Benign Paroxysmal Positional Vertigo (BPPV) is a common disorder that causes vertigo. The sensation makes you feel as if your surroundings are spinning around you. Needless to say, you become rather unsteady on your feet as you lose your sense of balance. Episodes of dizziness can occur suddenly when you move your head in a certain way. Lying down, turning over in bed, sitting up from a prone position, or lifting you head to look up or down can trigger the vertigo. Other symptoms such as nausea, vomiting and blurred vision may occur. While the actual cause for the condition is not always known for every individual, there are a number of speculations.
Theories as to Causes
There are currently two popular theories explaining the cause of BPPV. A generally accepted theory suggests that otoliths, or particles in the inner ear, dislodge from the utricle, which is located in the vestibule between the semicircular canals and the cochlea. The utricle and saccule are organs in the ear that sense gravity and motion. Thereby, helping a person to maintain balance. Movement of these small, stone-like particles against attached hair cells send conflicting messages to the brain. Another theory maintains that debris floating in the endolymph, the fluid in the labyrinth of the inner ear, attaches to the cupula, or hair cell receptors located in the semicircular canals of the ear. Again these hair cells become sensitive to changes in movement confusing visual and musculoskeletal impulses being sent to the brain. The two theories differ in that one proposes vertigo is caused by free-floating debris particles, and the other maintains that debris attaching to the hair receptors is the cause. But either way, simply stated, crystals in the ear become dislodged, causing you to become sensitive to changes in head position.
The condition often occurs in individuals who are older than age 60. A slow degeneration of the vestibular function in the inner ear is thought to a cause of positional vertigo. This can be accompanied by a decrease in vision and brain function, creating balance problems. Since the vestibular system plays a significant role in a person’s sense of balance and spatial orientation, positional vertigo puts older individuals at greater risk for falling.
Head injury in the form of a severe blow or trauma to the head may be the most common cause of BPPV in individuals younger than age 50. Vertigo often follows head trauma or injuries involving concussion to the inner ear or skull fracture. A person may experience sensations of spinning, or of falling forward or backward. He may feel nauseous, and he may find it difficult to focus. Attacks may last for a few minutes or for days. Whiplash injuries can cause damage to the nerves in the neck. This type of vertigo, known as cervical vertical, is related to the position of the neck and trunk. The posture of the neck, not the head, is what brings on the sensation.
Inner Ear Problems
Damage to the inner ear, damage that occurs during ear surgery, or lying on your back for too long can each be a cause of vertigo related to vestibular balance disorders. Ear infections may cause the vestibular system in the inner ear to malfunction. Labyrinthitis is an inflammation of the inner ear structure. When this occurs, receptors in the inner ear send incorrect information that does not agree with the messages that the brain receives from the eyes. In other words, the brain becomes confused about the position of the head causing the spinning sensation. Even though doctors can sometimes identify the cause of positional vertigo, many times they just do not know why it occurs. Yet according to a 2003 National Health and Nutrition Examination Survey (NHANES), although the actual numbers of Americans who suffer from balance disorders is unknown, it is estimated that at least half of the nation’s population are affected by balance or vestibular disorders at some time in their lives.
Meniere’s Disease, another inner ear disorder, can also cause problems with balance and hearing. Common symptoms include episodes of vertigo or dizziness. Pressure from too much fluid in the inner ear causes the vertigo. Attacks of vertigo can range in severity from minor motion sickness to episodes that are incapacitating, and it can cause a person to fall when the attack comes on. These drop attacks are considered to be a medical emergency.
In some cases, viruses and stroke have been associated with BPPV and other vestibular balance disorders. Vertigo caused by strokes or tumor occurs when signals to the brain are misinterpreted. People who suffer migraines can also experience dizziness and vertigo.