Central vestibular disorders are vertigo diseases that affect the brain. They are called central because the brain is a major part of the central nervous system. Problems in the inner ear are grouped together as peripheral vertigo because their causes lie outside the brain.
The last post on Wallenberg syndrome described one of these central disorders. Central dizziness arises when nerve fibers from the inner ear traveling through brain tissue become damaged, or when balance neurons located in the brain are damaged or destroyed. There are many diseases that result in progressive damage to the balance portions of the brain, although the underlying cause is not always known. Tumors, strokes, malformations, damage due to aging, autoimmune disorders and trauma can all affect the brain.
Sometimes central vertigo is mistaken for peripheral vertigo, but there are usually clues that indicate a central origin. In peripheral vertigo, things like viral infections of the ear or BPPV, the vertigo is very stereotyped and repetitive. Each spell resembles the others. The symptoms of hearing loss or ringing in the ears can accompany peripheral vertigo. This can help you decide which ear is the problem.
In central vertigo, there are usually other symptoms that seem quite strange. Having vertigo accompanied by numbness, tingling or weakness of half of the face, or half of the body indicates the cause is likely to be central. Developing a large blind spot, sparkling images before the eyes, trouble controlling eye movement or other vision problems are signs that the problem is central. Headaches are another suggestive symptom. Any difficulty with speech, swallowing, or control of the tongue are additional clues.
The cerebellum is a major part of the brain involved in balance and coordination. It is a bun-shaped structure lying just under the two large cerebral hemispheres and behind the brainstem, just above the point where the back of the neck joins the head. Neurons in the cerebellum can become damaged by exposure to toxins, nutritional deficiencies (particularly in alcoholism), because of genetic defects, due to malignancies in other parts of the body, or for unknown reasons. Regardless of the cause, many of the symptoms of cerebellar diseases will be similar.
Typically, the symptoms come on gradually and worsen over time, and causes symptoms similar to drunkenness. Your speech may become slurred and thick, and your hands may be shaky and uncoordinated. You may notice staggering when walking and your feet may need to be splayed widely apart to maintain balance. You may see the room drifting and have trouble focusing while looking off the side or downward; this can cause feelings of spinning in your head. When your eyes are observed, they may show nystagmus, a constant, jerking drift in one direction. Some of these symptoms also occur in inner ear disease, but when vertigo is due to the ear, they usually come in spells lasting no more than a few days at a time, rather than continuously and slowly worsening over weeks to months or years. The longer nystagmus lasts, the more likely it is central rather than peripheral in origin.
Neurologists are the best physicians to treat this form of dizziness. In our next posts we will go over a few other forms of central vertigo.