Vertigo, Not an Easy Diagnosis

Medical Author: Benjamin C. Wedro, MD, FAAEM
Medical Editor: Melissa Conrad Stöppler, MD

The room spins wildly around, and you become intensely nauseous. No, it's a ride at your local amusement park, not the residual of an all night party, but instead, you are challenged with vertigo. The symptoms are highly unpleasant and incapacitating, and the illness has a variety of causes including:

• trauma to the inner ear,
• stroke, or
• the most common cause, idiopathic, meaning we just don't know.

Balance is complicated. The labyrinth system (the inner ear, see diagram below) has a gyroscope mechanism that tells the brain where the body is in relation to the world. To be in tune with your surroundings, the gyroscope needs to work, and the brain needs to interpret the signals. The labyrinth can get confused (for example, from viral infections or repeated head movements - like using a computer to enter data or cleaning cupboards above your head), or - just because. The cerebellum (the back part of the brain), can misinterpret the signals (for example, due to a tumor or stroke), so vertigo is not a symptom to be taken lightly. Fortunately, with a detailed medical history and physical exam, the doctor should be able to distinguish loss of balance due to an inner ear problem - from incoordination resulting from a brain problem.

Also known as the labyrinth, the inner ear is located deep to the outer ear and middle ear, and is encased within the so-called petrous portion of the temporal bone of the skull. The figure below is a diagram showing the parts of the ear.

Figure 1. Diagram of outer, middle, and inner ear. The outer ear is labeled in the figure and includes the ear canal. The middle ear includes the eardrum (tympanic membrane) and three tiny bones for hearing. The bones are called the hammer (malleus), anvil (incus), and stirrup (stapes) to reflect their shapes. The middle ear connects to the back of the throat by the Eustachian tube. The inner ear (labyrinth) contains the semicircular canals and vestibule for balance, and the cochlea for hearing.

If it is an inner ear problem the treatment may include medications, physical therapy, or both. Vestibular therapy can be highly effective. People unable to move because of vertigo are up and walking in a few minutes after therapy. The downside? This requires a specially trained physical therapist and there aren't many around...yet.

As previously mentioned, diagnosing the cause of vertigo is often difficult. At the American Academy of Emergency Medicine Scientific Assembly I presented a case study in regard to a young woman with neck pain who had visited her local chiropractor for an adjustment. A couple of days later, she showed up in the ER with intense vertigo. The final diagnosis was cerebellar stroke due to tearing of both vertebral arteries in her neck because of her neck manipulation.

The brain has four big arteries that supply it with blood; two carotid arteries in front (right and left) and two vertebral arteries that supply the base of the brain that run in grooves within the vertebral bodies of the neck. This woman had the bone-encased arteries torn, stopping the blood supply to parts of her brain that dealt with coordination and balance.

Chiropractic medicine has its place in the care of patients, and their research has withstood scrutiny to show how effective it is with low back pain, but neck manipulation is a subject that generates great controversy. The Canadian Stroke Consortium and the American Academy of Neurology warn about the dangers of chiropractic neck manipulation. Both groups state that neck manipulation is the leading cause of stroke in people younger than 45, and those who have a stroke are five times more likely to have visited a chiropractor in the previous week than those without. Articles in the Journal of Manipulative and Physiologic Therapeutics, a chiropractic journal, discuss the risk, benefits, and the relative safety of neck manipulation.

Appreciate that while vertigo may seem to be an inconvenience, on occasion it can be a big deal.

References: Canadian Stroke Consortium. American Academy of Neurology. "Dissection, Vertebral Artery"; www.emedicine.com