Prism adaptation and spatial neglect: the need for dose-finding studies

Abstract

Spatial neglect is a devastating disorder in 50–70% of right-brain stroke survivors, who have problems attending to, or making movements towards, left-sided stimuli, and experience a high risk of chronic dependence. Prism adaptation is a promising treatment for neglect that involves brief, daily visuo-motor training sessions while wearing optical prisms. Its benefits extend to functional behaviors such as dressing, with effects lasting 6 months or longer. Because one to two sessions of prism adaptation induce adaptive changes in both spatial-motor behavior (Fortis et al., 2011) and brain function (Saj et al., 2013), it is possible stroke patients may benefit from treatment periods shorter than the standard, intensive protocol of ten sessions over two weeks—a protocol that is impractical for either US inpatient or outpatient rehabilitation. Demonstrating the effectiveness of a lower dose will maximize the availability of neglect treatment. We present preliminary data suggesting that four to six sessions of prism treatment may induce a large treatment effect, maintained three to four weeks post-treatment. We call for a systematic, randomized clinical trial to establish the minimal effective dose suitable for stroke intervention.

Prism adaptation treatment for spatial neglect post brain tumour removal: A case report

“…There were no adverse events or issues prohibiting continuation. Thus, even though the proposed dose via KF-PAT manual guidelines was not met, eight sessions can be interpreted as a successful implementation of the protocol because it was more than the suggested minimal dose (Goedert et al., 2015).…”

Applications of Functional Magnetic Resonance Imaging in Determining the Pathophysiological Mechanisms and Rehabilitation of Spatial Neglect

“…PA can be used to alleviate SN (64, 71, [80][81][82][83][84][85][86][87]. PA is dependent upon the mismatch between the perceived position of a target seen through prismatic goggles and its real position relative to the body (68).…”

Inducing Visuomotor Adaptation Using Virtual Reality Gaming with a Virtual Shift as a Treatment for Unilateral Spatial Neglect

“…Demonstrating that the experimental conditions used here are successful in inducing VMA is crucial first step in translating this research into new interventions for individuals with neglect. Additional studies will be required to determine the parameters that will give the greatest effect, similar to the call for studies to optimize the delivery of PA therapy [64].…”

“…Although this after-effect eventually wears off (deadaptation), studies examining the long-term treatment benefit of PA therapy have shown the effect to last up to 6 months with multiple sessions [64]. Limitations of PA therapy include visual disorientation, nausea, and boredom leading to lack of engagement and motivation [65].…”