The balance system is comprised of the inner ear working in concert with the brain and proprioception (sensation) in the feet to bring about balance. In addition, blood flow has to be consistent to the brain to make the above function properly.
Perhaps there is no symptom scarier to the patient than that of dizziness, which may be manifested as lightheadedness, vertigo (spinning sensation), or unsteadiness. However, once an etiology is established, generally an effective treatment regimen can be instituted. The causes of dizziness comprise a long list, of which the common culprits are highlighted here, but can usually be narrowed down to three main categories.
This may be from the inner ear where the vestibular (balance) system in located, or the middle ear (behind the eardrum). Common inner ear sources include benign paroxysmal positional vertigo(BPPV), Meniere’s, vestibular neuronitis, and rarely, a benign tumor called an acoustic neuroma.
BPPV, probably the most common source of true vertigo, is caused by calcium carbonate crystals (limestone) in the inner ear that become dislodged from the gel that they normally reside within, resulting in momentary severe spinning with lying down or rolling over in bed. Bending over or looking up can also exacerbate. This can occur following a blow to the head, or more commonly spontaneously, without antecedent trauma. Symptoms improve temporarily by remaining upright and keeping the head still. BPPV can be readily diagnosed in the office with a maneuver to elicit the rotary beating of the eyes (nystagmus) characteristic of vertigo in the offending head position. Treatment consists of a “barrel roll” maneuver in the office, followed by head elevation and keeping the head still for the next 48 hours. This will resolve the condition 95% of the time, rarely requiring a repeat treatment the next week. Alternatively, patients may go to Physical Therapy for balance exercises if unable to tolerate the maneuver, although this treatment takes longer for resolution.
Meniere’s disease is an imbalance of the fluids in the inner ear, and has the classic symptoms of fullness in one ear, loud roaring on that same side, and an attack of vertigo, which may last hours, and is independent of head position or movement. Nausea and vomiting may accompany the above symptoms. Hearing test will reveal a fluctuating low frequency nerve hearing loss during the attack. Balance testing (an ENG) may be warranted. This condition is treated with a fluid pill (diuretic) and avoidance of caffeine, alcohol, tobacco, and placement on a lower salt diet. Treatment is important not just to resolve the vertigo, nausea and vomiting, but to stabilize or improve hearing.
Vestibular neuronitis may be thought of as a viral infection of the inner ear, and typically follows an upper respiratory infection, although some patients have identical symptoms without any respiratory symptoms. Vertigo, nausea and vomiting predominate, aggravated by any movement, but particularly head movements. Symptoms can last days or weeks, and can take months to resolve completely. Hearing test and MRI of the head are obtained to rule out any other source, and balance testing (ENG) may be ordered. This condition has no medicine that will help, and physical therapy becomes the mainstay of treatment. Patients should be cautioned that this is not an overnight fix, and intensive physical therapy, typically 1-2 times per week, IN ADDITION to daily continued physical therapy exercises by the patient in the home, are essential for improvement, albeit gradual over 3-6 months.
Rarely, a benign growth on the hearing nerve (acoustic neuroma) can affect balance, and is frequently heralded by a unilateral hearing loss found by hearing test, then subsequent brain MRI to locate. This is also a treatable condition, but frequently requires surgical intervention.
Middle ear conditions include infection and eustachian tube dysfunction, the latter known to the public when descending in an airplane or during an upper respiratory infection, where the ear(s) will stop up or pop in the midst of allergies, sinus or a cold. Although this does not produce vertigo, lightheadedness can occur. Treatment of the underlying nasal condition will typically resolve the lightheadedness.
This includes the brain as well as sensory perception in the feet. Conditions which may produce dizziness include strokes, multiple sclerosis, tumors, and migraine variants, the latter a diagnosis of exclusion, among other neurologic conditions. Diabetes may produce peripheral neuropathy, with symptoms of numbness or decreased sensation in the feet. In the absence of an inner or middle ear source, referral to neurology is warranted.
Blood has to get to the brain in a continuous flow, and when this is interrupted because of poor carotid artery function, be that narrowed arteries or flaccid arteries (both associated with aging) or arrhythmias of the heart (skipped heartbeats or irregular rhythm to heartbeat), lightheadedness or unsteadiness may result. Certain medications can be culprits. In the absence of offending medications, or of known palpitations or low blood pressure, ear and neurologic work-up are instituted first, with cardiology evaluation reserved for those patients without ear or neurologic findings.
Successful treatment of dizziness, including vertigo, can be achieved, but as can be seen from this brief introduction, identification of the offending cause is critical for resolution. Otolaryngologists are uniquely trained to coordinate this journey.