Alexander A Tarnutzer1, Christopher J Bockisch2, Elena Buffone3, Konrad P Weber4. 1. Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland. Electronic address: alexander.tarnutzer@access.uzh.ch. 2. Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland; Department of Ophthalmology, University Hospital Zurich and University of Zurich, Zurich, Switzerland; Department of Otorhinolaryngology, University Hospital Zurich and University of Zurich, Zurich, Switzerland. 3. Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland. 4. Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland; Department of Ophthalmology, University Hospital Zurich and University of Zurich, Zurich, Switzerland.
Abstract
OBJECTIVES: The video-head-impulse test (vHIT) provides a functional assessment of all six semicircular canals (SCC). Occasionally isolated loss of the posterior canal(s) (ILPC) is diagnosed, though this finding is poorly characterized. Here we assessed how accurate that diagnosis is by measuring the co-occurrence of abnormalities on caloric irrigation, vestibular-evoked myogenic-potentials and audiometry. METHODS: We identified 52 patients with ILPC (unilateral=40, bilateral=12). We determined vHIT-gains and saccade-amplitudes and correlated vHIT-findings with other vestibulo-cochlear tests. RESULTS: The most frequent diagnoses were history of vestibular neuritis (13/52), Menière's disease (12/52) and vertigo/dizziness of unclear origin (13/52). Unilateral ILPC on vHIT was accompanied by a deficient horizontal canal on calorics, saccular and/or utricular deficits ipsilesionally in 33/40 (83%), while ipsilesional hearing-loss was noted in 24/40 (60%). Involvement of other sensors was highest for vestibular schwannoma (100%) and history of vestibular neuritis (92%). Bilateral deficits in ≥1 vestibulo-cochlear sensor(s) were noted in 2/12 cases with bilateral ILPC. CONCLUSIONS: >80% of patients with unilateral ILPC had additional deficits of other parts of the vestibular organ, while this rate was ≤20% for patients with bilateral ILPC. SIGNIFICANCE: Dizzy patients should receive testing of the posterior canals and if abnormalities are observed, additional vestibulo-cochlear testing should be obtained.
OBJECTIVES: The video-head-impulse test (vHIT) provides a functional assessment of all six semicircular canals (SCC). Occasionally isolated loss of the posterior canal(s) (ILPC) is diagnosed, though this finding is poorly characterized. Here we assessed how accurate that diagnosis is by measuring the co-occurrence of abnormalities on caloric irrigation, vestibular-evoked myogenic-potentials and audiometry. METHODS: We identified 52 patients with ILPC (unilateral=40, bilateral=12). We determined vHIT-gains and saccade-amplitudes and correlated vHIT-findings with other vestibulo-cochlear tests. RESULTS: The most frequent diagnoses were history of vestibular neuritis (13/52), Menière's disease (12/52) and vertigo/dizziness of unclear origin (13/52). Unilateral ILPC on vHIT was accompanied by a deficient horizontal canal on calorics, saccular and/or utricular deficits ipsilesionally in 33/40 (83%), while ipsilesional hearing-loss was noted in 24/40 (60%). Involvement of other sensors was highest for vestibular schwannoma (100%) and history of vestibular neuritis (92%). Bilateral deficits in ≥1 vestibulo-cochlear sensor(s) were noted in 2/12 cases with bilateral ILPC. CONCLUSIONS: >80% of patients with unilateral ILPC had additional deficits of other parts of the vestibular organ, while this rate was ≤20% for patients with bilateral ILPC. SIGNIFICANCE: Dizzy patients should receive testing of the posterior canals and if abnormalities are observed, additional vestibulo-cochlear testing should be obtained.
Authors: Sebastien P F JanssensdeVarebeke; Julie Moyaert; Erik Fransen; Britt Bulen; Celine Neesen; Katrien Devroye; Raymond van de Berg; Ronald J E Pennings; Vedat Topsakal; Olivier Vanderveken; Guy Van Camp; Vincent Van Rompaey Journal: Ear Hear Date: 2021 Nov-Dec 01 Impact factor: 3.570