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3.
Sensors (Basel) ; 23(3)2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36772603

ABSTRACT

We often interact with our environment through manual handling of objects and exploration of their properties. Object properties (OP), such as texture, stiffness, size, shape, temperature, weight, and orientation provide necessary information to successfully perform interactions. The human haptic perception system plays a key role in this. As virtual reality (VR) has been a growing field of interest with many applications, adding haptic feedback to virtual experiences is another step towards more realistic virtual interactions. However, integrating haptics in a realistic manner, requires complex technological solutions and actual user-testing in virtual environments (VEs) for verification. This review provides a comprehensive overview of recent wearable haptic devices (HDs) categorized by the OP exploration for which they have been verified in a VE. We found 13 studies which specifically addressed user-testing of wearable HDs in healthy subjects. We map and discuss the different technological solutions for different OP exploration which are useful for the design of future haptic object interactions in VR, and provide future recommendations.


Subject(s)
Virtual Reality , Wearable Electronic Devices , Humans , Haptic Technology , Haptic Interfaces , Feedback , User-Computer Interface , Touch
4.
J Neuroeng Rehabil ; 20(1): 2, 2023 01 12.
Article in English | MEDLINE | ID: mdl-36635679

ABSTRACT

BACKGROUND: Persons with Parkinson's disease (PD) often exhibit difficulties with dexterity during the performance of activities of daily living (ADL), inter alia due to dysfunctional supplementary motor area (SMA). Combined intermittent theta-burst stimulation (iTBS) over the SMA followed by video game-based training (VBT) may therefore improve dexterity related ADL. The VBT may induce high flow levels related to high performance during the training. The aim of this study is to evaluate the feasibility of a combined iTBS-VBT intervention in persons with PD. METHODS: A total of nine persons with PD (mean age 63.3 ± 8.76 years) with self-reported difficulties with dexterity related ADL were included in this pilot iTBS-VBT study. All participants received either iTBS or sham stimulation over the SMA followed by a 45-min VBT, three times a week for a total of three weeks. Feasibility was measured by means of the adherence rate and the system usability (System Usability Scale). Moreover, flow was measured after the last VBT session. RESULTS: Adherence rate was excellent with 100%. High system usability scores (i.e., mean 80%, range 55-97.5) and a significant Spearman's correlation with the Flow State Scale (r = .762, p = .017) further point to the high feasibility of the VBT. Neither demographic variables nor difficulties in dexterity related ADL affected the usability of the VBT. CONCLUSION: This study demonstrates the high feasibility of a combined iTBS-VBT intervention. Moreover, the level of self-reported usability was related to flow experience. Whether this kind of combined iTBS-VBT intervention improves dexterity will be evaluated in a randomized controlled trial. Trial registration clincaltrials.gov NCT04699149, date of registration 1. June 2021.


Subject(s)
Parkinson Disease , Video Games , Aged , Humans , Middle Aged , Activities of Daily Living , Feasibility Studies , Transcranial Magnetic Stimulation
5.
Neuropsychobiology ; 81(4): 311-321, 2022.
Article in English | MEDLINE | ID: mdl-35367989

ABSTRACT

INTRODUCTION: Deficits in social interaction and community functioning, including impaired use, performance, and perception of hand gestures, are key features in schizophrenia. A well-established tool to assess gesture deficits is the test of upper limb apraxia (TULIA). However, given its time-consuming application based on video analyses, research has proposed the bedside apraxia screen of TULIA (AST). This study aims to test the validity and reliability of the AST to detect gesture abnormalities at bedside in a sample of 27 patients diagnosed with schizophrenia, schizotypal disorder, acute and transient psychotic disorders, or schizoaffective disorder. METHODS: Patients completed the 48-item TULIA and the 12-item AST. Two different raters assessed the AST: one at bedside (online) and the other based on the video recordings. RESULTS: The total AST scores demonstrated a high parallel reliability, moderate inter-rater reliability on a single-item level, and good construct validities. CONCLUSIONS: The psychometric properties of the AST suggest it can well be used for the clinical assessment of gesture deficits in schizophrenia. However, when detailed information is required, the AST rated from video or conducting the full TULIA is recommended. The findings call for refining the selection of the TULIA items for a psychosis-AST bedside test to increase specificity.


Subject(s)
Apraxias , Psychotic Disorders , Schizophrenia , Apraxias/diagnosis , Apraxias/etiology , Gestures , Humans , Psychotic Disorders/complications , Psychotic Disorders/diagnosis , Reproducibility of Results , Schizophrenia/complications , Schizophrenia/diagnosis
6.
Schizophr Bull ; 48(1): 220-230, 2022 01 21.
Article in English | MEDLINE | ID: mdl-34355246

ABSTRACT

Neurological soft signs (NSS) are related to grey matter and functional brain abnormalities in schizophrenia. Studies in healthy subjects suggest, that NSS are also linked to white matter. However, the association between NSS and white matter abnormalities in schizophrenia remains to be elucidated. The present study investigated, if NSS are related to white matter alterations in patients with schizophrenia. The total sample included 42 healthy controls and 41 patients with schizophrenia. We used the Neurological Evaluation Scale (NES), and we acquired diffusion weighted magnetic resonance imaging to assess white matter on a voxel-wise between subject statistic. In patients with schizophrenia, linear associations between NES with fractional anisotropy (FA), radial, axial, and mean diffusivity were analyzed with tract-based spatial statistics while controlling for age, medication dose, the severity of the disease, and motion. The main pattern of results in patients showed a positive association of NES with all diffusion measures except FA in important motor pathways: the corticospinal tract, internal capsule, superior longitudinal fascicle, thalamocortical radiations and corpus callosum. In addition, exploratory tractography analysis revealed an association of the right aslant with NES in patients. These results suggest that specific white matter alterations, that is, increased diffusivity might contribute to NSS in patients with schizophrenia.


Subject(s)
Nervous System Diseases/physiopathology , Psychotic Disorders/pathology , Psychotic Disorders/physiopathology , Schizophrenia/pathology , Schizophrenia/physiopathology , White Matter/pathology , Adult , Corpus Callosum/diagnostic imaging , Corpus Callosum/pathology , Female , Humans , Internal Capsule/diagnostic imaging , Internal Capsule/pathology , Magnetic Resonance Imaging , Male , Middle Aged , Nervous System Diseases/etiology , Psychotic Disorders/complications , Psychotic Disorders/diagnostic imaging , Pyramidal Tracts/diagnostic imaging , Pyramidal Tracts/pathology , Schizophrenia/complications , Schizophrenia/diagnostic imaging
7.
Front Neurosci ; 16: 998729, 2022.
Article in English | MEDLINE | ID: mdl-36590287

ABSTRACT

Objectives: Apraxia is a common syndrome of left hemispheric stroke. A parieto-premotor-prefrontal network has been associated with apraxia, in which the left inferior parietal lobe (IPL-L) plays a major role. We hypothesized that transcranial continuous theta burst stimulation (cTBS) over the right inferior parietal lobe (IPL-R) improves gesturing by reducing its inhibition on the contralateral IPL in left hemispheric stroke patients. It was assumed that this effect is independent of lesion volume and that transcallosal connectivity is predictive for gestural effect after stimulation. Materials and methods: Nineteen stroke patients were recruited. Lesion volume and fractional anisotropy of the corpus callosum were acquired with structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Each patient had pseudorandomised sessions with sham or with stimulation over the IPL-R or over the right inferior frontal gyrus IFG-R. Gesturing was assessed in a double-blinded manner before and after each session. We tested the effects of stimulation on gesture performance using a linear mixed-effects model. Results: Pairwise treatment contrasts showed, that, compared to sham, the behavioral effect was higher after stimulation over IPL-R (12.08, 95% CI 6.04 - 18.13, p < 0.001). This treatment effect was approximately twice as high as the contrasts for IFG-R vs. sham (6.25, 95% CI -0.20 - 12.70, p = 0.058) and IPL-R vs. IFG-R vs. sham (5.83, 95% CI -0.49 - 12.15, p = 0.071). Furthermore, higher fractional anisotropy in the splenium (connecting the left and right IPL) were associated with higher behavioral effect. Relative lesion volume did not affect the changes after sham or stimulation over IPL-R or IFG-R. Conclusion: One single session of cTBS over the IPL-R improved gesturing after left hemispheric stroke. Denser microstructure in the corpus callosum correlated with favorable gestural response. We therefore propose the indirect transcallosal modulation of the IPL-L as a promising model of restoring interhemispheric balance, which may be useful in rehabilitation of apraxia.

8.
Front Neurol ; 12: 722762, 2021.
Article in English | MEDLINE | ID: mdl-34630296

ABSTRACT

Background: Magnetic resonance-guided high-intensity focused ultrasound (MRgHiFUS) has evolved into a viable ablative treatment option for functional neurosurgery. However, it is not clear yet, how this new technology should be integrated into current and established clinical practice and a consensus should be found about recommended indications, stereotactic targets, patient selection, and outcome measurements. Objective: To sum up and unify current knowledge and clinical experience of Swiss neurological and neurosurgical communities regarding MRgHiFUS interventions for brain disorders to be published as a national consensus paper. Methods: Eighteen experienced neurosurgeons and neurologists practicing in Switzerland in the field of movement disorders and one health physicist representing 15 departments of 12 Swiss clinical centers and 5 medical societies participated in the workshop and contributed to the consensus paper. All experts have experience with current treatment modalities or with MRgHiFUS. They were invited to participate in two workshops and consensus meetings and one online meeting. As part of workshop preparations, a thorough literature review was undertaken and distributed among participants together with a list of relevant discussion topics. Special emphasis was put on current experience and practice, and areas of controversy regarding clinical application of MRgHiFUS for functional neurosurgery. Results: The recommendations addressed lesioning for treatment of brain disorders in general, and with respect to MRgHiFUS indications, stereotactic targets, treatment alternatives, patient selection and management, standardization of reporting and follow-up, and initialization of a national registry for interventional therapies of movement disorders. Good clinical evidence is presently only available for unilateral thalamic lesioning in treating essential tremor or tremor-dominant Parkinson's disease and, to a minor extent, for unilateral subthalamotomy for Parkinson's disease motor features. However, the workgroup unequivocally recommends further exploration and adaptation of MRgHiFUS-based functional lesioning interventions and confirms the need for outcome-based evaluation of these approaches based on a unified registry. MRgHiFUS and DBS should be evaluated by experts familiar with both methods, as they are mutually complementing therapy options to be appreciated for their distinct advantages and potential. Conclusion: This multidisciplinary consensus paper is a representative current recommendation for safe implementation and standardized practice of MRgHiFUS treatments for functional neurosurgery in Switzerland.

9.
Drugs Aging ; 38(7): 559-577, 2021 07.
Article in English | MEDLINE | ID: mdl-34224103

ABSTRACT

Pain is a frequent and disabling non-motor feature of Parkinson's disease (PD). The recently proposed PD Pain Classification System (PD-PCS) allows for an association of pain with PD to be determined before being allocated to the main pain mechanism (i.e. nociceptive, neuropathic, and nociplastic). In this article, previous studies on treatments for pain in PD are summarized according to the pain mechanisms. A mechanistic approach to treatment is discussed. We suggest that the first step should be optimizing dopaminergic therapy before other therapy is started. When these treatments remain unsuccessful, further causes of pain must be considered. The role of drugs, invasive treatments, and physiotherapeutic interventions are discussed with a focus on older PD patients and considering polypharmacy, altered pharmacokinetics, and comorbidities.


Subject(s)
Parkinson Disease , Humans , Pain/diagnosis , Pain/drug therapy , Pain/etiology , Pain Measurement , Parkinson Disease/complications , Parkinson Disease/diagnosis , Parkinson Disease/drug therapy , Polypharmacy
10.
Brain Sci ; 11(3)2021 Mar 03.
Article in English | MEDLINE | ID: mdl-33802532

ABSTRACT

Freezing of gait (FOG) in Parkinson's disease (PD) occurs frequently in situations with high environmental complexity. The supplementary motor cortex (SMC) is regarded as a major network node that exerts cortical input for motor control in these situations. We aimed at assessing the impact of single-session (excitatory) intermittent theta burst stimulation (iTBS) of the SMC on established walking during FOG provoking situations such as passing through narrow spaces and turning for directional changes. Twelve PD patients with FOG underwent two visits in the off-medication state with either iTBS or sham stimulation. At each visit, spatiotemporal gait parameters were measured during walking without obstacles and in FOG-provoking situations before and after stimulation. When patients passed through narrow spaces, decreased stride time along with increased stride length and walking speed (i.e., improved gait) was observed after both sham stimulation and iTBS. These effects, particularly on stride time, were attenuated by real iTBS. During turning, iTBS resulted in decreased stride time along with unchanged stride length, a constellation compatible with increased stepping frequency. The observed iTBS effects are regarded as relative gait deterioration. We conclude that iTBS over the SMC increases stepping frequency in PD patients with FOG, particularly in FOG provoking situations.

11.
Cortex ; 138: 152-164, 2021 05.
Article in English | MEDLINE | ID: mdl-33691224

ABSTRACT

Non-invasive brain stimulation (NIBS) techniques are widely used in research settings to investigate brain mechanisms and increasingly being used for treatment purposes. The aim of this study was to systematically identify and review the current literature on NIBS studies of limb praxis and apraxia in healthy subjects and stroke patients with a scoping review using PRISMA-ScR guidelines. MEDLINE-PubMed, EMBASE and PsycINFO were searched. Inclusion criteria were English peer-reviewed studies focusing on the investigation of limb praxis/apraxia using repetitive transcranial magnetic stimulation (rTMS), or transcranial direct current stimulation (tDCS). Fourteen out of 139 records met the inclusion criteria, including thirteen studies with healthy subjects and one with stroke patients. The results of our systematic review suggest that in healthy subjects NIBS over left inferior parietal lobe (IPL) mainly interfered with gesture processing, by either affecting reaction times in judgment tasks or real gesturing. First promising results suggest that inhibitory continuous theta burst stimulation (cTBS) over right IPL may enhance gesturing in healthy subjects, explained by transcallosal facilitation of left IPL. In stroke patients, excitatory anodal tDCS over left IPL may improve limb apraxia. However, larger well powered and sham-controlled clinical trials are needed to expand on these proof-of-concept results, before NIBS could be a treatment option to improve limb apraxia in stroke patients.


Subject(s)
Apraxias , Stroke , Transcranial Direct Current Stimulation , Apraxias/therapy , Brain , Healthy Volunteers , Humans , Stroke/complications , Stroke/therapy , Transcranial Magnetic Stimulation
12.
Swiss Med Wkly ; 151: w20419, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33705561

ABSTRACT

AIMS OF THE STUDY: Currently, the characterisation of advanced Parkinson’s disease (APD) does not follow standardised diagnostic criteria, which complicates the evaluation of ongoing care and treatment strategies, such as eligibility for device-aided treatment (DAT). Therefore, this study aimed to determine the proportion of APD and non-advanced Parkinson’s disease (non-APD) patients treated at specialised movement disorder centres in Switzerland, to compare clinical characteristics of APD versus non-APD patients and to assess eligibility for and use of DAT. Furthermore, potential differences between the Swiss and international situation should be uncovered. METHODS: OBSERVE-PD was a cross-sectional, international, observational study including 2615 patients from 128 movement disorder centres in 18 countries. For the Swiss subgroup of the study analysed here, which included 134 patients from 5 movement disorder centres, motor and non-motor symptoms, activities of daily living and quality of life were assessed as endpoints. The correlation between physician’s judgement of APD and the Delphi criteria for APD, which were developed by an international expert group, as well as the clinical burden in APD and non-APD patients and eligibility for and use of DAT were evaluated. The results for the Swiss subgroup were subsequently compared with the international full analysis set of the OBSERVE-PD study. RESULTS: Based on physician’s judgement, 69.4% of patients included in the Swiss study suffered from APD. A moderate correlation between physician’s judgement and the Delphi criteria for APD was observed (Κ = 0.480, 95% confidence interval 0.317–0.642). Clinical burden was higher for APD patients, as shown by worse scores for activities of daily living, motor symptom severity, dyskinesia duration/disability, duration of “off” time, non-motor symptoms and quality of life as compared with non-APD patients (p <0.0001 for all). The Swiss data for disease burden were comparable to the international findings, except that the Swiss patients showed less “off” time. Amongst APD patients eligible for DAT, the main reason for no DAT in Switzerland was patient refusal, whereas patients needing more time to decide about it was the most frequent reason in the international analysis. CONCLUSIONS: The study shows that the burden of APD in tertiary care centres in Switzerland is comparable to the international situation. Patient refusal is the main reason for no DAT amongst eligible APD patients in such centres. The identification of standard APD classification parameters and evaluation of the reasons for no DAT are relevant for optimising treatment strategies and the transition to DAT.


Subject(s)
Parkinson Disease , Activities of Daily Living , Cross-Sectional Studies , Humans , Quality of Life , Switzerland
13.
Front Rehabil Sci ; 2: 777981, 2021.
Article in English | MEDLINE | ID: mdl-36188867

ABSTRACT

Introduction: Patients with Parkinson's disease (PD) often exhibit difficulties with dexterity during the performance of activities of daily living (ADL) due to dysfunctional supplementary motor area (SMA). The aim of this clinical trial protocol work is to describe how the effectiveness of a combined repetitive transcranial magnetic stimulation (rTMS) over SMA and video-game-based skill training (VBT) in PD will be evaluated. The short and long-term benefits are assessed. Methods and analysis: A single-blind (patients) stratified (based on Hoehn & Yahr) parallel randomized sham-controlled rTMS-VBT study with a baseline and two follow-up measurements (3 and 12 weeks) is being conducted. These measurements include the dexterity questionnaire 24 (DextQ-24) as a primary outcome, and nine hole peg test and coin rotation task as main secondary dexterity outcomes. Further secondary outcomes will be the subscale II of the movement disorders society unified PD rating scale (MDS-UPDRS) to assess improvements on overall ADL and the Parkinson's Disease Questionnaire-39 to assess quality of life. Thirty-six outpatients (from one neurorehabilitation center) with PD (diagnosis based on brain bank criteria) will be recruited who report difficulties with dexterity in performing ADL. All PD patients will receive a 45-min VBT three times a week for 3 weeks. The PD patients randomized in the experimental group will receive VBT preceded by real rTMS, being intermittent theta burst (iTBS) stimulation sessions. The PD patients randomized to the control group receive a VBT with sham rTMS. Discussion: The study will provide evidence to determine whether a combined iTBS and VBT skill intervention is more effective than a VBT intervention alone to improve dexterity in PD. Ethics and dissemination: The study was approved by the Ethics Committee for Northwest and Central Switzerland (EKNZ), Switzerland 2019-00433. The study will be conducted in accordance with the Helsinki Declaration and the Guidelines of Good Clinical Practice. Informed consent will be signed prior to subject enrolment. Dissemination will include submission to international peer-reviewed professional journals and presentation at international congresses. The study protocol has been registered in the clinicaltrials.gov registry with the identification code: NCT04699149.

15.
Brain Commun ; 2(2): fcaa157, 2020.
Article in English | MEDLINE | ID: mdl-33225278

ABSTRACT

Cognitive estimation is a mental ability applied to solve numerical problems when precise facts are unknown, unavailable or impractical to calculate. It has been associated with several underlying cognitive components, most often with executive functions and semantic memory. Little is known about the neural correlates of cognitive estimation. To address this issue, the present cross-sectional study applied lesion-symptom mapping in a group of 55 patients with left hemineglect due to right-hemisphere stroke. Previous evidence suggests a high prevalence of cognitive estimation impairment in these patients, as they might show a general bias towards large magnitudes. Compared to 55 age- and gender-matched healthy controls, the patient group demonstrated impaired cognitive estimation. However, the expected large magnitude bias was not found. Lesion-symptom mapping related their general estimation impairment predominantly to brain damage in the right anterior temporal lobe. Also critically involved were the right uncinate fasciculus, the anterior commissure and the right inferior frontal gyrus. The main findings of this study emphasize the role of semantic memory in cognitive estimation, with reference to a growing body of neuroscientific literature postulating a transmodal hub for semantic cognition situated in the bilateral anterior temporal lobe. That such semantic hub function may also apply to numerical knowledge is not undisputed. We here propose a critical contribution of the right anterior temporal lobe to at least one aspect of number processing, i.e. the knowledge about real-world numerical magnitudes.

16.
Cortex ; 132: 322-333, 2020 11.
Article in English | MEDLINE | ID: mdl-33011518

ABSTRACT

Hand gestures are an integral part of social interactions and communication. Several imaging studies in healthy subjects and lesion studies in patients with apraxia suggest the praxis network for gesture production, involving mainly left inferior frontal, posterior parietal and temporal regions. However, little is known about the structural connectivity underlying gesture production. We recruited 41 healthy participants and 39 patients with schizophrenia. All participants performed a gesture production test, the Test of Upper Limb Apraxia, and underwent diffusion tensor imaging. We hypothesized that gesture production is associated with structural network connectivity as well as with tract integrity. We defined the praxis network as an undirected graph comprised of 13 bilateral regions of interest and derived measures of local and global structural connectivity and tract integrity from Finsler geometry. We found an association of gesture deficit with reduced global and local efficiency of the praxis network. Furthermore, reduced tract integrity, for example in the superior longitudinal fascicle, arcuate fascicle or corpus callosum were related to gesture deficits. Our findings contribute to the understanding of structural correlates of gesture production as they first present diffusion tensor imaging data in a combined sample of healthy subjects and a patient cohort with gestural deficits.


Subject(s)
Gestures , Schizophrenia , Diffusion Tensor Imaging , Healthy Volunteers , Humans , Nerve Net/diagnostic imaging , Schizophrenia/diagnostic imaging
17.
Cortex ; 133: 65-75, 2020 12.
Article in English | MEDLINE | ID: mdl-33099076

ABSTRACT

Aberrant performance of skilled action has long been noted in schizophrenia and relatedly, recent reports have demonstrated impaired use, performance, and perception of hand gestures in this group. Still, this deficit is not acknowledged as apraxia, which to the broader medical field, characterizes impairments in skilled actions. Understanding the relationship between apraxia and schizophrenia may shed an invaluable new perspective on disease mechanism, and highlight novel treatment opportunities as well. To examine this potential link, we reviewed the evidence for the types of praxis errors, associated psychopathology, and cerebral correlates of the praxis deficit in schizophrenia. Notably, the review indicated that gesture deficits are severe enough to be considered genuine apraxia in a substantial proportion of patients (about 25%). Further, other potential contributors (e.g., hypokinetic motor abnormalities, cognitive impairment) are indeed associated with gesture deficits in schizophrenia, but do not sufficiently explain the abnormality. Finally, patients with praxis deficits have altered brain structure and function including the left parieto-premotor praxis network and these neural correlates are specific to the praxis deficit. Therefore, we argue that the gestural disorder frequently observed in schizophrenia shares both the clinical and neurophysiological features of true apraxia, as in other neuropsychiatric disorders with impaired higher order motor control, such as Parkinson's disease.


Subject(s)
Apraxias , Parkinson Disease , Schizophrenia , Apraxias/etiology , Brain , Gestures , Humans , Schizophrenia/complications
18.
Schizophr Res ; 223: 258-264, 2020 09.
Article in English | MEDLINE | ID: mdl-32883557

ABSTRACT

BACKGROUND: Gestures are an important part of communication. Patients with schizophrenia present gesture deficits that tend to deteriorate in the course of the disease and hamper functional outcome. This gesture deficit has been associated with motor abnormalities, cognitive impairment, and psychotic symptoms. Unaffected, first-degree relatives of schizophrenia patients share some subclinical motor and cognitive abnormalities. We aimed to investigate, whether gesture performance changes with symptomatic improvement in patients, and to test the longitudinal performance in unaffected, first-degree relatives. METHODS: In this study, we measured gesture performance using a validated test in 33 patients, 29 first-degree relatives and 38 healthy controls. Measurements were completed shortly after admission and before discharge in patients. Performance was rated blindly by experts using video recordings of the gesture task. Additionally, we evaluated cognitive function and psychotic symptoms at both visits. RESULTS: Gesture performance was poorer in relatives compared to controls and poorer in patients compared to both relatives and controls. Patients showed an improvement in psychopathology but a significant decrease in gesture performance at follow-up, while performance in the other groups remained stable. Proportional change of gesture performance correlated with change of cognitive function in patients, whereas there were no correlations with change of cognitive function in the other groups. CONCLUSION: While symptom severity was reduced, the gesture deficit further deteriorated in schizophrenia. The finding argues for distinct processes contributing to poor nonverbal communication skills in patients, requiring novel alternative treatment efforts.


Subject(s)
Psychotic Disorders , Schizophrenia , Gestures , Humans , Nonverbal Communication , Video Recording
19.
Clin Neurophysiol ; 131(9): 2171-2180, 2020 09.
Article in English | MEDLINE | ID: mdl-32683125

ABSTRACT

OBJECTIVE: Motor initiation failure is a key feature of freezing of gait (FOG) due to Parkinson's disease (PD). The supplementary motor cortex (SMC) plays a central role in its pathophysiology. We aimed at investigating SMC activation, connectivity and plasticity with regard to motor initiation in FOG. METHODS: Twelve patients with FOG and eleven without FOG underwent a multimodal electrophysiological evaluation of SMC functioning including the Bereitschaftspotential and movement-related desynchronisation of cortical beta oscillations. SMC plasticity was modulated by intermittent theta burst stimulation (iTBS) and its impact on gait initiation was assessed by a three-dimensional gait analysis. RESULTS: Prior to volitional movements the Bereitschaftspotential was smaller and beta power was less strongly attenuated over the SMC in patients with FOG compared to those without. Pre-motor coherence between the SMC and the primary motor cortex in the beta frequency range was also stronger in patients with FOG. iTBS resulted in a relative deterioration of gait initiation. CONCLUSIONS: Reduced activation of the SMC along with increased SMC connectivity in the beta frequency range hinder a flexible shift of the motor set as it is required for gait initiation. SIGNIFICANCE: Altered SMC functioning plays an important role for motor initiation failure in PD-related FOG.


Subject(s)
Contingent Negative Variation/physiology , Gait Disorders, Neurologic/physiopathology , Motor Cortex/physiopathology , Movement/physiology , Nerve Net/physiopathology , Parkinson Disease/physiopathology , Aged , Beta Rhythm/physiology , Female , Gait/physiology , Humans , Male , Middle Aged , Transcranial Magnetic Stimulation
20.
Cortex ; 129: 223-235, 2020 08.
Article in English | MEDLINE | ID: mdl-32512414

ABSTRACT

Neglect after stroke is most accurately diagnosed by a systematic, ecological observation during everyday behaviour using the Catherine Bergego Scale (CBS). However, the CBS is time-consuming and often omitted in clinical settings, especially stroke units. In this study, we aimed to explore if video-oculography during free visual exploration (FVE), which can be performed in few minutes, is sensitive in mirroring neglect in everyday behaviour and whether it is more sensitive than conventional neuropsychological paper-pencil tests. In this retrospective, observational, multicentre study, we identified 78 patients in our database with subacute right-hemispheric stroke, with and without neglect in everyday behaviour, diagnosed by the CBS, who also performed FVE. 40 age-matched healthy participants served as controls. The sensitivity to detect neglect was compared between FVE (i.e., mean gaze position on the horizontal axis) and conventional neuropsychological paper-pencil tests, i.e., Random Shape Cancellation, Line Bisection, Two-Part Picture, Bells, Star Cancellation, Letter Cancellation, Sensitive Neglect, and Five-Point. FVE correctly identified neglect in 85%of patients, with an AUC-value of .922 in ROC-analysis. Conventional neuropsychological paper-pencil tests, considered alone or in combination, showed heterogeneous results, and identified neglect significantly less often (21.74%-68.75%). Moreover, there was a significant correlation between mean gaze position and CBS scores, providing evidence for the relationship between FVE and neglect in everyday behaviour. Furthermore, VLSM analyses suggested that the absence of a pathological rightward bias in FVE might depend on the integrity of the second branch of the right Superior Longitudinal Fascicle (SLF II), a white-matter tract connecting cortical areas critical for visual attention. Video-oculography during FVE has a high sensitivity and specificity to diagnose neglect after stroke and it is more sensitive than conventional neuropsychological paper-pencil tests. It can be performed in short time and has the potential to be used as a fast and accurate screening tool that allows the initiation of comprehensive neuropsychological diagnostics and therapy from early on.


Subject(s)
Cerebrum , Perceptual Disorders , Stroke , Functional Laterality , Humans , Neuropsychological Tests , Perceptual Disorders/diagnosis , Retrospective Studies , Stroke/complications , Stroke/diagnosis
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