Download - His 120 vestibular disorders
Vestibular DisordersOzarks Technical Community College
HIS 110
The Human Ear
The inner ear/labyrinth houses both the organs of hearing and balance Hearing=cochlea Balance=semicircular canals and otolith
Balance is the ability to maintain the body’s center of gravity over its base of support
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Anatomy of the Vestibular System
Anatomy
•Semicircular Canals• Detect rotation in the different planes• 3 canals
• Superior, Horizontal, Posterior•Otolith Organs: contain otoconia (“ear rocks”) in a gelatinous membrane to stimulate hair cells to detect linear accelerations
• Utricle: horizontal plane (side-to-side)• Saccule: vertical plane (up and down, front to back)
The VOR
Vestibulo-Ocular Reflex stabilizes images on the retina during head
movement by producing an eye movement in the opposite direction of the head movement
This eye movement is called nystagmus Preserves the image on the center of the visual
field head moves right, eyes move left
Three Inputs to the Brain
Our brain integrates information from the following systems to help us keep our balance:Vision VestibularProprioception (sensors in our feet)
Balance
Dizziness
For patients of all ages, the three most common complaints to physicians are: Headache Back Pain Dizziness
Dizziness is the #1 medical complaint in patients over the age of 70
“Dizziness” is a vague term
Describe how you feel without using the word “dizzy” Swimmy feeling Lightheaded Heavy head Off-balance Dysequilibrium VERTIGO
Vertigo
Sensation of spinning Subjective vertigo=the patient feels like they are
spinning Objective vertigo=the patient feels like the room
is spinning
Vertigo is most commonly associated with a true vestibular disorder
A diagnostic conundrum…
LOTS of factors contribute to dizziness Vision Vestibular Musculoskeletal/orthopedic Neurological factors (MS, stroke) Aging Cardiovascular issues Metabolic (diabetes, thyroid, dehydration) Medications Stress/anxiety
Most Common Vestibular Disorders Benign paroxysmal positional vertigo (BPPV) Meniere’s disease Vestibular neuritis Vestibular labyrinthitis Migraine Or, if you are a college student…alcohol!
Alcohol is lighter than blood, so the hair cells float in the endolymph. This causes the “bed spins” when you close your eyes (take aways vision) and lay down (feet off ground=no proprioceptive cues)
BPPV Benign Paroxysmal Positional Vertigo
Most common complaint: “I get dizzy when I roll over in bed”
Due to loose otoconia floating in the semicircular canals
Diagnosed with Dix-Hallpike Test characterized by rotary nystagmus and vertigo which
lasts several seconds Treatment
Canalith repositioning =putting loose otoconia back where they belong
Epley manuever
Meniere’s Disease
Due to cochlear hydrops=overaccumulation of endolymph in the cochlea
Usually characterized by 4 symptoms: Periodic episodes of rotary vertigo or dizziness
(lasts hours to days) Fluctuating, progressive, low-frequency hearing
loss (SNHL) Tinnitus (often a “roar” or “buzz”) A sensation of "fullness" or pressure in the ear
Incidence
0.5 to 7.5/1000 persons Affects men and women equally Most common in the patient’s 40s and 50s
Diagnosed based on case history, audiogram, other specialized tests that look specifically at vestibular function
Meniere’s Treatment
Diuretic/Water pill=reduces fluid buildup in body
Meniere’s Diet Avoid triggers
Low salt, MSG, alcohol, chocolate, caffeine
Steroids Ototoxic medications Endolymphatic shunt labyrinthectomy
Neuritis vs. labyrinthitis
Usually viral inflammation of inner ear cavity Vestibular Neuritis=inflammation of nerve
Sudden onset vertigo (hours to days), nausea, and vomiting
Vestibular Labyrinthitis=inflammation of inner ear/labyrinth Same symptoms as neuritis AND otologic
symptoms Hearing Loss Tinnitus
Treatment for VN or VL
Patient will spontaneously recover after a period of days to weeks
Medications to reduce dizziness and nausea Antibiotics won’t help because this is not
ususally a bacterial infection BPPV is very common after a case of VN or
VL (Epley manuever) For those patient’s that do not recover
spontaneously: VESTIBULAR REHABILITATION
Vestibular Rehabilitation
May be performed by an audiologist More commonly performed by a physical
therapist Aids in compensation of the brain after a
vestibular insult, which makes the patient feel better faster
Uses exercises that result in varying inputs to the visual, vestibular and somatosensory systems
Improves functional balance
Migraine-Associated Dizziness
Very common cause of dizziness Approximately 35% of migraine patients have
some vestibular syndrome at one time or another May not get a physical headache, but instead
the migraine manifests itself as vestibular symptoms (vertigo, ear pressure, tinnitus, nausea) Commonly misdiagnosed as Meniere’s disease
Commonly accompanied by sound and light sensitivity
Other Otologic Conditions that Cause Dizziness Superior Semicircular Canal Dehiscence Perilymph Fistula Vestibular schwannoma/acoustic neuroma
These conditions may result in: Tullio Effect = sound-induced vertigo/nystagmus
Hennebert’s Phenomenon = pressure-induced vertigo/nystagmus
How do we know if vertigo is due to a vestibular weakness? Case History
Onset, duration, ear symptoms, nausea Audiologic and vestibular evaluation
Puretone and immittance audiometry Video- or electro-nystagmography Rotary chair testing Computerized dynamic posturography Vestibular-evoked myogenic potential (VEMP) Electrocochleography (ECoG)
Testing for Vestibular Disorders
The following slides contain “nice to know” information
You will NOT be responsible for learning these assessment tools
Videonystagmography (VNG)
Most common tool to assess vestibular function. Consists of 3 subtests: Oculomotor testing: the patient follows a visual
target with their eyes . Looking for nystagmus and abnormal patterns.
Positional testing: checking for BPPV Caloric testing: irrigate ears with water of calibrated
temperature, which stimulates the horizontal SCC so we can see how well the vestibular system works. The GOLD STANDARD for identifying the affected ear in a vestibular disorder.
Rotary Chair Testing
Preferred test method for children
Cannot provide ear specific information
Computerized Dynamic Posturography
Sensory Organization Test Varying inputs to the 3
systems: vision, vestibular, proprioception
Motor Control Test Measures reaction time to
disturbance of the platform (pulling the rug out from under them)
Assesses fall risk
VEMP (vestibular-evoked myogenic potential)
Loud click sound in test ear and we measure resulting muscle reflex in neck Abnormal VEMP in
patient’s with Meniere’s, perilymph fistula, SSCD
ECoG (electrocochleography)
Loud click in test ear and we record the electrical potential from the cochlea
Abnormal ECoG in pt with Meniere’s, perilymph fistula, SSCD