According to the NIH, 90% of all causes of dizziness can be found through evaluation and 85% of all cases are caused by disturbances in the inner ear.
STATISTICS: Dizziness will occur in 70% of the US population at
some point in their lives. Over 90
million Americans, 17 and older, have already experienced problems related to
dizziness or imbalance. Medical
care costs for patients with dizziness and balance disorders has been estimated
to exceed $20 billion per year.
It’s difficult to diagnose with standard tests: Vestibular Neuritis does
not show up on MRI, CTScan, blood work…, the inner ear is encased in dense bone
and cannot be imaged by otoscope.
“Dizziness” is now the most common complaint of patients over 75 years
old.
Benign
Positional Paroxysmal Vertigo
Most common cause of vertigo
due to Peripheral vestibular disorder; occurs spontaneously but can follow head
trauma, vestibular neuritis, labyrinthitis or ischemia in the distribution of
the anterior vestibular artery.
Brief episodes of vertigo are induced by change in head position, caused
by the incidental displacement of otoconia from the utricle into one of the SemiCircular
Canals (SCC). 39% of etiology is unknown, less than
50 years of age is usually due to mild to severe head trauma, (sports,
amusement rides, falls…), greater than 50 years of age can be related to
infarction, impaired circulation, aging, dehydration.
VESTIBULAR
NEURITIS: 2nd most common
cause of vertigo, due to viral infection (suspect Bell’s Palsy, herpes, cold
sores, shingles, Lymes), swelling may cause permanent damage to the vestibular
nerve. In the acute
phase dizziness is constant and not relieved with positional or visual
fixation. You may have to wait for
acute sx to settle down. The brain
can learn compensation strategies with visual and somatosensory education.
Therapy is not a cure for
a balance disorder, but simply a management technique.
Physical Therapy utilizes a
number of tests to determine the extent of a vestibular deficit and determine
the most appropriate course of treatment.
TESTING:
Visual: oculomotor control of location of fovea.
Gaze
Stability: can the eyes stay still when the pt wants eyes to be still (+sign is
spontaneous nystagmus (central function)
Saccade:
fast accurate eye movement (central function)
Smooth
Pursuit: moves eyes in space (central function)
Vestibular: SCCs detect pitch, yaw, and roll; Saccule detects
vertical movement; utricle detects horizontal movement.
Vestibulo-Occular
Reflex: visual stability during head or body movement, head moves and eyes stay
fixed (peripheral function) i.e. dancer or skater. Head Thrust: abrupt rapid
linear head movement while eyes stay fixed (peripheral test). Dynamic Visual Acuity: reading a
Snellen chart while head is moved.
Vestibulo-Somatic
Reflex: using somatosensory input from extremities for balance with ankle
strategy, hip strategy, step strategy.
Somatosensory: postural control
Static
Control: Rhomberg Test looks at visual dependence with Eyes Open
(EO) and Eyes Closed (EC).
Modified CTSIB: EO and EC, off and on foam.
Dynamic Control: unsolicited gait pattern is most common abnormality with variable BOS, “veering”, “staggering”. “looks a bit drunk.” Fukuda Step Test: progression of Rhomberg with movement now with EO and EC. Dynamic Gait Index: most sensitive to vestibular dysfunction.
Dizziness, feeling lightheaded, foggy, fuzzy, woozy or “medicine head.”
These complaints may be
the result of a VESTIBULAR DISORDER.
Vestibular disorders can
cause disequilibrium presenting as imbalance, unsteadiness, falls, near falls,
staggering, stumbling, veering or lack of “surefootedness.” Vestibular disorders may also be
accompanied by headaches, neck and back pain, increased motion sickness,
nausea, increased sensitivity to noise and bright lights, difficulty with
vision especially in areas of low lighting or full field stimulus (busy
carpets, clutter, busy wallpaper, heavy traffic areas).
GOALS: measurable goals based on objective measures
- resolve BPPV (negative Dix-Hallpike)
- increase gaze stability (Dynamic visual Acuity)
- decrease postural sway (mCTSIB)
- improve balance strategies (stepping)
- improve gait abnormalities (Dynamic Gait Index)
- decrease motion sensitivity (Motion Sensitivity Quotient)
- decrease subjective c/o dizziness (Dizziness Handicap Index)
- independent Home Exercise Program of static, dynamic and ADL-incorporated challenges to the Vestibular system.
Vestibular Rehabilitation Therapy is designed to provide small, controlled doses of movements and activities that provoke dizziness and/or unsteadiness in order to 1) desensitize (habituate) the balance system to the movement and 2) enhance the fine-tuning of the VOR and VSR involved in long-term compensation.
In setting treatment programs, we work with the three-part system: Eyes, Ears, and Feet.
We consider the potential to improve a weak system or the potential for substitution of a stronger system. (You can’t change foot numbness but you can change how they use their feet.)
Progressing challenges helps them develop “patterned responses”.