Benign Paroxysmal Positional Vertigo
Benign (non life-threatening) Paroxysmal
(sudden onset) Positional (occurring with certain changes in
head position) Vertigo (dizziness) or "BPPV"
is one of the most common causes of vertigo in adults. The classic symptom
is that of vertigo, the illusion of movement, which occurs within a
few seconds of a position change. Most commonly a brief sensation of
spinning is experienced after lying down in bed, arising
in the morning, or rolling over in bed at night, but may also occur
when one looks up to a high shelf, or down under furniture. Typically,
the symptoms last a minute or so before resolving. To many people, the
BPPV experience is very frightening, and should one observe a person
having this type vertigo, one would witness jerking movements of the eye called
nystagmus. Sometimes these eye movements are in a circular or torsional direction. View a short movie demonstrating nystagmus and a short movie demonstrating circular or torsional nystagmus.
BPPV is due to microscopic crystals, or otoconia, floating around in
one of the compartments of the inner ear. The movement of these particles
stimulate the sensory endings of the vestibular (balance) nerve, producing
vertigo. These crystals arise from the surface of a specialized
membrane in the inner ear and occasionally break loose from that membrane
to float freely in the inner ear and enter the semicircular canals.
Any of the three semi-circular canals can be affected and the changes in position
which precipitate the vertigo, vary according to the canal involved.
For an excellent description of the inner ear, please visit the BCM
web site of Dr. Brownell. 
The
Center for Balance Disorders routinely performs positional tests as
part of the ENG, or electronystagmography, used to evaluate patients
with dizziness.
The good news is that BPPV responds well to physical therapy maneuvers. Medications rarely help. A trained vestibular therapist can perform therapy which can rapidly eliminate the symptoms of dizziness. These maneuvers are designed to relocate the crystals to a part of the inner ear where they will not produce any symptoms. Treatments for BPPV can usually be performed in one or two sessions. Referral for treatment must come from a medical doctor.
It is important to remember that vertigo can be produced by a number of different medical problems, and a thorough evaluation is often necessary to determine the underlying cause. Most otolaryngologists (ear, nose, and throat doctors) are skilled in performing these evaluations. Baylor's otolaryngology head and neck physicians work in the Bobby R. Alford Department of Otolaryngology - Head and Neck Surgery.