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An illustration of left hemispatial neglect in right hemisphere stroke (A) Line bisection, (B) Modified Albert's line cancellation, (C) Copying of modified ogeden picture.
Source publication
Hemispatial neglect refers to a cognitive disorder in which patients with unilateral brain injury cannot recognize or respond to stimuli located in the contralesional hemispace. Hemispatial neglect in stroke patients is an important predictor for poor functional outcome. Therefore, there is a need for effective treatment for this condition. A numbe...
Contexts in source publication
Context 1
... of the major cognitive disorders resulting from right hemisphere damage. Hemispatial neglect usually recovers spontaneously 3 but can be persistent in about 10% of thepatients. 4 When a horizontal line is presented in front of the patients with hemispatial neglect, they place the bisection mark to the ipsilesional space from the true midpoint ( Fig. 1-A). When asked to cancel out lines randomly distributed in an A4 sized paper, they place the marks on the right side of the page ( Fig. 1-B). 5,6 This rightward bias or preference also occurs when copying figures ( Fig. ...Context 2
... persistent in about 10% of thepatients. 4 When a horizontal line is presented in front of the patients with hemispatial neglect, they place the bisection mark to the ipsilesional space from the true midpoint ( Fig. 1-A). When asked to cancel out lines randomly distributed in an A4 sized paper, they place the marks on the right side of the page ( Fig. 1-B). 5,6 This rightward bias or preference also occurs when copying figures ( Fig. ...Context 3
... of the patients with hemispatial neglect, they place the bisection mark to the ipsilesional space from the true midpoint ( Fig. 1-A). When asked to cancel out lines randomly distributed in an A4 sized paper, they place the marks on the right side of the page ( Fig. 1-B). 5,6 This rightward bias or preference also occurs when copying figures ( Fig. ...Citations
... For its application, the patient was rotated in a well-lit room for more than 1 min. 6 Currently, there are devices that facilitate its application, such as virtual reality glasses. ...
... In this way, slow eye movements to the left and rapid corrective movements to the right appear, changing the frame of reference from the centre to the left. 6 When the picture background rotates to the left, the subject feels that it is rotating to the right. Therefore, he orients his body to the left as a postural adjustment. ...
Introduction:
Unilateral spatial neglect (USN) is a stroke complication of stroke. Optokinetic stimulation (OKS) is one of the treatments, but its effects on motor symptoms, such as poverty or alterations in movements on the affected side, are not clear yet. The aim of this study will be to evaluate the OKS effects on the perceptual and postural complications of patients with USN.
Methods and analysis:
Randomised double-blinded clinical trial, with an intervention group that will undergo OKS and a control placebo group. The research will take place at the Faculty of Nursing and Physiotherapy, University of Salamanca, 102 patients older than 18 years with diagnosed USN will participate. The intervention group will receive 2 weekly OKS session for 10 weeks. Virtual reality glasses will be used for the application of a video. The video will project OKS at a preset speed and will request the participant's attention throughout the session. The control group will receive a placebo treatment, through a virtual reality video. The measurement variables will be posturography, Fluff test, line bisection, Fullerton Advance Balance Scale and Diller's cancellation test.
Ethics and dissemination:
This study has been approved by the Ethics Committee University of Salamanca on February 2020 (registration number: 584). All patients in the study will be informed about the objective of the study and will give their written informed consent to participate in the study. The anonymised database will be available from the publication of the results for 10 years in the repository of the University of Salamanca GREDOS (https://gredos.usal.es/). The trial results will be shared with the scientific community at international conferences and by publication in a peer-reviewed journal.
Trial registration number:
NCT04663646.
... However, existing evaluation methods mainly target egocentric neglect and they are insufficient for addressing other types of neglect [14]. For this reason, existing treatment methods are concentrated on the treatment of egocentric neglect, such as prism treatment, transcutaneous electrical nerve stimulation (TENS), optokinetic stimulation (OKS), etc. [15][16][17]. Moreover, the study of Turgut et al. mentioned the need to distinguish between egocentric neglect and allocentric neglect treatments, because existing treatments, such as prism treatment and cueing paradigm training, have only been verified to improve egocentric neglect [18]. ...
... Treatment methods for neglect have been combined with cutting-edge technologies such as virtual reality (VR), transcranial magnetic simulation (TMS) and optic simulation (OKS) [15][16][17]. However, these studies have failed to consider the various types of neglect and spatial constraints have been identified due to the size and high cost of equipment [17][18][19][20][21][22][23]25,26]. ...
... Treatment methods for neglect have been combined with cutting-edge technologies such as virtual reality (VR), transcranial magnetic simulation (TMS) and optic simulation (OKS) [15][16][17]. However, these studies have failed to consider the various types of neglect and spatial constraints have been identified due to the size and high cost of equipment [17][18][19][20][21][22][23]25,26]. Accordingly, this study was conducted to determine how the newly developed therapy, twins therapy (TT), affects stroke patients with neglect by improving these shortcomings. ...
(1) Background: Existing treatment methods for neglect are concentrated on egocentric neglect and may lead to various problems such as cost/space constraints and portability. Therefore, this study seeks to determine how a new treatment (also known as twins therapy, TT) for stroke patients can improve an existing problem associated with neglect. (2) Method: A pre/post-test control group research design was used and both groups continued to receive existing rehabilitation treatment, whilst TT intervention was only added to the experimental group. TT intervention was conducted for a total of 20 sessions (1 session for 30 min/day, 5 days/week, for 4 weeks). (3) Result: There was no significant difference in the manual function test (MFT) and the Korean version of the Modified Barthel Index (K-MBI) items (p > 0.05) before and after the TT intervention. However, the score and execution time of the apple cancellation test showed a significant reduction only in the experimental group (p < 0.05). (4) Conclusion: TT not only improved egocentric neglect, but also allocentric neglect symptoms in stroke patients.
... These perceptual cues should be further tested in vestibular disorders but also in complex cases such as hemispatial neglect. Since OKs has been reported to improve hemispatial neglect [17][18][19] and caloric vestibular stimulation aphasia syndrome e. opposite to the stimulus direction) and eye (thick line) movements to the right (i.e. same as stimulus direction). ...
Background
Optokinetic nystagmus (OKN) was studied in an immersive virtual reality (VR) environment with both typical optokinetic stimulation (OKs) wherein the head-tracking is active (similar to be sitting in front of a rotating drum) or a unique stimulus (VR-OKs) wherein the head-tracking is turned off, so head movements do not update the visual image (which moves with the head).
Objective
To study both the perception of the stimulus velocity and eye movements while subjects rotated their head from side to side and the visual scene was either a typical OKs or VR-OKs.
Methods
9 healthy participants (aged 23 ± 2.4 y/o) had head and eye movements recorded under typical OKs and VR-OKS while smoothly rotating their head horizontally from side to side. Stimulation was delivered using a virtual reality setup on top of an eye movements recording system.
Results
Under VR-OKs participants perceived faster stimulus velocity when the head and stimulus had the same direction as compared to the head and stimulus in opposite directions. When the head turned in the same direction as the stimulus, there were fewer fast phase eye movements than when it rotated counter to stimulus motion direction. Conversely, with typical OKs, participants perceived faster stimulus velocity when the head and stimulus had opposite directions as compared to the head and stimulus having the same direction.
Conclusions
The seemingly paradoxical results in which slower stimulus velocity is perceived in tandem with stronger nystagmus can be explained by the simultaneous activation of the Vestibulo-Ocular Reflex and OKN in accordance with the various visual and vestibular stimuli.
... Other top-down approaches include the limb activation treatment (LAT), in which patients are asked to perform intentional movements using their contralesional hemibody (Rizzolatti and Berti, 1990;North, 1992, 1993) (ii) bottom-up, non-activity-based interventions; these latter methods aim at reducing patients' bodily deficits using external instruments to manipulate the sensory environment. This kind of intervention also exploit physical stimulation and manipulate patients' sensory environment to improve neglect symptoms with methods such as hemiblinding, eyeblinding, caloric, galvanic or optokinetic stimulation (OKS; Pizzamiglio et al., 1990;Robertson et al., 1998;Moon et al., 2006;Kim et al., 2015;Azouvi et al., 2017), or prism adaptation (PA; Tsirlin et al., 2009;Jacquin-Courtois et al., 2010, 2013Azouvi et al., 2017;Liu et al., 2019). OKS has proved particularly effective for treating left hemispatial neglect; by activating brain stem, basal ganglia, cerebellum, and the parieto-occipital cortex, it improved distorted body orientation, tactile extinction, motor neglect, and even better attention to auditory stimuli. ...
... OKS has proved particularly effective for treating left hemispatial neglect; by activating brain stem, basal ganglia, cerebellum, and the parieto-occipital cortex, it improved distorted body orientation, tactile extinction, motor neglect, and even better attention to auditory stimuli. This is particularly true when OKS include leftward moving stimuli such as dots (Vallar et al., 1993(Vallar et al., , 1997, vertical strip or random dot backgrounds (Kim et al., 2007), or drums (Moon et al., 2006), whereas rightward OKS appear to worsen left hemispatial neglect . PA, instead, consists of actively exposing patients to a rightward optical deviation of their visual field, with the aim to reorient their behavior toward the neglected side. ...
... Five studies employed HMDs as a rehabilitative tool for USN. As previously mentioned, OKS has proved as an effective rehabilitative intervention for left hemispatial neglect, training patients to either look at or pay attention to stimuli placed in their left (neglected) hemispace (Pizzamiglio et al., 1990;Robertson et al., 1998;Moon et al., 2006;Kim et al., 2015). However, its utility has been limited to experimental settings within a laboratory so far: in order to be effective within a real-life environment, OKS should be projected in the background, which is often impossible or impractical . ...
Unilateral spatial neglect (USN) is a frequent repercussion of a cerebrovascular accident, typically a stroke. USN patients fail to orient their attention to the contralesional side to detect auditory, visual, and somatosensory stimuli, as well as to collect and purposely use this information. Traditional methods for USN assessment and rehabilitation include paper-and-pencil procedures, which address cognitive functions as isolated from other aspects of patients’ functioning within a real-life context. This might compromise the ecological validity of these procedures and limit their generalizability; moreover, USN evaluation and treatment currently lacks a gold standard. The field of technology has provided several promising tools that have been integrated within the clinical practice; over the years, a “first wave” has promoted computerized methods, which cannot provide an ecological and realistic environment and tasks. Thus, a “second wave” has fostered the implementation of virtual reality (VR) devices that, with different degrees of immersiveness, induce a sense of presence and allow patients to actively interact within the life-like setting. The present paper provides an updated, comprehensive picture of VR devices in the assessment and rehabilitation of USN, building on the review of Pedroli et al. (2015). The present paper analyzes the methodological and technological aspects of the studies selected, considering the issue of usability and ecological validity of virtual environments and tasks. Despite the technological advancement, the studies in this field lack methodological rigor as well as a proper evaluation of VR usability and should improve the ecological validity of VR-based assessment and rehabilitation of USN.
... CVS might correct this deviation [14]. This idea is supported by the fact that the multisensory vestibular system is part of the network that codes for the egocentric frame of reference [37] and by the fact that representational neglect might arise from an egocentric frame of reference imbalance [11,12,38]. Indeed, patients are able to create a mental representation using an allocentric reference frame, whereas a deficit is observed when a body-centered image is formed [11,12]. ...
Caloric vestibular stimulation (CVS) can temporarily reduce visuospatial neglect and related symptoms. The present study examined the effect of CVS on representational neglect during free exploration of the map of France. We asked patients to name cities they could mentally "see" on the map of France, without giving them any directional instructions related to the left or right sides of the map. In right brain damaged patients with left visuospatial neglect, the mental representation of the map was asymmetrical (favoring the right side). After stimulation, neglect patients named more towns on the left side of the map, leading to a significant reduction in map representation asymmetry. Our findings are consistent with previous studies on visuospatial neglect and are in favor of a central effect of vestibular stimulation on mechanisms involved in space representation.
... Very few randomised con-trolled trials (RCTs) have been conducted to study the effect of different therapeutic strategies in hemineglect. However, they have addressed only limited sensory domains [7][8][9][10][11][12][13][14][15][16][17][18][19], and most of them have not addressed the motor intentional deficit. These include, prism adaptation [7,8], eye patching [9,10], mirror therapy [11,12], visual scanning [13], optokinetic visual stimulation [9,14,15], vestibular stimulation-galvanic [16] as well as caloric stimulation [17], neck muscle vibration [18], transcranial magnetic stimulation [19], somatosensory stimulation [13] and Transcutaneous Electrical Nerve Stimulation (TENS) [15]. ...
... However, they have addressed only limited sensory domains [7][8][9][10][11][12][13][14][15][16][17][18][19], and most of them have not addressed the motor intentional deficit. These include, prism adaptation [7,8], eye patching [9,10], mirror therapy [11,12], visual scanning [13], optokinetic visual stimulation [9,14,15], vestibular stimulation-galvanic [16] as well as caloric stimulation [17], neck muscle vibration [18], transcranial magnetic stimulation [19], somatosensory stimulation [13] and Transcutaneous Electrical Nerve Stimulation (TENS) [15]. A combined multimodality sensory stimulation strategy along with motor tasking has not been tried before. ...
Objective:
To test the feasibility and efficacy of multimodality stimulation combined with motor tasking as a corrective strategy for hemineglect following right hemispheric ischemic strokes.
Material and methods:
A prospective randomized controlled single blinded clinical trial was conducted over eighteen months from January 2017. All patients with right hemispheric ischemic strokes were screened for hemineglect and those fulfilling criteria were recruited and randomized. Patients under the therapy group (TG) received the intervention based on a structured protocol in addition to standard physiotherapy. The control group (CG) received standard physiotherapy alone. NIHSS, mRS and Neuropsychological test scores were recorded at different time points. The primary outcome measures (neuropsychological test scores) were compared between the two groups (Student's t-test to find out the difference in outcome measures) at one and three months post-stroke.
Results:
Of the 14 patients recruited, data from 12 were available for analysis, 5 patients in TG and 7 in CG. There was a trend for better hemineglect and functional outcomes in TG.
Conclusion:
Multimodality stimulation, in addition to standard physiotherapy, is feasible and potentially results in better neurocognitive and functional recovery following right hemispheric ischemic strokes. However, larger studies are warranted to prove these preliminary observations beyond doubt.
... This experience seems to be associated with the occurrence of an ipsilesional spatial bias, as the pattern of exploratory eye movements is shifted towards the ipsilesional hemifield with respect to the objective trunk midline, while being symmetrical with respect to the subjective trunk midline (Hornak, 1992;Karnath et al., 1991). Furthermore, manipulations of the physical or perceived trunk midline (by neck muscle or caloric-vestibular stimulation) have been shown to reduce visual neglect symptoms ( Chokron et al., 2007;Johannsen et al., 2003;Karnath et al., 1993;Karnath et al., 1996;Karnath et al., 1991;Li et al., 2014;Moon et al., 2006;Rode and Perenin, 1994;Måns Magnusson and Ba, 1999;Schindler, 2002; Schindler and Kerkhoff, 1997;Wilkinson et al., 2014). Physical or illusionary trunk rotation towards the contralesional side shortened saccade latencies towards the disturbed hemifield ( Karnath et al., 1991), re-centered exploratory eye movement patterns, and improved the performance in visual detection even in the absence of an overt motor response ( Karnath et al., 1993). ...
The rotation of the trunk around its vertical midline could be shown to bias visuospatial temporal judgments towards targets in the hemifield ipsilateral to the trunk orientation and to improve visuospatial performance in patients with visual neglect. However, the underlying brain mechanisms are not well understood. Therefore, the goal of the present study was to investigate the neural effects associated with egocentric midplane shifts under consideration of individual handedness. We employed a visuospatial temporal order judgment (TOJ) task in healthy right- and left-handed subjects while their trunk rotation was varied. Participants responded by a saccade towards the stimulus perceived first out of two stimuli presented with different stimulus onset asynchronies (SOA). Apart from gaze behavior, BOLD-fMRI responses were measured using functional magnetic resonance imaging (fMRI). Based on findings from spatial neglect research, analyses of fMRI-BOLD responses were focused on a bilateral fronto-temporo-parietal network comprising Brodmann areas 22, 39, 40, and 44, as well as the basal ganglia core nuclei (caudate, putamen, pallidum). We observed an acceleration of saccadic speed towards stimuli ipsilateral to the trunk orientation modulated by individual handedness. Left-handed participants showed the strongest behavioral and neural effects, suggesting greater susceptibility to manipulations of trunk orientation. With respect to the dominant hand, a rotation around the vertical trunk midline modulated the activation of an ipsilateral network comprising fronto-temporo-parietal regions and the putamen with the strongest effects for saccades towards the hemifield opposite to the dominant hand. Within the investigated network, the temporo-parietal junction (TPJ) appears to serve as a region integrating sensory, motor, and trunk position information. Our results are discussed in the context of gain modulatory and laterality effects.
... There is a stronger activation in the hemisphere ipsilateral to the irrigated ear. Activation is stronger in hemisphere ipsilateral to the slow phase of vestibular caloric nystagmus [39]. In human studies, it has been found that left caloric vestibular stimulation temporarily ameliorates left and right hemianesthesia [40], relieves the symptoms of visual hemineglect in right brain-damaged patient [41], and an immediate and sustained relief of symptoms of convulsion [42]. ...
This study was undertaken to provide preliminary evidence for beneficial effects of both bilateral as well as unilateral caloric vestibular stimulation as an alternative therapy for enhancement of cognition and motor activity in Scopolamine induced dementia in Wistar albino rats. 36 healthy, adult male Wistar albino rats with body weight ranging from 150-200 g were used in the current study. Donepezil is used as standard drug in this study. Donepezil was administered orally at a dose of 5 mg/kg for 14 days. Caloric vestibular stimulation was administered by irrigating the middle ear cavity with hot water with a temperature of 45 degree centigrade with the help of syringe for 30 days. In conclusion, even though our study proves both unilateral left and bilateral hot water vestibular stimulation is beneficial in Scopolamine induced dementic rats in improving spatial cognition as well as motor control, unilateral left vestibular stimulation was found to be more beneficial. We recommend further detailed studies in this area to explore mechanisms of action.
... Even higher-level cognitive disorders, e.g., hemi-spatial neglect, might be helped by MVS. Such disorders have been shown previously to be temporarily ameliorated using caloric or galvanic stimulation (35,36), but these are cruder and less easily tolerated forms of labyrinthine activation. ...
Humans often experience dizziness and vertigo around strong static magnetic fields such as those present in an MRI scanner. Recent evidence supports the idea that this effect is the result of inner ear vestibular stimulation and that the mechanism is a magnetohydrodynamic force (Lorentz force) that is generated by the interactions between normal ionic currents in the inner ear endolymph and the strong static magnetic field of MRI machines. While in the MRI, the Lorentz force displaces the cupula of the lateral and anterior semicircular canals, as if the head was rotating with a constant acceleration. If a human subject’s eye movements are recorded when they are in darkness in an MRI machine (i.e., without fixation), there is a persistent nystagmus that diminishes but does not completely disappear over time. When the person exits the magnetic field, there is a transient aftereffect (nystagmus beating in the opposite direction) that reflects adaptation that occurred in the MRI. This magnetic vestibular stimulation (MVS) is a useful technique for exploring set-point adaptation, the process by which the brain adapts to a change in its environment, which in this case is vestibular imbalance. Here, we review the mechanism of MVS, how MVS produces a unique stimulus to the labyrinth that allows us to explore set-point adaptation, and how this technique might apply to the understanding and treatment of vestibular and other neurological disorders.
... Caloric stimulation involves the irrigation of the vestibular system with cold or warm water, thereby exciting the semicircular canal receptors and their vestibular afferents (Been, Ngo, Miller, & Fitzgerald, 2007). Several studies found an improvement of left-sided exploration (Adair, Na, Schwartz, & Heilman, 2003;Rode & Perenin, 1994;Rubens, 1985;Sturt & David Punt, 2013) and anosognosia (Cappa, Sterzi, Vallar, & Bisiach, 1987;Vallar, Sterzi, Bottini, Cappa, & Rusconi, 1990) after caloric stimulation of the contralesional (left) ear (for a review see Been et al., 2007;Moon, Lee, & Na, 2006). Whereas caloric stimulation can cause side effects like vertigo, nausea or vomiting (Been et al., 2007), galvanic vestibular stimulation (GVS) lacks such adverse effects, is well tolerated and is easy to apply (Utz, Korluss, Schmidt, et al., 2011). ...
ABSTRACT
Recent evidence shows that bipolar galvanic vestibular stimulation (GVS) with the cathode on the left (CL) or right (CR) mastoid ameliorates spatial neglect, extinction and verticality perception transiently and partly permanently. However, no randomised controlled trial evaluated the long-term effects of repetitive GVS in comparison to sham-GVS on exploration and verticality perception. To compare the effects of CL-GVS, CR-GVS and Sham-GVS on spatial exploration and verticality perception in right-hemispheric stroke patients with left neglect we conducted a randomised controlled trial with minimisation. Twenty-four patients completed 10–12 training sessions on a daily basis, 5 days/week. The CL-and CR-GVS group received 20 min of stimulation at 1.5 mA, the Sham-GVS group only 30 s of CL-GVS. Simultaneously, all patients performed a standard therapy of smooth pursuit eye movement training (SPT) followed by visual scanning training (VST). Outcome measures (Neglect test, visuo-tactile search task, subjective visual and tactile vertical) were assessed before and immediately after the intervention and at 2- and 4-week follow-ups. Our results show that neither our standard therapy nor the combination of standard therapy and GVS improved neglect symptoms significantly. The reasons for our non-significant results are discussed.
