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Vestibular disorders


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Vestibular disorders

  1. 1. Vestibular Disorders Ozarks Technical Community College HIS 125
  2. 2. 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
  3. 3. Anatomy
  4. 4. Anatomy of the Vestibular System
  5. 5. 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)
  6. 6. 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
  7. 7. Three Inputs to the Brain  Our brain integrates information from the following systems to help us keep our balance:  Vision  Vestibular  Proprioception (sensors in our feet)
  8. 8. Balance
  9. 9. 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
  10. 10. “Dizziness” is a vague term  Describe how you feel without using the word “dizzy” Swimmy feeling  Lightheaded  Heavy head  Off-balance  Dysequilibrium  VERTIGO 
  11. 11. 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
  12. 12. 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 
  13. 13. 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)
  14. 14. 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 
  15. 15. Common Audiogram in Meniere’s Disease    From: 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
  16. 16. Meniere’s Disease Cochlear Cross-Section *Note the displacement of the vestibular membrane due to the overabundance of endolymph in scala media
  17. 17. Causes of Meniere’s Disease Northern, J. Hearing Disorders (3rd ed)
  18. 18. 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
  19. 19. 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 
  20. 20. Meniere’s Treatment  Medication   Diuretic/Water pill=reduces fluid buildup in body Vestibular suppressant     Steroids Ototoxic medications Meniere’s Diet   Meclizine, valium, dramamine Restrict intake of salt, MSG, alcohol, chocolate, caffeine Surgery    Endolymphatic shunt Labyrinthectomy VIII Nerve Section
  21. 21. 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
  22. 22. 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  Tinnitus Loss
  23. 23. 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
  24. 24. 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 
  25. 25. Migraine-Associated Dizziness  Very common cause of dizziness   May not get a physical headache, but instead the migraine manifests itself as vestibular symptoms (vertigo, ear pressure, tinnitus, nausea)   Approximately 35% of migraine patients have some vestibular syndrome at one time or another Commonly misdiagnosed as Meniere’s disease Commonly accompanied by sound and light sensitivity
  26. 26. 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
  27. 27. 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) 
  28. 28. 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. 
  29. 29. Rotary Chair Testing   Preferred test method for children Cannot provide ear specific information
  30. 30. 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 
  31. 31. 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
  32. 32. 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 