Understanding the basic anatomy, function of the human ear, and the mechanism of balance and hearing are important pieces of information when addressing the many underlying causes and symptoms ear disorders. Many other disease processes are related to the ear such as: Migraine Disease or Labyrinthine Dysfunction.
About Migraine Disease
Migraine disease is a complex neurologic disorder in which headache is but one symptom. The disorder is usually inherited, and is extremely common. About 18% of women and 6% of men have the disease, although less than half of them are aware that their symptoms are migraine related. The disease has been categorized as Migraine with Aura and Migraine without Aura. The aura is a transient, usually reversible neurologic dysfunction. Although headaches are very common in migraine patients, they are not necessary to make the diagnosis. This type of migraine is termed a “migraine equivalent” or more properly, Migraine Aura without Headache. The disease tends to change throughout one’s lifetime, with headaches predominating at one time, and the aura at another.
The know association of dizziness and vertigo with migraine disease date back more then 100 years. 33% of migraine patients will experience true vertigo at some point in their lives, 72% will have dizziness, lightheadedness, or unsteadiness. Migraine disease is one of the more common causes of dizziness in children. Visual motion intolerance and motion sickness are frequent in migraine sufferers. Vertigo may be positional, spontaneous, or induced by stress, hormonal fluctuation, allergies, as well as certain foods or chemicals.
In addition to vertigo and dizziness, migraine disease can cause a variety of symptoms. Hearing loss, tinnitus, aural pain, visual loss, nausea, vomiting, imbalance, and blank outs are all possible. The vast majority of patients experience these symptoms independent of their headache.
Migraine is thought to be the hereditary manifestation of abnormal sensitivity to neurovascular changes. Simply stated, there is an abnormality in the part of the brain controlling or modulation incoming signals. Two theories are accepted: 1) neurovascular theory of inflammation and 2) serotonin deregulation. The first mechanism implies the presence of an irritable pain generator in the brain stem. When this is triggered, the trigeminal nerve releases inflammatory chemical substances (i.e. peptides) into the brain. The peptides cause a leakage of the meningeal blood vessels in the brain, causing them to distend, which result in inflammation and pain. According to the second theory, when an adequate trigger is received, serotonin platelet levels drop, and a headache ensues. Changes in hormonal level, sleep state, diet, altitude, stress, and allergy may each alter the amount of chemical neurotransmitter released from one nerve terminal to the next. The stimulus is thus amplified beyond that of the primary event. When these changes are occurring on a blood vessel, spasm ensues. Such vasospasms are thought to be responsible for the sudden hearing loss and blindness that can happen with migraine. When they occur on a nerve terminal, the normal function of the nerve is altered dramatically, causing symptoms like vertigo, motion sickness, and pain.
The diagnosis of migraine disease causing dizziness is made by a combination of historical information, physical exam findings, laboratory data, audio-vestibular testing, and occasionally imaging (CT or MRI). A family history of migraine disease is often a strong predictor of migraine as the diagnosis. The entire balance system is evaluated using a combination of tests, which identify any weaknesses in the inner ear, visual system, proprioceptive (sensation) system, and the brain. There is no characteristic pattern for migraine disease, but the absence of other processes makes the diagnosis more likely. Concern for an intracranial process (stroke, tumor, MS) may prompt an X-ray evaluation with either a CT or MRI scan.
Management of this disease process has many levels. Known triggers of migraine should be eliminated, such as nitrate/nitrite containing foods, sulfites, caffeine, aspartame, nuts, and certain fruits. Stress management can be useful for some, and regular sleep and exercise are also very important. Allergic trigger are extremely common, and formal allergy testing is often performed, followed by immunotherapy. Both inhalant allergy and food allergy are important to eliminate. Pharmacological management is often essential to obtain initial control of the disease. Many different classes of medications can be utilized, all with the same common goal to reduce neurotransmitter levels. Medications include: Verapamil, Midrin, Paxil, Elavil, Triptans and others. Triptans act on the 5HT-ID receptors on the nerve terminal to decrease the release of peptides, and on 1B receptors of the meningeal blood vessel to reduce vasodilation and leakage. Some of these medications are also used to treat depression, and often that can be useful given how debilitating this disease can be. The primary focus of their use is, however, management of neurovascular abnormalities causing the symptoms of migraine. The duration of medication therapy can range from 6 months to several years. Lastly, migraine may cause constant disequilibrium and balance problems, which are addressed with a specialized form of physical therapy, called vestibular rehabilitation. This is highly effective in eliminating these symptoms.
Foods to Avoid
- Avoid Caffeine: soda, coffee, tea, chocolate
- Eliminate nitrate/nitrite: wines, hams, bacon, sausage, lunch meats, hot dogs, red wine.
- Avoid large quantities of cheese, especially aged and cheddar (American, cottage, cream and velveeta are okay)
- Avoid Monosodium Glutamate (MSG), found in Chinese food (read labels and ask server to leave out of prepared dishes)
- Avoid Aspartame is found in artificial sweeteners (Nutrasweet and Equal)
- Avoid consumption of large quantities of nuts
- Limit citrus fruits to 1 serving per day
- Avoid skipping meals, prolonged fasting, or excessive ingestion of carbohydrates at a single sitting. Establish a routine sleep-wake cycle. Get regular exercise, avoid extreme exertion or fatigue.
Superior Semi-circular Canal Dehiscence
About Superior Semi-circular Canal Dehiscence
On occasion there is an absence of bone over the superior semicircular canal. When this entity is present, it causes a syndrome in which balance abnormalities occur as a result of hearing loud noises or experiencing pressure changes in the ear.
This syndrome produces some very specific symptoms. Patients can experience vertigo (an illusion of motion) caused by noises or pressure in the ear. The noises that can provoke such symptoms include loud music, being in a noisy environment such as a sports event, sounds on the telephone such as the dial tone or a busy signal, and sounds made by the patient such as singing at certain pitches. The pressure symptoms that can provoke the symptoms include pushing on the outer aspect of the ear, blowing through the nose while pinching the nostrils, and straining while lifting heavy objects. In addition to these symptoms that occur in specific association with the stimuli just described, patients with this syndrome may experience a generalized and more constant sense of disequilibrium and unsteadiness.
Surgical Procedures for Superior Semicircular Canal Occlusion
A Middle Fossa Craniotomy is performed affording access to the base of the skull and the superior semicircular canal. The canal is plugged thus alleviating the source of balance disturbance associated with this syndrome.