Sudden Onset HL Flashcards
What is sudden sensorineural hearing loss (SSNHL)?
- 30 dB+ decrease at 3 consecutive frequencies
- Rapid onset: 72 hours or less (usually instantaneous, rapidly progressive)
Describe the etiology of SSNL.
- Idiopathic (up 85-90%): ISSNHL
- Identified at initial presentation: 10-15%
- Long-term follow up: 30%
What is the presentation of SSNHL?
- AF (primary presenting sx)
- Noticed on awakening
- T in 70% (preceding or concurrent)
- Dizziness in 40-50%
What is the prognosis for SSNHL?
- 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)
What variables affect ISSNHL prognosis?
- Severity of loss
- Spontaneous recovery (better prognosis if recover 50% hearing first 2 weeks)
- Association with vertigo at onset
- Age 40 years+
What might cause a sudden CHL?
- Occluding cerumen
- Perf
- AOE
- Head trauma
What are differential diagnostic considerations: bilateral SSNHL?
- Vascular: bilateral IAA occlusion
- Metabolic
- Autoimmune: Cogan syndrome
- Infectious: Lyme, syphilis, HIV
- Neoplastic: NF2
- Toxic
- Traumatic
- Inflammatory: meningitis
What are differential diagnostic considerations: prior episodes of sudden or fluctuating HL?
- Meniere
- AIED
- Cogan syndrome
- Hyperviscosity syndromes
- EVA
What are infectious causes of SSNHL?
- Meningitis
- CMV
- Herpes
- Rubella
- Syphilis
- Toxoplasmosis
- HIV
- Rubeola
- Mumps
What are differential diagnostic considerations: SHL with focal neurologic findings?
- May be an early sign of second degree stroke
- MS
- Meningitis
- Tumors (VS, CPA)
- Metastasis to the IAV
What are other causes of SSNHL?
- Dental surgery
- Genetic predisposition
- Pseudohypoacusis
- Ototoxicity
What are some topics regarding patient education on SHL?
- Cause is not readily apparent
- Recovery
- Treatments (limited evidence)
- Watchful waiting as an alternative
- SHL can be frightening
- Audiologic rehabilitation
- Financial concerns
Describe corticosteroids as a treatment option for treating SHL.
- 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
How are outcomes of SHL treatment measured?
- Good: within 10 dB of pre-SHL levels
- Partial: within 50% of pre-SHL levels
- No recover: <50% of recovery of pre-SHL levels
What is AIED?
- 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
Describe the differential diagnosis of ASNHL/AIED.
- Sudden deafness
- Cochlear Meniere disease
- Chronic progressive deafness of adolescence
- Presenile presbycusis
- NIHL
- Recessive hereditary deafness
- Luetic labyrinthitis (syphilis)
Describe AIED treatment.
- 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
Describe AIED therapeutic outcomes.
- Successful taper off corticosteroids and no further hearing problems
- Successful taper with relapse or gradual, progressive HL over years
- Steroid dependent
- Steroid resistant
Describe the mechanisms of injury associated with viral causes of HL.
- Direct viral damage to inner ear
- Immune system mediated damage
- Immunocompromise leading to second degree infections
Describe the treatment/prevention associated with viral causes of HL.
- Vaccines
- Antivirals
- Amplification
Describe the auditory presentation of HIV-induced HL.
- Prevalence: 14-49% have auditory symptoms
- Unilateral or bilateral
- CHL, MHL, or SNHL
- Progressive or sudden
- Tinnitus
What are the audiological and vestibular manifestations of acquired measles HL?
- 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
What are the audiological and vestibular manifestations of mumps HL?
- 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)
What are the audiological and vestibular manifestations of Varicella Zoster Virus HL?
- 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
What are some bacterial and fungal causes of HL?
- Labyrinthitis
- Meningitis
- Syphilis
- Lyme disease
What is labyrinthitis?
- 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
What are the audiological and vestibular manifestations of labyrinthitis?
- Acute phase: severe SNHL and vertigo
- HL is permanent
- Vertigo slowly resolves over weeks to months
