The Anatomy of Your Dizziness
Dizziness is a common but often misunderstood or misdiagnosed condition. Almost 40% of people in the U.S. will experience dizziness or balance issues at some point in their lifetime. Symptoms can vary significantly from sensations of spinning, to feeling like you are floating or rocking, feeling foggy or lightheaded, or simply feeling imbalanced. In addition to the many individualized experiences with dizziness, there are also many different causes of these sensations. This complexity is one of the reasons getting a correct diagnosis can be challenging.
What causes the sensations of dizziness?
Our bodies use a special system called the vestibular system to sense motion and keep us balanced. This system uses information from our inner ears, coupled with input from our eyes, sensation in our skin, and joint movement to detect where we are in space. All of these inputs are processed in the brain to create a feeling of being steady and balanced. When any of these systems or the processing in the brain are not working correctly, it can bring on a sensation of dizziness or imbalance.
The Inner ear:
Disorders of the inner ear are one of the most common causes of dizziness. Because the vestibular system in the inner ear is responsible for sensing motion of your head, anything impacting the integrity of this system can make you feel like you are moving, even when you’re not.
You have one motion sensing system in each ear. The two parts of this system in the inner ear are the semicircular canals and the otolith organs. Each ear has 3 semi circular canals to detect motion in 3 dimensional space. Movement of fluid inside each canal sends messages to the brain about rotational movement. The otolith organs sense linear movement and the head’s position in relation to gravity. They contain very small calcium carbonate crystals that move around when your head does, sending messages back to the brain via the vestibular nerve.
Common inner ear conditions
Benign Paroxysmal Positional Vertigo
This condition is one of the most common causes of dizziness and becomes even more common as you get older. It is often characterized by brief but intense episodes of vertigo that occur with changes in body position such as turning over in bed or sitting up from lying down. This condition occurs when the crystals in the otolith organs become displaced into the semi circular canals, leading to inaccurate information being sent to the brain from the heavy crystals moving around in the canals. This condition can be treated with a quick, simple repositioning maneuver consisting of a series of body position changes that use gravity to move the crystals back into place.
Vestibular Neuritis
This condition results from inflammation of the nerve cells in the inner ear. This inflammation most commonly comes from a viral infection. The symptoms typically occur suddenly and can be quite severe initially. Vertigo, imbalance, nausea, and vomiting are all common. Intense symptoms may last for several days with more mild symptoms of imbalance or dizziness lasting weeks or months. Treatment can include medications to relieve the initial severe symptoms of nausea and dizziness. This should be followed by vestibular and balance rehabilitation with a physical therapist to help the body and brain relearn how to balance and deal with provoking movements.
Meniere’s Disease
This condition is different from the previous two in that it is characterized by recurring episodes of vertigo or dizziness. These episodes may occur days, weeks, months, or even years apart. The episodes typically last 24 hours or less but can be very intense. Meniere’s is often accompanied by tinnitus (ringing in the ear), ear fullness, or changes in hearing in one ear. The exact cause of Meniere’s is still unknown, but it is thought to be caused by a build up of fluid in the inner ear. Treatment can include diet changes (more information on this in my next blog post), medications for nausea and dizziness during an episode, and vestibular and balance rehabilitation if lingering impairments after an episode are noted.
Central Vestibular Disorders:
Dizziness can also occur if the processing center in your brain has been impacted. This is called central vestibular dysfunction. This could occur after a neurological event such as traumatic brain injury/concussion or stroke, or if you have a disease or disorder that impacts the central nervous system such as multiple sclerosis, migraine, myalgic encephalomyeltis/chronic fatigue syndrome, fibromyalgia, and many others. Treatment for this type of dizziness focuses on improving your balance and retraining your brain to be able to better handle movement of your head and eyes. Often times a team effort is best when managing central nervous system dizziness. This could include a neurologist, physical therapist trained in vestibular rehabilitation, and a neuro-optometrist or occupational therapist trained in vision rehabilitation.