What is the role of imaging and videos in diagnosing and managing sensorineural hearing loss?

Imaging in Sensorineural Hearing Loss

MRI with dedicated internal auditory canal protocol is the imaging modality of choice for evaluating patients with sensorineural hearing loss, while routine CT scans of the head should not be ordered in the initial evaluation. 1

Diagnostic Approach to Sensorineural Hearing Loss

Initial Assessment

• First distinguish sensorineural hearing loss (SNHL) from conductive hearing loss through history and physical examination 1
• Assess for concerning features that require further evaluation:
  • Bilateral sudden hearing loss
  • Recurrent episodes of sudden hearing loss
  • Focal neurologic findings 1

Audiometric Confirmation

• Obtain audiometry as soon as possible (within 14 days of symptom onset) to confirm SNHL 1
• Pure-tone audiometry is the most accurate method for hearing loss detection 2
• For comprehensive evaluation, combine with:
  • Tympanometry
  • Speech-reception thresholds
  • Word-recognition testing 2

Role of Imaging in SNHL

MRI Evaluation

• MRI with dedicated IAC (internal auditory canal) protocol is the primary imaging modality for evaluating SNHL 1
• Protocol should include:
  • High-resolution 3-D T2-weighted images with submillimeter assessment of fluid-filled inner ear structures
  • Thin sections across the IAC and inner ear
  • Evaluation of the brainstem and thalami 1

When to Use MRI

• MRI should be obtained to evaluate for retrocochlear pathology in patients with SNHL 1
• Particularly important for:
  • Unilateral or asymmetrical SNHL 2
  • Sudden SNHL without identifiable cause 1

What MRI Can Detect

• Signal alterations from inflammation or hemorrhage within cochlear contents
• Neoplasms within cochlear labyrinth or IAC (e.g., vestibular schwannomas)
• Size of vestibular aqueducts
• Abnormalities affecting auditory pathways 1

Contrast Enhancement

• IV contrast may facilitate visualization of inflammatory changes (labyrinthitis, neuritis) and neoplasms
• However, there is insufficient evidence to prove incremental benefit beyond non-contrast MRI IAC protocol 1

What Not to Do

Avoid Routine CT Head

• Strong recommendation against ordering routine CT of the head in the initial evaluation of presumptive SNHL 1
• CT head provides insufficient detail of inner ear structures and has low diagnostic yield for SNHL 1

Avoid Routine Laboratory Tests

• Strong recommendation against obtaining routine laboratory tests in patients with SNHL 1

Avoid Unnecessary Treatments

• Do not routinely prescribe antivirals, thrombolytics, vasodilators, or vasoactive substances 1

Alternative Imaging Options

CT Temporal Bone

• May be useful in specific cases:
  • When MRI cannot be performed
  • To evaluate mixed hearing loss (conductive and sensorineural components)
  • To delineate changes of otosclerosis
  • To assess temporal bone fractures in post-traumatic cases 1

Auditory Brainstem Response (ABR)

• Secondary option when MRI cannot be performed
• Can help evaluate retrocochlear pathology 1

Patient Education and Follow-up

• Educate patients about the natural history of SNHL, benefits/risks of interventions, and limitations of evidence 1
• Obtain follow-up audiometric evaluation at the conclusion of treatment and within 6 months 1
• Counsel patients with residual hearing loss about possible benefits of audiologic rehabilitation 1

Videos in SNHL Management

There is no evidence in the provided guidelines supporting the use of videos in the diagnosis or management of sensorineural hearing loss. The diagnostic approach relies primarily on audiometry and imaging studies, particularly MRI, rather than video-based assessments.