The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform

Patrick F. Chinnery - One of the best experts on this subject based on the ideXlab platform.

  • Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6.
    Journal of Neurology, 2009
    Co-Authors: Gráinne S. Gorman, David E. Bateman, R. John Leigh, Patrick F. Chinnery
    Abstract:

    Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4. Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel Goggles.

  • Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6
    Journal of Neurology, 2009
    Co-Authors: Grainne Gorman, David E. Bateman, R. John Leigh, Patrick F. Chinnery
    Abstract:

    Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4 . Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel Goggles. Brief, recurrent attacks of vertigo occurred in 13 patients, usually preceding the onset of ataxia. Nystagmus was observed behind Frenzel Goggles in 14 patients, and was induced either during positional testing, or head shaking in 20 patients. Only one patient had findings typical of benign paroxysmal positional vertigo (BPPV). Combined downbeat and horizontal gaze-evoked nystagmus (“side-pocket”) was the most common form, occurring most commonly in supine and head-hanging positions, and following horizontal head-shaking. Nystagmus beating away from the ground (apogeotropic) occurred in 9 patients as they lay on their side. In conclusion, vertigo and abnormalities on bedside vestibular examination are common in SCA6, with forms of nystagmus typical of cerebellar, rather than labyrinthine, disease. These findings demonstrate phenotypic overlap between SCA6 and episodic ataxia type 2, which are both due to mutations in CACNL1A4 .

Grainne Gorman - One of the best experts on this subject based on the ideXlab platform.

  • Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6
    Journal of Neurology, 2009
    Co-Authors: Grainne Gorman, David E. Bateman, R. John Leigh, Patrick F. Chinnery
    Abstract:

    Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4 . Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel Goggles. Brief, recurrent attacks of vertigo occurred in 13 patients, usually preceding the onset of ataxia. Nystagmus was observed behind Frenzel Goggles in 14 patients, and was induced either during positional testing, or head shaking in 20 patients. Only one patient had findings typical of benign paroxysmal positional vertigo (BPPV). Combined downbeat and horizontal gaze-evoked nystagmus (“side-pocket”) was the most common form, occurring most commonly in supine and head-hanging positions, and following horizontal head-shaking. Nystagmus beating away from the ground (apogeotropic) occurred in 9 patients as they lay on their side. In conclusion, vertigo and abnormalities on bedside vestibular examination are common in SCA6, with forms of nystagmus typical of cerebellar, rather than labyrinthine, disease. These findings demonstrate phenotypic overlap between SCA6 and episodic ataxia type 2, which are both due to mutations in CACNL1A4 .

R. John Leigh - One of the best experts on this subject based on the ideXlab platform.

  • Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6.
    Journal of Neurology, 2009
    Co-Authors: Gráinne S. Gorman, David E. Bateman, R. John Leigh, Patrick F. Chinnery
    Abstract:

    Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4. Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel Goggles.

  • Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6
    Journal of Neurology, 2009
    Co-Authors: Grainne Gorman, David E. Bateman, R. John Leigh, Patrick F. Chinnery
    Abstract:

    Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4 . Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel Goggles. Brief, recurrent attacks of vertigo occurred in 13 patients, usually preceding the onset of ataxia. Nystagmus was observed behind Frenzel Goggles in 14 patients, and was induced either during positional testing, or head shaking in 20 patients. Only one patient had findings typical of benign paroxysmal positional vertigo (BPPV). Combined downbeat and horizontal gaze-evoked nystagmus (“side-pocket”) was the most common form, occurring most commonly in supine and head-hanging positions, and following horizontal head-shaking. Nystagmus beating away from the ground (apogeotropic) occurred in 9 patients as they lay on their side. In conclusion, vertigo and abnormalities on bedside vestibular examination are common in SCA6, with forms of nystagmus typical of cerebellar, rather than labyrinthine, disease. These findings demonstrate phenotypic overlap between SCA6 and episodic ataxia type 2, which are both due to mutations in CACNL1A4 .

David E. Bateman - One of the best experts on this subject based on the ideXlab platform.

  • Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6.
    Journal of Neurology, 2009
    Co-Authors: Gráinne S. Gorman, David E. Bateman, R. John Leigh, Patrick F. Chinnery
    Abstract:

    Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4. Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel Goggles.

  • Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6
    Journal of Neurology, 2009
    Co-Authors: Grainne Gorman, David E. Bateman, R. John Leigh, Patrick F. Chinnery
    Abstract:

    Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4 . Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel Goggles. Brief, recurrent attacks of vertigo occurred in 13 patients, usually preceding the onset of ataxia. Nystagmus was observed behind Frenzel Goggles in 14 patients, and was induced either during positional testing, or head shaking in 20 patients. Only one patient had findings typical of benign paroxysmal positional vertigo (BPPV). Combined downbeat and horizontal gaze-evoked nystagmus (“side-pocket”) was the most common form, occurring most commonly in supine and head-hanging positions, and following horizontal head-shaking. Nystagmus beating away from the ground (apogeotropic) occurred in 9 patients as they lay on their side. In conclusion, vertigo and abnormalities on bedside vestibular examination are common in SCA6, with forms of nystagmus typical of cerebellar, rather than labyrinthine, disease. These findings demonstrate phenotypic overlap between SCA6 and episodic ataxia type 2, which are both due to mutations in CACNL1A4 .

S. Schmerber - One of the best experts on this subject based on the ideXlab platform.

  • The Skull Vibration-Induced Nystagmus Test of Vestibular Function—A Review
    Frontiers in Neurology, 2017
    Co-Authors: Georges Dumas, P. Perrin, Ian S. Curthoys, Alexis Lion, S. Schmerber
    Abstract:

    A 100 Hz bone conducted vibration (BCV) applied to either mastoid induces instantaneously a predominantly horizontal nystagmus, with quick phases beating away from the affected side in patients with a unilateral vestibular loss (UVL). The same stimulus in healthy asymptomatic subjects has little or no effect. This is skull vibration induced nystagmus (SVIN) and it is a useful, simple, non-invasive, robust indicator of asymmetry of vestibular function and the side of the vestibular loss. The nystagmus is precisely stimulus-locked: it starts with stimulation onset and stops at stimulation offset, with no post-stimulation reversal. It is sustained during long stimulus durations; it is reproducible; it beats in the same direction irrespective of which mastoid is stimulated; it shows little or no habituation; it is permanent – even well compensated UVL patients show SVIN. A SVIN is observed under Frenzel-Goggles or videonystagmoscopy and recorded under videonystagmography in absence of visual-fixation and strong sedative drugs. Stimulus frequency, location, and intensity modify the results and a large variability in skull morphology between people can modify the stimulus. SVIN to 100 Hz mastoid stimulation is a robust response. We describe the optimum method of stimulation on the basis of the literature data and testing more than 18,500 patients. Recent neural evidence clarifies which vestibular receptors are stimulated, how they cause the nystagmus, why the same vibration in patients with semicircular canal dehiscence (SCD) cause a nystagmus beating towards the affected ear. This review focuses on the optimal parameters of the stimulus and response of UVL and SCD patients, but also shows how other vestibular dysfunctions affect SVIN. We conclude that the presence of SVIN is a useful indicator of the symmetry of vestibular function between the two ears, but in order to identify which is the affected ear, other information and careful clinical judgement is needed.

  • How to perform the skull vibration-induced nystagmus test (SVINT).
    European Annals of Otorhinolaryngology Head and Neck Diseases, 2016
    Co-Authors: Georges Dumas, P. Perrin, E. Ouedraogo, S. Schmerber
    Abstract:

    Abstract The skull vibration-induced nystagmus test is a robust, nonintrusive and easy to perform test. This test acts as a vestibular Weber test and is performed as a bedside examination. It usually instantaneously reveals vibration-induced nystagmus (VIN) even in long standing or chronic compensated unilateral vestibular lesions. The test requires stimulation at 30, 60 or more efficiently at 100 Hz. The vibrator is applied perpendicularly to the skin on a subject sitting up straight on the right and then the left mastoid (level with external acoustic meatus) and vertex. The VIN can be observed under videonystagmoscopy or Frenzel Goggles. Either the direct tracing or the VIN slow phase velocity can be recorded on a 2D or 3D videonystagmograph. The patients should be relaxed and not treated by strong sedative medications. This rapid first-line test is not influenced by vestibular compensation and usefully complements other tests in the multifrequency evaluation of the vestibule. It acts as a global vestibular test by stimulating both canal and otolithic structures at 100 Hz. It is useful in case of external acoustic meatus or middle ear disease as a substitute for the water caloric test and is preferable in elderly patients with vascular disease or arthritis of the neck to the head-shaking-test or head-impulse-test.