Vestibular DisordersOzarks Technical Community College

HIS 125

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

An

ato

my

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 Meniere’s disease Benign paroxysmal positional vertigo (BPPV) 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 away vision) and lay down (feet off ground=no proprioceptive cues)

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

Common Audiogram in Meniere’s Disease

In the early stages of Meniere’s, the hearing loss effects only the low frequencies

As the disease progresses, the hearing loss will flatten

Usually results in poor word recognition scores

From: www.hearinglink.org

Meniere’s Disease Cochlear Cross-Section

*Note the displacement of the vestibular

membrane due to the

overabundance of endolymph in

scala media

Hawkelibrary.com

Causes of Meniere’s Disease

Northern, J. Hearing Disorders (3rd ed)

Incidence

2/1000 persons Most commonly unilateral (~75%) 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

Two Subvarieties of Meniere’s Disease Cochlear Meniere’s disease

No vertigo Fluctuating and progressive SNHL Aural fullness/pressure May or may not have tinnitus

Vestibular Meniere’s disease Spells of vertigo No hearing loss May have aural pressure

Meniere’s Treatment

Medication Diuretic/Water pill=reduces fluid buildup in body

Vestibular suppressant Meclizine, valium, dramamine

Steroids Ototoxic medications

Meniere’s Diet Restrict intake of salt, MSG, alcohol, chocolate, caffeine

Surgery Endolymphatic shunt Labyrinthectomy VIII Nerve Section

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

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 usually 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)

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