Otology and Neuro-otology
Core concepts
Master the tono-tympanometric picture of middle-ear disease: a type B flat tympanogram with normal canal volume suggests effusion, while a large canal volume with a type B trace suggests perforation or a patent grommet. Know the Weber/Rinne logic cold: sensorineural loss lateralises to the better ear on Weber; conductive loss to the affected ear, with bone > air on Rinne. For vertigo, anchor each diagnosis to a time course - seconds (BPPV), minutes-to-hours (Ménière), days (vestibular neuritis), progressive (acoustic neuroma).
Traps
Examiners love the HINTS exam in acute vestibular syndrome: a normal head-impulse test with direction-changing nystagmus and skew deviation points to a central cause, not vestibular neuritis. Another trap is confusing superior semicircular canal dehiscence (Tullio phenomenon, pseudoconductive low-frequency loss, supranormal bone conduction) with otosclerosis. Remember cholesteatoma is a clinical diagnosis - an attic retraction pocket with keratin is treated surgically regardless of imaging.
Worked example / rule of thumb
A patient with episodic vertigo, fluctuating low-frequency hearing loss, tinnitus and aural fullness: apply the AAO-HNS Ménière criteria - two or more spontaneous episodes of 20 minutes to 12 hours, audiometrically documented low-to-medium frequency SNHL on the affected side, plus fluctuating aural symptoms. Electrocochleography and MRI are supportive, not diagnostic. Rule of thumb: "20 minutes to 12 hours = Ménière; under 1 minute with positional trigger = BPPV."