Dizziness Caused by Vestibular Disorders
The vestibular organs of the inner ear provide the brain with information about changes in head movement. If the vestibular system is not functioning properly, dizziness, vertigo, imbalance, spatial disorientation, and other symptoms can result.Vestibular-system distress can be caused by a variety of influences, including viral infections of the labyrinth (labyrinthitis) or the vestibular nerve (vestibular neuronitis). Bacterial infection of either the middle ear (otitis media) or the brain coverings (meningitis) may spread to the inner ear. Allergies can cause changes in the inner ear fluids or middle ear pressure because of swelling of the Eustachian tube and production of fluid in the middle ear.
Head trauma is a common cause of inner ear damage in people under age 50. A blow to the head or a "whiplash" injury can result in, for example, perilymph fistula or benign paroxysmal positional vertigo (BPPV). Vestibular-system dysfunction may appear immediately following head trauma or after a delay of days, weeks, or months.
Vestibular disorders can also occur from exposure to ototoxins (drugs or chemicals that are harmful to the inner ear or the vestibulo-cochlear nerve). Degeneration of the hair cells in the inner ear is also thought to occur with aging and can result in dizziness and vertigo as well as hearing loss. A benign tumor known as an acoustic neuroma can grow on the vestibulo-cochlear nerve. In many cases of vestibular disorders, including Meniere's disease and other forms of endolymphatic hydrops, the underlying or original cause cannot be determined.
Other conditions that may affect vestibular function include migraine, mal de debarquement (a sensation of rocking that persists after a cruise or other travel), autoimmune inner ear disease, cervical (neck) problems, vascular compression of the vestibular nerve, superior canal dehiscence, cholesteatoma, enlarged vestibular aqueduct, and others.Reprinted from the Vestibular Disorders Association
