Body and peripersonal space representations in chronic stroke patients with upper limb motor deficits

Abstract

The continuous stream of multisensory information between the brain and the body during body–environment interactions is crucial to maintain the updated representation of the perceived dimensions of body parts (metric body representation) and the space around the body (the peripersonal space). Such flow of multisensory signals is often limited by upper limb sensorimotor deficits after stroke. This would suggest the presence of systematic distortions of metric body representation and peripersonal space in chronic patients with persistent sensorimotor deficits. We assessed metric body representation and peripersonal space representation in 60 chronic stroke patients with unilateral upper limb motor deficits, in comparison with age-matched healthy controls. We also administered a questionnaire capturing explicit feelings towards the affected limb. These novel measures were analysed with respect to patients’ clinical profiles and brain lesions to investigate the neural and functional origin of putative deficits. Stroke patients showed distortions in metric body representation of the affected limb, characterized by an underestimation of the arm length and an alteration of the arm global shape. A descriptive lesion analysis (subtraction analysis) suggests that these distortions may be more frequently associated with lesions involving the superior corona radiata and the superior frontal gyrus. Peripersonal space representation was also altered, with reduced multisensory facilitation for stimuli presented around the affected limb. These deficits were more common in patients reporting pain during motion. Explorative lesion analyses (subtraction analysis, disconnection maps) suggest that the peripersonal space distortions would be more frequently associated with lesions involving the parietal operculum and white matter frontoparietal connections. Moreover, patients reported altered feelings towards the affected limb, which were associated with right brain damage, proprioceptive deficits and a lower cognitive profile. These results reveal implicit and explicit distortions involving metric body representation, peripersonal space representation and the perception of the affected limb in chronic stroke patients. These findings might have important clinical implications for the longitudinal monitoring and the treatments of often-neglected deficits in body perception and representation.

Social Context and Tool Use Can Modulate Interpersonal Comfort Space

“…However, further studies are needed to understand to what extent and under what conditions these two spaces may reveal similar behavioural displays. Furthermore, many studies have identified alterations of the representation of the space around the body in neurological [ 70 ], psychopathological [ 64 , 71 , 72 ] or autistic [ 19 ] patients. Therefore, in-depth knowledge of the mechanisms of sharing or segregation between action space and interpersonal social space may potentially suggest new ways to improve or rehabilitate the functions of representing the space around our bodies.…”

Evaluation of upper limb perception after stroke: a prevalence and longitudinal study with the new Affected Limb Perception Questionnaire (ALPQ)

“…The overall prevalence of BPs de cits after stroke has only been seldom investigated. Schwoebel and Coslett [6], Raimo and coauthors [17], Razmus [18] as well as Bassolino and co-authors [13] estimated altogether from 39.5-81% of stroke patients with a de cit in at least one component of BPs. This wide range is explained by the different experimental tasks used in each study, targeting different BPs, as well as by the different pro les of the patients included, varying by the phase of the disease (acute, sub-acute and/or chronic), the inclusion [18] or exclusion [6,17] of bilateral lesions, the selection of speci c lesion lateralisation (e.g.…”

Assess and rehabilitate body representations via (neuro)robotics: An emergent perspective

“…allowing them to mimic the dynamic characteristics of natural movement (Krebs et al, 1998 ; Grange et al, 2001 ; Casadio et al, 2006 ). Movement-assistance robots would be particularly useful to improve the current assessment of BRs metrics in patients with sensorimotor deficits (Bassolino et al, 2022 ). For instance, motor impairments and spasticity (i.e., muscle stiffness, tightness, and rigidity) (Pantano et al, 1995 ; Sommerfeld et al, 2004 ) would prevent the use of active tasks in some patients with poststroke, thus limiting their assessment to static tasks (Longo and Haggard, 2012 ; Bassolino et al, 2015 ), or motor imagery skills (Shahvaroughi-Farahani et al, 2021 ).…”

“…For instance, amputation or deafferentation is characterized by unpleasant phantom sensations and pain (Flor et al, 2006 ). In patients with chronic stroke with persistent sensorimotor deficits, the affected limb can be perceived as “foreign,” “ill,” and “like dead” (Bassolino et al, 2022 ; Crema et al, 2022 ).…”

“…Although studies exploiting neurorobotics-based rehabilitation to improve altered BRs mainly focus on amputees with the aim of boosting artificial limb embodiment (Makin et al, 2020 ), alterations in BRs have also been reported in different clinical conditions such as eating disorders, chronic pain, or stroke (Moseley et al, 2012 ; Keizer et al, 2013 ; Bassolino et al, 2022 ). To tackle BRs alterations, rehabilitative training exploiting multisensory stimulations has been proposed (Bolognini et al, 2015 ; Garbarini et al, 2015 ).…”