Reference
Glossary
The working vocabulary of vertigo surgery. Inline dotted terms throughout the chapter link here.
- Canal plugging / occlusion
- Occluding a semicircular-canal lumen to stop pathological endolymph flow — used for SSCD and for intractable posterior-canal BPPV; generally hearing-sparing and longer-lasting than resurfacing.
- Central compensation
- The neuroplastic recalibration by which the brain adapts to unilateral vestibular loss after ablative surgery, restoring balance. It depends on a healthy opposite labyrinth and is accelerated by vestibular rehabilitation.
- Cochlear implantation
- Auditory rehabilitation that can restore hearing after schwannoma surgery or in NF2 when the cochlear nerve is anatomically and functionally intact — not a treatment for vertigo itself.
- Dizziness Handicap Inventory (DHI) · DHI
- A validated questionnaire quantifying the functional, emotional and physical impact of dizziness — used to gauge severity and to measure surgical outcome.
- Endolymphatic sac surgery (ESS) · sac decompression · sac shunt
- Decompression or shunting of the endolymphatic sac for refractory Ménière's disease — the least destructive option, hearing-sparing, with 60–80% vertigo control but debated efficacy.
- Intraoperative neurophysiological monitoring · IONM
- Real-time monitoring of facial-nerve EMG and auditory responses during surgery to protect nerve function — now standard in vestibular and skull-base procedures.
- Labyrinthectomy
- Ablation of the vestibular end-organs through a transmastoid approach — the most reliable vertigo control (>95%) but sacrifices all hearing on that side; reserved for non-serviceable ears.
- Perilymph fistula (PLF)
- An abnormal leak between the perilymphatic space and the middle ear (oval or round window), repaired with a soft-tissue graft. A contested diagnosis with no reliable confirmatory test.
- Serviceable hearing
- Hearing good enough to be worth preserving (often defined as ≤50 dB pure-tone average and ≥50% speech discrimination). It is the pivotal decision axis — serviceable hearing favours hearing-sparing operations; non-serviceable hearing permits ablative ones.
- Superior semicircular canal dehiscence (SSCD) · SCDS
- A bony defect over the superior canal creating a third window — treated surgically by plugging or resurfacing the canal via a middle-fossa or transmastoid approach.
- Third window
- An abnormal opening in the bony labyrinth (as in superior canal dehiscence) that lets sound and pressure energy dissipate, causing sound/pressure-induced vertigo and a low-frequency conductive-type loss.
- Translabyrinthine approach
- A route to the internal auditory canal through the labyrinth, used to resect vestibular schwannomas in ears with non-serviceable hearing — excellent facial-nerve outcomes but sacrifices hearing and balance on that side.
- Vestibular implant
- An emerging neuroprosthesis that delivers motion-encoded electrical stimulation to the vestibular nerve, aiming to restore function in bilateral vestibular loss — analogous to a cochlear implant.
- Vestibular neurectomy · vestibular nerve section
- Selective division of the vestibular nerve, abolishing pathological input while sparing the cochlear nerve — definitive vertigo control (>90%) with hearing preservation, via a middle-fossa or retrosigmoid approach.
- Vestibular schwannoma · acoustic neuroma
- A benign Schwann-cell tumour of the vestibular nerve; large or compressive tumours may need resection (commonly translabyrinthine when hearing is lost), with vestibular rehabilitation afterwards.