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Shukla S, Gupta K, Singh K, Mishra A, Kumar A. An Updated Canvas of the RFC1-mediated CANVAS (Cerebellar Ataxia, Neuropathy and Vestibular Areflexia Syndrome). Mol Neurobiol 2024:10.1007/s12035-024-04307-0. [PMID: 38898197 DOI: 10.1007/s12035-024-04307-0] [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: 03/13/2024] [Accepted: 06/13/2024] [Indexed: 06/21/2024]
Abstract
Proliferation of specific nucleotide sequences within the coding and non-coding regions of numerous genes has been implicated in approximately 40 neurodegenerative disorders. Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS), a neurodegenerative disorder, is distinguished by a pathological triad of sensory neuropathy, bilateral vestibular areflexia and cerebellar impairments. It manifests in adults gradually and is autosomal recessive and multi-system ataxia. Predominantly, CANVAS is associated with biallelic AAGGG repeat expansions in intron 2 of the RFC1 gene. Although various motifs have been identified, only a subset induces pathological consequences, by forming stable secondary structures that disrupt gene functions both in vitro and in vivo. The pathogenesis of CANVAS remains a subject of intensive research, yet its precise mechanisms remain elusive. Herein, we aim to comprehensively review the epidemiology, clinical ramifications, molecular mechanisms, genetics, and potential therapeutics in light of the current findings, extending an overview of the most significant research on CANVAS.
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Affiliation(s)
- Sakshi Shukla
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Kanav Gupta
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Krishna Singh
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India
| | - Amit Kumar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India.
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2
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Garces P, Antoniades CA, Sobanska A, Kovacs N, Ying SH, Gupta AS, Perlman S, Szmulewicz DJ, Pane C, Németh AH, Jardim LB, Coarelli G, Dankova M, Traschütz A, Tarnutzer AA. Quantitative Oculomotor Assessment in Hereditary Ataxia: Systematic Review and Consensus by the Ataxia Global Initiative Working Group on Digital-motor Biomarkers. CEREBELLUM (LONDON, ENGLAND) 2024; 23:896-911. [PMID: 37117990 PMCID: PMC11102387 DOI: 10.1007/s12311-023-01559-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/18/2023] [Indexed: 04/30/2023]
Abstract
Oculomotor deficits are common in hereditary ataxia, but disproportionally neglected in clinical ataxia scales and as outcome measures for interventional trials. Quantitative assessment of oculomotor function has become increasingly available and thus applicable in multicenter trials and offers the opportunity to capture severity and progression of oculomotor impairment in a sensitive and reliable manner. In this consensus paper of the Ataxia Global Initiative Working Group On Digital Oculomotor Biomarkers, based on a systematic literature review, we propose harmonized methodology and measurement parameters for the quantitative assessment of oculomotor function in natural-history studies and clinical trials in hereditary ataxia. MEDLINE was searched for articles reporting on oculomotor/vestibular properties in ataxia patients and a study-tailored quality-assessment was performed. One-hundred-and-seventeen articles reporting on subjects with genetically confirmed (n=1134) or suspected hereditary ataxia (n=198), and degenerative ataxias with sporadic presentation (n=480) were included and subject to data extraction. Based on robust discrimination from controls, correlation with disease-severity, sensitivity to change, and feasibility in international multicenter settings as prerequisite for clinical trials, we prioritize a core-set of five eye-movement types: (i) pursuit eye movements, (ii) saccadic eye movements, (iii) fixation, (iv) eccentric gaze holding, and (v) rotational vestibulo-ocular reflex. We provide detailed guidelines for their acquisition, and recommendations on the quantitative parameters to extract. Limitations include low study quality, heterogeneity in patient populations, and lack of longitudinal studies. Standardization of quantitative oculomotor assessments will facilitate their implementation, interpretation, and validation in clinical trials, and ultimately advance our understanding of the evolution of oculomotor network dysfunction in hereditary ataxias.
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Affiliation(s)
- Pilar Garces
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland
| | - Chrystalina A Antoniades
- NeuroMetrology Lab, Nuffield Department of Clinical Neurosciences, Clinical Neurology, Medical Sciences Division, University of Oxford, Oxford, OX3 9DU, UK
| | - Anna Sobanska
- Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Norbert Kovacs
- Department of Neurology, University of Pécs, Medical School, Pécs, Hungary
| | - Sarah H Ying
- Department of Otology and Laryngology and Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Anoopum S Gupta
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Susan Perlman
- University of California Los Angeles, Los Angeles, California, USA
| | - David J Szmulewicz
- Balance Disorders and Ataxia Service, Royal Victoria Eye and Ear Hospital, East Melbourne, Melbourne, VIC, 3002, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, Melbourne, VIC, 3052, Australia
| | - Chiara Pane
- Department of Neurosciences and Reproductive and Odontostomatological Sciences, University of Naples "Federico II", Naples, Italy
| | - Andrea H Németh
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Laura B Jardim
- Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Serviço de Genética Médica/Centro de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Giulia Coarelli
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm U1127, CNRS UMR7225, Paris, France
- Department of Genetics, Neurogene National Reference Centre for Rare Diseases, Pitié-Salpêtrière University Hospital, Assistance Publique, Hôpitaux de Paris, Paris, France
| | - Michaela Dankova
- Department of Neurology, Centre of Hereditary Ataxias, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Andreas Traschütz
- Research Division "Translational Genomics of Neurodegenerative Diseases", Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
| | - Alexander A Tarnutzer
- Neurology, Cantonal Hospital of Baden, 5404, Baden, Switzerland.
- Faculty of Medicine, University of Zurich, Zurich, Switzerland.
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Abstract
Aims of the present article are: 1) assessing vestibular contribution to spatial navigation, 2) exploring how age, global positioning systems (GPS) use, and vestibular navigation contribute to subjective sense of direction (SOD), 3) evaluating vestibular navigation in patients with lesions of the vestibular-cerebellum (patients with downbeat nystagmus, DBN) that could inform on the signals carried by vestibulo-cerebellar-cortical pathways. We applied two navigation tasks on a rotating chair in the dark: return-to-start (RTS), where subjects drive the chair back to the origin after discrete angular displacement stimuli (path reversal), and complete-the-circle (CTC) where subjects drive the chair on, all the way round to origin (path completion). We examined 24 normal controls (20-83 yr), five patients with DBN (62-77 yr) and, as proof of principle, two patients with early dementia (84 and 76 yr). We found a relationship between SOD, assessed by Santa Barbara Sense of Direction Scale, and subject's age (positive), GPS use (negative), and CTC-vestibular-navigation-task (positive). Age-related decline in vestibular navigation was observed with the RTS task but not with the complex CTC task. Vestibular navigation was normal in patients with vestibulo-cerebellar dysfunction but abnormal, particularly CTC, in the demented patients. We conclude that vestibular navigation skills contribute to the build-up of our SOD. Unexpectedly, perceived SOD in the elderly is not inferior, possibly explained by increased GPS use by the young. Preserved vestibular navigation in cerebellar patients suggests that ascending vestibular-cerebellar projections carry velocity (not position) signals. The abnormalities in the cognitively impaired patients suggest that their vestibulo-spatial navigation is disrupted.NEW & NOTEWORTHY Our subjective sense-of-direction is influenced by how good we are at spatial navigation using vestibular cues. Global positioning systems (GPS) may inhibit sense of direction. Increased use of GPS by the young may explain why the elderly's sense of direction is not worse than the young's. Patients with vestibulo-cerebellar dysfunction (downbeat nystagmus syndrome) display normal vestibular navigation, suggesting that ascending vestibulo-cerebellar-cortical pathways carry velocity rather than position signals. Pilot data indicate that dementia disrupts vestibular navigation.
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Affiliation(s)
- Athena Zachou
- Neuro-otology Unit, Department of Brain Sciences, Imperial College London, Charing Cross Hospital Campus, London, United Kingdom
- 1st Department of Neurology, Eginition Hospital, National and Kapodistrian University of Athens, Greece
| | - Adolfo M Bronstein
- Neuro-otology Unit, Department of Brain Sciences, Imperial College London, Charing Cross Hospital Campus, London, United Kingdom
- 1st Department of Neurology, Eginition Hospital, National and Kapodistrian University of Athens, Greece
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Dietrich H, Pradhan C, Heidger F, Schniepp R, Wuehr M. Downbeat nystagmus becomes attenuated during walking compared to standing. J Neurol 2022; 269:6222-6227. [PMID: 35412151 DOI: 10.1007/s00415-022-11106-x] [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: 10/04/2021] [Revised: 03/24/2022] [Accepted: 03/24/2022] [Indexed: 11/28/2022]
Abstract
Downbeat nystagmus (DBN) is a common form of acquired fixation nystagmus related to vestibulo-cerebellar impairments and associated with impaired vision and postural imbalance. DBN intensity becomes modulated by various factors such as gaze direction, head position, daytime, and resting conditions. Further evidence suggests that locomotion attenuates postural symptoms in DBN. Here, we examined whether walking might analogously influence ocular-motor deficits in DBN. Gaze stabilization mechanisms and nystagmus frequency were examined in 10 patients with DBN and 10 age-matched healthy controls with visual fixation during standing vs. walking on a motorized treadmill. Despite their central ocular-motor deficits, linear and angular gaze stabilization in the vertical plane were functional during walking in DBN patients and comparable to controls. Notably, nystagmus frequency in patients was considerably reduced during walking compared to standing (p < 0.001). The frequency of remaining nystagmus during walking was further modulated in a manner that depended on the specific phase of the gait cycle (p = 0.015). These attenuating effects on nystagmus intensity during walking suggest that ocular-motor control disturbances are selectively suppressed during locomotion in DBN. This suppression is potentially mediated by locomotor efference copies that have been shown to selectively govern gaze stabilization during stereotyped locomotion in animal models.
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Affiliation(s)
- Haike Dietrich
- German Center for Vertigo and Balance Disorders, University Hospital, LMU, Munich, Germany
| | - Cauchy Pradhan
- German Center for Vertigo and Balance Disorders, University Hospital, LMU, Munich, Germany
| | - Felix Heidger
- German Center for Vertigo and Balance Disorders, University Hospital, LMU, Munich, Germany
| | - Roman Schniepp
- German Center for Vertigo and Balance Disorders, University Hospital, LMU, Munich, Germany
| | - Max Wuehr
- German Center for Vertigo and Balance Disorders, University Hospital, LMU, Munich, Germany.
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5
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Liu XH, Wang ZY, Li Y, Xu HL, Sikandar A, Ni J, Gan SR. Impaired Lower Limb Proprioception in Spinocerebellar Ataxia Type 3 and Its Affected Factors. Front Neurol 2022; 13:833908. [PMID: 35185776 PMCID: PMC8847775 DOI: 10.3389/fneur.2022.833908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 01/11/2022] [Indexed: 11/21/2022] Open
Abstract
Background Spinocerebellar ataxia type 3 (SCA3) is one of the most common hereditary neurodegenerative diseases. Postural control dysfunction is the main symptom of SCA3, and the proprioceptive system is a critical sensory component of postural control. Accordingly, proprioception quantification assessment is necessary in monitoring the progression of SCA3. Objective We aimed to quantitatively assess lower limb proprioception and investigate the relationship between proprioception and clinical characteristics in patients with SCA3. Methods A total of 80 patients with SCA3 and 62 health controls were recruited, and their lower limb proprioception was measured using the Pro-kin system. Clinical characteristics of the SCA3 patients were collected. Multivariable linear regression was used to investigate potential affected factors for lower limb proprioception. Results We found that the patients with SCA3 experience poorer lower limb proprioception characterized by significant impairment in the average trace error (ATE) and time to carry out the test time execution (TTE) compared to controls (P < 0.05). Moreover, there were significant differences in TTE between the right and left lower limbs (P < 0.05) of the patients. Regression analyses revealed that increasing age at onset (AAO) predicts poorer lower limb proprioception for both ATE (β = 2.006, P = 0.027) and TTE (β = 1.712, P = 0.043) and increasing disease duration predicts poorer lower limb proprioception for ATE (β = 0.874, P = 0.044). AAO (β = 0.328, P = 0.019) along with the expanded alleles (β = 0.565, P = 0.000) could affect the severity of ataxia. By contrast, ATE (β = 0.036, P = 0.800) and TTE (β = −0.025, P = 0.862) showed no significant predictors. Conclusions Lower limb proprioception in patients with SCA3 is significantly impaired when compared to healthy controls. Increasing AAO and disease duration are related to impaired lower limb proprioception.
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Affiliation(s)
- Xia-Hua Liu
- Department of Rehabilitation Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Zhi-Yong Wang
- Department of Rehabilitation Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
- *Correspondence: Zhi-Yong Wang
| | - Ying Li
- The Third Clinical Medical College, Fujian Medical University, Fuzhou, China
| | - Hao-Ling Xu
- Department of Neurology, Institute of Neurology, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Arif Sikandar
- Department of Neurology, Institute of Neurology, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Jun Ni
- Department of Rehabilitation Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Shi-Rui Gan
- Department of Neurology, Institute of Neurology, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China
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6
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Millar JL, Schubert MC. Report of oscillopsia in ataxia patients correlates with activity, not vestibular ocular reflex gain. J Vestib Res 2021; 32:381-388. [PMID: 34897108 DOI: 10.3233/ves-210106] [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 Patients with cerebellar ataxia report oscillopsia, "bouncy vision" during activity, yet little is known how this impacts daily function. The purpose of this study was to quantify the magnitude of oscillopsia and investigate its relation to vestibulo-ocular reflex (VOR) function and daily activity in cerebellar ataxia. METHODS 19 patients diagnosed with cerebellar ataxia and reports of oscillopsia with activity were examined using the video head impulse test (vHIT), Oscillopsia Functional Index (OFI), and clinical gait measures. Video head impulse data was compared against 40 healthy controls. RESULTS OFI scores in ataxia patients were severe and inversely correlated with gait velocity (r = -0.55, p < 0.05), but did not correlate with VOR gains. The mean VOR gain in the ataxic patients was significantly reduced and more varied compared with healthy controls. All patients had abnormal VOR gains and eye/head movement patterns in at least one semicircular canal during VHIT with passive head rotation. CONCLUSIONS Patients with cerebellar ataxia and oscillopsia have impaired VOR gains, yet severity of oscillopsia and VOR gains are not correlated. Patients with cerebellar ataxia have abnormal oculomotor behavior during passive head rotation that is correlated with gait velocity, but not magnitude of oscillopsia.
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Affiliation(s)
- Jennifer L Millar
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, Maryland, USA
| | - Michael C Schubert
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, Maryland, USA.,Laboratory of Vestibular NeuroAdaptation, Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland, USA
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7
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Effects of perceptible and imperceptible galvanic vestibular stimulation on the postural control of patients with bilateral vestibulopathy. J Neurol 2020; 267:2383-2397. [DOI: 10.1007/s00415-020-09852-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 01/01/2023]
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8
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Sexton BM, Liu Y, Block HJ. Increase in weighting of vision vs. proprioception associated with force field adaptation. Sci Rep 2019; 9:10167. [PMID: 31308399 PMCID: PMC6629615 DOI: 10.1038/s41598-019-46625-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/02/2019] [Indexed: 11/30/2022] Open
Abstract
Hand position can be estimated by vision and proprioception (position sense). The brain is thought to weight and integrate these percepts to form a multisensory estimate of hand position with which to guide movement. Force field adaptation, a type of cerebellum-dependent motor learning, is associated with both motor and proprioceptive changes. The cerebellum has connections with multisensory parietal regions; however, it is unknown if force adaptation is associated with changes in multisensory perception. If force adaptation affects all relevant sensory modalities similarly, the brain’s weighting of vision vs. proprioception should be maintained. Alternatively, if force perturbation is interpreted as somatosensory unreliability, vision may be up-weighted relative to proprioception. We assessed visuo-proprioceptive weighting with a perceptual estimation task before and after subjects performed straight-ahead reaches grasping a robotic manipulandum. Each subject performed one session with a clockwise or counter-clockwise velocity-dependent force field, and one session in a null field. Subjects increased their weight of vision vs. proprioception in the force field session relative to the null session, regardless of force field direction, in the straight-ahead dimension (F1,44 = 5.13, p = 0.029). This suggests that force field adaptation is associated with an increase in the brain’s weighting of vision vs. proprioception.
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Affiliation(s)
- Brandon M Sexton
- Department of Kinesiology & Program in Neuroscience, Indiana University Bloomington, Bloomington, USA
| | - Yang Liu
- Department of Kinesiology & Program in Neuroscience, Indiana University Bloomington, Bloomington, USA
| | - Hannah J Block
- Department of Kinesiology & Program in Neuroscience, Indiana University Bloomington, Bloomington, USA.
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9
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Ahmadi SA, Vivar G, Frei J, Nowoshilow S, Bardins S, Brandt T, Krafczyk S. Towards computerized diagnosis of neurological stance disorders: data mining and machine learning of posturography and sway. J Neurol 2019; 266:108-117. [PMID: 31286203 DOI: 10.1007/s00415-019-09458-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 10/26/2022]
Abstract
We perform classification, ranking and mapping of body sway parameters from static posturography data of patients using recent machine-learning and data-mining techniques. Body sway is measured in 293 individuals with the clinical diagnoses of acute unilateral vestibulopathy (AVS, n = 49), distal sensory polyneuropathy (PNP, n = 12), anterior lobe cerebellar atrophy (CA, n = 48), downbeat nystagmus syndrome (DN, n = 16), primary orthostatic tremor (OT, n = 25), Parkinson's disease (PD, n = 27), phobic postural vertigo (PPV n = 59) and healthy controls (HC, n = 57). We classify disorders and rank sway features using supervised machine learning. We compute a continuous, human-interpretable 2D map of stance disorders using t-stochastic neighborhood embedding (t-SNE). Classification of eight diagnoses yielded 82.7% accuracy [95% CI (80.9%, 84.5%)]. Five (CA, PPV, AVS, HC, OT) were classified with a mean sensitivity and specificity of 88.4% and 97.1%, while three (PD, PNP, and DN) achieved a mean sensitivity of 53.7%. The most discriminative stance condition was ranked as "standing on foam-rubber, eyes closed". Mapping of sway path features into 2D space revealed clear clusters among CA, PPV, AVS, HC and OT subjects. We confirm previous claims that machine learning can aid in classification of clinical sway patterns measured with static posturography. Given a standardized, long-term acquisition of quantitative patient databases, modern machine learning and data analysis techniques help in visualizing, understanding and utilizing high-dimensional sensor data from clinical routine.
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Affiliation(s)
- Seyed-Ahmad Ahmadi
- German Center for Vertigo and Balance Disorders, Ludwig Maximilians Universität, Marchioninistr. 15, 81377, Munich, Germany. .,Computer Aided Medical Procedures, Technical University of Munich, 85748, Garching, Germany.
| | - Gerome Vivar
- German Center for Vertigo and Balance Disorders, Ludwig Maximilians Universität, Marchioninistr. 15, 81377, Munich, Germany.,Computer Aided Medical Procedures, Technical University of Munich, 85748, Garching, Germany
| | - Johann Frei
- German Center for Vertigo and Balance Disorders, Ludwig Maximilians Universität, Marchioninistr. 15, 81377, Munich, Germany.,Computer Aided Medical Procedures, Technical University of Munich, 85748, Garching, Germany
| | - Sergej Nowoshilow
- IMP Research Institute of Molecular Pathology, Campus-Vienna-Biocenter 1, 1030, Vienna, Austria
| | - Stanislav Bardins
- German Center for Vertigo and Balance Disorders, Ludwig Maximilians Universität, Marchioninistr. 15, 81377, Munich, Germany
| | - Thomas Brandt
- German Center for Vertigo and Balance Disorders, Ludwig Maximilians Universität, Marchioninistr. 15, 81377, Munich, Germany
| | - Siegbert Krafczyk
- German Center for Vertigo and Balance Disorders, Ludwig Maximilians Universität, Marchioninistr. 15, 81377, Munich, Germany
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10
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Postural control during galvanic vestibular stimulation in patients with persistent perceptual-postural dizziness. J Neurol 2019; 266:1236-1249. [PMID: 30809703 DOI: 10.1007/s00415-019-09255-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 12/15/2022]
Abstract
Over the past years galvanic vestibular stimulation (GVS) has been increasingly applied to stimulate the vestibular system in health and disease, but not in patients with persistent postural-perceptual dizziness (PPPD) yet. We functionally tested motion perception thresholds and postural responses to imperceptible noisy (nGVS) and perceptible bimastoidal GVS intensities in patients with PPPD with normal vestibulo-ocular reflexes. We hypothesized that GVS destabilizes PPPD patients under simple postural conditions stronger compared to healthy controls. They were compared to healthy subjects under several conditions each with the eyes open and closed: baseline with firm platform support, standing on foam and cognitive demand (count backward). Low and high GVS intensities (range 0.8-2.8 mA) were applied according to the individual thresholds and compared with no GVS. PPPD patients showed a reduced perception threshold to GVS compared to healthy control subjects. Median postural sway speed increased with stimulus intensity and on eye closure, but there was no group difference, irrespective of the experimental condition. Romberg's ratio was consistently lower during nGVS than in all other conditions. Group-related dissociable effects were found with the eyes closed in (i) the baseline condition in which high GVS elicited higher postural sway of PPPD patients and (ii) in the foam condition, with better postural stability of PPPD patients during perceptible GVS. Group and condition differences of postural control were neither related to anxiety nor depression scores. GVS may be helpful to identify thresholds of vestibular perception and to modulate vestibulo-spinal reflexes in PPPD, with dissociable effects with respect to perceptible and imperceptible stimuli. The sway increase in the baseline of PPPD may be related to an earlier transition from open- to closed-loop mode of postural control. In contrast, the smaller sway of PPPD in the foam condition under visual deprivation is in line with the known balance improvement under more demanding postural challenges in PPPD. It is associated with a prolonged transition from open- to closed-loop postural feedback control. It could also reflect a shift of intersensory weighting with a smaller dependence on proprioceptive feedback control in PPPD patients under complex tasks. In summary, GVS discloses differences between simple and complex balance tasks in PPPD.
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11
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Anagnostou E, Gerakoulis S, Voskou P, Kararizou E. Postural instability during attacks of migraine without aura. Eur J Neurol 2018; 26:319-e21. [PMID: 30295375 DOI: 10.1111/ene.13815] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 10/03/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND AND PURPOSE Migraine has long been associated with unsteadiness and dizziness but postural control has not been studied in the ictal state. Here, the stability of upright stance during migraine attacks was measured. METHODS Static balance was assessed prospectively in migraine patients (n = 30) during quiet stance for 40 s on a posturographic force platform. Recordings were performed both ictally and in the pain-free interval. Subjects were assessed under four different conditions yielding different visual and proprioceptive feedback environments. Both ictal and interictal data were compared with age-matched healthy controls (n = 30). RESULTS Postural instability increased significantly under all experimental conditions during migraine attacks. Whilst standing on a foam pad with eyes closed, median sway area was 353 mm2 in control subjects, 318 mm2 in migraineurs in the pain-free period and 618 mm2 in the ictal state. However, Romberg and vestibular Romberg quotients were not altered during migraine attacks. Spectral analyses of postural sway also showed similar profiles in migraineurs and controls. The severity of headache was inversely correlated to Romberg quotients. CONCLUSIONS The demonstrated pattern of balance disorder during migraine attacks suggests a transient cerebellar dysfunction. Our findings also indicate that intense headache induces a re-weighting of sensory processing toward less dependence on visual and proprioceptive information.
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Affiliation(s)
- E Anagnostou
- Department of Neurology, Eginition Hospital, University of Athens, Athens, Greece
| | - S Gerakoulis
- Department of Neurology, Eginition Hospital, University of Athens, Athens, Greece
| | - P Voskou
- Department of Neurology, Eginition Hospital, University of Athens, Athens, Greece
| | - E Kararizou
- Department of Neurology, Eginition Hospital, University of Athens, Athens, Greece
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12
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Sprenger A, Wojak JF, Jandl NM, Helmchen C. Postural Control in Bilateral Vestibular Failure: Its Relation to Visual, Proprioceptive, Vestibular, and Cognitive Input. Front Neurol 2017; 8:444. [PMID: 28919878 PMCID: PMC5585141 DOI: 10.3389/fneur.2017.00444] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/14/2017] [Indexed: 02/04/2023] Open
Abstract
Patients with bilateral vestibular failure (BVF) suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC), visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance. Between-group analysis revealed larger postural sway in BVF patients on eye closure; but with the eyes open, BVF did not differ from healthy controls (HCs). Head tilts and horizontal head shaking increased sway but did not differ between groups. In the dual task condition, BVF patients maintained posture indistinguishable from controls. On foam and tandem stance, postural sway was larger in BVF, even with the eyes open. The best predictor for the severity of bilateral vestibulopathy was standing on foam with eyes closed. Postural control of our BVF was indistinguishable from HCs once visual and proprioceptive feedback is provided. This distinguishes them from patients with vestibulo-cerebellar disorders or functional dizziness. It confirms previous reports and explains that postural unsteadiness of BVF patients can be missed easily if not examined by conditions of visual and/or proprioceptive deprivation. In fact, the best predictor for vestibular hypofunction (VOR gain) was examining patients standing on foam with the eyes closed. Postural sway in that condition increased with the severity of vestibular impairment but not with disease duration. In the absence of visual control, impaired otolith input destabilizes BVF with head retroflexion. Stimulating deficient SSC does not distinguish patients from controls possibly reflecting a shift of intersensory weighing toward proprioceptive-guided postural control. Accordingly, proprioceptive deprivation heavily destabilizes BVF, even when visual control is provided.
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Affiliation(s)
- Andreas Sprenger
- Department of Neurology, University of Lübeck, Lubeck, Germany.,Institute of Psychology II, University of Lübeck, Lubeck, Germany
| | - Jann F Wojak
- Department of Neurology, University of Lübeck, Lubeck, Germany
| | - Nico M Jandl
- Department of Neurology, University of Lübeck, Lubeck, Germany
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Postural control during recall of vestibular sensation in patients with functional dizziness and unilateral vestibulopathy. J Neurol 2017; 264:42-44. [DOI: 10.1007/s00415-017-8446-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 10/20/2022]
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