Balance is controlled by the vestibular system, a very complex mechanism in the body. The balance organ, located in the inner ear, lets the brain know where the head and body are in three dimensions. Proprioceptive nerves in the lower extremities "feel" the ground, and allow the brain maintain a sense of steadiness.
Additionally, the eyes constantly assess the surroundings, providing valuable information about the orientation of the horizon. All of this information is processed by the brain, which is the center of the nervous system. In addition, other important factors such as blood pressure and blood sugar level can play a role in balance.
Vertigo is the sensation of movement when the body is stationary with respect to the surroundings. It can feel like spinning, swaying, or generalized imbalance. Vertigo may be associated with nausea, vomiting, and visual disturbances. When vertigo is severe, it can even cause difficulty walking.
Vertigo is generally separated into two categories, depending on the location of the abnormality in the vestibular system. Peripheral vertigo refers to a problem within the inner ear balance organ or the balance nerve. Central vertigo implies an abnormality in the brain and central nervous system.
Peripheral vertigo falls under the purview of the Otolaryngologist (Ear, Nose, and Throat Specialist). There are numerous causes of peripheral vertigo. Some of the more common causes treated by the Otolaryngologist include benign paroxysmal postural vertigo (BPPV), labyrinthitis/vestibular neuritis, Meniere's disease, and motion sickness after a long or turbulent airplane flight or a cruise. Less commonly, a tumor on the vestibular nerve referred to as a vestibular schwannoma or acoustic neuroma can cause vertigo or imbalance.
The list of central causes of vertigo/dizziness is much more extensive. Some of the common causes include multiple sclerosis, tumors of the brain and central nervous system, migraine headaches, stroke, and medication side effects. These conditions are usually treated by a Neurologist and/or Neurosurgeon.
The workup for vertigo will include a complete head and neck examination, including neurologic testing and an audiogram (hearing test). The audiogram is obtained because vertigo can occur in association with hearing loss. Additional testing may include an MRI of the brain, an MRA of the blood vessels in the head and neck, and an Electronystagmogram (ENG). Electrocochleography testing is sometimes utilized in the diagnosis of Meniere's disease.
Since vertigo is such a complex and often difficult problem to diagnose, treatment may require a multidisciplinary approach involving several specialties. These will include the Otolaryngologist, Neurologist, Neurosurgeon, Cardiologist, Primary Care Physician, audiologist, and physical therapist. Although there are benign causes of vertigo, it can be the sign of a serious illness. If you have these symptoms, please contact your physician as soon as possible.