Other Vestibular Disorders / Dizziness

Other Vestibular Disorders / Dizziness

Module Summary

Ability to realize that the history is vital and can be very helpful in focusing your workup and ancillary testing such as audiogram, VNG, and imaging can provide helpful information. Multiple therapy modalities are available, including medications, lifestyle management, surgery, and physical therapy. Many patients with vertigo can be helped.

Module Learning Objectives 
  1. Identify the anatomy and physiology of the vestibular system.
  2. Describe the role of examination and diagnostic testing to differentiate cause.
  3. Explain medical treatment.
  4. Recognize the indications for surgical intervention.

 

Embryology

Learning Objectives 

Mesoderm envelopes the otocyst and then forms a cartilaginous otic capsule. Ossification completes by week sixteen. Inner ear is full size at birth. The otic cyst forms the membranous labyrinth.

Anatomy

Learning Objectives 
  1. Describe the three balance canals, each with an ampulla, where the crista ampularis, the sensory element of the canal, lies. Cite that superior and posterior have a common crus on the non-ampullated end.
  2. Recognize that these organs detect head movements and control the vestibular ocular reflex.
  3. Review the otolithic organs, saccule and utricle, lie in the vestibule. Saccule detects vertical acceleration and gravity changes, and utricle detects linear.
  4. Review the superior vestibular nerve innervates the superior canal, superior canal, and the utricle. Inferior vestibular nerve innervates the posterior canal and the saccule. 

 

References 

1. Pearson AA. Developmental Anatomy of the Ear. In: English GM, editor Otolaryngology. Philadelphia: Harper & Row; 1984. p.1-68.

Pathogenesis

Learning Objectives 
  1. Explain that vestibular disorders can occur due to inflammatory processes, trauma, or ototoxicity.
  2. Discuss how inflammatory processes lead to labyrinthitis, thought to be of viral origin.
  3. Review Meniere’s disease, unknown cause leads to dilation of the scala media.
  4. Recognize that ototoxic medication, Amino glycosides, loop diuretic cisplatin can lead to cell damage.
  5. Cite that Gentamicin, Streptomycin and Tobramycin are the most vestibulotoxic aminoglycosides.
  6. Explain that blunt trauma, URIs can lead to development of BPPV more common in women. 
  7. Describe that abnormal stimulation of vestibular system creates a signal and the brain moves the eyes when the head is stable causing nystagmus and vertigo.
  8. Cite that superior semi-circular canal dehiscence can occur over time and leads to vertigo with straining, autophony, and CHL.
  9. Review that thirty five percent of patients over 40 can suffer age related vestibular loss and patients can have an increased risk of falls.

 

References 
  1. Parnes, Lorne S., et al. Diagnosis and management of benign paroxysmal positional vertigo (BPPV). CMAJ. 2003; 169(7): 681–693.
  2. Zhao, Jeff G., et al. Predictive capability of historical data for diagnosis of dizziness. Otology & Neurotology, vol. 32, no. 2, 2011, pp. 284–290.
  3. Dominic Allen, Luis Ribeiro, Qadeer Arshad, and Barry M. Seemungal. Age-related vestibular loss: Current understanding and future research directions. Front Neurol. 2016; 7: 231. 

 

Genetics

Learning Objectives 
  1. Read that there is a small portion of the population with a mitochondrial mutation that make them more susceptible to aminoglycoside ototoxicity.
References 
  1. Casano, Rosaria et al. Inherited susceptibility to aminoglycoside ototoxicity: genetic heterogeneity and clinical implications. Am J Otolaryngol. 1999 May-Jun;20(3):151-6.

Patient Evaluation

Learning Objectives 
  1. Recognize that history may offer clues as to nature. 
  2. Remember to always ask patient to describe the nature of the “dizziness.”
  3. Cite the need for them to describe room spinning vertigo.
  4. Recognize that duration may be a clue. Short episodes are most likely BPPV.
  5. Remember to always ask for associated symptoms including hearing loss and aural fullness.

Examination

  1. Review general otologic exam.
  2. Describe cranial nerve testing with special attention to eye movements.
  3. Explain head thrust from lateral to medial. May use video goggle (VHIT). Looking for correction saccade that would indicate a peripheral lesion.
  4. Describe Dix Hallpike looking for fatigable rotary or lateral nystagmus. Prolonged vertigo can be associated with a cerebellar lesion.
  5. Review postural testing (eyes close tandem Romberg).
References 
  1. Zhao, Jeff G., et al. Predictive Capability of Historical Data for Diagnosis of Dizziness. Otology & Neurotology, vol. 32, no. 2, 2011, p. 284–290.
  2. Minor, Lloyd B. Clinical Manifestations of Superior Semicircular Canal Dehiscence. The Laryngoscope, vol. 115, no. 10, 2005, p. 1717–1727.
  3. Goebel JA. The ten-minute examination of the dizzy patient. Semin Neurol. 2001;21:391-8. 

 

Measurement of Functional Status

Learning Objectives 
  1. Explain how audiograms can be very helpful, especially in inner ear dis orders such as Meniere’s disease.
  2. Recognize that a conductive hearing loss can indicate a superior canal dehiscence.
  3. Cite that a VNG test is helpful in determining if the inner ear is the cause of the imbalance.
  4. Recognize that VNG’s are helpful in delineating peripheral versus central causes of vertigo.
  5. Explain that oVEMP and cVEMP are helpful, especially with superior canal dehiscence.

 

References 
  1. Superior Canal Dehiscence Syndrome and VEMPs: Detection of Hypersensitivity of the Vestibular System to Sound. Vestibular Evoked Myogenic Potential, 2009, p. 73–77.
  2. Gianoli, Gerard J., and James Soileau. Pathophysiology and Diagnosis of Superior Canal Dehiscence. Diagnosis and Treatment of Vestibular Disorders, 2019, pp. 215–227.

 

Imaging

Learning Objectives 
  1. Cite that radiologic studies are not always indicated or helpful.  
  2. Explain that any unilateral signs, such as hearing loss or tinnitus, may require MRI to rule out CPA lesion and are also helpful for any other neurogenic lesion. 
  3. Recognize that a CT is helpful for fractures SC dehiscence. 

 

References 
  1. Jackler RK, Dillon WP. Computed tomography and magnetic resonance imaging of the inner ear. Otolaryngol Head Neck Surg. 1988 Nov;99(5):494-504.

Pathology

Learning Objectives 
  1. Review that no routine pathology is conducted with this inner ear disorder except in the incidence of a lesion, typically a schwannoma.
  2. Cite that the bulk of pathologic knowledge has been obtained through temporal bone banks and the histopathology garnered from the specimens.

 

References 
  1. Cureoglu S, da Costa Monsanto R, Paparella M, Histopathology of meniere’s disease, Oper Tech in Otolaryn. 2016 Volume 27, Issue 4, P. 194–204

Medical Therapies

Learning Objectives 
  1. Explain that many vestibular disorders resolve on their own. BPPV has a high incidence of resolution. Traumatic injuries to the vestibular system usually resolve. 90% of patients will compensate.
  2. Cite that vestibular suppressants such as antihistamine drugs (meclizine) or benzodiazepine (valium) are effective in stopping vertigo.
  3. Discuss that many patients will need antinausea medicines, since there can be stimulation of the reticular formation leading to nausea and vomiting. Medications such as compazine or odansetron are effective.
  4. Explain that physical therapy has also been very effective in many vestibular disorders. Balance training exercises are very helpful for issues such as labyrinthitis or Meniere’s disease.
  5. Recognize that a liberatory maneuver (Epley) is very effective in the treatment if unrelenting. 
  6. Discuss how intratympanic medication such as steroids and gentamicin can be very effective.  Steroids are typically used in the early stages of the disease. Not all Meniere’s patient respond. Gentamicin can be between 85-90% effective as a chemical labyrinthtomy.
References 
  1. Crowson MG, Patki A, Tucci DL. A Systematic Review of Diuretics in the Medical Management of Ménière’s Disease. Otolaryngol Head Neck Surg. 2016 May;154(5):824-34.

Surgical Therapies

Learning Objectives 
  1. Recognize the indications for surgery. Surgery can be very effective for Meniere’s Disease– ELS can be done for hearing fluctuations and vertigo. control; more definitive procedures such as a labyrinthectomy and nerve section can also be very effective. 
  2. Cite that intratympanic gentamicin is also very effective in controlling vertigo in Meniere’s disease.
  3. Repair/resurface Superior Canal Dehiscence can be effective.
  4. Explain that canal plugging for BPPV is not done often due to development of hearing loss. It also does not work well for cupulolithisis.

 

References 
  1. Lustig LR, Carey J. Intratympanic treatment of inner ear disease. Philadelphia: W.B. Saunders Company, 2004.
  2. Mikulec AA, Poe DS. Operative Management of a Posterior Semicircular Canal Dehiscence. Laryngoscope. 2006 Mar;116(3):375-8.

 

Rehabilitation

Learning Objectives 
  1. Explain that vestibular therapy is very helpful after definitive procedures such as nerve section or labyrinthectomy and cite that compensation can take months.
References 
  1. Arnold, Scott A., et al. The Effectiveness of Vestibular Rehabilitation Interventions in Treating Unilateral Peripheral Vestibular Disorders: A Systematic Review. Physiotherapy Research International, vol. 22, no. 3, 2015.
  2. Regrain E, Boyer FC, Chays A. Effectiveness of rehabilitation of balance disorders after a peripheral vestibular: State of the art. Annals of Physical and Rehabilitation Medicine. Volume 56, Supplement 1, October 2013, Page e153

 

Case Studies

  1. A 42 year old female presents with a history of a spinning sensation with straining. Also complains of hearing her voice in her right ear. She denies any barotrauma events. How do you work up this patient’s complaint? 
  2. 52 year old male presents with a second episode of sudden hearing loss in his right ear. He now complains of vertigo episodes that last for at least one hour. Previous MRI with his first episode of sudden hearing loss one year ago was negative. How should you proceed?

Review

Review Questions 
  1. What are the presenting symptoms of BPPV?
  2. What factors exacerbate vertigo?
  3. What is the first step in management of acute vertigo?
  4. When is surgery indicated for vestibular disorders?