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Peng K, Moussavi Z, Karunakaran KD, Borsook D, Lesage F, Nguyen DK. iVR-fNIRS: studying brain functions in a fully immersive virtual environment. NEUROPHOTONICS 2024; 11:020601. [PMID: 38577629 PMCID: PMC10993907 DOI: 10.1117/1.nph.11.2.020601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 04/06/2024]
Abstract
Immersive virtual reality (iVR) employs head-mounted displays or cave-like environments to create a sensory-rich virtual experience that simulates the physical presence of a user in a digital space. The technology holds immense promise in neuroscience research and therapy. In particular, virtual reality (VR) technologies facilitate the development of diverse tasks and scenarios closely mirroring real-life situations to stimulate the brain within a controlled and secure setting. It also offers a cost-effective solution in providing a similar sense of interaction to users when conventional stimulation methods are limited or unfeasible. Although combining iVR with traditional brain imaging techniques may be difficult due to signal interference or instrumental issues, recent work has proposed the use of functional near infrared spectroscopy (fNIRS) in conjunction with iVR for versatile brain stimulation paradigms and flexible examination of brain responses. We present a comprehensive review of current research studies employing an iVR-fNIRS setup, covering device types, stimulation approaches, data analysis methods, and major scientific findings. The literature demonstrates a high potential for iVR-fNIRS to explore various types of cognitive, behavioral, and motor functions in a fully immersive VR (iVR) environment. Such studies should set a foundation for adaptive iVR programs for both training (e.g., in novel environments) and clinical therapeutics (e.g., pain, motor and sensory disorders and other psychiatric conditions).
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Affiliation(s)
- Ke Peng
- University of Manitoba, Department of Electrical and Computer Engineering, Price Faculty of Engineering, Winnipeg, Manitoba, Canada
| | - Zahra Moussavi
- University of Manitoba, Department of Electrical and Computer Engineering, Price Faculty of Engineering, Winnipeg, Manitoba, Canada
| | - Keerthana Deepti Karunakaran
- Massachusetts General Hospital, Harvard Medical School, Department of Psychiatry, Boston, Massachusetts, United States
| | - David Borsook
- Massachusetts General Hospital, Harvard Medical School, Department of Psychiatry, Boston, Massachusetts, United States
- Massachusetts General Hospital, Harvard Medical School, Department of Radiology, Boston, Massachusetts, United States
| | - Frédéric Lesage
- University of Montreal, Institute of Biomedical Engineering, Department of Electrical Engineering, Ecole Polytechnique, Montreal, Quebec, Canada
- Montreal Heart Institute, Montreal, Quebec, Canada
| | - Dang Khoa Nguyen
- University of Montreal, Department of Neurosciences, Montreal, Quebec, Canada
- Research Center of the Hospital Center of the University of Montreal, Department of Neurology, Montreal, Quebec, Canada
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2
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Yeo SS, Kim CJ, Yun SH, Son SM, Kim YJ. Effects of Transcranial Direct Current Stimulation on Clinical Features of Dizziness and Cortical Activation in a Patient with Vestibular Migraine. Brain Sci 2024; 14:187. [PMID: 38391761 PMCID: PMC10887163 DOI: 10.3390/brainsci14020187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 02/15/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND Vestibular migraine (VM) is common migraine that occurs in patients with dizziness. Vestibular rehabilitation for managing VM generally remains unclear. Recently, it has been reported that transcranial direct current stimulation (tDCS) has positive effects in alleviating dizziness. This study investigated the effects of tDCS on dizziness and cortical activation in a patient with VM. METHODS We recruited a male patient aged 31 years with no dizziness. The patient watched a video to induce dizziness using a virtual reality device. The study applied the intervention using tDCS for 4 weeks and measured 4 assessments: functional near-infrared spectroscopy (fNIRS), quantitative electroencephalography (qEEG), dizziness handicap inventory, and visual vertigo analog scale. RESULTS We showed the activation in the middle temporal gyrus and inferior temporal gyrus (ITG) of the left hemisphere and in the superior temporal gyrus and ITG of the right hemisphere in the pre-intervention. After the intervention, the activation of these areas decreased. In the results of qEEG, excessive activation of C3, P3, and T5 in the left hemisphere and C4 in the right hemisphere before intervention disappeared after the intervention. CONCLUSIONS This study indicated that tDCS-based intervention could be considered a viable approach to treating patients with vestibular dysfunction and dizziness caused by VM.
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Affiliation(s)
- Sang Seok Yeo
- Department of Physical Therapy, College of Health Sciences, Dankook University, Cheonan-si 31116, Republic of Korea
| | - Chang Ju Kim
- Department of Physical Therapy, College of Health Science, Cheongju University, Cheongju-si 28503, Republic of Korea
| | - Seong Ho Yun
- Department of Health, Graduate School, Dankook University, Cheonan-si 31116, Republic of Korea
| | - Sung Min Son
- Department of Physical Therapy, College of Health Science, Cheongju University, Cheongju-si 28503, Republic of Korea
| | - Yoon Jae Kim
- Department of Health, Graduate School, Dankook University, Cheonan-si 31116, Republic of Korea
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3
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Acuña K, Sapahia R, Jiménez IN, Antonietti M, Anzola I, Cruz M, García MT, Krishnan V, Leveille LA, Resch MD, Galor A, Habash R, DeBuc DC. Functional Near-Infrared Spectrometry as a Useful Diagnostic Tool for Understanding the Visual System: A Review. J Clin Med 2024; 13:282. [PMID: 38202288 PMCID: PMC10779649 DOI: 10.3390/jcm13010282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/24/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
This comprehensive review explores the role of Functional Near-Infrared Spectroscopy (fNIRS) in advancing our understanding of the visual system. Beginning with an introduction to fNIRS, we delve into its historical development, highlighting how this technology has evolved over time. The core of the review critically examines the advantages and disadvantages of fNIRS, offering a balanced view of its capabilities and limitations in research and clinical settings. We extend our discussion to the diverse applications of fNIRS beyond its traditional use, emphasizing its versatility across various fields. In the context of the visual system, this review provides an in-depth analysis of how fNIRS contributes to our understanding of eye function, including eye diseases. We discuss the intricacies of the visual cortex, how it responds to visual stimuli and the implications of these findings in both health and disease. A unique aspect of this review is the exploration of the intersection between fNIRS, virtual reality (VR), augmented reality (AR) and artificial intelligence (AI). We discuss how these cutting-edge technologies are synergizing with fNIRS to open new frontiers in visual system research. The review concludes with a forward-looking perspective, envisioning the future of fNIRS in a rapidly evolving technological landscape and its potential to revolutionize our approach to studying and understanding the visual system.
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Affiliation(s)
- Kelly Acuña
- School of Medicine, Georgetown University, Washington, DC 20007, USA;
| | - Rishav Sapahia
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Irene Newman Jiménez
- Department of Cognitive Science, Faculty of Arts & Science, McGill University, Montreal, QC H4A 3J1, Canada;
| | - Michael Antonietti
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Ignacio Anzola
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Marvin Cruz
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Michael T. García
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Varun Krishnan
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Lynn A. Leveille
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Miklós D. Resch
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary;
| | - Anat Galor
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Ranya Habash
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
| | - Delia Cabrera DeBuc
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (R.S.); (M.A.); (M.T.G.); (V.K.); (L.A.L.); (A.G.)
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Li XX, Yu HY, Li JJ, Liu XL, Zheng HY, Li YF, Li Q, Liu SY. Cross-cultural adaptation and construct validity of the Chinese Version of Visual Vertigo Analogue Scale by using structural equation modeling. J Vestib Res 2024; 34:125-132. [PMID: 38042999 DOI: 10.3233/ves-220102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2023]
Abstract
BACKGROUND Visual vertigo (VV) is a disease characterized by various visual signal-induced discomforts, including dizziness, unsteady balance, activity avoiding, and so forth. Distinguishing it from other kinds of dizziness is important because it needs the combination of visual training and vestibular rehabilitation together. However, there is no appropriate tool to diagnose VV in China, thus we would like to introduce an effective tool to China. OBJECTIVE The aim of this study was to establish the reliability and validity of the Chinese version of visual vertigo analogue scale (VVAS-CH) and to achieve its cross-cultural adaptation in order to promote its further usage in China. METHODS A total of 1681 patients complaining of vertigo or dizziness were enrolled and they were asked to complete the VVAS-CH. The cross-cultural adaptation, reliability and construct validity of the VVAS-CH were determined. RESULTS Split-half reliability was 0.939, showing a good reliability. Factor analysis identified only one common factor for the nine items that explained 64.83% of the total variance. Most fit indices reached acceptable levels, proving the good fit of the VVAS-CH model. CONCLUSIONS The VVAS-CH validated in this study can be used as an effective tool for diagnosing and evaluating VV in patients whose native language is Chinese.
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Affiliation(s)
- Xiao-Xiao Li
- Department of Otolaryngology, Head and Neck Surgery, Nan-fang Hospital, Southern Medical University, Guang-Zhou, Guangdong, China
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Hai-Yun Yu
- Teaching and Researching Section of Physiology, School of Basic Medical Sciences, Southern Medical University, Guang-Zhou, Guangdong, China
| | - Jing-Jing Li
- Department of Otolaryngology, Head and Neck Surgery, Nan-fang Hospital, Southern Medical University, Guang-Zhou, Guangdong, China
- Distinct Health Care, Cheng-Du, Si-Chuan, China
| | - Xiao-Long Liu
- Department of Otolaryngology, Head and Neck Surgery, Nan-fang Hospital, Southern Medical University, Guang-Zhou, Guangdong, China
| | - Hang-Yu Zheng
- Department of Otolaryngology, Head and Neck Surgery, Nan-fang Hospital, Southern Medical University, Guang-Zhou, Guangdong, China
| | - Yan-Fei Li
- Department of Otolaryngology, Head and Neck Surgery, Nan-fang Hospital, Southern Medical University, Guang-Zhou, Guangdong, China
| | - Qi Li
- Department of Otolaryngology, Head and Neck Surgery, Nan-fang Hospital, Southern Medical University, Guang-Zhou, Guangdong, China
| | - Si-Yuan Liu
- Department of Otolaryngology, Head and Neck Surgery, Nan-fang Hospital, Southern Medical University, Guang-Zhou, Guangdong, China
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Li F, Xu J, Liu D, Wang J, Lu L, Gao R, Zhou X, Zhuang J, Zhang S. Optimizing vestibular neuritis management with modular strategies. Front Neurol 2023; 14:1243034. [PMID: 37780705 PMCID: PMC10538530 DOI: 10.3389/fneur.2023.1243034] [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: 06/21/2023] [Accepted: 08/29/2023] [Indexed: 10/03/2023] Open
Abstract
Objective This study proposes a "modular management" approach for vestibular neuritis (VN) to reduce chronicization and improve patient prognosis. The approach involves multi-factor grading and hierarchical intervention and was found to be more effective than traditional treatment strategies. Methods This retrospective analysis compared two groups of VN patients from two medical institutions. The intervention group of 52 patients received "modular management," while the control group of 51 patients did not receive this kind of management. Analyzed the early treatment strategies, 6-month prognosis, and other indicators of the two groups of patients, compared and analyzed their overall prognosis, and identified the risk factors affecting the chronicization. Results The modular management group had lower dizziness severity, better balance, lower anxiety, and higher video head impulse testing (v-HIT) gain after 6 months of onset. Analysis of factors related to persistent postural-perceptual dizziness (PPPD) in patients with VN showed positive correlations between the time from onset to diagnosis and PPPD, and Vertigo Symptom Scale (VSS), Dizziness Handicap Inventory (DHI), anxiety, and depression. Normalized vestibular rehabilitation was negatively correlated with PPPD, while gender, age, and early steroid use had no significant correlation. The multi-factor logistic regression model correctly classified 93.20% of the study subjects with a sensitivity of 87.50% and specificity of 94.90%. Conclusion The proposed "modular management" scheme for VN is a comprehensive and dynamic approach that includes health education, assessment, rehabilitation, therapy, evaluation, and prevention. It can significantly improve patient prognosis and reduce chronicization by shifting from simple acute treatment to continuous management.
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Affiliation(s)
- Fei Li
- Department of Neurology, Second Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Jin Xu
- Department of Neurology, Second Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Dan Liu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Institute of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Wang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Institute of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lingmei Lu
- Department of Neurology, Qidong People's Hospital, Qidong Liver Cancer Institute, Affiliated Qidong Hospital of Nantong University, Qidong, China
| | - Rui Gao
- Department of Neurology, Second Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Xiaowen Zhou
- Department of Neurology, Second Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Jianhua Zhuang
- Department of Neurology, Second Affiliated Hospital of Naval Medical University, Shanghai, China
| | - Sulin Zhang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Institute of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Wibble T, Pansell T. Clinical characteristics of visual motion hypersensitivity: a systematic review. Exp Brain Res 2023:10.1007/s00221-023-06652-3. [PMID: 37341755 DOI: 10.1007/s00221-023-06652-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/11/2023] [Indexed: 06/22/2023]
Abstract
This qualitative systematic review presents an overview of the state of the research relating to visual motion hypersensitivity (VMH) and offers a reference tool for future studies in the field. The study set out to identify and collate articles investigating risk groups with aberrant responses to visual motion as compared to healthy control groups, presenting evidence for risk factors associated with visual motion hypersensitivity. Data were synthesized into the state of the research and analyzed in the context of the clinical characteristics of each risk factor. Literature searches were performed on Medline Ovid, EMBASE, Web of Science, and Cinahl, identifying a total of 586 studies of which 54 were finally included. Original articles published between the dates of commencement for each database and 19th January 2021 were included. JBI critical appraisal tools were implemented for each corresponding article type. In total, the following number of studies was identified for each respective risk factor: age (n = 6), migraines (n = 8), concussions (n = 8), vestibular disorders (n = 13), psychiatric conditions (n = 5), and Parkinson's disease (n = 5). Several studies described VMH as the primary concern (n = 6), though these primarily included patients with vestibulopathies. There were considerable differences in the nomenclature employed to describe VMH, depending largely on the investigating group. An overview of investigated risk factors and their evaluation methods was presented in a Sankey diagram. Posturography was the most implemented methodology but due to diverse measurements meta-analyses were not possible. One may however note that while the easily implemented Vestibular Ocular Motor Screening (VOMS) was designed for concussed patients, it may prove useful for other risk groups.
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Affiliation(s)
- Tobias Wibble
- Department of Clinical Neuroscience, Division of Ophthalmology and Vision, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden.
- St. Erik Eye Hospital, Stockholm, Sweden.
| | - Tony Pansell
- Department of Clinical Neuroscience, Division of Ophthalmology and Vision, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden
- St. Erik Eye Hospital, Stockholm, Sweden
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Castro P, Bancroft MJ, Arshad Q, Kaski D. Persistent Postural-Perceptual Dizziness (PPPD) from Brain Imaging to Behaviour and Perception. Brain Sci 2022; 12:brainsci12060753. [PMID: 35741638 PMCID: PMC9220882 DOI: 10.3390/brainsci12060753] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 12/17/2022] Open
Abstract
Persistent postural-perceptual dizziness (PPPD) is a common cause of chronic dizziness associated with significant morbidity, and perhaps constitutes the commonest cause of chronic dizziness across outpatient neurology settings. Patients present with altered perception of balance control, resulting in measurable changes in balance function, such as stiffening of postural muscles and increased body sway. Observed risk factors include pre-morbid anxiety and neuroticism and increased visual dependence. Following a balance-perturbing insult (such as vestibular dysfunction), patients with PPPD adopt adaptive strategies that become chronically maladaptive and impair longer-term postural behaviour. In this article, we explore the relationship between behavioural postural changes, perceptual abnormalities, and imaging correlates of such dysfunction. We argue that understanding the pathophysiological mechanisms of PPPD necessitates an integrated methodological approach that is able to concurrently measure behaviour, perception, and cortical and subcortical brain function.
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Affiliation(s)
- Patricia Castro
- Neuro-Otology Department, University College London Hospitals, London WC1E 6DG, UK;
- Department of Brain Sciences, Imperial College London, London W6 8RF, UK
- Departamento de Fonoaudiología, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Matthew J. Bancroft
- Centre for Vestibular and Behavioural Neuroscience, Department of Clinical and Movement Neurosciences, Institute of Neurology, University College London, London WC1N 3BG, UK;
| | - Qadeer Arshad
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK;
| | - Diego Kaski
- Neuro-Otology Department, University College London Hospitals, London WC1E 6DG, UK;
- Centre for Vestibular and Behavioural Neuroscience, Department of Clinical and Movement Neurosciences, Institute of Neurology, University College London, London WC1N 3BG, UK;
- Correspondence:
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Powell G, Penacchio O, Derry-Sumner H, Rushton SK, Rajenderkumar D, Sumner P. Visual stress responses to static images are associated with symptoms of Persistent Postural Perceptual Dizziness (PPPD). J Vestib Res 2022; 32:69-78. [PMID: 34151873 DOI: 10.3233/ves-190578] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Images that deviate from natural scene statistics in terms of spatial frequency and orientation content can produce visual stress (also known as visual discomfort), especially for migraine sufferers. These images appear to over-activate the visual cortex. OBJECTIVE To connect the literature on visual discomfort with a common chronic condition presenting in neuro-otology clinics known as persistent postural perceptual dizziness (PPPD). Patients experience dizziness when walking through highly cluttered environments or when watching moving stimuli. This is thought to arise from maladaptive interaction between vestibular and visual signals for balance. METHODS We measured visual discomfort to stationary images in patients with PPPD (N = 30) and symptoms of PPPD in a large general population cohort (N = 1858) using the Visual Vertigo Analogue Scale (VVAS) and the Situational Characteristics Questionnaire (SCQ). RESULTS We found that patients with PPPD, and individuals in the general population with more PPPD symptoms, report heightened visual discomfort to stationary images that deviate from natural spectra (patient comparison, F (1, 1865) = 29, p < 0.001; general population correlations, VVAS, rs (1387) = 0.46, p < 0.001; SCQ, rs (1387) = 0.39, p < 0.001). These findings were not explained by co-morbid migraine. Indeed, PPPD symptoms showed a significantly stronger relationship with visual discomfort than did migraine (VVAS, zH = 8.81, p < 0.001; SCQ, zH = 6.29, p < 0.001). CONCLUSIONS We speculate that atypical visual processing -perhaps due to a visual cortex more prone to over-activation -may predispose individuals to PPPD, possibly helping to explain why some patients with vestibular conditions develop PPPD and some do not.
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Affiliation(s)
- Georgina Powell
- School of Psychology, Cardiff University, Tower building, Park Place, Cardiff, UK
| | - Olivier Penacchio
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
| | - Hannah Derry-Sumner
- Department of Audiovestibular Medicine, University Hospital of Wales, Cardiff, UK
| | - Simon K Rushton
- School of Psychology, Cardiff University, Tower building, Park Place, Cardiff, UK
| | - Deepak Rajenderkumar
- Department of Audiovestibular Medicine, University Hospital of Wales, Cardiff, UK
| | - Petroc Sumner
- School of Psychology, Cardiff University, Tower building, Park Place, Cardiff, UK
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Zhang Y, Lin X, Bi A, Cao N, Zhang T, Wang S, Wen Y, Bi H. Changes in visual cortical function in moderately myopic patients: a functional near-infrared spectroscopy study. Ophthalmic Physiol Opt 2021; 42:36-47. [PMID: 34796534 DOI: 10.1111/opo.12921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 10/07/2021] [Accepted: 10/07/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate haemoglobin oxygenation in the visual cortex of myopic patients using functional near-infrared spectroscopy (fNIRS). METHODS The experiment consisted of two parts. Part 1 examined functional changes in the visual cortex before and after refractive correction in myopic patients. Subjects were divided into normal controls, uncorrected and corrected myopes. Part 2 examined functional changes in the visual cortex caused by lens-induced myopia in normal subjects, and whether this activity recovered after a period of rest. Here, subjects were divided into three groups: emmetropes, lens-induced myopia and a rest group. The rest group completed a test with the uncorrected eye following lens removal and 5 min of rest. The visual stimulus was a black and white checkerboard. fNIRS was used to detect changes in oxyhaemoglobin content within the visual cortex. The original fNIRS data were analysed using MATLAB to obtain the β values (the visual cortical activity response caused by the task); these were used to calculate Δβ, which represents the degree of change in oxygenated haemoglobin caused by visual stimulation. RESULTS The Δβ value measured in each single channel or only in the region of interest (ROI) was significantly higher in the emmetropic control group than the uncorrected myopic group. After optical correction, the responses of myopic subjects approached those of the emmetropes and were not significantly different. If myopia was induced in emmetropic subjects by imposing defocus with positive lenses, a decline in functional activity was observed similar that observed in uncorrected myopes. Activity recovered after the lenses were removed. CONCLUSIONS Myopic defocus reduced the level of haemoglobin oxygenation in the visual cortex, but activity could be restored by optical correction.
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Affiliation(s)
- Ying Zhang
- Shandong University of Traditional Chinese Medicine (TCM), Jinan, China.,Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases, Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of Shandong, Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xiao Lin
- Shandong University of Traditional Chinese Medicine (TCM), Jinan, China.,Affiliated Eye Hospital of Shandong, University of Traditional Chinese Medicine, Jinan, China
| | - Ailing Bi
- Shandong University of Traditional Chinese Medicine (TCM), Jinan, China.,Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases, Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of Shandong, Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, China.,Affiliated Eye Hospital of Shandong, University of Traditional Chinese Medicine, Jinan, China
| | - Ning Cao
- Shandong University of Traditional Chinese Medicine (TCM), Jinan, China.,Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases, Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of Shandong, Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Tingyu Zhang
- Affiliated Eye Hospital of Shandong, University of Traditional Chinese Medicine, Jinan, China
| | - Sha Wang
- Shandong University of Traditional Chinese Medicine (TCM), Jinan, China.,Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases, Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of Shandong, Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Ying Wen
- Shandong University of Traditional Chinese Medicine (TCM), Jinan, China.,Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases, Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of Shandong, Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, China.,Affiliated Eye Hospital of Shandong, University of Traditional Chinese Medicine, Jinan, China
| | - Hongsheng Bi
- Shandong University of Traditional Chinese Medicine (TCM), Jinan, China.,Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases, Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of Shandong, Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, China.,Affiliated Eye Hospital of Shandong, University of Traditional Chinese Medicine, Jinan, China
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10
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Tramontano M, Princi AA, De Angelis S, Indovina I, Manzari L. Vestibular rehabilitation in patients with persistent postural-perceptual dizziness: a scoping review. HEARING, BALANCE AND COMMUNICATION 2021. [DOI: 10.1080/21695717.2021.1975986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Marco Tramontano
- Fondazione Santa Lucia IRCCS, Rome, Italy
- Department of Movement, Human and Health Sciences, Interuniversity Centre of Bioengineering of the Human Neuromusculoskeletal System, University of Rome ‘Foro Italico’, Roma, Italy
| | | | | | - Iole Indovina
- Fondazione Santa Lucia IRCCS, Rome, Italy
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy
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11
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Nazerian R, Korhan O, Shakeri E. A novel cost-effective postural tracking algorithm using marker-based video processing. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2021; 28:1882-1893. [PMID: 34114517 DOI: 10.1080/10803548.2021.1941650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Recently, many postural analysis techniques have been developed in order to reduce the risk of musculoskeletal problems. Methods such as rapid entire body assessment are capable of analyzing the most constant or awkward positions, but the selection of these postures is subjective. To make an objective postural analysis, devices such as electromagnetic trackers can be used continuously during the job task, but utilizing such devices is costly. Therefore, in this study a cost-effective marker-based video processing algorithm is developed for measuring three-dimensional (3D) information regarding both the location and the orientation of human posture. To investigate the precision of the measurements, an experiment was designed. With the average of 2.88 mm and 1.34° for location and orientation, respectively, the algorithm was able to measure six degrees of freedom information regarding 3D space. Furthermore, the precision of the algorithm is found to be significantly affected by the marker pattern.
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Affiliation(s)
- Ramtin Nazerian
- Department of Industrial Engineering, Eastern Mediterranean University, Turkey
| | - Orhan Korhan
- Department of Industrial Engineering, Eastern Mediterranean University, Turkey
| | - Ehsan Shakeri
- Department of Industrial Engineering, Eastern Mediterranean University, Turkey
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12
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Verdecchia DH, Hernandez D, Andreu MF, Salzberg SE, Whitney SL. Validated argentine version of the visual vertigo analogue scale. J Vestib Res 2021; 32:235-243. [PMID: 34308920 DOI: 10.3233/ves-210062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Visual vertigo (VV), triggered by environmental or dynamic visual stimuli and repetitive visual patterns, can affect daily life activities. The Visual Vertigo Analogue Scale (VVAS) is a valid and reliable self-administered questionnaire to assess VV, which has been culturally adapted to the Argentine population but has not been validated. OBJECTIVE To validate the Argentine version of VVAS (VVAS-A) by confirming its psychometric properties in patients with vestibular disorders. METHODS Vestibular patients (n = 82) completed the VVAS-A and the Dizziness Handicap Inventory Argentine version (DHI-A) during their initial visit and one week later. The VVAS-A's internal consistency, test retest reliability, ceiling and floor effects, and construct validity were determined. Test-retest data (n = 71) was used to calculate reliability using the intraclass correlation coefficient (ICC 2.1). RESULTS A ceiling effect was observed in 12 patients (14.6%). Internal consistency was acceptable (Cronbach's alpha: 0.91). The reliability was r = 0.764 [CI 95%: 0.7 -0.86]). Correlations were observed between the VVAS-A and the total DHI-A score (rho = 0.571), the DHI-A physical subscale (rho: 0.578), and DHI-A functional and emotional subscales of the DHI-A (rho: 0.537 and 0.387, respectively). CONCLUSION VVAS-A is a valid, reliable tool to evaluate VV in patients with vestibular disorders.
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Affiliation(s)
- Daniel H Verdecchia
- Physical Therapy Program, Health SciencesDepartment, Universidad Nacional de la Matanza, Buenos Aires, Argentina.,Physical Therapy Program, UniversidadMaimónides, City of Buenos Aires, Argentina.,Physical Therapy Program, Medical School, Universidad de Buenos Aires
| | - Daniel Hernandez
- Physical Therapy Program, Medical School, Universidad de Buenos Aires.,Physical TherapyUnit, Acute Care Hospital "Carlos G. Durand". City of BuenosAires, Argentina
| | - Mauro F Andreu
- Physical Therapy Program, Health SciencesDepartment, Universidad Nacional de la Matanza, Buenos Aires, Argentina
| | - Sandra E Salzberg
- Physical TherapyUnit, Acute Care Hospital "Carlos G. Durand". City of BuenosAires, Argentina
| | - Susan L Whitney
- Departments of Physical Therapyand Otolaryngology, University of Pittsburgh, Pittsburgh, PA, USA
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13
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Neuroimaging studies in persistent postural-perceptual dizziness and related disease: a systematic review. J Neurol 2021; 269:1225-1235. [PMID: 34019178 DOI: 10.1007/s00415-021-10558-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/09/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Persistent Postural-Perceptual Dizziness (PPPD) is one of the most common types of chronic dizziness. The pathogenesis remains unclear. OBJECTIVE This study aimed to systematically review neuroimaging literature for investigating the central mechanism of PPPD and related disorders. METHODS PubMed, EMBASE, Medline, Cochrane, and Web of Science were searched by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The articles analyzing structural and functional neuroimaging features of PPPD and related disorders were selected according to eligibility criteria. RESULTS Fifteen articles, including 4 structural, 10 functional, and 1 multimodal imaging, were eligible for inclusion in this review. The whiter matter alterations in PPPD are not entirely consistent. The changes of grey matter mainly in multisensory vestibular cortices, visual cortex, cerebellum, as well as anxiety-related network. Consistent with structural imaging, functional imaging conducted during the specific tasks or in the resting state has both found abnormal functional activation and connectivity in the vestibular cortex, especially in the parieto-insular vestibular cortex (PIVC), visual cortex, cerebellum, and anxiety-related network in PPPD and related disorder. CONCLUSIONS The current review provides up-to-date knowledge and summarizes the possible central mechanism for PPPD and related disorders, and it is helpful to understanding the mechanism of PPPD.
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Lubetzky AV, Aharoni MMH, Arie L, Krasovsky T. People with persistent postural-perceptual dizziness demonstrate altered postural strategies in complex visual and cognitive environments. J Vestib Res 2021; 31:505-517. [PMID: 33749625 DOI: 10.3233/ves-201552] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND People with PPPD report imbalance, increase in symptoms and impaired function within complex visual environments, but understanding of the mechanism for these behaviors is still lacking. OBJECTIVE To investigate postural control in PPPD we compared changes in center of pressure (COP) and head kinematics of people with PPPD (N = 22) and healthy controls (N = 20) in response to different combinations of visual and cognitive perturbations during a challenging balance task. METHODS Participants stood in a tandem position. Static or moving stars (0.2 Hz, 5 mm or 32 mm amplitude, anterior-posterior direction) were displayed through a head-mounted display (HTC Vive). On half the trials, participants performed a serial-3 subtraction task. We measured medio-lateral and anterior-posterior path and acceleration of COP and head. RESULTS Controls significantly increased all COP and head parameters with the cognitive task whereas PPPD increased only COP ML path and acceleration. Only controls significantly increased head anterior-posterior & medio-lateral acceleration with moving visual load. Cognitive task performance was similar between groups. CONCLUSIONS We observed altered postural strategies in people with PPPD, in the form of reduced movement with challenge, particularly around the head segment. The potential of this simple and portable head-mounted display setup for differential diagnosis of vestibular disorders should be further explored.
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Affiliation(s)
- Anat V Lubetzky
- Department of Physical Therapy, Steinhardt School of Culture Education and Human Development, New York University, New York, NY, USA
| | | | - Liraz Arie
- Department of Physical Therapy, Steinhardt School of Culture Education and Human Development, New York University, New York, NY, USA
| | - Tal Krasovsky
- Department of Physical Therapy, University of Haifa, Haifa, Israel.,Pediatric Rehabilitation Department, Sheba Medical Center, Ramat Gan, Israel
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15
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Zuniga JM, Pierce JE, Copeland C, Cortes-Reyes C, Salazar D, Wang Y, Arun KM, Huppert T. Brain lateralization in children with upper-limb reduction deficiency. J Neuroeng Rehabil 2021; 18:24. [PMID: 33536034 PMCID: PMC7860186 DOI: 10.1186/s12984-020-00803-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/25/2020] [Indexed: 01/11/2023] Open
Abstract
Background The purpose of the current study was to determine the influence of upper-limb prostheses on brain activity and gross dexterity in children with congenital unilateral upper-limb reduction deficiencies (ULD) compared to typically developing children (TD). Methods Five children with ULD (3 boys, 2 girls, 8.76 ± 3.37 years of age) and five age- and sex-matched TD children (3 boys, 2 girls, 8.96 ± 3.23 years of age) performed a gross manual dexterity task (Box and Block Test) while measuring brain activity (functional near-infrared spectroscopy; fNIRS). Results There were no significant differences (p = 0.948) in gross dexterity performance between the ULD group with prosthesis (7.23 ± 3.37 blocks per minute) and TD group with the prosthetic simulator (7.63 ± 5.61 blocks per minute). However, there was a significant (p = 0.001) difference in Laterality Index (LI) between the ULD group with prosthesis (LI = − 0.2888 ± 0.0205) and TD group with simulator (LI = 0.0504 ± 0.0296) showing in a significant ipsilateral control for the ULD group. Thus, the major finding of the present investigation was that children with ULD, unlike the control group, showed significant activation in the ipsilateral motor cortex on the non-preferred side using a prosthesis during a gross manual dexterity task. Conclusions This ipsilateral response may be a compensation strategy in which the existing cortical representations of the non-affected (preferred) side are been used by the affected (non-preferred) side to operate the prosthesis. This study is the first to report altered lateralization in children with ULD while using a prosthesis. Trial registration The clinical trial (ClinicalTrial.gov ID: NCT04110730 and unique protocol ID: IRB # 614-16-FB) was registered on October 1, 2019 (https://clinicaltrials.gov/ct2/show/NCT04110730) and posted on October 1, 2019. The study start date was January 10, 2020. The first participant was enrolled on January 14, 2020, and the trial is scheduled to be completed by August 23, 2023. The trial was updated January 18, 2020 and is currently recruiting
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Affiliation(s)
- Jorge M Zuniga
- Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE, 68182, USA.
| | - James E Pierce
- Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE, 68182, USA
| | - Christopher Copeland
- Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE, 68182, USA
| | - Claudia Cortes-Reyes
- Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE, 68182, USA
| | - David Salazar
- Department of Biomechanics, University of Nebraska at Omaha, Omaha, NE, 68182, USA
| | - YingYing Wang
- Department of Special Education and Communication Disorders (SECD), University of Nebraska-Lincoln, Lincoln, NE, 68182, USA
| | - K M Arun
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Science and Technology, Thiruvananthapuram, India
| | - Theodore Huppert
- Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, 16148, USA
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16
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Changes in Cortical Activation During Dual-Task Walking in Individuals With and Without Visual Vertigo. J Neurol Phys Ther 2020; 44:156-163. [PMID: 32168158 DOI: 10.1097/npt.0000000000000310] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND PURPOSE Persons with vestibular disorders are known to have slower gait speed with greater imbalance and veering during dual-task walking than healthy individuals, but the cerebral mechanisms are unknown. The purpose of this study was to determine whether individuals with visual vertigo (VV) have different cerebral activation during dual-task walking compared with control subjects. METHODS Fourteen individuals with VV and 14 healthy controls (CON) were included (mean 39 years old, 85% women). A cross-sectional experimental study consisting of 4 combinations of 2 surfaces (even and uneven) and 2 task conditions (single- and dual-task) was performed. Participants walked over an even (level flooring) or uneven (wood prisms underneath carpeting) surface, either quietly or while reciting every other letter of the alphabet. Changes in cerebral activation over the bilateral prefrontal cortices were recorded using functional near-infrared spectroscopy during 4 task conditions relative to quiet standing. Gait speed and cognitive performance were recorded. RESULTS There were no between-group differences in cognitive performance. Both groups slowed when walking on an uneven surface or performing a dual-task; participants in the VV group walked more slowly than those in the CON group in all conditions. Participants with VV had decreased cerebral activation in the bilateral prefrontal regions in comparison to CON participants in all conditions. DISCUSSION AND CONCLUSIONS Participants with VV had lower prefrontal cortex activation than CON participants during dual-task walking. Lower cortical activity in those with VV may be due to shifted attention away from the cognitive task to prioritize maintenance of dynamic balance.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A303).
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Verdecchia DH, Hernandez D, Andreu MF, Salzberg S. Translation and cross-cultural adaptation of the Visual Vertigo Analogue Scale for use in Argentina. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2020. [DOI: 10.1016/j.otoeng.2019.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Traducción y adaptación transcultural del cuestionario Visual Vertigo Analogue Scale para uso en Argentina. ACTA OTORRINOLARINGOLOGICA ESPANOLA 2020; 71:289-295. [DOI: 10.1016/j.otorri.2019.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/15/2019] [Accepted: 10/20/2019] [Indexed: 11/21/2022]
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Powell G, Derry-Sumner H, Rajenderkumar D, Rushton SK, Sumner P. Persistent postural perceptual dizziness is on a spectrum in the general population. Neurology 2020; 94:e1929-e1938. [PMID: 32300064 PMCID: PMC7274923 DOI: 10.1212/wnl.0000000000009373] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 11/14/2019] [Indexed: 11/29/2022] Open
Abstract
Objective To examine the idea that symptoms of persistent postural perceptual dizziness (PPPD) are more common than previously assumed and lie on a spectrum in the general population, thus challenging current theories that PPPD is only a consequence of a vestibular insult. Methods We collected 2 common clinical questionnaires of PPPD (Visual Vertigo Analogue Scale [VVAS] and Situational Characteristics Questionnaire [SCQ]) in 4 cohorts: community research volunteers (n = 1941 for VVAS, n = 1,474 for SCQ); paid online participants (n = 190 for VVAS, n = 125 for SCQ); students (n = 204, VVAS only); and patients diagnosed with PPPD (n = 25). Results We found that around 9%, 4%, and 11%, respectively, of the 3 nonclinical cohorts scored above the 25th percentile patient score on 1 PPPD measure (VVAS) and 49% and 54% scored above the 25th percentile patient score on the other measure (SCQ). Scores correlated negatively with age (counter to expectation). As expected, scores correlated with migraine in 2 populations, but this only explained a small part of the variance, suggesting that migraine is not the major factor underlying the spectrum of PPPD symptoms in the general population. Conclusion We found high levels of PPPD symptoms in nonclinical populations, suggesting that PPPD is a spectrum that preexists in the population, rather than only being a consequence of vestibular insult. Atypical visuo-vestibular processing predisposes some individuals to visually induced dizziness, which is then exacerbated should vestibular insult (or more generalized insult) occur.
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Affiliation(s)
- Georgina Powell
- From the School of Psychology (G.P., S.K.R., P.S.), Cardiff University; and University Hospital of Wales (H.D.-S., D.R.), Cardiff, UK.
| | - Hannah Derry-Sumner
- From the School of Psychology (G.P., S.K.R., P.S.), Cardiff University; and University Hospital of Wales (H.D.-S., D.R.), Cardiff, UK
| | - Deepak Rajenderkumar
- From the School of Psychology (G.P., S.K.R., P.S.), Cardiff University; and University Hospital of Wales (H.D.-S., D.R.), Cardiff, UK
| | - Simon K Rushton
- From the School of Psychology (G.P., S.K.R., P.S.), Cardiff University; and University Hospital of Wales (H.D.-S., D.R.), Cardiff, UK
| | - Petroc Sumner
- From the School of Psychology (G.P., S.K.R., P.S.), Cardiff University; and University Hospital of Wales (H.D.-S., D.R.), Cardiff, UK
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20
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Abstract
PURPOSE A case study of a 12-year-old boy with Irlen syndrome illustrates the overlapping symptoms of Irlen syndrome and vestibular-related dizziness. SUMMARY OF KEY POINTS Individuals with Irlen syndrome have eyestrain and headache, and often report visual perceptual distortions of blurring, doubling, and movement of print on the page. These symptoms can be relieved with the use of individually prescribed tinted lenses or overlays. Visually induced dizziness, also known as visual vertigo, is characterized by dizziness and/or unsteadiness that is triggered by complex, distorted, large field/moving visual stimuli. Visually induced dizziness can be effectively treated with progressive, controlled exposure to optokinetic visual stimuli. The child with Irlen syndrome had impaired balance, impaired gaze stability, and symptoms of visual vertigo. His complaint of visually induced dizziness resolved following vestibular rehabilitation. CONCLUSIONS AND RECOMMENDATIONS FOR CLINICAL PRACTICE When an individual with Irlen syndrome complains of dizziness, ruling out a concomitant diagnosis of a central and/or peripheral vestibular disorder is warranted. WHAT THIS ADDS TO THE EVIDENCE The visual symptoms associated with Irlen syndrome can overlap with those of visually induced dizziness. This case report is the first to describe overlapping visual and vestibular complaints of dizziness in an individual with Irlen syndrome.
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Abstract
PURPOSE OF REVIEW Disorders of posture and balance cause significant patient morbidity, with reduction of quality of life as patients refrain from critical activities of daily living such as walking outside the home and driving. This review describes recent efforts to characterize visual disorders that interact with the neural integrators of positional maintenance and emerging therapies for these disorders. RECENT FINDINGS Abnormalities of gait and body position sense may be unrecognized by patients but are correlated with focal neurological injury (stroke). Patients with traumatic brain injury can exhibit visual vertigo despite otherwise normal visual functioning. The effect of visual neglect on posture and balance, even in the absence of a demonstrable visual field defect, has been characterized quantitatively through gait analysis and validates the potential therapeutic value of prism treatment in some patients. In addition, the underlying neural dysfunction in visual vertigo has been explored further using functional imaging, and these observations may allow discrimination of patients with structural causes from those whose co-morbid psychosocial disorders may be primarily contributory.
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Affiliation(s)
- Jeffrey R Hebert
- Department of Physical Medicine and Rehabilitation, University of Colorado School of Medicine, Aurora, CO, 80045, USA.,Department of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045, USA.,Marcus Institute for Brain Health, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Prem S Subramanian
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO, 80045, USA. .,Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, 80045, USA. .,Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO, 80045, USA. .,Sue Anschutz-Rodgers UCHealth Eye Center, 1675 Aurora Ct Mail Stop F731, Aurora, CO, 80045, USA.
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