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Smaczny S, Behle L, Kuppe S, Karnath HO, Lindner A. Sustained bias of spatial attention in a 3 T MRI scanner. Sci Rep 2024; 14:12657. [PMID: 38825633 PMCID: PMC11144696 DOI: 10.1038/s41598-024-62981-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/23/2024] [Indexed: 06/04/2024] Open
Abstract
When lying inside a MRI scanner and even in the absence of any motion, the static magnetic field of MRI scanners induces a magneto-hydrodynamic stimulation of subjects' vestibular organ (MVS). MVS thereby not only causes a horizontal vestibular nystagmus but also induces a horizontal bias in spatial attention. In this study, we aimed to determine the time course of MVS-induced biases in both VOR and spatial attention inside a 3 T MRI-scanner as well as their respective aftereffects after participants left the scanner. Eye movements and overt spatial attention in a visual search task were assessed in healthy volunteers before, during, and after a one-hour MVS period. All participants exhibited a VOR inside the scanner, which declined over time but never vanished completely. Importantly, there was also an MVS-induced horizontal bias in spatial attention and exploration, which persisted throughout the entire hour within the scanner. Upon exiting the scanner, we observed aftereffects in the opposite direction manifested in both the VOR and in spatial attention, which were statistically no longer detectable after 7 min. Sustained MVS effects on spatial attention have important implications for the design and interpretation of fMRI-studies and for the development of therapeutic interventions counteracting spatial neglect.
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Affiliation(s)
- Stefan Smaczny
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe Seyler Str. 3, 72076, Tübingen, Germany
| | - Leonie Behle
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe Seyler Str. 3, 72076, Tübingen, Germany
- Tübingen Center for Mental Health, Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Sara Kuppe
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe Seyler Str. 3, 72076, Tübingen, Germany
| | - Hans-Otto Karnath
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe Seyler Str. 3, 72076, Tübingen, Germany.
- Department of Psychology, University of South Carolina, Columbia, SC, 29208, USA.
| | - Axel Lindner
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe Seyler Str. 3, 72076, Tübingen, Germany.
- Tübingen Center for Mental Health, Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany.
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Pogson JM, Shemesh A, Roberts DC, Zee DS, Otero-Milan J, Ward BK. Longer duration entry mitigates nystagmus and vertigo in 7-Tesla MRI. Front Neurol 2023; 14:1255105. [PMID: 38046576 PMCID: PMC10690370 DOI: 10.3389/fneur.2023.1255105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 10/10/2023] [Indexed: 12/05/2023] Open
Abstract
Introduction Patients and technologists commonly describe vertigo, dizziness, and imbalance near high-field magnets, e.g., 7-Tesla (T) magnetic resonance imaging (MRI) scanners. We sought a simple way to alleviate vertigo and dizziness in high-field MRI scanners by applying the understanding of the mechanisms behind magnetic vestibular stimulation and the innate characteristics of vestibular adaptation. Methods We first created a three-dimensional (3D) control systems model of the direct and indirect vestibulo-ocular reflex (VOR) pathways, including adaptation mechanisms. The goal was to develop a paradigm for human participants undergoing a 7T MRI scan to optimize the speed and acceleration of entry into and exit from the MRI bore to minimize unwanted vertigo. We then applied this paradigm from the model by recording 3D binocular eye movements (horizontal, vertical, and torsion) and the subjective experience of eight normal individuals within a 7T MRI. The independent variables were the duration of entry into and exit from the MRI bore, the time inside the MRI bore, and the magnetic field strength; the dependent variables were nystagmus slow-phase eye velocity (SPV) and the sensation of vertigo. Results In the model, when the participant was exposed to a linearly increasing magnetic field strength, the per-peak (after entry into the MRI bore) and post-peak (after exiting the MRI bore) responses of nystagmus SPV were reduced with increasing duration of entry and exit, respectively. There was a greater effect on the per-peak response. The entry/exit duration and peak response were inversely related, and the nystagmus was decreased the most with the 5-min duration paradigm (the longest duration modeled). The experimental nystagmus pattern of the eight normal participants matched the model, with increasing entry duration having the strongest effect on the per-peak response of nystagmus SPV. Similarly, all participants described less vertigo with the longer duration entries. Conclusion Increasing the duration of entry into and exit out of a 7T MRI scanner reduced or eliminated vertigo symptoms and reduced nystagmus peak SPV. Model simulations suggest that central processes of vestibular adaptation account for these effects. Therefore, 2-min entry and 20-s exit durations are a practical solution to mitigate vertigo and other discomforting symptoms associated with undergoing 7T MRI scans. In principle, these findings also apply to different magnet strengths.
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Affiliation(s)
- Jacob M. Pogson
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Neurology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Ari Shemesh
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Ophthalmology, Hadassah Medical Center, Jerusalem, Israel
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, United States
| | - Dale C. Roberts
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Neuroscience, The Johns Hopkins University, Baltimore, MD, United States
| | - David S. Zee
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Neuroscience, The Johns Hopkins University, Baltimore, MD, United States
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Wilmer Eye Institute, The Johns Hopkins University, Baltimore, MD, United States
| | - Jorge Otero-Milan
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, CA, United States
| | - Bryan K. Ward
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Li X, Si L, Song N, Wu Y, Zhang M, Feng Y, Yang X. Characteristics and Possible Mechanisms of Direction-Reversing Nystagmus During Positional Testing in Patients With Benign Paroxysmal Positional Vertigo. Otol Neurotol 2023:00129492-990000000-00323. [PMID: 37400137 DOI: 10.1097/mao.0000000000003928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
OBJECTIVES The occurrence of direction-reversing nystagmus during positional testing in patients with benign paroxysmal positional vertigo (BPPV) is not uncommon. Further in-depth analysis of the characteristics and possible mechanisms of direction-reversing nystagmus will help us to diagnose and treat BPPV more precisely. The study aimed to analyze the incidence and characteristics of direction-reversing nystagmus during positional testing in BPPV patients, evaluate the outcomes of canalith repositioning procedure for these patients, and further explore the possible mechanism of reversal nystagmus in BPPV patients. STUDY DESIGN Retrospective study. SETTING Single-center study. PATIENTS A total of 575 patients with BPPV who visited the Vertigo Clinic of our hospital between April 2017 and June 2021 were enrolled. MAIN OUTCOME MEASURES Dix-Hallpike and supine roll tests were performed. The nystagmus was recorded using videonystagmography. The characteristics of direction-reversing nystagmus and the possible underlying mechanism were analyzed. RESULTS Patients with BPPV who showed reversal nystagmus accounted for 9.39% (54 of 575) of all BPPV patients visiting our hospital during the same period, of which 5.57% (32 of 575) had horizontal semicircular canal BPPV (HC-BPPV), and 3.83% (22 of 575) had posterior semicircular canal BPPV (PC-BPPV). The maximum slow-phase velocities (mSPVs) of the first-phase nystagmus were greater in HC-BPPV and PC-BPPV patients with reversal nystagmus than those without (p = 0.04 and p = 0.01, respectively). In all HC-BPPV and PC-BPPV patients with reversal nystagmus, the mSPV of the first-phase nystagmus was greater than that of the second-phase nystagmus (p < 0.01). The duration of the second-phase nystagmus was longer than 60 seconds in 93.75% (30 of 32) of the HC-BPPV patients and 77.27% (17 of 22) of the PC-BPPV patients (p = 0.107, Fisher exact test). HC-BPPV and PC-BPPV patients with reversal nystagmus both required more than one canalith repositioning procedure compared with those without (HC-BPPV: 75 versus 28.13%, p < 0.001; PC-BPPV: 59.09 versus 13.64%, p = 0.002). CONCLUSIONS The cause of second-phase nystagmus in BPPV patients with direction-reversing nystagmus may be related to the involvement of central adaptation mechanisms secondary to the overpowering mSPV of the first-phase nystagmus.
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Affiliation(s)
- Xiang Li
- Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, PR China
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Lin TF, Mohammadi M, Cullen KE, Chacron MJ, Huang MYY. Optokinetic set-point adaptation functions as an internal dynamic calibration mechanism for oculomotor disequilibrium. iScience 2022; 25:105335. [PMID: 36325052 PMCID: PMC9619307 DOI: 10.1016/j.isci.2022.105335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/06/2022] [Accepted: 10/10/2022] [Indexed: 11/30/2022] Open
Abstract
Experience-dependent brain circuit plasticity underlies various sensorimotor learning and memory processes. Recently, a novel set-point adaptation mechanism was identified that accounts for the pronounced negative optokinetic afternystagmus (OKAN) following a sustained period of unidirectional optokinetic nystagmus (OKN) in larval zebrafish. To investigate the physiological significance of optokinetic set-point adaptation, animals in the current study were exposed to a direction-alternating optokinetic stimulation paradigm that better resembles their visual experience in nature. Our results reveal that not only was asymmetric alternating stimulation sufficient to induce the set-point adaptation and the resulting negative OKAN, but most strikingly, under symmetric alternating stimulation some animals displayed an inherent bias of the OKN gain in one direction, and that was compensated by the similar set-point adaptation. This finding, supported by mathematical modeling, suggests that set-point adaptation allows animals to cope with asymmetric optokinetic behaviors evoked by either external stimuli or innate oculomotor biases. Optokinetic set-point adaptation reflects the temporal integration of visual input Wild-type zebrafish larvae may display innate optokinetic left-right asymmetries The degree of the optokinetic asymmetry among larvae is normally distributed The innate optokinetic asymmetry can be compensated by the set-point adaptation
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Affiliation(s)
- Ting-Feng Lin
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
- Corresponding author
| | - Mohammad Mohammadi
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Kathleen E. Cullen
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, USA
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Kavli Neuroscience Discovery Institute, The Johns Hopkins University, Baltimore, MD, USA
| | | | - Melody Ying-Yu Huang
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
- Corresponding author
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Go CC, Taskin HO, Ahmadi SA, Frazzetta G, Cutler L, Malhotra S, Morgan JI, Flanagin VL, Aguirre GK. Persistent horizontal and vertical, MR-induced nystagmus in resting state Human Connectome Project data. Neuroimage 2022; 255:119170. [PMID: 35367649 DOI: 10.1016/j.neuroimage.2022.119170] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVE Strong magnetic fields from magnetic resonance (MR) scanners induce a Lorentz force that contributes to vertigo and persistent nystagmus. Prior studies have reported a predominantly horizontal direction for healthy subjects in a 7 Tesla (T) MR scanner, with slow phase velocity (SPV) dependent on head orientation. Less is known about vestibular signal behavior for subjects in a weaker, 3T magnetic field, the standard strength used in the Human Connectome Project (HCP). The purpose of this study is to characterize the form and magnitude of nystagmus induced at 3T. METHODS Forty-two subjects were studied after being introduced head-first, supine into a Siemens Prisma 3T scanner. Eye movements were recorded in four separate acquisitions over 20 minutes. A biometric eye model was fitted to the recordings to derive rotational eye position and then SPV. An anatomical template of the semi-circular canals was fitted to the T2 anatomical image from each subject, and used to derive the angle of the B0 magnetic field with respect to the vestibular apparatus. RESULTS Recordings from 37 subjects yielded valid measures of eye movements. The population-mean SPV ± SD for the horizontal component was -1.38 ± 1.27 deg/sec, and vertical component was -0.93 ± 1.44 deg/sec, corresponding to drift movement in the rightward and downward direction. Although there was substantial inter-subject variability, persistent nystagmus was present in half of subjects with no significant adaptation over the 20 minute scanning period. The amplitude of vertical drift was correlated with the roll angle of the vestibular system, with a non-zero vertical SPV present at a 0 degree roll. INTERPRETATION Non-habituating vestibular signals of varying amplitude are present in resting state data collected at 3T.
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Affiliation(s)
- Cammille C Go
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Huseyin O Taskin
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Seyed-Ahmad Ahmadi
- NVIDIA GmbH, Einsteinstraße 172, 81677 Munich, Germany; German Center for Vertigo and Balance Disorders, LMU Klinikum, 81377, Munich, Germany
| | - Giulia Frazzetta
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laura Cutler
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Saguna Malhotra
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jessica Iw Morgan
- Department of Ophthalmology, Scheie Eye Institute, Penn Presbyterian Medical Center, 51 N 39th St, Philadelphia, PA 19104, USA
| | - Virginia L Flanagin
- German Center for Vertigo and Balance Disorders, LMU Klinikum, 81377, Munich, Germany
| | - Geoffrey K Aguirre
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Kim B, Lohman E, Yim J. Effects of stabilizing reversal technique and vestibular rehabilitation exercise on dizziness and balance ability in patients with vestibular neuritis: An observational study. Medicine (Baltimore) 2022; 101:e28740. [PMID: 35089249 PMCID: PMC8797558 DOI: 10.1097/md.0000000000028740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 01/08/2022] [Indexed: 01/05/2023] Open
Abstract
Vestibular neuritis is a common disease of peripheral dizziness. Studies have shown that vestibular rehabilitation exercise (VRE) and proprioceptive neuromuscular facilitation (PNF) are effective to treat the symptoms of vestibular neuritis. However, the effect of VRE and PNF on the balance ability and dizziness in this patient cohort remains unclear.The aim of our observational study was to determine the changes in dizziness and balance ability of patients with vestibular neuritis who participated in the VRE program with stabilizing reversal technique (SRT).The reporting of this study conforms to the STROBE statement. Ten men and women aged ≥ 20 years who were diagnosed with vestibular neuritis were included. Patients performed VRE with SRT for 4 weeks with assistance from a therapist. VRE without SRT can also be performed at home. Dizziness was evaluated using the dizziness handicap inventory (DHI) and visual analog scale (VAS). Balance ability was assessed using the Berg's balance scale (BBS) and timed up and go test (TUG). At pre- and post-exercise, paired t test was performed to compare the within-group differences.After the program, DHI (45.40 ± 6.74 to 21.00 ± 7.07), VAS (5.90 ± 1.20 to 2.80 ± 0.92), BBS (45.10 ± 2.77 to 52.70 ± 1.83), and TUG (15.29 ± 1.13 to 12.06 ± 1.61) scores improved significantly in the VRE program group (P = .05).The VRE program combined with SRT was effective in reducing dizziness and increasing balance ability in patients with vestibular neuritis.
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Affiliation(s)
- Beomryong Kim
- Department of Physical Therapy, Design Hospital, Jeonju, Republic of Korea
- Department of Physical Therapy, The Graduate School of Sahmyook University, Seoul, Republic of Korea
| | - Everett Lohman
- Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma Linda, CA
| | - JongEun Yim
- Department of Physical Therapy, The Graduate School of Sahmyook University, Seoul, Republic of Korea
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Basic framework of the vestibulo-ocular reflex. PROGRESS IN BRAIN RESEARCH 2022; 267:131-153. [DOI: 10.1016/bs.pbr.2021.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Shemesh AA, Kocoglu K, Akdal G, Ala RT, Halmagyi GM, Zee DS, Otero-Millan J. Modeling the interaction among three cerebellar disorders of eye movements: periodic alternating, gaze-evoked and rebound nystagmus. J Comput Neurosci 2021; 49:295-307. [PMID: 34003422 PMCID: PMC9169448 DOI: 10.1007/s10827-021-00790-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 10/21/2022]
Abstract
A woman, age 44, with a positive anti-YO paraneoplastic cerebellar syndrome and normal imaging developed an ocular motor disorder including periodic alternating nystagmus (PAN), gaze-evoked nystagmus (GEN) and rebound nystagmus (RN). During fixation there was typical PAN but changes in gaze position evoked complex, time-varying oscillations of GEN and RN. To unravel the pathophysiology of this unusual pattern of nystagmus, we developed a mathematical model of normal function of the circuits mediating the vestibular-ocular reflex and gaze-holding including their adaptive mechanisms. Simulations showed that all the findings of our patient could be explained by two, small, isolated changes in cerebellar circuits: reducing the time constant of the gaze-holding integrator, producing GEN and RN, and increasing the gain of the vestibular velocity-storage positive feedback loop, producing PAN. We conclude that the gaze- and time-varying pattern of nystagmus in our patient can be accounted for by superposition of one model that produces typical PAN and another model that produces typical GEN and RN, without requiring a new oscillator in the gaze-holding system or a more complex, nonlinear interaction between the two models. This analysis suggest a strategy for uncovering gaze-evoked and rebound nystagmus in the setting of a time-varying nystagmus such as PAN. Our results are also consistent with current ideas of compartmentalization of cerebellar functions for the control of the vestibular velocity-storage mechanism (nodulus and ventral uvula) and for holding horizontal gaze steady (the flocculus and tonsil).
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Affiliation(s)
- Ari A Shemesh
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Koray Kocoglu
- Department of Neurosciences, Institute of Health Sciences, Dokuz Eylül University, İzmir, Turkey
| | - Gülden Akdal
- Department of Neurosciences, Institute of Health Sciences, Dokuz Eylül University, İzmir, Turkey
- Department of Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Rahmi Tümay Ala
- Department of Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - G Michael Halmagyi
- Department of Neurology, Royal Prince Alfred Hospital and University of Sydney, Sydney, Australia
| | - David S Zee
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Departments of Ophthalmology, Otolaryngology-Head and Neck Surgery and Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jorge Otero-Millan
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- School of Optometry, University of California Berkeley, Berkeley, CA, USA.
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Boegle R, Kirsch V, Gerb J, Dieterich M. Modulatory effects of magnetic vestibular stimulation on resting-state networks can be explained by subject-specific orientation of inner-ear anatomy in the MR static magnetic field. J Neurol 2020; 267:91-103. [PMID: 32529576 PMCID: PMC7718185 DOI: 10.1007/s00415-020-09957-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 12/26/2022]
Abstract
Strong static magnetic fields, as used in magnetic resonance imaging (MRI), stimulate the vestibular inner ear leading to a state of imbalance within the vestibular system that causes nystagmus. This magnetic vestibular stimulation (MVS) also modulates fluctuations of resting-state functional MRI (RS-fMRI) networks. MVS can be explained by a Lorentz force model, indicating that MVS is the result of the interaction of the static magnetic field strength and direction (called "B0 magnetic field" in MRI) with the inner ear's continuous endolymphatic ionic current. However, the high variability between subjects receiving MVS (measured as nystagmus slow-phase velocity and RS-fMRI amplitude modulations) despite matching head position, remains to be explained. Furthermore, within the imaging community, an "easy-to-acquire-and-use" proxy accounting for modulatory MVS effects in RS-fMRI fluctuations is needed. The present study uses MRI data of 60 healthy volunteers to examine the relationship between RS-fMRI fluctuations and the individual orientation of inner-ear anatomy within the static magnetic field of the MRI. The individual inner-ear anatomy and orientation were assessed via high-resolution anatomical CISS images and related to fluctuations of RS-fMRI networks previously associated with MVS. More specifically, we used a subject-specific proxy for MVS (pMVS) that corresponds to the orientation of the individual inner-ear anatomy within the static magnetic field direction (also called "z-direction" in MR imaging). We found that pMVS explained a considerable fraction of the total variance in RS-fMRI fluctuations (for instance, from 11% in the right cerebellum up to 36% in the cerebellar vermis). In addition to pMVS, we examined the angle of Reid's plane, as determined from anatomical imaging as an alternative and found that this angle (with the same sinus transformation as for pMVS) explained considerably less variance, e.g., from 2 to 16%. In our opinion, an excess variability due to MVS should generally be addressed in fMRI research analogous to nuisance regression for movement, pulsation, and respiration effects. We suggest using the pMVS parameter to deal with modulations of RS-fMRI fluctuations due to MVS. MVS-induced variance can easily be accounted by using high-resolution anatomical imaging of the inner ear and including the proposed pMVS parameter in fMRI group-level analysis.
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Affiliation(s)
- R Boegle
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität München, Marchioninistraße 15, 81377, Munich, Germany.
- German Center for Vertigo and Balance Disorders DSGZ-IFB LMU, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany.
| | - V Kirsch
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität München, Marchioninistraße 15, 81377, Munich, Germany
- Graduate School of Systemic Neuroscience (GSN), Ludwig-Maximilians-Universität, Munich, Germany
- German Center for Vertigo and Balance Disorders DSGZ-IFB LMU, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - J Gerb
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität München, Marchioninistraße 15, 81377, Munich, Germany
| | - M Dieterich
- Department of Neurology, University Hospital, Ludwig-Maximilians-Universität München, Marchioninistraße 15, 81377, Munich, Germany
- Graduate School of Systemic Neuroscience (GSN), Ludwig-Maximilians-Universität, Munich, Germany
- German Center for Vertigo and Balance Disorders DSGZ-IFB LMU, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
- Munich Cluster for Systems Neurology (Synergy), Munich, Germany
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Kutz DF, Kolb FP, Glasauer S, Straka H. Somatosensory Influence on Platform-Induced Translational Vestibulo-Ocular Reflex in Vertical Direction in Humans. Front Neurol 2020; 11:332. [PMID: 32477240 PMCID: PMC7238866 DOI: 10.3389/fneur.2020.00332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/07/2020] [Indexed: 11/13/2022] Open
Abstract
The vestibulo-ocular reflex (VOR) consists of two components, the rotational VOR (rVOR) elicited by semicircular canal signals and the translational VOR (tVOR) elicited by otolith signals. Given the relevant role of the vertical tVOR in human walking, this study aimed at measuring the time delay of eye movements in relation to whole-body vertical translations in natural standing position. Twenty (13 females and 7 males) healthy, young subjects (mean 25 years) stood upright on a motor-driven platform and were exposed to sinusoidal movements while fixating a LED, positioned at a distance of 50 cm in front of the eyes. The platform motion induced a vertical translation of 2.6 cm that provoked counteracting eye movements similar to self-paced walking. The time differences between platform and eye movements indicated that the subject's timing of the extraocular motor reaction depended on stimulus frequency and number of repetitions. At low stimulus frequencies (<0.8 Hz) and small numbers of repetitions (<3), eye movements were phase advanced or in synchrony with platform movements. At higher stimulus frequencies or continuous stimulation, eye movements were phase lagged by ~40 ms. Interestingly, the timing of eye movements depended on the initial platform inclination. Starting with both feet in dorsiflexion, eye movements preceded platform movements by 137 ms, whereas starting with both feet in plantar flexion eye movement precession was only 19 ms. This suggests a remarkable influence of foot proprioceptive signals on the timing of eye movements, indicating that the dynamics of the vertical tVOR is controlled by somatosensory signals.
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Affiliation(s)
- Dieter F Kutz
- Institute of Human Movement Sciences, Faculty of Behavioral and Social Sciences, Chemnitz University of Technology, Chemnitz, Germany
| | - Florian P Kolb
- Department of Physiological Genomics, Institute of Physiology, Ludwig-Maximilian-University Munich, Munich, Germany
| | - Stefan Glasauer
- Computational Neuroscience, Institute of Medical Technology, Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, Germany
| | - Hans Straka
- Department of Biology II, Ludwig-Maximilians-University Munich, Munich, Germany
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Choi SY, Lee MJ, Oh EH, Choi JH, Choi KD. Short-Term Central Adaptation in Benign Paroxysmal Positional Vertigo. Front Neurol 2020; 11:260. [PMID: 32373046 PMCID: PMC7186433 DOI: 10.3389/fneur.2020.00260] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/20/2020] [Indexed: 11/14/2022] Open
Abstract
Objective: To elucidate the frequency, underlying mechanisms, and clinical implications of spontaneous reversal of positional nystagmus (SRPN) in benign paroxysmal positional vertigo (BPPV). Methods: We prospectively recruited 182 patients with posterior canal (PC, n = 119) and horizontal canal (HC) BPPV (n = 63) canalolithiasis. We analyzed the maximal slow phase velocity (maxSPV), duration, and time constant (Tc) of positional nystagmus, and compared the measures between groups with and without SRPN. We also compared the treatment outcome between two groups. Results: The frequency of SRPN in PC- and HC-BPPV was 47 and 68%, respectively. The maxSPVs were greater in BPPV with SRPN than without, larger in HC-BPPV than PC-BPPV (114.3 ± 56.8 vs. 57.1 ± 38.1°/s, p < 0.001). The reversed nystagmus last longer in HC-BPPV than PC-BPPV. The Tc of positional nystagmus got shorter in PC-BPPV with SRPN (3.7 ± 1.8 s) than without SRPN (4.5 ± 2.0 s, p = 0.034), while it was longer during contralesional head turning in HC-BPPV with SRPN (14.8 ± 7.5 s) than that of ipsilesional side (7.3 ±2.8 s, p < 0.001). The treatment response did not significantly differ between groups with and without SRPN in both PC- and HC-BPPV (p = 0.378 and p = 0.737, respectively). Conclusion: The SRPN is common in both PC- and HC-BPPV canalolithiasis. The intensity of rotational stimuli may be a major determinant for the development of short-term central adaptation which utilizes the velocity-storage system below a certain velocity limit. The presence of SRPN is not related to treatment outcome in BPPV.
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Affiliation(s)
- Seo-Young Choi
- Department of Neurology, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Myung-Jun Lee
- Department of Neurology, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Eun Hye Oh
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Jae-Hwan Choi
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Kwang-Dong Choi
- Department of Neurology, Pusan National University School of Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
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12
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Ramos BF, Cal R, Carmona S, Weber KP, Zuma e Maia F. Corrective Saccades in Unilateral and Bilateral Vestibular Hypofunction During Slow Rotation Expressed by Visually Enhanced VOR and VOR Suppression: Role of the Cerebellum. THE CEREBELLUM 2019; 20:673-677. [DOI: 10.1007/s12311-019-01066-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Abstract
Essential infantile esotropia (EIE) is often attributed to a primary disturbance within the visual cortex based upon the findings of monocular horizontal optokinetic asymmetry and correlative horizontal motion detection asymmetry. However, these physiologic aberrations conform to what would be observed if the visual cortex secondarily reconfigured itself to the preexisting subcortical optokinetic motion template. This analysis examines the perspective that the measured cortical aberrations can be explained by prolonged subcortical neuroplasticity, leading to a secondary rewiring of cortical motion pathways. Evolutionary evidence indicates that EIE is generated by subcortical ocular motor centers that subserve nasalward optokinesis. These phylogenetically older subcortical visuo-vestibular pathways include the nucleus of the optic tract, accessory optic system, inferior olive, cerebellar flocculus, and vestibular nucleus. In normal humans, the subcortical visual system becomes inactivated after the first few months of infancy. Mutations or other perturbations that prolong subcortical neuroplasticity may create a persistent simultaneous nasalward optokinetic bias in both eyes to generate infantile esotropia.
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14
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Ward BK, Roberts DC, Otero-Millan J, Zee DS. A decade of magnetic vestibular stimulation: from serendipity to physics to the clinic. J Neurophysiol 2019; 121:2013-2019. [PMID: 30969883 DOI: 10.1152/jn.00873.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
For many years, people working near strong static magnetic fields of magnetic resonance imaging (MRI) machines have reported dizziness and sensations of vertigo. The discovery a decade ago that a sustained nystagmus can be observed in all humans with an intact labyrinth inside MRI machines led to a possible mechanism: a Lorentz force occurring in the labyrinth from the interactions of normal inner ear ionic currents and the strong static magnetic fields of the MRI machine. Inside an MRI, the Lorentz force acts to induce a constant deflection of the semicircular canal cupula of the superior and lateral semicircular canals. This inner ear stimulation creates a sensation of rotation, and a constant horizontal/torsional nystagmus that can only be observed when visual fixation is removed. Over time, the brain adapts to both the perception of rotation and the nystagmus, with the perception usually diminishing over a few minutes, and the nystagmus persisting at a reduced level for hours. This observation has led to discoveries about how the central vestibular mechanisms adapt to a constant vestibular asymmetry and is a useful model of set-point adaptation or how homeostasis is maintained in response to changes in the internal milieu or the external environment. We review what is known about the effects of stimulation of the vestibular system with high-strength magnetic fields and how the understanding of the mechanism has been refined since it was first proposed. We suggest future ways that magnetic vestibular stimulation might be used to understand vestibular disease and how it might be treated.
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Affiliation(s)
- Bryan K Ward
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Dale C Roberts
- Department of Neurology, The Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - Jorge Otero-Millan
- Department of Neurology, The Johns Hopkins University School of Medicine , Baltimore, Maryland
| | - David S Zee
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine , Baltimore, Maryland.,Department of Neurology, The Johns Hopkins University School of Medicine , Baltimore, Maryland.,Department of Neuroscience, The Johns Hopkins University School of Medicine , Baltimore, Maryland.,Department of Ophthalmology, The Johns Hopkins University School of Medicine , Baltimore, Maryland
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15
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Ward BK, Zee DS, Roberts DC, Schubert MC, Pérez-Fernández N, Otero-Millan J. Visual Fixation and Continuous Head Rotations Have Minimal Effect on Set-Point Adaptation to Magnetic Vestibular Stimulation. Front Neurol 2019; 9:1197. [PMID: 30723456 PMCID: PMC6349782 DOI: 10.3389/fneur.2018.01197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 12/31/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Strong static magnetic fields such as those in an MRI machine can induce sensations of self-motion and nystagmus. The proposed mechanism is a Lorentz force resulting from the interaction between strong static magnetic fields and ionic currents in the inner ear endolymph that causes displacement of the semicircular canal cupulae. Nystagmus persists throughout an individual's exposure to the magnetic field, though its slow-phase velocity partially declines due to adaptation. After leaving the magnetic field an after effect occurs in which the nystagmus and sensations of rotation reverse direction, reflecting the adaptation that occurred while inside the MRI. However, the effects of visual fixation and of head shaking on this early type of vestibular adaptation are unknown. Methods: Three-dimensional infrared video-oculography was performed in six individuals just before, during (5, 20, or 60 min) and after (4, 15, or 20 min) lying supine inside a 7T MRI scanner. Trials began by entering the magnetic field in darkness followed 60 s later, either by light with visual fixation and head still, or by continuous yaw head rotations (2 Hz) in either darkness or light with visual fixation. Subjects were always placed in darkness 10 or 30 s before exiting the bore. In control conditions subjects remained in the dark with the head still for the entire duration. Results: In darkness with head still all subjects developed horizontal nystagmus inside the magnetic field, with slow-phase velocity partially decreasing over time. An after effect followed on exiting the magnet, with nystagmus in the opposite direction. Nystagmus was suppressed during visual fixation; however, after resuming darkness just before exiting the magnet, nystagmus returned with velocity close to the control condition and with a comparable after effect. Similar after effects occurred with continuous yaw head rotations while in the scanner whether in darkness or light. Conclusions: Visual fixation and sustained head shaking either in the dark or with fixation inside a strong static magnetic field have minimal impact on the short-term mechanisms that attempt to null unwanted spontaneous nystagmus when the head is still, so called VOR set-point adaptation. This contrasts with the critical influence of vision and slippage of images on the retina on the dynamic (gain and direction) components of VOR adaptation.
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Affiliation(s)
- Bryan K Ward
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, MD, United States
| | - David S Zee
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, MD, United States.,Department of Neurology, The Johns Hopkins University, Baltimore, MD, United States.,Department of Neuroscience, The Johns Hopkins University, Baltimore, MD, United States.,Department of Ophthalmology, The Johns Hopkins University, Baltimore, MD, United States
| | - Dale C Roberts
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, MD, United States.,Department of Neurology, The Johns Hopkins University, Baltimore, MD, United States
| | - Michael C Schubert
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, MD, United States.,Department of Physical Medicine and Rehabilitation, The Johns Hopkins University, Baltimore, MD, United States
| | | | - Jorge Otero-Millan
- Department of Neurology, The Johns Hopkins University, Baltimore, MD, United States
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16
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Otero-Millan J, Colpak AI, Kheradmand A, Zee DS. Rebound nystagmus, a window into the oculomotor integrator. PROGRESS IN BRAIN RESEARCH 2019; 249:197-209. [DOI: 10.1016/bs.pbr.2019.04.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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17
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Sadeghpour S, Zee DS, Leigh RJ. Clinical applications of control systems models: The neural integrators for eye movements. PROGRESS IN BRAIN RESEARCH 2019; 248:103-114. [DOI: 10.1016/bs.pbr.2018.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Lin TF, Gerth-Kahlert C, Hanson JVM, Straumann D, Huang MYY. Spontaneous Nystagmus in the Dark in an Infantile Nystagmus Patient May Represent Negative Optokinetic Afternystagmus. Front Neurol 2018; 9:151. [PMID: 29593643 PMCID: PMC5861190 DOI: 10.3389/fneur.2018.00151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/28/2018] [Indexed: 11/13/2022] Open
Abstract
Abnormal projection of the optic nerves to the wrong cerebral hemisphere transforms the optokinetic system from its usual negative feedback loop to a positive feedback loop with characteristic ocular motor instabilities including directional reversal of the optokinetic nystagmus (OKN) and spontaneous nystagmus, which are common features of infantile nystagmus syndrome (INS). Visual input plays a critical role in INS linked to an underlying optic nerve misprojection such as that often seen in albinism. However, spontaneous nystagmus often continues in darkness, making the visual, sensory-driven etiology questionable. We propose that sensorimotor adaptation during the constant nystagmus of patients in the light could account for continuing nystagmus in the dark. The OKN is a stereotyped reflexive eye movement in response to motion in the surround and serves to stabilize the visual image on the retina, allowing high resolution vision. Robust negative optokinetic afternystagmus (negative OKAN), referring to the continuous nystagmus in the dark with opposite beating direction of the preceding OKN, has been identified in various non-foveated animals. In humans, a robust afternystagmus in the same direction as previous smooth-pursuit movements (the eye's continuous tracking and foveation of a moving target) induced by visual stimuli has been known to commonly mask negative OKAN. Some INS patients are often associated with ocular hypopigmentation, foveal hypoplasia, and compromised smooth pursuit. We identified an INS case with negative OKAN in the dark, in contrast to the positive afternystagmus in healthy subjects. We hypothesize that spontaneous nystagmus in the dark in INS patients may be attributable to sensory adaptation in the optokinetic system after a sustained period of spontaneous nystagmus with directional visual input in light.
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Affiliation(s)
- Ting-Feng Lin
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
| | | | - James V M Hanson
- Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland.,Neuroimmunology and Multiple Sclerosis Research, Clinic for Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Dominik Straumann
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Melody Ying-Yu Huang
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich (ZNZ), University of Zurich and ETH Zurich, Zurich, Switzerland
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19
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Zee DS. A neurologist and ataxia: using eye movements to learn about the cerebellum. CEREBELLUM & ATAXIAS 2018; 5:2. [PMID: 29445510 PMCID: PMC5804057 DOI: 10.1186/s40673-018-0081-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 01/25/2018] [Indexed: 11/22/2022]
Abstract
The cerebellum, its normal functions and its diseases, and especially its relation to the control of eye movements, has been at the heart of my academic career. Here I review how this came about, with an emphasis on epiphanies, "tipping points" and the influences of mentors, colleagues and trainees. I set a path for young academicians, both clinicians and basic scientists, with some guidelines for developing a productive and rewarding career in neuroscience.
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Affiliation(s)
- David S. Zee
- Departments of Neurology, Ophthalamology, Otolaryngology-Head and Neck Surgery, and Neuroscience, The Johns Hopkins University School of Medicine, The Johns Hopkins Hospital, Path 2-210, Baltimore, MD 21287 USA
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20
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21
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Noorani I, Carpenter RHS. Not moving: the fundamental but neglected motor function. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160190. [PMID: 28242724 PMCID: PMC5332849 DOI: 10.1098/rstb.2016.0190] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2016] [Indexed: 01/04/2023] Open
Abstract
The function of the motor system in preventing rather than initiating movement is often overlooked. Not only are its highest levels predominantly, and tonically, inhibitory, but in general behaviour it is often intermittent, characterized by relatively short periods of activity separated by longer periods of stillness: for most of the time we are not moving, but stationary. Furthermore, these periods of immobility are not a matter of inhibition and relaxation, but require us to expend almost as much energy as when we move, and they make just as many demands on the central nervous system in controlling their performance. The mechanisms that stop movement and maintain immobility have been a greatly neglected area of the study of the brain. This paper introduces the topics to be examined in this special issue of Philosophical Transactions, discussing the various types of stopping and stillness, the problems that they impose on the motor system, the kinds of neural mechanism that underlie them and how they can go wrong.This article is part of the themed issue 'Movement suppression: brain mechanisms for stopping and stillness'.
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Affiliation(s)
- Imran Noorani
- Department of Physiology, Development and Neuroscience, University of Cambridge CB2 3EG, UK
| | - R H S Carpenter
- Department of Physiology, Development and Neuroscience, University of Cambridge CB2 3EG, UK
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22
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Ward BK, Otero-Millan J, Jareonsettasin P, Schubert MC, Roberts DC, Zee DS. Magnetic Vestibular Stimulation (MVS) As a Technique for Understanding the Normal and Diseased Labyrinth. Front Neurol 2017; 8:122. [PMID: 28424657 PMCID: PMC5380677 DOI: 10.3389/fneur.2017.00122] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 03/15/2017] [Indexed: 12/03/2022] Open
Abstract
Humans often experience dizziness and vertigo around strong static magnetic fields such as those present in an MRI scanner. Recent evidence supports the idea that this effect is the result of inner ear vestibular stimulation and that the mechanism is a magnetohydrodynamic force (Lorentz force) that is generated by the interactions between normal ionic currents in the inner ear endolymph and the strong static magnetic field of MRI machines. While in the MRI, the Lorentz force displaces the cupula of the lateral and anterior semicircular canals, as if the head was rotating with a constant acceleration. If a human subject’s eye movements are recorded when they are in darkness in an MRI machine (i.e., without fixation), there is a persistent nystagmus that diminishes but does not completely disappear over time. When the person exits the magnetic field, there is a transient aftereffect (nystagmus beating in the opposite direction) that reflects adaptation that occurred in the MRI. This magnetic vestibular stimulation (MVS) is a useful technique for exploring set-point adaptation, the process by which the brain adapts to a change in its environment, which in this case is vestibular imbalance. Here, we review the mechanism of MVS, how MVS produces a unique stimulus to the labyrinth that allows us to explore set-point adaptation, and how this technique might apply to the understanding and treatment of vestibular and other neurological disorders.
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Affiliation(s)
- Bryan K Ward
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, MD, USA
| | - Jorge Otero-Millan
- Department of Neurology, The Johns Hopkins University, Baltimore, MD, USA
| | - Prem Jareonsettasin
- Department of Neuroscience, Exeter College, University of Oxford, Oxford, UK
| | - Michael C Schubert
- Department of Neuroscience, Exeter College, University of Oxford, Oxford, UK.,Department of Physical Medicine and Rehabilitation, The Johns Hopkins University, Baltimore, MD, USA
| | - Dale C Roberts
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, MD, USA.,Department of Neurology, The Johns Hopkins University, Baltimore, MD, USA
| | - David S Zee
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, MD, USA.,Department of Neurology, The Johns Hopkins University, Baltimore, MD, USA.,Department of Neuroscience, The Johns Hopkins University, Baltimore, MD, USA.,Department of Ophthalmology, The Johns Hopkins University, Baltimore, MD, USA
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