ABSTRACT
OBJECTIVES: To assess oculomotor dysfunction and the effectiveness of neuro-optometric visual rehabilitation in improving oculomotor parameters in participants with homonymous hemianopia. MATERIALS AND METHODS: Fifty subjects diagnosed with homonymous hemianopia (HH), referred through the neuro-ophthalmology department, were recruited for the study. All the subjects underwent a detailed neuro-optometric evaluation that included testing for sensory, visuo-motor and oculomotor functions. Subjects with homonymous hemianopia were then prescribed with yoked prisms and were randomized to two treatments at one month, namely group 1: yoked prisms (n = 15) and group 2: yoked prisms with in-office visual search training (n = 15). RESULTS: The mean ± SD age of the subjects was 46 ± 12 years. Subjects with HH exhibited a significant delay in the completion time, response and accuracy of tasks on proactive, saccadic and visual search parameters using the SVI compared to age-matched controls (Independent t-test, p < 0.05). A significant improvement in the reading speed and visual search parameters (RM ANOVA, p < 0.001) was seen post neuro-optometric visual rehabilitation with both yoked prisms and SVI. Statistically significant differences were observed in the reaction time of the visual search paradigms between the two rehabilitative modalities yoked (group1), yoked and SVI (group2) (Mann-Whitney U test, p < 0.001), with the group 2 showing better visual search performance outcomes compared to group 1 (yoked). CONCLUSION: Visual search parameters among participants with homonymous hemianopia improved following combined rehabilitation (yoked prisms and visual search trainng).
Subject(s)
Hemianopsia , Visual Fields , Humans , Adult , Middle Aged , Hemianopsia/rehabilitation , Reaction Time , Eye Movements , SaccadesABSTRACT
PURPOSE: To evaluate the efficacy of motion discrimination training as a potential therapy for stroke-induced hemianopic visual field defects. DESIGN: Clinical trial. PARTICIPANTS: Forty-eight patients with stroke-induced homonymous hemianopia (HH) were randomized into 2 training arms: intervention and control. Patients were between 21 and 75 years of age and showed no ocular issues at presentation. METHODS: Patients were trained on a motion discrimination task previously evidenced to reduce visual field deficits, but not in a randomized clinical trial. Patients were randomized with equal allocation to receive training in either their sighted or deficit visual fields. Training was performed at home for 6 months, consisting of repeated visual discriminations at a single location for 20 to 30 minutes daily. Study staff and patients were masked to training type. Testing before and after training was identical, consisting of Humphrey visual fields (Carl Zeiss Meditech), macular integrity assessment perimetry, OCT, motion discrimination performance, and visual quality-of-life questionnaires. MAIN OUTCOME MEASURES: Primary outcome measures were changes in perimetric mean deviation (PMD) on Humphrey Visual Field Analyzer in both eyes. RESULTS: Mean PMDs improved over 6 months in deficit-trained patients (mean change in the right eye, 0.58 dB; 95% confidence interval, 0.07-1.08 dB; mean change in the left eye 0.84 dB; 95% confidence interval, 0.22-1.47 dB). No improvement was observed in sighted-trained patients (mean change in the right eye, 0.12 dB; 95% confidence interval, -0.38 to 0.62 dB; mean change in the left eye, 0.10 dB; 95% confidence interval, -0.52 to 0.72 dB). However, no significant differences were found between the alternative training methods (right eye, P = 0.19; left eye, P = 0.10). CONCLUSIONS: To date, no widely accepted therapy is available to treat HH. This study evaluated the efficacy of a promising potential treatment, visual perceptual training. We failed to find a difference between treatment training within the deficit field and control training within the sighted field when performed in a home environment.
Subject(s)
Discrimination, Psychological , Hemianopsia/rehabilitation , Stroke/complications , Therapy, Computer-Assisted/methods , Visual Fields/physiology , Visual Perception/physiology , Adult , Aged , Female , Hemianopsia/etiology , Hemianopsia/physiopathology , Humans , Male , Middle Aged , Visually Impaired Persons/rehabilitation , Young AdultABSTRACT
Hemianopia can be rehabilitated by an auditory-visual "training" procedure, which restores visual responsiveness in midbrain neurons indirectly compromised by the cortical lesion and reinstates vision in contralesional space. Presumably, these rehabilitative changes are induced via mechanisms of multisensory integration/plasticity. If so, the paradigm should fail if the stimulus configurations violate the spatiotemporal principles that govern these midbrain processes. To test this possibility, hemianopic cats were provided spatially or temporally noncongruent auditory-visual training. Rehabilitation failed in all cases even after approximately twice the number of training trials normally required for recovery, and even after animals learned to approach the location of the undetected visual stimulus. When training was repeated with these stimuli in spatiotemporal concordance, hemianopia was resolved. The results identify the conditions needed to engage changes in remaining neural circuits required to support vision in the absence of visual cortex, and have implications for rehabilitative strategies in human patients.
Subject(s)
Acoustic Stimulation/methods , Hemianopsia/physiopathology , Hemianopsia/rehabilitation , Photic Stimulation/methods , Visual Cortex/physiopathology , Animals , Cats , Female , Hemianopsia/pathology , Male , Visual Cortex/pathologyABSTRACT
Stroke has become one of the main causes of visual impairment, with more than 15 million incidences of first-time strokes, per year, worldwide. One-third of stroke survivors exhibit visual impairment, and most of them will not fully recover. Some recovery is possible, but this usually happens in the first few weeks after a stroke. Most of the rehabilitation options that are offered to patients are compensatory, such as optical aids or eye training. However, these techniques do not seem to provide a sufficient amount of improvement transferable to everyday life. Based on the relatively recent idea that the visual system can actually recover from a chronic lesion, visual retraining protocols have emerged, sometimes even in combination with noninvasive brain stimulation (NIBS), to further boost plastic changes in the residual visual tracts and network. The present article reviews the underlying mechanisms supporting visual retraining and describes the first clinical trials that applied NIBS combined with visual retraining. As a further perspective, it gathers the scientific evidence demonstrating the relevance of interregional functional synchronization of brain networks for visual field recovery, especially the causal role of α and γ oscillations in parieto-occipital regions. Because transcranial alternating current stimulation (tACS) can induce frequency-specific entrainment and modulate spike timing-dependent plasticity, we present a new promising interventional approach, consisting of applying physiologically motivated tACS protocols based on multifocal cross-frequency brain stimulation of the visuoattentional network for visual field recovery.
Subject(s)
Brain Waves , Cerebral Cortex , Hemianopsia/rehabilitation , Neurological Rehabilitation , Neuronal Plasticity , Stroke/complications , Transcranial Direct Current Stimulation , Brain Waves/physiology , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Hemianopsia/etiology , Humans , Neurological Rehabilitation/methods , Neuronal Plasticity/physiology , Transcranial Direct Current Stimulation/methodsABSTRACT
OBJECTIVES: The purpose of this pilot study was to investigate the feasibility and effects of computer-based cognitive rehabilitation (CBCR) in patients with symptoms of visuospatial neglect or homonymous hemianopia in the subacute phase following stroke. METHOD: A randomized, controlled, unblinded cross-over design was completed with early versus late CBCR including 7 patients in the early intervention group (EI) and 7 patients in the late intervention group (LI). EI received CBCR training immediately after inclusion (mâ¯=â¯19 days after stroke onset) for 3 weeks and LI waited for 3 weeks after inclusion before receiving CBCR training for 3 weeks (mâ¯=â¯44 days after stroke onset). RESULTS: CBCR improved visuospatial symptoms after stroke significantly when administered early in the subacute phase after stroke. The same significant effect was not found when CBCR was administered later in the rehabilitation. The difference in the development of the EI and LI groups during the first 3 weeks was not significant, which could be due to a lack of statistical power. CBCR did not impact mental well-being negatively in any of the groups. In the LI group, the anticipation of CBCR seemed to have a positive impact of mental well-being. CONCLUSION: CBCR is feasible and has a positive effect on symptoms in patients with visuospatial symptoms in the subacute phase after stroke. The study was small and confirmation in larger samples with blinded outcome assessors is needed.
Subject(s)
Agnosia/rehabilitation , Cognitive Remediation , Hemianopsia/rehabilitation , Stroke Rehabilitation/methods , Stroke/therapy , Therapy, Computer-Assisted , Adult , Aged , Aged, 80 and over , Agnosia/diagnosis , Agnosia/physiopathology , Agnosia/psychology , Cross-Over Studies , Feasibility Studies , Female , Hemianopsia/diagnosis , Hemianopsia/physiopathology , Hemianopsia/psychology , Humans , Male , Middle Aged , Pilot Projects , Recovery of Function , Stroke/diagnosis , Stroke/physiopathology , Stroke/psychology , Time Factors , Treatment OutcomeABSTRACT
OBJECTIVE: To evaluate the effectiveness of activity-based, nonactivity-based, and combined activity- and nonactivity-based rehabilitative interventions for individuals presenting with unilateral spatial neglect (USN) and hemianopia. DATA SOURCES: We searched CINAHL, Cochrane Library, EMBASE, MEDLINE, and PubMed from 2006 to 2016. STUDY SELECTION: Randomized controlled trials (RCTs) with a score of 6 or more in the Physiotherapy Evidence Database Scale that examined the effects of activity-based and nonactivity-based rehabilitation interventions for people with USN or hemianopia. Two reviewers selected studies independently. DATA EXTRACTION: Extracted data from the published RCTs. Mean differences (MD) or standardized mean differences (SMD), and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the I2 statistic. DATA SYNTHESIS: A total of 20 RCTs for USN and 5 for hemianopia, involving 594 and 206 stroke participants respectively, were identified. Encouraging results were found in relation to activity-based interventions for visual scanning training and compensatory training for hemianopia (MD=5.11; 95% confidence intervals [95% CI], 0.83-9.4; P=.019; I2=25.16% on visual outcomes), and optokinetic stimulation and smooth pursuit training for USN (SMD=0.49; 95% CI, 0.01-0.97; P=.045; I2=49.35%) on functional performance in activities of daily living, (SMD=0.96; 95% CI, 0.09-1.82; P=.031; I2=89.57%) on neglect. CONCLUSIONS: Activity-based interventions are effective and commonly used in the treatment of USN and hemianopia. Nonactivity-based and combined approaches, for both impairments, have not been refuted, because more studies are required for substantiated conclusions to be drawn.
Subject(s)
Hemianopsia/rehabilitation , Perceptual Disorders/rehabilitation , Stroke Rehabilitation/methods , Stroke/complications , Hemianopsia/etiology , Humans , Perceptual Disorders/etiology , Randomized Controlled Trials as TopicABSTRACT
BACKGROUND: Damage to the primary visual cortex (V1) due to stroke often results in permanent loss of sight affecting one side of the visual field (homonymous hemianopia). Some rehabilitation approaches have shown improvement in visual performance in the blind region, but require a significant time investment. METHODS: Seven patients with cortical damage performed 400 trials of a motion direction discrimination task daily for 5 days. Three patients received anodal transcranial direct current stimulation (tDCS) during training, three received sham stimulation and one had no stimulation. Each patient had an assessment of visual performance and a functional magnetic resonance imaging (fMRI) scan before and after training to measure changes in visual performance and cortical activity. RESULTS: No patients showed improvement in visual function due to the training protocol, and application of tDCS had no effect on visual performance. However, following training, the neural response in motion area hMT+ to a moving stimulus was altered. When the stimulus was presented to the sighted hemifield, activity decreased in hMT+ of the damaged hemisphere. There was no change in hMT+ response when the stimulus was presented to the impaired hemifield. There was a decrease in activity in the inferior precuneus after training when the stimulus was presented to either the impaired or sighted hemifield. Preliminary analysis of tDCS data suggested that anodal tDCS interacted with the delivered training, modulating the neural response in hMT+ in the healthy side of the brain. CONCLUSION: Training can affect the neural responses in hMT+ even in the absence of change in visual performance.
Subject(s)
Behavior/physiology , Hemianopsia/rehabilitation , Magnetic Resonance Imaging/methods , Transcranial Direct Current Stimulation/methods , Visual Cortex/physiopathology , Visual Fields/physiology , Adult , Female , Hemianopsia/diagnosis , Hemianopsia/physiopathology , Humans , Male , Middle Aged , Photic Stimulation/methods , Pilot Projects , Visual Cortex/diagnostic imagingABSTRACT
PURPOSE: On-road testing is considered the standard for assessment of driving performance; however, it lacks standardization. In contrast, driving simulators provide controlled experimental settings in a virtual reality environment. This study compares both testing conditions in patients with binocular visual field defects due to bilateral glaucomatous optic neuropathy or due to retro-chiasmal visual pathway lesions. METHODS: Ten glaucoma patients (PG), ten patients with homonymous visual field defects (PH), and 20 age- and gender-matched ophthalmologically normal control subjects (CG and CH, respectively) participated in a 40-min on-road driving task using a dual brake vehicle. A subset of this sample (8 PG, 8 PH, 8 CG, and 7 CH) underwent a subsequent driving simulator test of similar duration. For both settings, pass/fail rates were assessed by a masked driving instructor. RESULTS: For on-road driving, hemianopia patients (PH) and glaucoma patients (PG) showed worse performance than their controls (CH and CG groups): PH 40%, CH 30%, PG 60%, CG 0%, failure rate. Similar results were obtained for the driving simulator test: PH 50%, CH 29%, PG 38%, CG 0%, failure rate. Twenty-four out of 31 participants (77%) showed concordant results with regard to pass/fail under both test conditions (p > 0.05; McNemar test). CONCLUSIONS: Driving simulator testing leads to results comparable to on-road driving, in terms of pass/fail rates in subjects with binocular (glaucomatous or retro-chiasmal lesion-induced) visual field defects. Driving simulator testing seems to be a well-standardized method, appropriate for assessment of driving performance in individuals with binocular visual field loss.
Subject(s)
Automobile Driving , Computer Simulation , Hemianopsia/rehabilitation , Vision, Ocular , Visual Fields/physiology , Adult , Aged , Female , Hemianopsia/diagnosis , Hemianopsia/physiopathology , Humans , Male , Middle Aged , ROC Curve , Visual Field TestsABSTRACT
OBJECTIVE: Hemianopia is a visual field defect following post-chiasmatic damage. We now applied functional magnetic resonance imaging (fMRI) in hemianopic patients before and after visual rehabilitation training (VRT) to examine the impact of VRT on attentional function networks. METHODS: Seven chronic hemianopic patients with post- chiasmatic lesions carried out a VRT for five weeks under fixation control. Before vs. after intervention, we assessed the area of residual vision (ARV), contrast sensitivity function (CSF) and functional MRI data and correlated them with each other. RESULTS: VRT significantly improved the visual function of grating detection at the training location. Using fMRI, we found that the training led to a strengthening of connectivity between the right temporoparietal junction (rTPJ) to the insula and the anterior cingulate cortex (ACC), all of which belong to the cortical attentional network. However, no significant correlation between alterations of brain activity and improvements of either CSF or ARV was found. CONCLUSION: Visual rehabilitation training partially restored the deficient visual field sectors and could improve attentional network function in hemianopia. SIGNIFICANCE: Our MRI results highlight the role of attention and the rTPJ activation as one, but not the only, component of VRT in hemianopia.
Subject(s)
Attention/physiology , Brain/diagnostic imaging , Hemianopsia/rehabilitation , Learning/physiology , Visual Fields/physiology , Adult , Brain/physiopathology , Female , Hemianopsia/diagnostic imaging , Hemianopsia/physiopathology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Treatment Outcome , Visual Field Tests , Young AdultABSTRACT
BACKGROUND: Homonymous hemianopia post-stroke reduces independence. OBJECTIVE: To compare the effectiveness of a standardised program versus current individualized therapy in patients with homonymous hemianopia. METHODS: Single-blind randomized controlled trial, 24 patients (54% male), mean age (65±4.3), mean time since stroke (51±52.3 days), recruited from rehabilitation and vision services in Adelaide, Australia. Participants were randomized to a combined standardized scanning and mobility program of 7 weeks, 3 times per week or to individualized therapy recommended by clinicians. Primary outcome was an assessment of scanning ability whilst walking. Secondary outcomes included measures of visual scanning, reading, and vision related quality of life (QOL). RESULTS: No significant differences were found between intervention groups for the primary outcome measure of scanning ability whilst walking at 7 weeks and at 3 months (P > 0.05). However, at 3 months significant differences were found for the QOL National Eye Institute Visual functioning Questionnaire (NEI VFQ25) total score (P = 0.03) and dependency sub-score (P = 0.03) measures. CONCLUSIONS: A standardized intervention of static scanning and mobility training improved QOL. Allocation of resources to visual rehabilitation services point towards the implementation of more mobility practice over a longer period of time.
Subject(s)
Hemianopsia/rehabilitation , Reading , Stroke Rehabilitation/methods , Stroke/complications , Walking , Aged , Australia , Female , Hemianopsia/etiology , Humans , Male , Middle AgedABSTRACT
OBJECTIVE: To improve visual performance and perception in stroke patients suffering from visual impairments by the use of therapist-assisted vision therapy. METHODS: This study was an interventional efficacy open-label investigation. The vision therapy was designed to enhance binocular vision, and saccadic ability, and vergence ranges maximally, and for patients with hemianopia also to improve peripheral awareness. The vision training consisted of one lesson a week for 12 weeks carried out by an optometrist and a vision therapist. Between lessons, patients were to train at home for a minimum of 15-20 min daily. RESULTS: Twenty-four patients completed the course. Significant improvements in visual performance were measured for all test parameters from the baseline to the evaluation after the last lesson of vision training. The COPM results improved both in terms of satisfaction with the completion of a task and with the way the task was carried out (p = 0.001). Groffman tracing test results improved from median 7.5 to 16 (p = 0.002), reading speed in words increased (p = 0.0004), and peripheral awareness of visual markers improved (p = 0.002). CONCLUSION: Therapist-assisted vision therapy increased peripheral visual awareness. Furthermore patients felt safer in the traffic and in outdoor activities. Reading speed significantly increased, and the ability to keep a moving object in focus improved.
Subject(s)
Hemianopsia/rehabilitation , Ocular Motility Disorders/rehabilitation , Stroke Rehabilitation , Hemianopsia/etiology , Hemianopsia/physiopathology , Humans , Middle Aged , Ocular Motility Disorders/etiology , Ocular Motility Disorders/physiopathology , Patient Satisfaction , Saccades , Stroke/complications , Stroke/physiopathology , Stroke Rehabilitation/methods , Treatment Outcome , Vision, Binocular , Visual PerceptionABSTRACT
BACKGROUND: In recent years, the introduction of visual rehabilitation for patients with homonymous visual field defects has been met with both enthusiasm and caution. Despite the evidence that restitutive training results in expansion of the visual field, several concerns have been raised. OBJECTIVE: We tested the effectiveness of a new rehabilitative protocol called "Neuro Restoration Training" (NRT) in reducing visual field defects and in restituting visual functions in the restored hemianopic area. METHODS: Ten patients with homonymous visual field defects (lesion age >6 months) where trained in detecting low contrast Gabor patches randomly presented in the blind field, which refers to regions of 0âdB sensitivity, and along the hemianopic boundary between absolute (0âdB) and partial blindness (>0âdB). Training included static, drifting, and flickering Gabors in different blocks. Positions along the hemianopic boundary were systematically shifted toward the blind field according to the threshold reduction during the training. Before and after the training, we assessed visual field expansion and improvement in different high-level transfer tasks (i.e., letter identification and shape recognition) performed in the hemianopic boundary and in the blind field. RESULTS: NRT led to significant visual field enlargement (≈5 deg), as indicated by the conventional Humphrey perimetry, and two custom made evaluations of visual field expansion with eye movement control (one static and one dynamic). The restored area acquired new visual functions such as small letter recognition and perception of moving shapes. Finally, for some patients, NRT also improved detection, either aware or not, of high contrast flickering grating and recognition of geometrical shapes entirely presented within the blind field. CONCLUSION: These results suggest that NRT may lead to visual field enlargement and translate into untrained visual functions.
Subject(s)
Hemianopsia/rehabilitation , Stroke Rehabilitation , Therapy, Computer-Assisted/methods , Visual Fields/physiology , Adult , Analysis of Variance , Eye Movements/physiology , Female , Functional Laterality , Humans , Male , Middle Aged , Pattern Recognition, Visual/physiology , Recovery of Function , Statistics, Nonparametric , Stroke/complications , Visual Field TestsABSTRACT
BACKGROUND: Spontaneous recovery of visual loss resulting from injury to the brain is variable. A variety of traditional rehabilitative strategies, including the use of prisms or compensatory saccadic eye movements, have been used successfully to improve visual function and quality-of-life for patients with homonymous hemianopia. More recently, repetitive visual stimulation of the blind area has been reported to be of benefit in expanding the field of vision. EVIDENCE ACQUISITION: We performed a literature review with main focus on clinical studies spanning from 1963 to 2016, including 52 peer-reviewed articles, relevant cross-referenced citations, editorials, and reviews. RESULTS: Repetitive visual stimulation is reported to expand the visual field, although the interpretation of results is confounded by a variety of methodological factors and conflicting outcomes from different research groups. Many studies used subjective assessments of vision and did not include a sufficient number of subjects or controls. CONCLUSIONS: The available clinical evidence does not strongly support claims of visual restoration using repetitive visual stimulation beyond the time that spontaneous visual recovery might occur. This lack of firm supportive evidence does not preclude the potential of real benefit demonstrated in laboratories. Additional well-designed clinical studies with adequate controls and methods to record ocular fixation are needed.
Subject(s)
Blindness/rehabilitation , Hemianopsia/rehabilitation , Blindness/physiopathology , Hemianopsia/physiopathology , Humans , Quality of Life , Recovery of Function/physiology , Visual Acuity/physiology , Visual Fields/physiologyABSTRACT
PURPOSE: Prisms used for field expansion are limited by the optical scotoma at a prism apex (apical scotoma). For a patient with two functioning eyes, fitting prisms unilaterally allows the other eye to compensate for the apical scotoma. A monocular patient's field loss cannot be expanded with a conventional or Fresnel prism because of the apical scotoma. A newly invented optical device, the multiplexing prism (MxP), was developed to overcome the apical scotoma limitation in monocular field expansion. METHODS: A Fresnel-prism-like device with alternating prism and flat elements superimposes shifted and see-through views, thus creating the (monocular) visual confusion required for field expansion and eliminating the apical scotoma. Several implementations are demonstrated and preliminarily evaluated for different monocular conditions with visual field loss. The field expansion of the MxP is compared with the effect of conventional prisms using calculated and measured perimetry. RESULTS: Field expansion without apical scotomas is shown to be effective for monocular patients with hemianopia or constricted peripheral field. The MxPs are shown to increase the nasal field for a patient with only one eye and for patients with bitemporal hemianopia. The MxPs placed at the far temporal field are shown to expand the normal visual field. The ability to control the contrast ratio between the two images is verified. CONCLUSIONS: A novel optical device is demonstrated to have the potential for field expansion technology in a variety of conditions. The devices may be inexpensive and can be constructed in a cosmetically acceptable format.
Subject(s)
Hemianopsia/rehabilitation , Optical Devices , Vision, Binocular/physiology , Visual Fields/physiology , Adult , Female , Hemianopsia/physiopathology , Humans , Male , Middle Aged , Vision, Monocular/physiology , Visual Field TestsABSTRACT
BACKGROUND: Visual field defects after posterior cerebral artery stroke can be improved by vision restoration training (VRT), but when combined with transcranial direct current stimulation (tDCS), which alters brain excitability, vision recovery can be potentiated in the chronic stage. To date, the combination of VRT and tDCS has not been evaluated in postacute stroke rehabilitation. OBJECTIVES: To determine whether combined tDCS and VRT can be effectively implemented in the early recovery phase following stroke, and to explore the feasibility, safety and efficacy of an early intervention. DESIGN: Open-label pilot study including a case series of 7 tDCS/VRT versus a convenience sample of 7 control patients (ClinicalTrials.gov ID: NCT02935413). SETTING: Rehabilitation center. SUBJECTS: Patients with homonymous visual field defects following a posterior cerebral artery stroke. METHODS: Seven homonymous hemianopia patients were prospectively treated with 10 sessions of combined tDCS (2.mA, 10 daily sessions of 20 minutes) and VRT at 66 (±50) days on average poststroke. Visual field recovery was compared with the retrospective data of 7 controls, whose defect sizes and age of lesions were matched to those of the experimental subjects and who had received standard rehabilitation with compensatory eye movement and exploration training. RESULTS: All 7 patients in the treatment group completed the treatment protocol. The safety and acceptance were excellent, and patients reported occasional skin itching beneath the electrodes as the only minor side effect. Irrespective of their treatment, both groups (treatment and control) showed improved visual fields as documented by an increased mean sensitivity threshold in decibels in standard static perimetry. Recovery was significantly greater (P < .05) in the tDCS/VRT patients (36.73% ± 37.0%) than in the controls (10.74% ± 8.86%). CONCLUSION: In this open-label pilot study, tDCS/VRT in subacute stroke was demonstrated to be safe, with excellent applicability and acceptance of the treatment. Preliminary effectiveness calculations show that tDCS/VRT may be superior to standard vision training procedures. A confirmatory, larger-sample, controlled, randomized, and double-blind trial is now underway to compare real-tDCS- versus sham-tDCS-supported visual field training in the early vision rehabilitation phase. LEVEL OF EVIDENCE: IV.
Subject(s)
Hemianopsia/rehabilitation , Stroke Rehabilitation/methods , Stroke/complications , Transcranial Direct Current Stimulation/methods , Adult , Aged , Eye Movements/physiology , Female , Follow-Up Studies , Hemianopsia/etiology , Humans , Male , Middle Aged , Pilot Projects , Prospective Studies , Recovery of Function , Reference Values , Risk Assessment , Severity of Illness Index , Statistics, Nonparametric , Treatment Outcome , Visual Field Tests/methodsABSTRACT
Homonymous hemianopia from stroke causes visual disability. Although some patients experience spontaneous improvement, others have limited to no change and may be left with a severe disability. Current rehabilitation strategies are compensatory and cannot restore function. Animal studies suggest that central nervous system plasticity could allow for redirection of lost visual function into undamaged areas of cortex. A commercial therapy system was developed, from which claims of visual field expansion were disputed by independent researchers. The treatment remains controversial with seemingly contradictory data being generated. Continued research is underway to demonstrate the (non-)efficacy of this treatment method.
Subject(s)
Hemianopsia/rehabilitation , Stroke/complications , Hemianopsia/etiology , Hemianopsia/physiopathology , Humans , Neuronal Plasticity/physiology , Recovery of Function , Stroke/physiopathology , Visual Fields/physiologyABSTRACT
OBJECTIVE: Pilot trial to compare prism therapy and visual search training, for homonymous hemianopia, to standard care (information only). METHODS: Prospective, multicentre, parallel, single-blind, three-arm RCT across fifteen UK acute stroke units. PARTICIPANTS: Stroke survivors with homonymous hemianopia. INTERVENTIONS: Arm a (Fresnel prisms) for minimum 2 hours, 5 days per week over 6 weeks. Arm b (visual search training) for minimum 30 minutes, 5 days per week over 6 weeks. Arm c (standard care-information only). INCLUSION CRITERIA: Adult stroke survivors (>18 years), stable hemianopia, visual acuity better than 0.5 logMAR, refractive error within ±5 dioptres, ability to read/understand English and provide consent. OUTCOMES: Primary outcomes were change in visual field area from baseline to 26 weeks and calculation of sample size for a definitive trial. Secondary measures included Rivermead Mobility Index, Visual Function Questionnaire 25/10, Nottingham Extended Activities of Daily Living, Euro Qual, Short Form-12 questionnaires and Radner reading ability. Measures were post-randomization at baseline and 6, 12 and 26 weeks. RANDOMIZATION: Randomization block lists stratified by site and partial/complete hemianopia. BLINDING: Allocations disclosed to patients. Primary outcome assessor blind to treatment allocation. RESULTS: Eighty-seven patients were recruited: 27-Fresnel prisms, 30-visual search training and 30-standard care; 69% male; mean age 69 years (SD 12). At 26 weeks, full results for 24, 24 and 22 patients, respectively, were compared to baseline. Sample size calculation for a definitive trial determined as 269 participants per arm for a 200 degree2 visual field area change at 90% power. Non-significant relative change in area of visual field was 5%, 8% and 3.5%, respectively, for the three groups. Visual Function Questionnaire responses improved significantly from baseline to 26 weeks with visual search training (60 [SD 19] to 68.4 [SD 20]) compared to Fresnel prisms (68.5 [SD 16.4] to 68.2 [18.4]: 7% difference) and standard care (63.7 [SD 19.4] to 59.8 [SD 22.7]: 10% difference), P=.05. Related adverse events were common with Fresnel prisms (69.2%; typically headaches). CONCLUSIONS: No significant change occurred for area of visual field area across arms over follow-up. Visual search training had significant improvement in vision-related quality of life. Prism therapy produced adverse events in 69%. Visual search training results warrant further investigation.
Subject(s)
Activities of Daily Living , Eyeglasses , Hemianopsia/rehabilitation , Quality of Life , Stroke Rehabilitation/methods , Stroke/complications , Adult , Aged , Aged, 80 and over , Female , Hemianopsia/etiology , Humans , Male , Middle Aged , Pilot Projects , Prospective Studies , Single-Blind Method , Surveys and Questionnaires , Treatment Outcome , Visual Acuity/physiology , Visual Fields/physiologySubject(s)
Brain Injury, Chronic/diagnosis , Brain Injury, Chronic/rehabilitation , Cerebrovascular Disorders/diagnosis , Cerebrovascular Disorders/rehabilitation , Neurological Rehabilitation/methods , Vision Disorders/diagnosis , Vision Disorders/rehabilitation , Brain Injury, Chronic/complications , Cerebrovascular Disorders/complications , Combined Modality Therapy , Hemianopsia/diagnosis , Hemianopsia/etiology , Hemianopsia/rehabilitation , Humans , Interdisciplinary Communication , Intersectoral Collaboration , Oculomotor Nerve Diseases/diagnosis , Oculomotor Nerve Diseases/etiology , Oculomotor Nerve Diseases/rehabilitation , Perceptual Disorders/diagnosis , Perceptual Disorders/etiology , Perceptual Disorders/rehabilitation , Vision Disorders/etiology , Visual Acuity , Visual Fields , Visual PerceptionABSTRACT
INTRODUCTION: People with homonymous visual field defects (HVFD) often report difficulty detecting obstacles in the periphery on their blind side in time when moving around. Recently, a randomized controlled trial showed that the InSight-Hemianopia Compensatory Scanning Training (IH-CST) specifically improved detection of peripheral stimuli and avoiding obstacles when moving around, especially in dual task situations. METHOD: The within-group training effects of the previously reported IH-CST are examined in an extended patient group. Performance of patients with HVFD on a pre-assessment, post-assessment and follow-up assessment and performance of a healthy control group are compared. Furthermore, it is examined whether training effects can be predicted by demographic characteristics, variables related to the visual disorder, and neuropsychological test results. RESULTS: Performance on both subjective and objective measures of mobility-related scanning was improved after training, while no evidence was found for improvement in visual functions (including visual fields), reading, visual search and dot counting. Self-reported improvement did not correlate with improvement in objective mobility performance. According to the participants, the positive effects were still present six to ten months after training. No demographic characteristics, variables related to the visual disorder, and neuropsychological test results were found to predict the size of training effect, although some inconclusive evidence was found for more improvement in patients with left-sided HVFD than in patients with right-sided HFVD. CONCLUSION: Further support was found for a positive effect of IH-CST on detection of visual stimuli during mobility-related activities specifically. Based on the reports given by patients, these effects appear to be long-term effects. However, no conclusions can be drawn on the objective long-term training effects.
Subject(s)
Hemianopsia/physiopathology , Hemianopsia/rehabilitation , Psychomotor Performance/physiology , Visual Fields/physiology , Activities of Daily Living , Adult , Aged , Female , Follow-Up Studies , Humans , Male , Middle Aged , Reaction Time/physiology , Reading , Self Report , Surveys and Questionnaires , Treatment Outcome , Visual Field TestsABSTRACT
Visual field deficits are common in patients with damaged retinogeniculostriate pathways. The patient's eye movements are often affected leading to inefficient visual search. Systematic eye movement training also called compensatory therapy is needed to allow patients to develop effective coping strategies. There is a lack of evidence-based, clinical gold-standard registered medical device accessible to patients at home or in clinical settings and NeuroEyeCoach (NEC) is developed to address this need. In three experiments, we report on performance of patients on NEC compared to the data obtained previously on the earlier versions of the search task (n = 32); we assessed whether the self-administered computerised tasks can be used to monitor the progress (n = 24) and compared the findings in a subgroup of patients to a healthy control group. Performance on cancellation tasks, simple visual search, and self-reported responses on activities of daily living was compared, before and after training. Patients performed similarly well on NEC as on previous versions of the therapy; the inbuilt functionality for pre- and postevaluation functions was sensitive to allowing assessment of improvements; and improvements in patients were significantly greater than those in a group of healthy adults. In conclusion, NeuroEyeCoach can be used as an effective rehabilitation tool to develop compensatory strategies in patients with visual field deficits after brain injury.