In auditory brainstem response (ABR), the wave V latency is prolonged by 0.5 ms relative to the contralateral ear. Which parameter, calculated from absolute latencies, is most clinically useful in detecting retrocochlear pathology?

• A Absolute latency of wave I
• B Interpeak interval I–III
• C Absolute amplitude of wave V
• D Interaural wave V latency difference (ILD V) ✓

Explanation

The interaural wave V latency difference (ILD-V) compares absolute wave V latencies between ears. A difference greater than 0.2–0.4 ms (depending on the laboratory) is considered abnormal and is one of the most sensitive indicators of retrocochlear pathology, specifically acoustic neuroma. Interpeak intervals (I–III, III–V, I–V) assess conduction within specific brainstem segments. Absolute amplitude of wave V varies considerably between individuals.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.