B

barotrauma Damage to the structures of the EAR
resulting from the ear’s inability to equalize pres-
sure with abrupt and extreme changes in atmos-
pheric pressure. Such changes most often occur in
situations of sudden altitude change such as air
travel or diving, though also may result from a
sharp blow to the ear that forces a blast of air into
the auditory canal. Any of the three parts of the
ear—outer, middle, and inner—can experience
injury from barotrauma.

• Outer ear barotrauma typically takes the form
  of small, painful blisters and hemorrhages
  along the walls of the auditory canal.


• Middle ear barotrauma commonly includes a
  ruptured TYMPANIC MEMBRANE (eardrum). The
  pressure within the middle ear can become
  intense before the tympanic membrane gives
  way, causing much PAIN. With rupture the pres-
  sure immediately equalizes, though hearing
  ability temporarily diminishes.


• Inner ear barotrauma causes sudden and usu-
  ally significant VERTIGO(extreme dizziness and
  balance disturbances) and HEARING LOSSthat can
  be permanent.

Most outer and middle ear barotrauma heals on
its own. Many ruptured eardrums heal naturally,
though large or irregular tears require surgical
repair (TYMPANOPLASTY). Inner ear barotrauma may
require surgery to repair damaged structures and
may result in permanent functional loss if the
damage is extensive.
Preventive measures to reduce the likelihood of
barotrauma include chewing gum, frequent swal-
lowing, and yawning during activities that involve
changes in barometric pressure such as descending

during air travel. Some people benefit from nasal

decongestant sprays that clear the nasal passages

and eustachian tubes. Recreational divers are at

greatest risk for inner ear barotrauma; pressure

changes are most drastic nearer the surface than

deep in the water.

See also BLISTER; EUSTACHIAN TUBE; HEMORRHAGE.

benign paroxysmal positional vertigo (BPPV) A

disorder of the inner EARin which certain posi-

tions of the head cause sudden and severe, though

brief, episodes of VERTIGO(sensations of spinning

or motion). Many people experience symptoms

upon awakening from sleep, as they roll from one

position to another or tilt their heads. Though the

vertigo episode typically lasts only a few minutes,

it can result in feelings of NAUSEAand dizziness as

well as balance disturbances, that continue for

several hours.

Doctors believe calcifications called otoconia,

small “stones” of calcium carbonate, cause BPPV.

Otoconia occur naturally in the utricle and sac-

cule, two of the structures within the inner ear

that are part of the vestibular system, the body’s

balance mechanisms. When otoconia escape from

the utricle they can enter the semicircular canals,

where they collide with NERVEendings that send

positional messages to the BRAIN. These collisions

overwhelm the messaging network. The otoconia

tend to dissolve in the inner ear fluid over time.

About half the people who develop BPPV

experience head trauma or serious INFECTION, such

as OTITIS(ear infection) or SINUSITIS (sinus infec-

tion), before BPPV symptoms begin, leading doc-

tors to believe that such assaults on the integrity

of the inner ear jars the otoconia out of the

utricle.

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