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Rehabilitation of Visual Perceptual Deficits

2016 UPDATE
February 2016

The Canadian Stroke Best Practice Recommendations for Stroke Rehabilitation, 5th Edition (2015) is published in the International Journal of Stroke (IJS) and available freely online. To access the specific recommendations for Rehabilitation of Visual Perceptual Deficits, and all other sections of the Stroke Rehabilitation recommendations, please click on this URL which will take you to the recommendations online in the IJS: http://journals.sagepub.com/doi/pdf/10.1177/1747493016643553

For the French version of these recommendations, open the appendix at this link :  http://wso.sagepub.com/content/suppl/2016/04/18/1747493016643553.DC1/Stroke_Rehabilitation_2015_IJS_Manuscript_FINAL_FRENCH.pdf

All other supporting information, including performance measures, implementation resources, evidence summaries and references, remain available through www.strokebestpractices.ca, and not through the IJS.  Please click on the appropriate sections on our website below for this additional content.

Rationale

Visual perceptual disorders are a common clinical consequence of stroke. They include unilateral neglect, which has a major impact on rehabilitation outcome. Visual perceptual disorders result in processing changes in the integration of visual information with other systems. These changes decrease a patient’s ability to adapt to the basic requirements of daily life. The incidence of unilateral spatial neglect is estimated to be approximately 23%. The presence of neglect has been associated with both severity of stroke and age of the individual.

Limb apraxias are more common in those with left hemisphere involvement (28 – 57%) but can also be seen in right hemisphere damage (0 – 34%) (Donkervoort et al., 2000). While apraxia improves with early recovery, up to 20 percent of those initially identified will continue to demonstrate persistent problems.   Severity of apraxia is associated with changes in functional performance.

 

 

System Implications

To achieve timely and appropriate assessment and management of perceptual deficits, the organization should provide:

  • Initial standardized assessment of visual perceptual deficits (including inattention and apraxia) performed by clinicians experienced in the field of stroke.
  • Timely access to specialized, interprofessional stroke rehabilitation services where therapies of appropriate type and intensity are provided.
  • Access to appropriate equipment to aid in recovery when necessary without financial barriers.
  • Long-term rehabilitation services widely available in nursing and continuing care facilities, and in outpatient and community programs.

 

 

 

Performance Measures

  1. Proportion of stroke patients with documentation that an initial screening for visual perceptual deficits was performed as part of a comprehensive rehabilitation assessment.
  2. Proportion of stroke patients with poor results on initial screening who then receive a comprehensive assessment by appropriately trained healthcare professionals.

 

 

 

Implementation Resources and Knowledge Transfer Tools

Patient Information

Summary of the Evidence

Evidence Table 8: Rehabilitation of Visual Perceptual Deficits

Perceptual deficits or disorders may affect any of the sensory modalities, resulting in disorders that may include visual, tactile, location, auditory, spatial, object (object agnosia), prosopagnosia, and colour processing, among others (Bowen et al., 2011). The prevalence of post-stroke perceptual deficits has been estimated to be as high as 69% one-month post-stroke and 74% two-years post-stroke (Edmans et al., 2000).

Of the perceptual deficits that affect individuals post-stroke, visual perceptual disorders, including unilateral spatial neglect (USN), may be the most frequently selected for investigation. In the Copenhagen Stroke Study, the incidence rate of post-stroke USN was found to be 23%, with USN being more common among individuals with a right-sided, as compared to a left-sided lesion (42% vs. 8%) (Pedersen et al., 1997). Presence of neglect has been reported to have a negative impact on functional recovery, length of rehabilitation stay, and independence following discharge (Katz et al., 1999; Paolucci et al., 2001; Gillen et al., 2005; Wee & Hopman, 2008).

In terms of non-pharmacological treatment of perceptual disorders post stroke, a Cochrane review by Bowen and colleagues (2011) identified five studies (n=308), each of which examined forms of sensory stimulation including cueing or visual stimulation. Based on the results of three trials providing sufficient data for pooling, no significant between group differences were found in perceptual impairment at the end of treatment (SMD=0.07, 95% CI -0.29 to 0.43). In another Cochrane review, 12 trials (n=306) were identified examining cognitive rehabilitation for the treatment of spatial neglect (Bowen and Lincoln, 2007). Although cognitive rehabilitation was associated with significant improvement in standardized neglect outcomes, treatment was not found to have a significant effect on functional disability (end of treatment: SMD=0.26 95% CI -0.2 to 0.7; follow-up: SMD=0.61, 95% CI -0.4 to 1.6). In both of these reviews, the authors concluded that there is insufficient evidence to support or refute the effectiveness of the interventions examined (Bowen et al., 2011; Bowen and Lincoln, 2007).

In a third Cochrane review examining interventions for visual field defects, Pollock and colleagues identified 13 studies (n=344, 83% post-stroke) exploring vision restorative therapy, visual scanning, and prism therapy (Pollock et al. 2011). Of the three treatments, only prism therapy was associated with significant improvement in visual field outcomes (MD=8.40, 95% CI 4.0 to 12.8). While both prism therapy and visual scanning were associated with improvement in scanning outcomes, neither treatment was found to have a significant treatment effect on functional ADLs (Pollock et al. 2011). Recently conducted randomized controlled trials (RCTs) have revealed conflicting evidence regarding the effectiveness of visual scanning therapy on visual perception (Ferreira et al. 2011; Chan et al. 2013; Kerkhoff et al. 2013), and more recent evidence regarding prism therapy has not provided further support for its use (Mancuso et al. 2012).

Other forms of treatment for spatial neglect and visual field deficits include the use of virtual reality and transcranial magnetic stimulation. Kim et al. (2011) conducted a RCT which investigated the effect of virtual reality training compared to conventional therapy on post stroke unilateral neglect. Patients who received virtual reality training demonstrated significantly greater changes in score on both the star cancellation test and Catherine Bergego scale compared to patients who received conventional therapy. However, no differences after treatment were observed between the two groups with respect to scores on the line bisection test or the Korean version of the modified Barthel Index. Regarding the use of repetitive transcranial magnetic stimulation (rTMS), Kim et al. (2013) examined the effect of this therapy at high and low frequencies on spatial neglect in acute stroke patients. Participants were randomly assigned to receive 1 Hz stimulation over the nonlesioned posterior parietal cortex (PPC), 10 Hz over the lesioned PPC, or sham stimulation. After 10 stimulation sessions over a two-week period, the improvement in the line bisection test score in the high frequency rTMS group was statistically significant compared to that in the sham stimulation group (p=0.03). Additionally, the improvements in the Korean-Modified Barthel Index scores in both the high and low frequency groups were statistically significant compared to those in the sham stimulation group (p<0.01 and p=0.02, respectively).