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Namgung E, Kwon SU, Han M, Kim G, Kim HY, Park K, Cho M, Choi H, Nah H, Lim HT, Kang D. Digital therapeutics using virtual reality-based visual perceptual learning for visual field defects in stroke: A double-blind randomized trial. Brain Behav 2024; 14:e3525. [PMID: 38773793 PMCID: PMC11109502 DOI: 10.1002/brb3.3525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 04/04/2024] [Accepted: 04/19/2024] [Indexed: 05/24/2024] Open
Abstract
INTRODUCTION Visual field defects (VFDs) represent a debilitating poststroke complication, characterized by unseen parts of the visual field. Visual perceptual learning (VPL), involving repetitive visual training in blind visual fields, may effectively restore visual field sensitivity in cortical blindness. This current multicenter, double-blind, randomized, controlled clinical trial investigated the efficacy and safety of VPL-based digital therapeutics (Nunap Vision [NV]) for treating poststroke VFDs. METHODS Stroke outpatients with VFDs (>6 months after stroke onset) were randomized into NV (defective field training) or Nunap Vision-Control (NV-C, central field training) groups. Both interventions provided visual perceptual training, consisting of orientation, rotation, and depth discrimination, through a virtual reality head-mounted display device 5 days a week for 12 weeks. The two groups received VFD assessments using Humphrey visual field (HVF) tests at baseline and 12-week follow-up. The final analysis included those completed the study (NV, n = 40; NV-C, n = 35). Efficacy measures included improved visual area (sensitivity ≥6 dB) and changes in the HVF scores during the 12-week period. RESULTS With a high compliance rate, NV and NV-C training improved the visual areas in the defective hemifield (>72 degrees2) and the whole field (>108 degrees2), which are clinically meaningful improvements despite no significant between-group differences. According to within-group analyses, mean total deviation scores in the defective hemifield improved after NV training (p = .03) but not after NV-C training (p = .12). CONCLUSIONS The current trial suggests that VPL-based digital therapeutics may induce clinically meaningful visual improvements in patients with poststroke VFDs. Yet, between-group differences in therapeutic efficacy were not found as NV-C training exhibited unexpected improvement comparable to NV training, possibly due to learning transfer effects.
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Affiliation(s)
- Eun Namgung
- Asan Institute for Life SciencesAsan Medical CenterSeoulSouth Korea
| | - Sun U. Kwon
- Department of Neurology, Asan Medical CenterUniversity of Ulsan College of MedicineSeoulSouth Korea
| | - Moon‐Ku Han
- Department of NeurologySeoul National University Bundang Hospital, Seoul National University College of MedicineSeongnamSouth Korea
| | - Gyeong‐Moon Kim
- Department of Neurology, Samsung Medical CenterSungkyunkwan University School of MedicineSeoulSouth Korea
| | - Hahn Young Kim
- Department of NeurologyKonkuk University Medical Center, Konkuk University College of MedicineSeoulSouth Korea
| | - Kwang‐Yeol Park
- Department of NeurologyChung‐Ang University Hospital, Chung‐Ang University College of MedicineSeoulSouth Korea
| | | | | | - Hyun‐Wook Nah
- Department of NeurologyChungnam National University Sejong Hospital, Chungnam National University College of MedicineSejongSouth Korea
| | - Hyun Taek Lim
- Department of Ophthalmology, Asan Medical CenterUniversity of Ulsan College of MedicineSeoulSouth Korea
| | - Dong‐Wha Kang
- Department of Neurology, Asan Medical CenterUniversity of Ulsan College of MedicineSeoulSouth Korea
- Nunaps Inc.SeoulSouth Korea
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Tol S, de Haan GA, Postuma EMJL, Jansen JL, Heutink J. Reading Difficulties in Individuals with Homonymous Visual Field Defects: A Systematic Review of Reported Interventions. Neuropsychol Rev 2024:10.1007/s11065-024-09636-4. [PMID: 38639880 DOI: 10.1007/s11065-024-09636-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 02/20/2024] [Indexed: 04/20/2024]
Abstract
Reading difficulties are amongst the most commonly reported problems in individuals with homonymous visual field defects (HVFDs). To be able to provide guidance for healthcare professionals considering offering reading training, researchers in this field and interested individuals with HVFDs, this systematic review aims to (1) provide an overview of the contextual and intervention characteristics of all published HVFD interventions and (2) generate insights into the different reading outcome measures that these studies adopted. A search on PsycINFO, MEDLINE and Web of Science was conducted up to February 2, 2023. All intervention studies for HVFD in which reading was measured were included. Data was collected about the intervention type, session duration, number of sessions, the intensity, duration, circumstance of the interventions, country in which the intervention was studied and reading measures. Sixty records are included, describing 70 interventions in total of which 21 are specifically reading interventions. Overall, adjusted saccadic behaviour interventions occur most in the literature. A wide range within all intervention characteristics was observed. Forty-nine records reported task-performance reading measures, and 33 records reported self-reported reading measures. The majority of task-performance measures are based on self-developed paragraph reading tasks with a time-based outcome measure (e.g. words per minute). Future research could benefit from making use of validated reading tests, approaching the measurement of reading mixed-methods and providing participants the possibility to supply outcomes relevant to them.
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Affiliation(s)
- S Tol
- Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands.
| | - G A de Haan
- Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands
- Royal Dutch Visio, Centre of Expertise for Blind and Partially Sighted People, Amersfoortsestraatweg 180, 1272 RR, Huizen, The Netherlands
| | - E M J L Postuma
- Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands
| | - J L Jansen
- Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands
| | - J Heutink
- Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands
- Royal Dutch Visio, Centre of Expertise for Blind and Partially Sighted People, Amersfoortsestraatweg 180, 1272 RR, Huizen, The Netherlands
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Yang (杨菁艺) J, Saionz EL, Cavanaugh MR, Fahrenthold BK, Melnick MD, Tadin D, Briggs F, Carrasco M, Huxlin KR. Limited restoration of contrast sensitivity with training after V1 damage in humans. eNeuro 2024; 11:ENEURO.0020-24.2024. [PMID: 38395611 PMCID: PMC10941636 DOI: 10.1523/eneuro.0020-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
Stroke damage to the primary visual cortex (V1) causes severe visual deficits, which benefit from perceptual retraining. However, whereas training with high-contrast stimuli can locally restore orientation and motion direction discrimination abilities at trained locations, it only partially restores luminance contrast sensitivity (CS). Recent work revealed that high-contrast discrimination abilities may be preserved in the blind field of some patients early after stroke. Here, we asked if CS for orientation and direction discrimination is similarly preserved inside the blind field, to what extent, and whether it could benefit from a visual training intervention. Thirteen subacute patients (<3 months post-V1-stroke) and 12 chronic patients (>6 months post-V1-stroke) were pre-tested, then trained to discriminate either orientation or motion direction of Gabor patches of progressively lower contrasts as their performance improved. At baseline, more subacute than chronic participants could correctly discriminate the orientation of high-contrast Gabors in their blind field, but all failed to perform this task at lower contrasts, even when 10Hz flicker or motion direction were added. Training improved CS in a greater portion of subacute than chronic participants, but no-one attained normal CS, even when stimuli contained flicker or motion. We conclude that, unlike the near-complete training-induced restoration of high-contrast orientation and motion direction discrimination abilities, V1 damage in adulthood may severely limit the residual visual system's ability to regain normal CS. Our results support the notion that CS involves different neural substrates and computations than those required for orientation and direction discrimination in V1-damaged visual systems.Significance statement Stroke-induced V1 damage in adult humans induces a rapid and severe impairment of contrast sensitivity for orientation and motion direction discrimination in the affected hemifield, although discrimination of high-contrast stimuli can persist for several months. Adaptive training with Gabor patches of progressively lower contrasts improves contrast sensitivity for both orientation and motion discriminations in the blind-field of subacute (<3 months post-stroke) and chronic (>6 months post-stroke) participants; however, it fails to restore normal contrast sensitivity. Nonetheless, more subacute than chronic stroke participants benefit from such training, particularly when discriminating the orientation of static, non-flickering targets. Thus, contrast sensitivity appears critically dependent on processing within V1, with perceptual training displaying limited potential to fully restore it after V1 damage.
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Affiliation(s)
- Jingyi Yang (杨菁艺)
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Elizabeth L. Saionz
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Matthew R. Cavanaugh
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Berkeley K. Fahrenthold
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Michael D. Melnick
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
| | - Duje Tadin
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
| | - Farran Briggs
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
| | - Marisa Carrasco
- Department of Psychology and Center for Neural Science, New York University, New York, New York 10003
| | - Krystel R. Huxlin
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
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Maeyama T, Okada H, Sakai S. The effects of rehabilitative interventions on reading disorders caused by homonymous visual field defects: a meta-analysis focusing on improvement in reading speed. Acta Neurol Belg 2024; 124:123-140. [PMID: 37572263 DOI: 10.1007/s13760-023-02327-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/27/2023] [Indexed: 08/14/2023]
Abstract
INTRODUCTION Reading disorders caused by homonymous visual field defects (HVFDs) have a significant impact on a patient's quality of life. However, no review has been conducted to evaluate the available evidence on the effects of rehabilitative interventions on reading disorders caused by HVFDs. Thus, the aim of this study was to systematically evaluate the effects of rehabilitative interventions on reading disorders caused by HVFDs. METHODS We searched the MEDLINE/PubMed, Cochrane Library, ClinicalTrials.gov, CINAHL, and ScienceDirect databases for relevant articles. Relevant search terms were used to identify reports of randomized controlled trials or randomized crossover trials published between January 1990 and December 2021. Only studies that included reading-speed-related outcomes were analyzed. Risk of bias was assessed using the PEDro scale. Meta-analysis was conducted using a random-effects model, and standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using the Ι2 statistic. RESULTS Nine studies were included in the meta-analysis. The results showed that rehabilitative interventions significantly improved reading disorders caused by HVFDs (SMD = 0.30; 95% CI 0.08-0.51; P < 0.01; Ι2 = 0.0%). Subgroup analysis showed that reading training significantly improved reading disorders (SMD = 0.35; 95% CI 0.05-0.66; P = 0.02; Ι2 = 0.0%). CONCLUSION Reading disorders caused by HVFDs can be improved through rehabilitation. In addition, reading training for the improvement of eye movement and fixation to compensate for foveal and parafoveal visual field defects may improve reading speed.
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Affiliation(s)
- Takaya Maeyama
- Graduate School of Health Sciences, Hokkaido University, Kita 12-Jo Nishi 5-Chome, Kitaku, Sapporo, Hokkaido, Japan
| | - Hiroki Okada
- Department of Rehabilitation Sciences, Hokkaido University, Kita 12-Jo Nishi 5-Chome, Kita-Ku, Sapporo, Hokkaido, Japan.
| | - Shinya Sakai
- Department of Rehabilitation Sciences, Hokkaido University, Kita 12-Jo Nishi 5-Chome, Kita-Ku, Sapporo, Hokkaido, Japan
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5
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Yang J, Saionz EL, Cavanaugh MR, Fahrenthold BK, Melnick MD, Tadin D, Briggs F, Carrasco M, Huxlin KR. Contrast sensitivity: a fundamental limit to vision restoration after V1 damage. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.31.23294827. [PMID: 37693553 PMCID: PMC10491352 DOI: 10.1101/2023.08.31.23294827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Stroke damage to the primary visual cortex (V1) causes severe visual deficits, which benefit from perceptual retraining. However, whereas training with high-contrast stimuli can locally restore orientation and direction discrimination abilities at trained locations, it only partially restores luminance contrast sensitivity (CS). Recent work revealed that high-contrast discrimination abilities may be preserved in the blind field of some patients early after stroke. Here, we asked if CS for orientation and direction discrimination is similarly preserved inside the blind field, to what extent, and whether it could benefit from a visual training intervention. Thirteen subacute (<3 months post-V1-stroke) and 12 chronic (>6 months post-V1-stroke) participants were pre-tested, then trained to discriminate either orientation or motion direction of Gabor patches of progressively lower contrasts. At baseline, more subacute than chronic participants could correctly discriminate the orientation of high-contrast Gabors in their blind field, but all failed to perform this task at lower contrasts, even when 10Hz flicker or motion direction were added. Training improved CS in a greater portion of subacute than chronic participants, but no-one attained normal CS, even when stimuli contained flicker or motion. We conclude that, unlike the near-complete training-induced restoration of high-contrast orientation and direction discrimination, there is limited capacity for restoring CS after V1 damage in adulthood. Our results suggest that CS involves different neural substrates and computations than those required for orientation and direction discrimination in V1-damaged visual systems.
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Affiliation(s)
- Jingyi Yang
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Elizabeth L. Saionz
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Matthew R. Cavanaugh
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Berkeley K. Fahrenthold
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Michael D. Melnick
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Duje Tadin
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Farran Briggs
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
- Center for Visual Science, University of Rochester, Rochester, New York 14627
| | - Marisa Carrasco
- Department of Psychology and Center for Neural Science, New York University, NY, NY 10003
| | - Krystel R. Huxlin
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, New York 14642
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642
- Department of Brain & Cognitive Sciences, University of Rochester, Rochester, New York 14627
- Center for Visual Science, University of Rochester, Rochester, New York 14627
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Kwon S, Fahrenthold BK, Cavanaugh MR, Huxlin KR, Mitchell JF. Perceptual restoration fails to recover unconscious processing for smooth eye movements after occipital stroke. eLife 2022; 11:67573. [PMID: 35730931 PMCID: PMC9255960 DOI: 10.7554/elife.67573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 06/21/2022] [Indexed: 11/28/2022] Open
Abstract
The visual pathways that guide actions do not necessarily mediate conscious perception. Patients with primary visual cortex (V1) damage lose conscious perception but often retain unconscious abilities (e.g. blindsight). Here, we asked if saccade accuracy and post-saccadic following responses (PFRs) that automatically track target motion upon saccade landing are retained when conscious perception is lost. We contrasted these behaviors in the blind and intact fields of 11 chronic V1-stroke patients, and in 8 visually intact controls. Saccade accuracy was relatively normal in all cases. Stroke patients also had normal PFR in their intact fields, but no PFR in their blind fields. Thus, V1 damage did not spare the unconscious visual processing necessary for automatic, post-saccadic smooth eye movements. Importantly, visual training that recovered motion perception in the blind field did not restore the PFR, suggesting a clear dissociation between pathways mediating perceptual restoration and automatic actions in the V1-damaged visual system.
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Affiliation(s)
- Sunwoo Kwon
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, Berkeley, United States
| | | | - Matthew R Cavanaugh
- Center for Visual Science, University of Rochester, Rochester, United States
| | - Krystel R Huxlin
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, United States
| | - Jude F Mitchell
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, United States
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Awada A, Bakhtiari S, Legault C, Odier C, Pack CC. Training with optic flow stimuli promotes recovery in cortical blindness. Restor Neurol Neurosci 2022; 40:1-16. [PMID: 35213337 DOI: 10.3233/rnn-211223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Cortical blindness is a form of severe vision loss that is caused by damage to the primary visual cortex (V1) or its afferents. This condition has devastating effects on quality of life and independence. While there are few treatments currently available, accumulating evidence shows that certain visual functions can be restored with appropriate perceptual training: Stimulus sensitivity can be increased within portions of the blind visual field. However, this increased sensitivity often remains highly specific to the trained stimulus, limiting the overall improvement in visual function. OBJECTIVE Recent advances in the field of perceptual learning show that such specificity can be overcome with training paradigms that leverage the properties of higher-level visual cortical structures, which have greater capacity to generalize across stimulus positions and features. This targeting can be accomplished by using more complex training stimuli that elicit robust responses in these visual structures. METHODS We trained cortically blind subjects with a complex optic flow motion stimulus that was presented in a location of their blind field. Participants were instructed to train with the stimulus at home for approximately 30 minutes per day. Once performance plateaued, the stimulus was moved deeper into the blind field. A battery of pre- and post-training measures, with careful eye tracking, was performed to quantify the improvements. RESULTS We show that 1) optic flow motion discrimination can be relearned in cortically blind fields; 2) training with an optic flow stimulus can lead to improvements that transfer to different tasks and untrained locations; and 3) such training leads to a significant expansion of the visual field. The observed expansion of the visual field was present even when eye movements were carefully controlled. Finally, we show that regular training is critical for improved visual function, as sporadic training reduced the benefits of training, even when the total numbers of training sessions were equated. CONCLUSIONS These findings are consistent with the hypothesis that complex training stimuli can improve outcomes in cortical blindness, provided that patients adhere to a regular training regimen. Nevertheless, such interventions remain limited in their ability to restore functional vision.
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Affiliation(s)
- Asmara Awada
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Shahab Bakhtiari
- Department of Computer Science, McGill University, Montreal, Canada
| | - Catherine Legault
- McGill University Health Center (MUHC), Montreal, Canada.,Montreal Neurological Institute and Hospital, Montreal, Canada
| | - Celine Odier
- Neurovascular Health Program, Department of Medicine (Neurology), Centre Hospitalier de l'Universite de Montreal, Montreal, Canada
| | - Christopher C Pack
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
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Saionz EL, Busza A, Huxlin KR. Rehabilitation of visual perception in cortical blindness. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:357-373. [PMID: 35034749 PMCID: PMC9682408 DOI: 10.1016/b978-0-12-819410-2.00030-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Blindness is a common sequela after stroke affecting the primary visual cortex, presenting as a contralesional, homonymous, visual field cut. This can occur unilaterally or, less commonly, bilaterally. While it has been widely assumed that after a brief period of spontaneous improvement, vision loss becomes stable and permanent, accumulating data show that visual training can recover some of the vision loss, even long after the stroke. Here, we review the different approaches to rehabilitation employed in adult-onset cortical blindness (CB), focusing on visual restoration methods. Most of this work was conducted in chronic stroke patients, partially restoring visual discrimination and luminance detection. However, to achieve this, patients had to train for extended periods (usually many months), and the vision restored was not entirely normal. Several adjuvants to training such as noninvasive, transcranial brain stimulation, and pharmacology are starting to be investigated for their potential to increase the efficacy of training in CB patients. However, these approaches are still exploratory and require considerably more research before being adopted. Nonetheless, having established that the adult visual system retains the capacity for restorative plasticity, attention recently turned toward the subacute poststroke period. Drawing inspiration from sensorimotor stroke rehabilitation, visual training was recently attempted for the first time in subacute poststroke patients. It improved vision faster, over larger portions of the blind field, and for a larger number of visual discrimination abilities than identical training initiated more than 6 months poststroke (i.e., in the chronic period). In conclusion, evidence now suggests that visual neuroplasticity after occipital stroke can be reliably recruited by a range of visual training approaches. In addition, it appears that poststroke visual plasticity is dynamic, with a critical window of opportunity in the early postdamage period to attain more rapid, more extensive recovery of a larger set of visual perceptual abilities.
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Affiliation(s)
- Elizabeth L Saionz
- Medical Scientist Training Program, University of Rochester, Rochester, NY, United States
| | - Ania Busza
- Department of Neurology, University of Rochester, Rochester, NY, United States
| | - Krystel R Huxlin
- Flaum Eye Institute, University of Rochester, Rochester, NY, United States.
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9
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Ajina S, Jünemann K, Sahraie A, Bridge H. Increased Visual Sensitivity and Occipital Activity in Patients With Hemianopia Following Vision Rehabilitation. J Neurosci 2021; 41:5994-6005. [PMID: 34035137 PMCID: PMC8276743 DOI: 10.1523/jneurosci.2790-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/22/2021] [Accepted: 03/26/2021] [Indexed: 11/21/2022] Open
Abstract
Hemianopia, loss of vision in half of the visual field, results from damage to the visual pathway posterior to the optic chiasm. Despite negative effects on quality of life, few rehabilitation options are currently available. Recently, several long-term training programs have been developed that show visual improvement within the blind field, although little is known of the underlying neural changes. Here, we have investigated functional and structural changes in the brain associated with visual rehabilitation. Seven human participants with occipital lobe damage enrolled in a visual training program to distinguish which of two intervals contained a drifting Gabor patch presented within the blind field. Participants performed ∼25 min of training each day for 3-6 months and undertook psychophysical tests and a magnetic resonance imaging scan before and after training. A control group undertook psychophysical tests before and after an equivalent period without training. Participants who were not at ceiling on baseline tests showed on average 9.6% improvement in Gabor detection, 8.3% in detection of moving dots, and 9.9% improvement in direction discrimination after training. Importantly, psychophysical improvement only correlated with improvement in Humphrey perimetry in the trained region of the visual field. Whole-brain analysis showed an increased neural response to moving stimuli in the blind visual field in motion area V5/hMT. Using a region-of-interest approach, training had a significant effect on the blood oxygenation level-dependent signal compared with baseline. Moreover, baseline V5/hMT activity was correlated to the amount of improvement in visual sensitivity using psychophysical and perimetry tests. This study, identifying a critical role for V5/hMT in boosting visual function, may allow us to determine which patients may benefit most from training and design adjunct interventions to increase training effects.SIGNIFICANCE STATEMENT Homonymous visual field loss is a common consequence of brain injury and is estimated to affect more than 230,000 people in the United Kingdom. Despite its high prevalence and well-described impact on quality of life, treatments to improve visual sensitivity remain experimental, and deficits are considered permanent after 6 months. Our study shows that behavioral changes following vision rehabilitation are associated with enhanced visually-evoked occipital activity to stimuli in the blind visual field. Unlike previous behavioral studies, we observe clinical changes that are specific to the trained region of vision. This lends significant weight to such training paradigms and offers a mechanism by which visual function can be improved despite damage to the primary visual pathway.
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Affiliation(s)
- Sara Ajina
- Department of Neurorehabilitation and Therapy Services, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, United Kingdom
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Kristin Jünemann
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, United Kingdom
- Division of Clinical Psychology and Sexual Medicine, Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, 30635 Hannover, Germany
| | - Arash Sahraie
- School of Psychology, University of Aberdeen, Kings College, Old Aberdeen AB24 3FX, United Kingdom
| | - Holly Bridge
- Wellcome Centre for Integrative Neuroimaging, Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, United Kingdom
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10
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Elshout JA, Bergsma DP, van den Berg AV, Haak KV. Functional MRI of visual cortex predicts training-induced recovery in stroke patients with homonymous visual field defects. NEUROIMAGE-CLINICAL 2021; 31:102703. [PMID: 34062384 PMCID: PMC8173295 DOI: 10.1016/j.nicl.2021.102703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/28/2022]
Abstract
Damage to the visual brain typically leads to vision loss. Vision loss may be partially recovered with visual restitution training (VRT) Cortical responses to visual stimulation do not always lead to visual awareness. A mismatch between Humphrey and neural perimetry predicts training outcome. This finding has important implications for better rehabilitation strategies.
Post-chiasmatic damage to the visual system leads to homonymous visual field defects (HVDs), which can severely interfere with daily life activities. Visual Restitution Training (VRT) can recover parts of the affected visual field in patients with chronic HVDs, but training outcome is variable. An untested hypothesis suggests that training potential may be largest in regions with ‘neural reserve’, where cortical responses to visual stimulation do not lead to visual awareness as assessed by Humphrey perimetry—a standard behavioural visual field test. Here, we tested this hypothesis in a sample of twenty-seven hemianopic stroke patients, who participated in an assiduous 80-hour VRT program. For each patient, we collected Humphrey perimetry and wide-field fMRI-based retinotopic mapping data prior to training. In addition, we used Goal Attainment Scaling to assess whether personal activities in daily living improved. After training, we assessed with a second Humphrey perimetry measurement whether the visual field was improved and evaluated which personal goals were attained. Confirming the hypothesis, we found significantly larger improvements of visual sensitivity at field locations with neural reserve. These visual field improvements implicated both regions in primary visual cortex and higher order visual areas. In addition, improvement in daily life activities correlated with the extent of visual field enlargement. Our findings are an important step toward understanding the mechanisms of visual restitution as well as predicting training efficacy in stroke patients with chronic hemianopia.
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Affiliation(s)
- J A Elshout
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - D P Bergsma
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - A V van den Berg
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - K V Haak
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands.
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11
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Abstract
PURPOSE OF REVIEW Homonymous visual field defects are a common sequela of stroke, and are assumed to be permanent within a few weeks of the event. Because consensus about the efficacy of rehabilitation is lacking, visual therapy is rarely prescribed. Here, we review current rehabilitation options and strategies in the translational pipeline that could change these perspectives. RECENT FINDINGS The mainstays of available therapy for homonymous visual defects are compensation training and substitution, which allow patients to better use their spared vision. However, early clinical studies suggest that vision can partially recover following intensive training inside the blind field. Research into the relative efficacy of different restorative approaches continues, providing insights into neurophysiologic substrates of recovery and its limitations. This, in turn, has led to new work examining the possible benefits of earlier intervention, advanced training procedures, noninvasive brain stimulation, and pharmacological adjuvants, all of which remain to be vetted through properly powered, randomized, clinical trials. SUMMARY Research has uncovered substantial visual plasticity after occipital strokes, suggesting that rehabilitative strategies for this condition should be more aggressive. For maximal benefit, poststroke vision-restorative interventions should begin early, and in parallel with strategies that optimize everyday use of an expanding field of view.
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Affiliation(s)
| | - Steven E Feldon
- Flaum Eye Institute
- Center for Visual Science, University of Rochester, Rochester, NY, USA
| | - Krystel R Huxlin
- Flaum Eye Institute
- Center for Visual Science, University of Rochester, Rochester, NY, USA
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12
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Efficacy of Visual Retraining in the Hemianopic Field after Stroke: Results of a Randomized Clinical Trial. Ophthalmology 2020; 128:1091-1101. [PMID: 33242498 DOI: 10.1016/j.ophtha.2020.11.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 11/21/2022] Open
Abstract
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.
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Halbertsma HN, Elshout JA, Bergsma DP, Norris DG, Cornelissen FW, van den Berg AV, Haak KV. Functional connectivity of the Precuneus reflects effectiveness of visual restitution training in chronic hemianopia. NEUROIMAGE-CLINICAL 2020; 27:102292. [PMID: 32554320 PMCID: PMC7303670 DOI: 10.1016/j.nicl.2020.102292] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 04/17/2020] [Accepted: 05/19/2020] [Indexed: 01/10/2023]
Abstract
Visual field defects in chronic hemianopia can improve through visual restitution training, yet not all patients benefit equally from this long and exhaustive procedure. Here, we asked if resting-state functional connectivity prior to visual restitution could predict training success. In two training sessions of eight weeks each, 20 patients with chronic hemianopia performed a visual discrimination task by directing spatial selective attention towards stimuli presented in either hemifield, while suppressing eye movements. We examined two effects: a sensitivity change in the attended (trained) minus the unattended (control) hemifield (i.e., a training-specific improvement), and an overall improvement (i.e., a total change in sensitivity after both sessions). We then identified five visual resting-state networks and evaluated their functional connectivity in relation to both training effects. We found that the functional connectivity strength between the anterior Precuneus and the Occipital Pole Network was positively related to the attention modulated (i.e., training-specific) improvement. No such relationship was found for the overall improvement or for the other visual networks of interest. Our finding suggests that the anterior Precuneus plays a role in attention-modulated visual field improvements. The resting-state functional connectivity between the anterior Precuneus and the Occipital Pole Network may thus serve as an imaging-based biomarker that quantifies a patient's potential capacity to direct spatial attention. This may help to identify hemianopia patients that are most likely to benefit from visual restitution training.
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Affiliation(s)
- Hinke N Halbertsma
- Laboratory for Experimental Ophthalmology, University Medical Center Groningen, Groningen, the Netherlands.
| | - Joris A Elshout
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Douwe P Bergsma
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - David G Norris
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Frans W Cornelissen
- Laboratory for Experimental Ophthalmology, University Medical Center Groningen, Groningen, the Netherlands
| | - Albert V van den Berg
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Koen V Haak
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
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van Nispen RMA, Virgili G, Hoeben M, Langelaan M, Klevering J, Keunen JEE, van Rens GHMB. Low vision rehabilitation for better quality of life in visually impaired adults. Cochrane Database Syst Rev 2020; 1:CD006543. [PMID: 31985055 PMCID: PMC6984642 DOI: 10.1002/14651858.cd006543.pub2] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Low vision rehabilitation aims to optimise the use of residual vision after severe vision loss, but also aims to teach skills in order to improve visual functioning in daily life. Other aims include helping people to adapt to permanent vision loss and improving psychosocial functioning. These skills promote independence and active participation in society. Low vision rehabilitation should ultimately improve quality of life (QOL) for people who have visual impairment. OBJECTIVES To assess the effectiveness of low vision rehabilitation interventions on health-related QOL (HRQOL), vision-related QOL (VRQOL) or visual functioning and other closely related patient-reported outcomes in visually impaired adults. SEARCH METHODS We searched relevant electronic databases and trials registers up to 18 September 2019. SELECTION CRITERIA We included randomised controlled trials (RCTs) investigating HRQOL, VRQOL and related outcomes of adults, with an irreversible visual impairment (World Health Organization criteria). We included studies that compared rehabilitation interventions with active or inactive control. DATA COLLECTION AND ANALYSIS We used standard methods expected by Cochrane. We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS We included 44 studies (73 reports) conducted in North America, Australia, Europe and Asia. Considering the clinical diversity of low vision rehabilitation interventions, the studies were categorised into four groups of related intervention types (and by comparator): (1) psychological therapies and/or group programmes, (2) methods of enhancing vision, (3) multidisciplinary rehabilitation programmes, (4) other programmes. Comparators were no care or waiting list as an inactive control group, usual care or other active control group. Participants included in the reported studies were mainly older adults with visual impairment or blindness, often as a result of age-related macular degeneration (AMD). Study settings were often hospitals or low vision rehabilitation services. Effects were measured at the short-term (six months or less) in most studies. Not all studies reported on funding, but those who did were supported by public or non-profit funders (N = 31), except for two studies. Compared to inactive comparators, we found very low-certainty evidence of no beneficial effects on HRQOL that was imprecisely estimated for psychological therapies and/or group programmes (SMD 0.26, 95% CI -0.28 to 0.80; participants = 183; studies = 1) and an imprecise estimate suggesting little or no effect of multidisciplinary rehabilitation programmes (SMD -0.08, 95% CI -0.37 to 0.21; participants = 183; studies = 2; I2 = 0%); no data were available for methods of enhancing vision or other programmes. Regarding VRQOL, we found low- or very low-certainty evidence of imprecisely estimated benefit with psychological therapies and/or group programmes (SMD -0.23, 95% CI -0.53 to 0.08; studies = 2; I2 = 24%) and methods of enhancing vision (SMD -0.19, 95% CI -0.54 to 0.15; participants = 262; studies = 5; I2 = 34%). Two studies using multidisciplinary rehabilitation programmes showed beneficial but inconsistent results, of which one study, which was at low risk of bias and used intensive rehabilitation, recorded a very large and significant effect (SMD: -1.64, 95% CI -2.05 to -1.24), and the other a small and uncertain effect (SMD -0.42, 95%: -0.90 to 0.07). Compared to active comparators, we found very low-certainty evidence of small or no beneficial effects on HRQOL that were imprecisely estimated with psychological therapies and/or group programmes including no difference (SMD -0.09, 95% CI -0.39 to 0.20; participants = 600; studies = 4; I2 = 67%). We also found very low-certainty evidence of small or no beneficial effects with methods of enhancing vision, that were imprecisely estimated (SMD -0.09, 95% CI -0.28 to 0.09; participants = 443; studies = 2; I2 = 0%) and multidisciplinary rehabilitation programmes (SMD -0.10, 95% CI -0.31 to 0.12; participants = 375; studies = 2; I2 = 0%). Concerning VRQOL, low-certainty evidence of small or no beneficial effects that were imprecisely estimated, was found with psychological therapies and/or group programmes (SMD -0.11, 95% CI -0.24 to 0.01; participants = 1245; studies = 7; I2 = 19%) and moderate-certainty evidence of small effects with methods of enhancing vision (SMD -0.24, 95% CI -0.40 to -0.08; participants = 660; studies = 7; I2 = 16%). No additional benefit was found with multidisciplinary rehabilitation programmes (SMD 0.01, 95% CI -0.18 to 0.20; participants = 464; studies = 3; I2 = 0%; low-certainty evidence). Among secondary outcomes, very low-certainty evidence of a significant and large, but imprecisely estimated benefit on self-efficacy or self-esteem was found for psychological therapies and/or group programmes versus waiting list or no care (SMD -0.85, 95% CI -1.48 to -0.22; participants = 456; studies = 5; I2 = 91%). In addition, very low-certainty evidence of a significant and large estimated benefit on depression was found for psychological therapies and/or group programmes versus waiting list or no care (SMD -1.23, 95% CI -2.18 to -0.28; participants = 456; studies = 5; I2 = 94%), and moderate-certainty evidence of a small benefit versus usual care (SMD -0.14, 95% CI -0.25 to -0.04; participants = 1334; studies = 9; I2 = 0%). ln the few studies in which (serious) adverse events were reported, these seemed unrelated to low vision rehabilitation. AUTHORS' CONCLUSIONS In this Cochrane Review, no evidence of benefit was found of diverse types of low vision rehabilitation interventions on HRQOL. We found low- and moderate-certainty evidence, respectively, of a small benefit on VRQOL in studies comparing psychological therapies or methods for enhancing vision with active comparators. The type of rehabilitation varied among studies, even within intervention groups, but benefits were detected even if compared to active control groups. Studies were conducted on adults with visual impairment mainly of older age, living in high-income countries and often having AMD. Most of the included studies on low vision rehabilitation had a short follow-up, Despite these limitations, the consistent direction of the effects in this review towards benefit justifies further research activities of better methodological quality including longer maintenance effects and costs of several types of low vision rehabilitation. Research on the working mechanisms of components of rehabilitation interventions in different settings, including low-income countries, is also needed.
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Affiliation(s)
- Ruth MA van Nispen
- Amsterdam University Medical Centers, Vrije UniversiteitDepartment of Ophthalmology, Amsterdam Public Health research instituteAmsterdamNetherlands
| | - Gianni Virgili
- University of FlorenceDepartment of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA)Largo Palagi, 1FlorenceItaly50134
| | - Mirke Hoeben
- Amsterdam University Medical Centers, Vrije UniversiteitDepartment of Ophthalmology, Amsterdam Public Health research instituteAmsterdamNetherlands
| | - Maaike Langelaan
- Netherlands institute for health services, NIVEL researchP.O. Box 1568UtrechtNetherlands3500 BN
| | - Jeroen Klevering
- Radboud University Medical CenterDepartment of OphthalmologyNijmegenNetherlands
| | - Jan EE Keunen
- Radboud University Medical CenterDepartment of OphthalmologyNijmegenNetherlands
| | - Ger HMB van Rens
- Amsterdam University Medical Centers, Vrije UniversiteitDepartment of Ophthalmology, Amsterdam Public Health research instituteAmsterdamNetherlands
- Elkerliek HospitalDepartment of OphthalmologyHelmondNetherlands
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15
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Pollock A, Hazelton C, Rowe FJ, Jonuscheit S, Kernohan A, Angilley J, Henderson CA, Langhorne P, Campbell P. Interventions for visual field defects in people with stroke. Cochrane Database Syst Rev 2019; 5:CD008388. [PMID: 31120142 PMCID: PMC6532331 DOI: 10.1002/14651858.cd008388.pub3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Visual field defects are estimated to affect 20% to 57% of people who have had a stroke. Visual field defects can affect functional ability in activities of daily living (commonly affecting mobility, reading and driving), quality of life, ability to participate in rehabilitation, and depression and anxiety following stroke. There are many interventions for visual field defects, which are proposed to work by restoring the visual field (restitution); compensating for the visual field defect by changing behaviour or activity (compensation); substituting for the visual field defect by using a device or extraneous modification (substitution); or ensuring appropriate diagnosis, referral and treatment prescription through standardised assessment or screening, or both. OBJECTIVES To determine the effects of interventions for people with visual field defects after stroke. SEARCH METHODS We searched the Cochrane Stroke Group Trials Register, the Cochrane Eyes and Vision Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, AMED, PsycINFO, and PDQT Databse, and clinical trials databases, including ClinicalTrials.gov and WHO Clinical Trials Registry, to May 2018. We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts. SELECTION CRITERIA Randomised trials in adults after stroke, where the intervention was specifically targeted at improving the visual field defect or improving the ability of the participant to cope with the visual field loss. The primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, reading ability, visual field measures, balance, falls, depression and anxiety, discharge destination or residence after stroke, quality of life and social isolation, visual scanning, adverse events, and death. DATA COLLECTION AND ANALYSIS Two review authors independently screened abstracts, extracted data and appraised trials. We undertook an assessment of methodological quality for allocation concealment, blinding of outcome assessors, method of dealing with missing data, and other potential sources of bias. We assessed the quality of evidence for each outcome using the GRADE approach. MAIN RESULTS Twenty studies (732 randomised participants, with data for 547 participants with stroke) met the inclusion criteria for this review. However, only 10 of these studies compared the effect of an intervention with a placebo, control, or no treatment group, and eight had data which could be included in meta-analyses. Only two of these eight studies presented data relating to our primary outcome of functional abilities in activities of daily living. One study reported evidence relating to adverse events.Three studies (88 participants) compared a restitutive intervention with a control, but data were only available for one study (19 participants). There was very low-quality evidence that visual restitution therapy had no effect on visual field outcomes, and a statistically significant effect on quality of life, but limitations with these data mean that there is insufficient evidence to draw any conclusions about the effectiveness of restitutive interventions as compared to control.Four studies (193 participants) compared the effect of scanning (compensatory) training with a control or placebo intervention. There was low-quality evidence that scanning training was more beneficial than control or placebo on quality of life, measured using the Visual Function Questionnaire (VFQ-25) (two studies, 96 participants, mean difference (MD) 9.36, 95% confidence interval (CI) 3.10 to 15.62). However, there was low or very-low quality evidence of no effect on measures of visual field, extended activities of daily living, reading, and scanning ability. There was low-quality evidence of no significant increase in adverse events in people doing scanning training, as compared to no treatment.Three studies (166 participants) compared a substitutive intervention (a type of prism) with a control. There was low or very-low quality evidence that prisms did not have an effect on measures of activities of daily living, extended activities of daily living, reading, falls, or quality of life, and very low-quality evidence that they may have an effect on scanning ability (one study, 39 participants, MD 9.80, 95% CI 1.91 to 17.69). There was low-quality evidence of an increased odds of an adverse event (primarily headache) in people wearing prisms, as compared to no treatment.One study (39 participants) compared the effect of assessment by an orthoptist to standard care (no assessment) and found very low-quality evidence that there was no effect on measures of activities of daily living.Due to the quality and quantity of evidence, we remain uncertain about the benefits of assessment interventions. AUTHORS' CONCLUSIONS There is a lack of evidence relating to the effect of interventions on our primary outcome of functional ability in activities of daily living. There is limited low-quality evidence that compensatory scanning training may be more beneficial than placebo or control at improving quality of life, but not other outcomes. There is insufficient evidence to reach any generalised conclusions about the effect of restitutive interventions or substitutive interventions (prisms) as compared to placebo, control, or no treatment. There is low-quality evidence that prisms may cause minor adverse events.
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Affiliation(s)
- Alex Pollock
- Nursing, Midwifery and Allied Health Professions Research Unit, Glasgow Caledonian University, 6th Floor, Govan Mbeki Building, Cowcaddens Road, Glasgow, UK, G4 0BA
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16
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Elshout JA, Bergsma DP, Sibbel J, Baars-Elsinga A, Lubbers P, Van Asten F, Visser-Meily J, Van Den Berg AV. Improvement in activities of daily living after visual training in patients with homonymous visual field defects using Goal Attainment Scaling. Restor Neurol Neurosci 2018; 36:1-12. [DOI: 10.3233/rnn-170719] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Joris A. Elshout
- Department of Cognitive Neuroscience, Section of Biophysics, Donders Centre for Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Douwe P. Bergsma
- Department of Cognitive Neuroscience, Section of Biophysics, Donders Centre for Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Jacqueline Sibbel
- Department of Rehabilitation, Physical Therapy Science & Sports, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Annette Baars-Elsinga
- Department of Rehabilitation, Physical Therapy Science & Sports, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Paula Lubbers
- St. Maartenskliniek Rehabilitation, Nijmegen, The Netherlands
| | - Freekje Van Asten
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Johanna Visser-Meily
- Department of Rehabilitation, Physical Therapy Science & Sports, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Center of Excellence for Rehabilitation Medicine, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht University and De Hoogstraat Rehabilitation, Utrecht, The Netherlands
| | - Albert V. Van Den Berg
- Department of Cognitive Neuroscience, Section of Biophysics, Donders Centre for Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
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17
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Bergsma DP, Elshout JA, van den Berg AV. Segregation of Spontaneous and Training Induced Recovery from Visual Field Defects in Subacute Stroke Patients. Front Neurol 2017; 8:681. [PMID: 29326645 PMCID: PMC5736566 DOI: 10.3389/fneur.2017.00681] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/29/2017] [Indexed: 12/17/2022] Open
Abstract
Whether rehabilitation after stroke profits from an early start is difficult to establish as the contributions of spontaneous recovery and treatment are difficult to tease apart. Here, we use a novel training design to dissociate these components for visual rehabilitation of subacute stroke patients with visual field defects such as hemianopia. Visual discrimination training was started within 6 weeks after stroke in 17 patients. Spontaneous and training-induced recoveries were distinguished by training one-half of the defect for 8 weeks, while monitoring spontaneous recovery in the other (control) half of the defect. Next, trained and control regions were swapped, and training continued for another 8 weeks. The same paradigm was also applied to seven chronic patients for whom spontaneous recovery can be excluded and changes in the control half of the defect point to a spillover effect of training. In both groups, field stability was assessed during a no-intervention period. Defect reduction was significantly greater in the trained part of the defect than in the simultaneously untrained part of the defect irrespective of training onset (p = 0.001). In subacute patients, training contributed about twice as much to their defect reduction as the spontaneous recovery. Goal Attainment Scores were significantly and positively correlated with the total defect reduction (p = 0.01), percentage increase reading speed was significantly and positively correlated with the defect reduction induced by training (epoch 1: p = 0.0044; epoch 2: p = 0.023). Visual training adds significantly to the spontaneous recovery of visual field defects, both during training in the early and the chronic stroke phase. However, field recovery as a result of training in this subacute phase was as large as in the chronic phase. This suggests that patients benefited primarily of early onset training by gaining access to a larger visual field sooner.
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Affiliation(s)
- Douwe P Bergsma
- Department of Cognitive Neuroscience, Section of Biophysics, Donders Centre for Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Joris A Elshout
- Department of Cognitive Neuroscience, Section of Biophysics, Donders Centre for Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Albert V van den Berg
- Department of Cognitive Neuroscience, Section of Biophysics, Donders Centre for Neuroscience, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
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18
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Geuzebroek AC, van den Berg AV. Impaired visual competition in patients with homonymous visual field defects. Neuropsychologia 2017; 97:152-162. [PMID: 28209521 DOI: 10.1016/j.neuropsychologia.2017.02.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 02/06/2017] [Accepted: 02/12/2017] [Indexed: 10/20/2022]
Abstract
Intense visual training can lead to partial recovery of visual field defects caused by lesions of the primary visual cortex. However, the standard visual detection and discrimination tasks, used to assess this recovery process tend to ignore the complexity of the natural visual environment, where multiple stimuli continuously interact. Visual competition is an essential component for natural search tasks and detecting unexpected events. Our study focused on visual decision-making and to what extent the recovered visual field can compete for attention with the 'intact' visual field. Nine patients with visual field defects who had previously received visual discrimination training, were compared to healthy age-matched controls using a saccade target-selection paradigm, in which participants actively make a saccade towards the brighter of two flashed targets. To further investigate the nature of competition (feed-forward or feedback inhibition), we presented two flashes that reversed their intensity difference during the flash. Both competition between recovered visual field and intact visual field, as well as competition within the intact visual field, were assessed. Healthy controls showed the expected primacy effect; they preferred the initially brighter target. Surprisingly, choice behaviour, even in the patients' supposedly 'intact' visual field, was significantly different from the control group for all but one. In the latter patient, competition was comparable to the controls. All other patients showed a significantly reduced preference to the brighter target, but still showed a small hint of primacy in the reversal conditions. The present results indicate that patients and controls have similar decision-making mechanisms but patients' choices are affected by a strong tendency to guess, even in the intact visual field. This tendency likely reveals slower integration of information, paired with a lower threshold. Current rehabilitation should therefore also include training focused on improving visual decision-making of the defective and the intact visual field.
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Affiliation(s)
- A C Geuzebroek
- Department Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Postbus 9101, 6500 HB Nijmegen (route 205), The Netherlands.
| | - A V van den Berg
- Department Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Postbus 9101, 6500 HB Nijmegen (route 205), The Netherlands.
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