Sudden Onset HL

Question 1

What is sudden sensorineural hearing loss (SSNHL)?

Answer 1

• 30 dB+ decrease at 3 consecutive frequencies

- Rapid onset: 72 hours or less (usually instantaneous, rapidly progressive)

Question 2

Describe the etiology of SSNL.

Answer 2

• Idiopathic (up 85-90%): ISSNHL
• Identified at initial presentation: 10-15%
• Long-term follow up: 30%

Question 3

What is the presentation of SSNHL?

Answer 3

• AF (primary presenting sx)
• Noticed on awakening
• T in 70% (preceding or concurrent)
• Dizziness in 40-50%

Question 4

What is the prognosis for SSNHL?

Answer 4

• Spontaneous recovery (partial or complete): 32-65%
• Timing (most recovery in first 2 weeks; 90% of all improvement within 4 weeks)
• Medical intervention for known causes and ISSNHL (timing is critical)

Question 5

What variables affect ISSNHL prognosis?

Answer 5

• Severity of loss
• Spontaneous recovery (better prognosis if recover 50% hearing first 2 weeks)
• Association with vertigo at onset
• Age 40 years+

Question 6

What might cause a sudden CHL?

Answer 6

• Occluding cerumen
• Perf
• AOE
• Head trauma

Question 7

What are differential diagnostic considerations: bilateral SSNHL?

Answer 7

• Vascular: bilateral IAA occlusion
• Metabolic
• Autoimmune: Cogan syndrome
• Infectious: Lyme, syphilis, HIV
• Neoplastic: NF2
• Toxic
• Traumatic
• Inflammatory: meningitis

Question 8

What are differential diagnostic considerations: prior episodes of sudden or fluctuating HL?

Answer 8

• Meniere
• AIED
• Cogan syndrome
• Hyperviscosity syndromes
• EVA

Question 9

What are infectious causes of SSNHL?

Answer 9

• Meningitis
• CMV
• Herpes
• Rubella
• Syphilis
• Toxoplasmosis
• HIV
• Rubeola
• Mumps

Question 10

What are differential diagnostic considerations: SHL with focal neurologic findings?

Answer 10

• May be an early sign of second degree stroke
• MS
• Meningitis
• Tumors (VS, CPA)
• Metastasis to the IAV

Question 11

What are other causes of SSNHL?

Answer 11

• Dental surgery
• Genetic predisposition
• Pseudohypoacusis
• Ototoxicity

Question 12

What are some topics regarding patient education on SHL?

Answer 12

• Cause is not readily apparent
• Recovery
• Treatments (limited evidence)
• Watchful waiting as an alternative
• SHL can be frightening
• Audiologic rehabilitation
• Financial concerns

Question 13

Describe corticosteroids as a treatment option for treating SHL.

Answer 13

• Evidence of an inflammatory cell death cascade in ISSNHL which is modified by steroid therapy
• Corticosteroids have efficacy for a variety of causes of HL
• Greatest effects in first 2 weeks
• Little effect after 4-6 weeks
• Can be oral or intratympanic

Question 14

How are outcomes of SHL treatment measured?

Answer 14

• Good: within 10 dB of pre-SHL levels
• Partial: within 50% of pre-SHL levels
• No recover: <50% of recovery of pre-SHL levels

Question 15

What is AIED?

Answer 15

• Autoimmune inner ear disease
• Cochleovestibular system is compromised by ones own immune system
• First clinical evidence 1979 (McCabe)
• Inner ear specific auto-reactive T-cells as mediators of ASNHL

Question 16

Describe the differential diagnosis of ASNHL/AIED.

Answer 16

• Sudden deafness
• Cochlear Meniere disease
• Chronic progressive deafness of adolescence
• Presenile presbycusis
• NIHL
• Recessive hereditary deafness
• Luetic labyrinthitis (syphilis)

Question 17

Describe AIED treatment.

Answer 17

• Corticosteroids
• Trial of oral prednisone X30 and retest hearing
• If hearing improves: taper off steroids with monthly hearing tests
• If hearing declines during, continue at current dose for another month or increase does back up until HL stabilizes
• Total treatment time: 6-12 months

Question 18

Describe AIED therapeutic outcomes.

Answer 18

• Successful taper off corticosteroids and no further hearing problems
• Successful taper with relapse or gradual, progressive HL over years
• Steroid dependent
• Steroid resistant

Question 19

Describe the mechanisms of injury associated with viral causes of HL.

Answer 19

• Direct viral damage to inner ear
• Immune system mediated damage
• Immunocompromise leading to second degree infections

Question 20

Describe the treatment/prevention associated with viral causes of HL.

Answer 20

• Vaccines
• Antivirals
• Amplification

Question 21

Describe the auditory presentation of HIV-induced HL.

Answer 21

• Prevalence: 14-49% have auditory symptoms
• Unilateral or bilateral
• CHL, MHL, or SNHL
• Progressive or sudden
• Tinnitus

Question 22

What are the audiological and vestibular manifestations of acquired measles HL?

Answer 22

• Sudden onset at time of rash
• Bilateral, moderate to profound, permanent SNHL
• OM incidence: 8-25%
• 70% reduced caloric responses in one or both ears

Question 23

What are the audiological and vestibular manifestations of mumps HL?

Answer 23

• HL 4-5 days after onset of symptoms
• Unilateral in 80%
• Most often reversible, but can be permanent
• Reversible vestibular dysfunction (reduced/absent caloric response)

Question 24

What are the audiological and vestibular manifestations of Varicella Zoster Virus HL?

Answer 24

• Painful vesicles (pinna, post auricular, along EAC)
• 1-2 days later facial weakness and otalgia
• 25% develop: hyperacusis, tinnitus, nystagmus, dysequillibrium
• 6% develop SNHL
• Severe vertigo in few

Question 25

What are some bacterial and fungal causes of HL?

Answer 25

• Labyrinthitis
• Meningitis
• Syphilis
• Lyme disease

Question 26

What is labyrinthitis?

Answer 26

• Bacteria and fungi damage to peripheral auditory and vestibular systems through:
• Suppurative labyrinth
• Toxic labyrinthine damage via round window or modiolus
• Purulent exudate or infectious agent

Question 27

What are the audiological and vestibular manifestations of labyrinthitis?

Answer 27

• Acute phase: severe SNHL and vertigo
• HL is permanent
• Vertigo slowly resolves over weeks to months