression
- Delay and fatigue in the Dix-Hallpike test
- Abnormal head impulse to the side of the lesion
- Horizontal rotary and unidirectional nystagmus
- No skew deviation present
- Central Vertigo:
- Mild symptoms
- Pure horizontal or vertical, directional-changing nystagmus
- Abnormal brainstem signs
- Eyes closed during visual suppression
- No latency or fatigue in the Dix-Hallpike test
- Normal head impulse
- Vertical or directional-changing nystagmus
- Skew deviation present
Testing for Central Vertigo
If you’re experiencing dizziness, your doctor may want to perform certain tests to figure out what’s causing it. For instance, the Dix-Hallpike test and hearing tests can help identify the possible causes of peripheral vertigo, a feeling of spinning coming from issues within the inner ear or nerves connecting to the brain.
Your doctor will also do a thorough check-up of your nervous system. This can involve tests for balance issues while you’re either sitting or standing, as well as how you walk. These checks help your doctor determine if there are issues with the parts of your brain responsible for balance and movement.
If your doctor thinks the dizziness may be due to central vertigo, which comes from problems with the brain, more tests will be necessary, often requiring a stay in the hospital. An MRI of your brain is normally the first step and it can show if there’s a clot, tumor, bleeding, or signs of damage to the protective coating of nerve fibers that could explain why you’re experiencing vertigo. In cases where an MRI can’t be done, a CT scan might be used instead.
Your doctor might also undertake a CT angiogram or MR angiogram. This is a way of getting a detailed view of the blood vessels in your brain to see if there’s a blockage in an area that could be causing the vertigo symptoms. It’s important to investigate these things quickly, especially if treatment options like drugs that break down clots (thrombolytics) or surgery are being considered.
One thing to note is that within the first 48 hours after a stroke that affects the back part of your brain, an MRI can sometimes miss the signs. This is why if you have particular examination findings called a positive HINTS result, it’s a cause for concern, regardless of what the brain scan might show.
Treatment Options for Central Vertigo
When a patient comes in feeling dizzy, the first step is to figure out if the vertigo (a spinning sensation) originates from an issue within the body (primary vertigo) or if it’s due to other factors such as medications, alcohol, or decreased blood flow to the brain. Once the doctors determine that the vertigo is internal, treatment will be directed at the root cause.
To establish an accurate diagnosis, it’s necessary to conduct imaging tests as quickly as possible. Also, the patient should always be under observation until a diagnosis is confirmed. Often, patients with vertigo may need to be admitted to the hospital for appropriate treatment.
If the vertigo is due to an acute stroke interrupting blood flow to the back of the brain, and the onset was within 3 to 4.5 hours, doctors may consider thrombolytic therapy, which involves using medication to break up a blood clot. But healthcare professionals must take into account any reasons why the patient may not be suitable for this treatment – like if the patient recently had surgery, suffers from high blood pressure, shows signs of bleeding or swelling in the brain, or if their symptoms are getting better quickly. However, if imaging tests show a significant blockage within the 12-hour window – especially in the main artery at the back of the brain, doctors may consider mechanical thrombectomy (removal of the clot through a catheter) even after the 4.5-hour window.
Patients whose consciousness levels are affected need an electrocardiogram (a test that checks heart rhythm), pulse oximetry (a test that measures oxygen levels in the blood), and close monitoring. If the patient’s condition worsens, emergency actions may be necessary to reduce pressure within the brain and lessen compression of the brainstem. This could include procedures like endotracheal intubation (inserting a tube into the windpipe to assist breathing), the use of aggressive diuretics (medications that increase urine production to decrease swelling), and corticosteroids.
Patients experiencing vertigo should always have a consultation with a neurologist. If there’s underlying bleeding, swelling, or compression of the brainstem, then a neurosurgical consultation is also necessary as surgical procedures like ventriculostomy (drainage of cerebrospinal fluid) or craniectomy (removal of part of the skull) may be needed.
If diagnoses like an acute episode of multiple sclerosis are established, then an intravenous dose of a corticosteroid like methylprednisolone could be administered for 3 to 5 days.
What else can Central Vertigo be?
When a doctor encounters a patient with vertigo, they might consider a range of health issues that could be causing the condition. The most important ones to evaluate in an emergency situation are acute labyrinthitis or vestibular neuritis. These conditions often present with severe vertigo that comes on suddenly, intense nausea and vomiting, and uncontrollable eye movement in one direction.
Benign paroxysmal positional vertigo, a common reason for vertigo, can be easily identified through a specific test called the Dix-Hallpike maneuver. The physician can then treat the patient with a different repositioning procedure. If a patient has recurring vertigo paired with a ringing sound in their ears, it may be a sign of Meniere’s disease – a disorder of the inner ear. It can be confirmed with an audiometry, a hearing test that can detect hearing loss in lower frequencies.
If a patient experiences gradual hearing loss paired with occasional vertigo, and later facial weakness and lack of coordination, the doctor might suspect the presence of a slow-growing tumor in the brain, such as a vestibular schwannoma or meningioma. Migraine is sometimes the cause of recurring vertigo, especially when other conditions have been ruled out through a detailed medical history, thorough physical examination, and normal brain imaging results.
What to expect with Central Vertigo
The future health outcome of central vertigo, a type of dizziness, largely depends on what’s causing it. For instance, if central vertigo is due to vestibular migraines, the outlook is usually excellent.
The most common cause of this condition is acute lateral medullary syndrome, often due to blockage in the arteries supplying the brain. With the right treatment, many patients recover well and return to good levels of functioning.
However, there are more severe causes, such as basilar thrombosis – a blockage in a major brain artery, which can result in much worse outcomes and a higher chance of death.
Central vertigo can also be a symptom of acute demyelination, often associated with multiple sclerosis. If the brainstem is involved, it can make the outlook more challenging compared to patients without brainstem relapses. Often, the symptoms improve after receiving intravenous steroids. But, the long-term outlook can depend on several factors like a person’s age, gender, the frequency, and severity of their symptoms relapses.
Preventing Central Vertigo
Vertigo can be extremely uncomfortable and often leads people to seek medical help. It’s critically important that people understand vertigo can sometimes be a sign of a stroke. Stroke symptoms can include sudden problems with speech, a weak or numb feeling, trouble walking, and changes in vision. An easy way to check for signs of a stroke is by using the FAST test.
The FAST test includes looking for unevenness in the face, checking if one arm drifts downwards when raised, assessing speech for any abnormalities, and taking note of when these symptoms first began. If these signs are observed, it’s recommended to call 911 or go to the emergency department right away.
