Is it possible to influence Pusher Syndrome with Tilted Reality? A series of four cases

Pusher syndrome is a disorder of postural control, characterized by an altered perception of upright body orientation. While visual verticality perception remains intact, patients incorrectly perceive their tilted body posture as upright, resulting in active resistance to posture correction. This perceptual mismatch offers a potential target for therapeutic interventions. We evaluated a newly developed Tilted Reality Device (TRD) designed to recalibrate body verticality perception by subtly tilting the patients real-time visual environment towards the ipsilesional side in a series of four patients with pusher syndrome. We implemented a three-phase experimental design: pre-manipulation (normal view), manipulation (TRD tilted 20{degrees} ipsilesionally), and post-manipulation (normal view). Passive body tilts were performed while we recorded body orientation. Fifteen healthy older adults served as controls. The behavioral changes were assessed via tilt angle analysis and were statistically compared using Crawford-Garthwaite Bayesian methods. Two of the four patients showed reduced resistance to ipsilesional body tilts during the TRD manipulation. Two patients also demonstrated an aftereffect. Our findings only partly confirmed our expectations; possible limitations are discussed. Further research is needed to evaluate our TRD in its potential treatment effects in pusher syndrome and better understand the mechanisms involved in the recalibration of upright body orientation perception in patients with pusher syndrome.