BAERs Flashcards
What do the different BAER waveforms represent?
ECOLI
- I: Eighth nerve (distal)
- II: Eighth nerve (proximal)/Cochlear nucleus
- III:Olivary nucleus (opposite)
- IV:Lateral lemniscus (large)
- V:Inferior colliculus (upper pons/lower midbrain)
Delayed wave I but all others are normal. Where is the pathology?
Cochlea
Wave I is normal but all other inter-latency distances are increased. Where is the pathology?
The pathology is somewhere between the distal cochlear nerve and the lateral lemniscus
Only wave I is present. All other waves absent. Where is the pathology?
Pathology is somewhere in the retrocochlear region
If the inter-aural latency (of which wave?) is > 0.2 mm, what is the diagnosis (on the slower side?)?
Acoustic neuroma
4 Best uses for BAER?
- Hearing loss in child or neonate (if loss too severe can’t use)
- Malingering
- Acoustic neuroma
- Cochlear vs. retrocochlear lesion
BAERs can be used for IOM of what 3 areas?
- Ears
- 8th cranial nerves
- Brainstem
What 2 patterns are seen on BAEPs with central lesions?
Prolonged I - V interpeak latency
Reduced V/I amplitude ratio
What pattern is seen in a BAEP with peripheral auditory dysfunction?
Prolongation of the absolute latencies of waves I through V with a normal I - V interpeak latency
What are the 3 patterns on BAEP can be seen peripheral auditory dysfunction resulting in severe hearing loss?
Absence of wave I with a delay in the other waveforms absolute latencies
Prolonged latency of all waveforms (a shift to the right)
Absence of all waveforms
At what age is a normal BAEP seen?
2 y/o
What happens to the BAEP after age 60?
Gradual increase in interpeak latencies
Who has shorter BAEP latencies, men or women?
Women
What is the critical delay in BAEP wave V latency during acoustic neuroma surgery?
A delay of 1 ms or > is associated permanent hearing loss
What kind of clicks are used in BAEP clinically?
Rarefaction
