Alternobaric vertigo
Encyclopedia
In aviation
and underwater diving
, alternobaric vertigo is dizziness resulting from unequal pressures being exerted between the ears due to one Eustachian tube
being less patent than the other.
of descent, and/or the effects of nasal decongestant
s. It is due to unequal increase in middle ear
pressures on ascent, is usually mild, and most often cleared by further ascent. When the pressures in both ears reach ambient levels, the stimulus for the dizziness stops. Although most often mild, the vertigo can persist until the diver reaches the surface continuing the unequal pressures, which can damage the inner ear or ear drum.
Alternobaric vertigo is most pronounced when the diver is in the vertical position; the spinning is towards the ear with the higher pressure and tends to develop when the pressures differ by 60 cm of water or more. Ear clearing
may be a remedy. A similar vertigo can also occur as a result of unequal heating stimulation of one inner ear
labyrinth over the other due to diving in a prone position in cold water - the undermost ear being stimulated.
Aviation
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...
and underwater diving
Underwater diving
Underwater diving is the practice of going underwater, either with breathing apparatus or by breath-holding .Recreational diving is a popular activity...
, alternobaric vertigo is dizziness resulting from unequal pressures being exerted between the ears due to one Eustachian tube
Eustachian tube
The Eustachian tube is a tube that links the nasopharynx to the middle ear. It is a part of the middle ear. In adult humans the Eustachian tube is approximately 35 mm long. It is named after the sixteenth-century anatomist Bartolomeo Eustachi...
being less patent than the other.
Causes
This might have occurred due to barotraumaBarotrauma
Barotrauma is physical damage to body tissues caused by a difference in pressure between an air space inside or beside the body and the surrounding fluid...
of descent, and/or the effects of nasal decongestant
Decongestant
A decongestant or nasal decongestant is a type of drug that is used to relieve nasal congestion.-Pharmacology:The vast majority of decongestants act via enhancing norepinephrine and epinephrine or adrenergic activity by stimulating the α-adrenergic receptors...
s. It is due to unequal increase in middle ear
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...
pressures on ascent, is usually mild, and most often cleared by further ascent. When the pressures in both ears reach ambient levels, the stimulus for the dizziness stops. Although most often mild, the vertigo can persist until the diver reaches the surface continuing the unequal pressures, which can damage the inner ear or ear drum.
Alternobaric vertigo is most pronounced when the diver is in the vertical position; the spinning is towards the ear with the higher pressure and tends to develop when the pressures differ by 60 cm of water or more. Ear clearing
Ear clearing
Ear clearing or clearing the ears is any of various maneuvers to equalize the pressure in the middle ear with the outside pressure, by letting air enter along the Eustachian tubes, as this does not always happen automatically when the pressure in the middle ear is lower than the outside pressure...
may be a remedy. A similar vertigo can also occur as a result of unequal heating stimulation of one inner ear
Inner ear
The inner ear is the innermost part of the vertebrate ear. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:...
labyrinth over the other due to diving in a prone position in cold water - the undermost ear being stimulated.