Vertigo or Dizziness?
Very Hazardous Underwater
Whatever the cause, loss of spatial balance sense at depth is extremely hazardous and requires immediate controlled ascent (look at your bubbles to be sure which way is up). If vomiting occurs, leave one side of your regulator in your mouth and throw up out the other side. Don't try to dive any more and seek immediate help from a diving aware ENT physician for a thorough evaluation of your inner ear. Recompression may be a treatment choice if decompression sickness is a strong possibility. The association of hearing loss, ringing in the ear and vertigo in a no-decompression dive suggests round window damage requiring immediate care by an ENT surgeon for repair of a fistula.
Treatment of most vertigo patients is symptomatic, suspension of diving and bed rest. If the vertigo is really bad - the patient cannot get out of bed due to the whirling sensation. Drugs most often used are antihistamines, topical decongestants, topical steroid sprays and antibiotics. Some items in the diver's history may lead to prevention of problems with vertigo: chronic Eustachian tube dysfunction; recent upper respiratory infection; previous barotrauma, either diving or flying; nasal airway obstruction; history of major facial trauma or fractures; any congenital or surgical disease process leading to interference with the palatal muscles; and previous major sinus or ear surgery.
Transient vertigo almost always is due to " alternobaric vertigo " due to unequal middle ear pressures during ascent with resultant unequal vestibular end-organ stimulation. Pressure differences as little as 20 mm Hg can produce this in the chamber. Approximately 15% of all divers have been shown to have experienced this type of vertigo at some time in their diving careers. (Pullen).
This same type of vertigo can be produced by unequal caloric stimulation of the eardrum, as with colder water entering the undermost ear in the prone position. An external ear partially blocked with wax can cause this inequality.
The fact that it can happen every time and is transient and not associated with other symptoms such as deafness or severe pain makes me think that it's not reverse squeeze (pain) or DCS (deafness, tinnitus, nystagmus, vomiting).
The first thing you want to do is to see a "diving aware" physician to check out your ears (canals, eardrums, hearing, Eustachian tubes). If everything checks out OK, then you must consider that alternobaric vertigo is the problem and understand that unequal clearing on ascent is the cause. Treatment is by returning to depth, if only a foot or two, continuing to clear by whatever method you use, and ascending more slowly.
Prevention is the best treatment, by assuring that your Eustachian tubes remain open. Practice of clearing several hours and minutes before descent and the careful use of decongestants can be of some help.
Ernest Campbell, MD, FACS All Rights Reserved.