VIDEO HEAD IMPULSE TESTING
WHAT IS VIDEO HEAD IMPULSE TESTING?
Video head impulse testing (vHIT) gives us important information about how your vestibular system is working. The vestibular system includes the balance receptors of the inner ear and the vestibular nerves, along with the brainstem, cerebellum and brain areas that process inner ear signals. It is one of the main ways your brain knows where you are in space. It helps you make sense of gravity and head movement, and compares that information with signals from your eyes and body, so you can know where you are in the world.
The vestibular system has several working parts, including six semicircular canals, three in each inner ear. These canals sense head rotation, while other inner ear sensors, called the otoliths, sense gravity, head tilt and straight-line movement. Together, they provide signals the brain uses to activate the core muscles that keep you steady. The canals also work with the brainstem and cerebellum to produce the vestibulo-ocular reflexes, which keep your vision steady and help you know where the world is as your head moves. Problems with these reflexes often lead to dizziness and vertigo. Vestibular problems are common after concussion and traumatic brain injury, and changes in how these systems work have been linked to conditions ranging from movement disorders and neurodegenerative diseases to some psychiatric conditions. vHIT testing lets us measure how well each of the six canals and their reflexes are working, and repeated testing can help show how they respond as they tire. This is another important part of your NeuroRescue Program.
HOW DOES VHIT HELP ME?
Video head impulse testing helps us measure how your vestibular system is working. This system provides one of the main signals your brain uses to make sense of where you are in the world. The reflexes from the six semicircular canals, together with signals from the otoliths, play a key role in your brain’s automatic sense of where your head is in space and how it is moving. Your brain uses this information to help locate your body in your surroundings and to choose the right strategies for steadying yourself with your muscles. If this automatic sense of where your body is in space is off, the brain may activate the wrong stabilizing reflexes, which can lead to balance problems and a higher risk of falls and injury. When vestibular signals don’t match the signals from your eyes and body, the result is often dizziness and vertigo. Problems with the vestibular canals and their reflexes can be involved in many neurological conditions, including:
Dizziness & Vertigo | Traumatic Brain Injuries & Concussions | Movement Disorders | Headaches & Migraines | Balance Disorders | Anxiety & Depression | Cognitive Difficulties | Neurodegenerative Disorders | Neurodevelopmental Disorders
WHAT TO EXPECT:
During vHIT testing, you wear a pair of lightweight goggles while a technician gently moves your head in different directions. The goggles contain a motion sensor that measures your head movement and an infrared camera that tracks your eye. You sit up straight and focus on a target on the wall while your technician turns your head with a series of small, quick movements. As your head moves, specific vestibulo-ocular reflexes move your eyes in roughly the opposite direction, so your eyes can stay on the target. The movements are small and brief, but please let us know if you have neck pain or a neck injury so we can adjust the test.
The computer tracks your eye movement, compares it with your head movement and measures how well the reflex is working. It calculates the reflex gain, which is the relationship between head movement and eye movement, and provides both a numerical score and a graph of the reflex. We use this information to see how well these reflexes are working and how evenly they work on each side, and to design targeted rehabilitation strategies, with the goal of helping them work well and work together.
FAQs
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Yes. vHIT testing is very safe and is usually comfortable. Before the test begins, your technician will check how well your neck moves to make sure you can do the test comfortably. Some people may feel briefly dizzy during or after the test, and this usually passes quickly.
In some cases, such as certain neck injuries or advanced degeneration of the spine, this test may not be appropriate. Your provider will review your history before testing to decide whether vHIT is safe for you.
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The vestibular pathways can be affected in many different ways. Causes range from viral infections that affect the inner ear receptors or the vestibular nerve, to tiny inner ear crystals that come loose and settle in the semicircular canals where they don’t belong, a condition called benign paroxysmal positional vertigo (BPPV). Vestibular reflexes are commonly affected by concussion and traumatic brain injury. In some cases, problems with these reflexes can be present from birth.
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No. vHIT testing is usually very comfortable, and most people don’t notice any symptoms. A few people may feel briefly dizzy, which usually passes quickly.
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VHIT testing shows us how well all six of your semicircular canal reflexes are working. It measures the gain of each canal and how evenly the paired canals on each side work together. It gives us insight into how well your brain senses head movement in different directions and planes of motion. It shows whether your brain can produce the right eye movement to keep your eyes on a target when your head moves. The same canals also send signals that help your brain activate the muscles from your ankles up to your neck to keep you steady, so vHIT results, combined with balance testing, help us understand how well your brain may be stabilizing your body when you move your head.
Your vestibular system does much more than help you balance. Vestibular problems have been linked to conditions ranging from difficulties with thinking and emotional regulation to chronic pain. Addressing vestibular problems is a core part of many NeuroRescue Programs.
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In many cases, yes. Vestibular function is a major focus in many of our NeuroRescue Programs, and vestibular rehabilitation is one of the most foundational things we do. Vestibular therapy is a well-established, research-supported treatment, and it typically uses several strategies. Adaptation exercises help the inner ear reflexes respond more accurately. Substitution exercises help the brain rely on other senses to make up for what the inner ear isn’t doing well. Habituation exercises repeatedly expose you to movements that bring on symptoms, so your brain gradually becomes less sensitive to them. For example, if turning your head to the left brings on dizziness because a vestibular reflex isn’t moving your eyes far enough to the right, habituation might involve practicing that movement until your brain adjusts, often with help from the cerebellum and frontal lobes. Because habituation is designed to bring on some symptoms, it can feel uncomfortable for some people.
Compensation and habituation strategies can be very helpful. Our emphasis is on also training the specific reflexes that aren’t working well, whenever possible, rather than relying only on ways to work around them.
We start by measuring which reflexes may be affected, using our computerized testing and exam. We then use a range of therapies to activate those specific reflexes, with the goal of improving how well they work. As those reflexes start to work better, we use strategies to help them work together with your visual and body position systems.
When it’s helpful, we then gradually return to the movements and situations that were bringing on your symptoms, at a pace your nervous system can handle. Our goal is to keep your care as comfortable as possible while still challenging your system enough to make progress. In some cases, building compensation strategies is still an important part of care, and we include them when they are needed. Results vary from person to person, and our care can work alongside your vestibular therapist and other providers.
TAKE THE FIRST STEP BACK TO LIVING YOUR BEST LIFE
“I’m very very thankful that I came here. It is the only place that I went to out of all of them that had the answers that I needed.”
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We use computerized neurological testing and targeted rehabilitation strategies designed for your brain and condition.
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We offer intensive programs with frequent therapy sessions over 5 to 10 days, designed to give your nervous system consistent, repeated stimulation in a short period of time.