In ABR (Auditory Brainstem Response) testing, Wave I originates from the distal portion of the cochlear nerve, and Wave V is the most robust clinically. Which structure generates Wave III?
- A Superior olivary complex (pons) ✓
- B Cochlear nucleus (medulla)
- C Inferior colliculus (midbrain)
- D Medial geniculate body (thalamus)
Correct answer: A. Superior olivary complex (pons)
Explanation
ABR wave generators: Wave I = distal cochlear nerve (near cochlea), Wave II = proximal cochlear nerve / cochlear nucleus, Wave III = superior olivary complex (first point of binaural convergence), Wave IV = lateral lemniscus, Wave V = inferior colliculus. The I-III interpeak interval reflects pontine conduction and is prolonged in brainstem lesions at the level of the caudal pons. The I-V interpeak interval (normally <4.4 ms) is the overall brainstem conduction time.
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.