Visual perceptual deficits and their contribution to walking dysfunction in individuals with post-stroke visual neglect

Recent advances in treatment of spatial neglect: networks and neuropsychology

INTRODUCTION

Spatial neglect remains an underdiagnosed and undertreated consequence of stroke that imposes significant disability. A growing appreciation of brain networks involved in spatial cognition is helping us to develop a mechanistic understanding of different therapies under development.

AREAS COVERED

This review focuses on neuromodulation of brain networks for the treatment of spatial neglect after stroke, using evidence-based approaches including 1) Cognitive strategies that are more likely to impact frontal lobe executive function networks; 2) Visuomotor adaptation, which may depend on the integrity of parietal and parieto- and subcortical-frontal connections and the presence of a particular subtype of neglect labeled Aiming neglect; 3) Non-invasive brain stimulation that may modulate relative levels of activity of the two hemispheres and depend on corpus callosum connectivity; and 4) Pharmacological modulation that may exert its effect primarily via right-lateralized networks more closely involved in arousal.

EXPERT OPINION

Despite promising results from individual studies, significant methodological heterogeneity between trials weakened conclusions drawn from meta-analyses. Improved classification of spatial neglect subtypes will benefit research and clinical care. Understanding the brain network mechanisms of different treatments and different types of spatial neglect will make possible a precision medicine treatment approach.

Research hotspots and frontiers about role of visual perception in stroke: A bibliometric study

Background

Visual perception is a dynamic process of perceiving the environment through sensory input and transforming sensory input into meaningful concepts related to environmental visual knowledge. Many studies focusing on the role of visual perception after stroke have been published in various journals. However, a bibliometric analysis in the domain of visual perception after stroke is still lacking. This study aimed to deliver a visual analysis to analyze the global trends in research on the role of visual perception after stroke in the last 10 years.

Methods

The literature was derived from the Web of Science core collection database from 2012 to 2021. The collected material was limited to English articles and reviews. CiteSpace and Microsoft Excel were used for bibliographic analysis.

Results

A total of 298 articles were included in the analysis. The annual number of publications increased from 23 to 42 in the last decade. Rehabilitation was the main research hotspot (n = 85). Journal of Physical Therapy Science published the largest number of papers (n = 14). The most influential author, institution, and country were Rowe FJ (n = 17), League of European Research Universities (n = 45), and England (n = 54), respectively. The keywords with the longest burst period are field defect, hemineglect, disorder, and quality of life.

Conclusion

This study analyzes the papers on the role of visual perception after stroke in the past 10 years and provides a new perspective for research in this field. At present, the number of articles in this field is not large and the cooperation network is not close enough. In the future, it is necessary to strengthen the cooperation among various countries, institutions, and authors. In addition, large samples and randomized controlled trials are needed to identify the potential treatments and pathophysiology for visual perceptual impairment after stroke.

The Untapped Potential of Virtual Reality in Rehabilitation of Balance and Gait in Neurological Disorders

Dynamic systems theory transformed our understanding of motor control by recognizing the continual interaction between the organism and the environment. Movement could no longer be visualized simply as a response to a pattern of stimuli or as a demonstration of prior intent; movement is context dependent and is continuously reshaped by the ongoing dynamics of the world around us. Virtual reality is one methodological variable that allows us to control and manipulate that environmental context. A large body of literature exists to support the impact of visual flow, visual conditions, and visual perception on the planning and execution of movement. In rehabilitative practice, however, this technology has been employed mostly as a tool for motivation and enjoyment of physical exercise. The opportunity to modulate motor behavior through the parameters of the virtual world is often ignored in practice. In this article we present the results of experiments from our laboratories and from others demonstrating that presenting particular characteristics of the virtual world through different sensory modalities will modify balance and locomotor behavior. We will discuss how movement in the virtual world opens a window into the motor planning processes and informs us about the relative weighting of visual and somatosensory signals. Finally, we discuss how these findings should influence future treatment design.

A novel computerized assessment of manual spatial exploration in unilateral spatial neglect

Unilateral spatial neglect is a neuropsychological syndrome commonly observed after stroke and defined by the inability to attend or respond to contralesional stimuli. Typically, symptoms are assessed using clinical tests that rely upon visual/perceptual abilities. However, neglect may affect high-level representations controlling attention in other modalities as well. Here we developed a novel manual exploration test using a touch screen computer to quantify spatial search behaviour without visual input. Twelve chronic stroke patients with left neglect and 27 patients without neglect (based on clinical tests) completed our task. Four of the 12 "neglect" patients exhibited clear signs of neglect on our task as compared to "non-neglect" patients and healthy controls, and six other patients (from both groups) also demonstrated signs of neglect compared to healthy controls only. While some patients made asymmetrical responses on only one task, generally, patients with the strongest neglect performed poorly on multiple tasks. This suggests that representations associated with different modalities may be affected separately, but that severe forms of neglect are more likely related to damage in a common underlying representation. Our manual exploration task is easy to administer and can be added to standard neglect screenings to better measure symptom severity.