Retrocochlear Disorders

Question 1

Auditory Neuropathy Spectrum Disorder (ANSD)

Answer 1

impaired fxn of the auditory nerve

Symptoms:
Adults-
Hearing loss
Difficulty with speech in noise

Children-
Abnormal birth hx
Delay of speech milestone

Dx:
ART absent
Audio: varies from normal to profound SNHL
OAEs: present but can progress to absent
ABR: absent or highly abormal with CM only

Question 2

Labyrinthitis

Answer 2

Viral inflammation of CN 8

Symptoms:
Possible recent viral infection
Vertigo
Unilateral hearing loss
Tinnitus
Imbalance
Nausea

Dx:
Audio: unilateral SNHL
Tymps: A
ART and OAEs matching audi
VNG

Question 3

Multiple Sclerosis

Answer 3

Autoimmune disease that causes demyelination

Symptoms:
Numbness of extremities
Neural shock during neck mvt
Tremors
Loss of vision/double vision
Speech and swallowing difficulties
Vertigo
Ataxia

Dx:
Type A
Audio: asymmetrical HF SNHL
ARTs and OAEs are consistent with audio
ABR: Possibly abnormal; abnormal morphology, abnormal latency with prolonged with high rates

Question 4

Vestibular Schwannoma

Answer 4

Benign tumor of the vestibular branch (primarily) of CN 8 originating from Schwann cells

Commonly resulting from Neurofibromatosis Type 2

Symptoms:
Gradual changes
Unilateral tinnitus
Progressive unsteadiness and vertigo
Nausea
Possible facial weakness
Possible headaches
Aural fullness
Difficulty on the phone

Dx:
ART: retrocochlear pattern
Reflex decay: Postive
Audio: unilateral SNHL with positive rollover
OAEs: consistent with audio
ABR: prolonged wave V
VNG

Question 5

Type __ tymp is common with retrocochlear pathology

Answer 5

A