Publications by authors named "G Michael Halmagyi"

303 Publications

Clinical, oculographic, and vestibular test characteristics of vestibular migraine.

Cephalalgia 2021 May 2:3331024211006042. Epub 2021 May 2.

Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.

Background: We characterise the history, vestibular tests, ictal and interictal nystagmus in vestibular migraine.

Method: We present our observations on 101 adult-patients presenting to an outpatient facility with recurrent spontaneous and/or positional vertigo whose final diagnosis was vestibular migraine (n = 27) or probable vestibular migraine (n = 74). Ictal and interictal video-oculography, caloric and video head impulse tests, vestibular-evoked myogenic potentials and audiometry were performed.

Results: Common presenting symptoms were headache (81.2%), spinning vertigo (72.3%), Mal de Débarquement (58.4%), and motion sensitivity (30.7%). With fixation denied, ictal and interictal spontaneous nystagmus was observed in 71.3 and 14.9%, and purely positional nystagmus in 25.8 and 55.4%. Spontaneous ictal nystagmus was horizontal in 49.5%, and vertical in 21.8%. Ictal spontaneous and positional nystagmus velocities were 5.3 ± 9.0°/s (range 0.0-57.4), and 10.4 ± 5.8°/s (0.0-99.9). Interictal spontaneous and positional nystagmus velocities were <3°/s in 91.8 and 23.3%. Nystagmus velocities were significantly higher when ictal ( < 0.001/confidence interval: 2.908‒6.733,  < 0.001/confidence interval: 5.308‒10.085). Normal lateral video head impulse test gains were found in 97.8% (mean gain 0.95 ± 0.12) and symmetric caloric results in 84.2% (mean canal paresis 7.0 ± 23.3%). Air- and bone-conducted cervical-vestibular-evoked myogenic potential amplitudes were symmetric in 88.4 and 93.4% (mean corrected amplitude 1.6 ± 0.7, 1.6 ± 0.8) with mean asymmetry ratios of 13.0 and 9.0%. Air- and bone-conducted ocular-vestibular-evoked myogenic potentials were symmetric in 67.7 and 97.2% (mean amplitude 9.2 ± 6.4 and 20.3 ± 12.8 µV) with mean asymmetry ratios of 15.7 and 9.9%. Audiometry was age consistent and symmetric in 85.5%.

Conclusion: Vestibular migraine is characterised by low velocity ictal spontaneous nystagmus, which can be horizontal, vertical, or torsional, and normal audiovestibular test results.
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http://dx.doi.org/10.1177/03331024211006042DOI Listing
May 2021

One Bedside Test - Two Clinical Signs: One Vestibular, The Other Ocular Motor.

Neurology 2021 Apr 23. Epub 2021 Apr 23.

Department of Neurology, Royal Prince Alfred Hospital, University of Sydney, Sydney, Australia.

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http://dx.doi.org/10.1212/WNL.0000000000012080DOI Listing
April 2021

Selective Bilateral Vestibular Neuropathy in a Turkish CMT1B Family With a Novel Mutation.

Neurol Clin Pract 2021 Apr;11(2):e129-e134

Department of Neurology (GA, RTA, İŞŞ) and Department of Neurosciences (GA, KK), Institute of Health Sciences, Department of Medical Genetics (E. Bora, AK, AÜ), Dokuz Eylül University, İzmir, Turkey; Department of Neurology (MB), Mardin State Hospital, Mardin, Turkey; Department of Molecular Biology and Genetics (E. Battaloğlu), Boğaziçi University, İstanbul, Turkey; Hearing, Speech and Balance Unit (GK), Department of Otorhinolaryngology, Dokuz Eylül University, İzmir, Turkey; and Department of Neurology (GMH), Royal Prince Alfred Hospital, University of Sydney, Australia.

Purpose Of Review: To report the findings in 12 members over 3 generations of a family with dominantly inherited Charcot-Marie-Tooth disease (CMT1B) due to a novel mutation, who all had moderately severe selective impairment of vestibular function with normal hearing. Methods used were video head impulse testing of the function of all 6 semicircular canals, Romberg test on foam, nerve conduction studies, and whole exome and Sanger sequencing.

Recent Findings: All affected patients had a demyelinating neuropathy and a novel mutation: c.362A>G (chr1: 161276584, p.D121G). All also had normal hearing for age but a moderately severe impairment of semicircular canal function and a positive Romberg test on foam.

Summary: Some CMT mutations can impair vestibular function, presumably because of a vestibular nerve involvement but spare hearing. In such patients, impairment of vestibular function and impairment of proprioception contribute to imbalance.
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http://dx.doi.org/10.1212/CPJ.0000000000000930DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8032420PMC
April 2021

The Pathology of the Vestibular System in CANVAS.

Otol Neurotol 2021 03;42(3):e332-e340

Otopathology Laboratory, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear.

Objective: To describe the site of lesion responsible for the severe, bilateral, symmetrical, selective loss of vestibular function in Cerebellar Ataxia with Neuronopathy and Vestibular Areflexia Syndrome (CANVAS), an adult-onset recessively-inherited ataxia, characterized by progressive imbalance due to a combination of cerebellar, somatosensory, and selective vestibular impairment with normal hearing.

Methods: Histologic examination of five temporal bones and the brainstems from four CANVAS patients and the brainstem only from one more, each diagnosed and followed from diagnosis to death by one of the clinician authors.

Results: All five temporal bones showed severe loss of vestibular ganglion cells (cell counts 3-16% of normal), and atrophy of the vestibular nerves, whereas vestibular receptor hair cells and the vestibular nuclei were preserved. In contrast, auditory receptor hair cells, the auditory ganglia (cell counts 51-100% of normal), and the auditory nerves were relatively preserved. In addition, the cranial sensory ganglia (geniculate and trigeminal), present in two temporal bones, also showed severe degeneration.

Conclusions: In CANVAS there is a severe cranial sensory ganglionopathy neuronopathy (ganglionopathy) involving the vestibular, facial, and trigeminal ganglia but sparing the auditory ganglia. These observations, when coupled with the known spinal dorsal root ganglionopathy in CANVAS, indicate a shared pathogenesis of its somatosensory and cranial nerve manifestations. This is the first published account of both the otopathology and neuropathology of CANVAS, a disease that involves the central as well as the peripheral nervous system.
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http://dx.doi.org/10.1097/MAO.0000000000002985DOI Listing
March 2021

Pulsatile Tinnitus in Superior Semicircular Canal Dehiscence Cured by Endovascular Coil Occlusion of the Superior Petrosal Sinus.

Otol Neurotol 2021 Jun;42(5):e629-e630

Department of Otorhinolaryngology, Head and Neck Surgery, Royal Prince Alfred Hospital, Sydney, Australia.

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http://dx.doi.org/10.1097/MAO.0000000000003012DOI Listing
June 2021