Body size perception in stroke patients with paresis

Overestimation associated with walking and balance function in individuals diagnosed with a stroke

BACKGROUND

An estimation error is the difference between motor imagery and actual motor time. Previous studies have reported that overestimation (motor imagery time < actual motor time) is related to physical functions in healthy individuals. However, this finding is unclear among individuals diagnosed with a stroke.

OBJECTIVE

We investigated whether overestimation is related to physical function in individuals diagnosed with a stroke.

METHODS

This study included 71 individuals diagnosed with a stroke (mean age, 67.2 ± 13.4 years; mean time since stroke, 68.4 ± 44.7 days). Imagined timed up and go test (iTUGT) was performed to assess the estimation error. First, the iTUGT was performed; subsequently, the TUGT was performed. The estimation error was calculated by subtracting the TUGT from the iTUGT, with two standard deviations (2 SDs) being calculated. Furthermore, patients were classified into appropriate estimation (AE, within ±2 SD) and overestimation (OE, over -2 SD) groups. Both groups were tested using the estimation error, iTUGT, TUGT, Berg Balance Scale (BBS), and Brunnstrom Recovery Stage (BRS). Subsequently, a correlation analysis was performed.

RESULTS

The OE group had a significantly higher estimation error than the AE group (OE: -7.08 ± 6.87 s, AE: -0.29 ± 1.53 s, P < .001). Moreover, the OE group had significantly lower TUGT and BBS than the AE group. The estimation error was correlated with the TUGT, BBS, and lower-limb BRS (ρ = -0.454, 0.431, 0.291, respectively; P < .05).

CONCLUSIONS

Overestimation was associated with TUGT and balance function in individuals diagnosed with a stroke.

Body Image and Emotional Status in Patients with Acquired Brain Injury

Emotional experiences can lead to a real or distorted self-representation. After brain damage, altered self-perception of one's own body image is frequent. This study evaluates the relationship of mood disorders and lesion sites on body image in a cohort of ABI patients. A total of 46 patients (26 men, 20 women) without severe physical impairments were found eligible for this study. Patients underwent Beck's Depression Inventory and the Hamilton Rating Scale for Anxiety to assess mood disorders, whereas the Body Image Scale and Human Figure Drawing were used to evaluate body dissatisfaction and implicit body image. The Montreal Cognitive Assessment was used to assess patients' cognitive condition. We found a moderate correlation between depression and body image (r = 0.48), as well as between anxiety and body image (r = 0.52), and the regression model also reported the right lesion site as a predictive variable for body image score. In addition, the regression model built by Human Figure Drawing scores showed anxiety, cognitive functioning, and a marital status of single to be significant predictors. The study confirmed that participants with acquired brain injury have deficits in body representation associated with mood disorders, regardless of the side of the lesions. A neuropsychological intervention could be useful for these patients to improve their cognitive performance and learn to manage emotional dysfunction in order to increase their self-perception of body image and improve their quality of life.

Estimation Error Consisting of Motor Imagery and Motor Execution in Patients with Stroke

Previous studies demonstrate that the difference between motor imagery and actual tasks (estimation error) is related to cognitive and physical functions and that a large estimation error (LE) is related to motor imagery ability, including cognitive and physical functions in healthy subjects. The purpose of this study investigated whether estimation error is related to physical and cognitive function in patients with stroke. The study included 60 patients with stroke. The Timed Up and Go Test (TUGT) was employed to assess estimation error. First, the imagined TUGT (iTUGT) was performed; thereafter, the actual TUGT was performed. The estimation error was calculated by subtracting TUGT from iTUGT, with conversion to the absolute value. The patients were classified into the small estimation error (SE) and LE groups, with comparisons of various clinical scores (Mini-Mental State Examination, Berg Balance Scale, 10-m walking speed, Brunnstrom Recovery Stage, and Functional Independence Measure). As a result, the estimation error was significantly larger in the LE group than in the SE group. Cognitive function and balance ability were significantly lower in the LE group than in the SE group. In conclusion, the estimation error was related to physical and cognitive functions in patients with stroke.

Body image and perception among adults with and without phantom limb pain

BACKGROUND

Following lower-limb amputation, phantom limb pain (i.e., pain perceived as coming from the amputated portion of the limb) is common. Phantom limb pain may be associated with impaired body image and perception, which may be targets for rehabilitative intervention.

OBJECTIVE

To compare measures of body image and perception between adults with and without phantom limb pain post amputation and evaluate associations between measures of body image and perception and phantom limb pain.

DESIGN

Survey.

SETTING

Online, remote assessment.

PARTICIPANTS

Seventy-two adults ≥1 year post unilateral lower-limb loss (n = 42 with phantom limb pain, n = 30 without phantom limb pain or pain in the remaining portion of the limb).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Self-reported outcome measures assessing body image (i.e., Amputee Body Image Scale-Revised), perceptual disturbances associated with the phantom limb (i.e., a modified Bath Complex Regional Pain Syndrome Body Perception Disturbance Scale), and prosthesis satisfaction (i.e., Trinity Amputation and Prosthesis Experience Scale) were administered; participants with phantom limb pain reported pain interference via the Brief Pain Inventory-Short Form. Between-group comparisons of self-reported outcome measure scores were conducted using Mann Whitney U or chi-square tests, as appropriate (a = .05).

RESULTS

Compared to peers without phantom limb pain, adults with phantom limb pain reported more negative body image; increased phantom limb ownership, attention, and awareness; and reduced prosthesis satisfaction and embodiment (U = 175.50-364.00, p < .001 to .034). Disturbances in phantom limb perception (i.e., size, weight, pressure, temperature) were similar between groups (p = .086 to >.999). More negative body image was associated with increased phantom limb pain interference (τb  = .25, p = .026).

CONCLUSIONS

Adults with phantom limb pain demonstrate more negative body image and hypervigilance of the phantom limb as compared to peers with nonpainful phantom sensations. Mind-body treatments that target impaired body image and perception may be critical interventions for adults with phantom limb pain.

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

The perceptions of our own body (e.g., size and shape) do not always coincide with its real characteristics (e.g., dimension). To track the complexity of our perception, the concept of mental representations (model) of the body has been conceived. Body representations (BRs) are stored in the brain and are maintained and updated through multiple sensory information. Despite being altered in different clinical conditions and being tightly linked with self-consciousness, which is one of the most astonishing features of the human mind, the BRs and, especially, the underlying mechanisms and functions are still unclear. In this vein, here we suggest that (neuro)robotics can make an important contribution to the study of BRs. The first section of the study highlights the potential impact of robotics devices in investigating BRs. Far to be exhaustive, we illustrate major examples of its possible exploitation to further improve the assessment of motor, haptic, and multisensory information building up the BRs. In the second section, we review the main evidence showing the contribution of neurorobotics-based (multi)sensory stimulation in reducing BRs distortions in various clinical conditions (e.g., stroke, amputees). The present study illustrates an emergent multidisciplinary perspective combining the neuroscience of BRs and (neuro)robotics to understand and modulate the perception and experience of one's own body. We suggest that (neuro)robotics can enhance the study of BRs by improving experimental rigor and introducing new experimental conditions. Furthermore, it might pave the way for the rehabilitation of altered body perceptions.

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

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.