Rasch validation of the German version of the Prosthesis Embodiment Scale for lower limb amputees and proposal of a revised version.

PURPOSE: To perform a detailed psychometric Rasch analysis of the Prosthesis Embodiment Scale (PEmbS) administered in adults with lower limb amputation (LLA). METHODS: A convenience sample of German-speaking adults with LLA (n = 150), recruited from German state agencies' databases, was asked to complete the PEmbS, a 10-item patient-reported scale assessing prosthesis embodiment. RESULTS: The local dependency between two items was resolved by keeping for the global score only the lower score of these two items (#9 and #10). Collapsing the seven response categories to four (two expressing disagreement and two agreement) eliminated disordered thresholds. After that, the PEmbS demonstrated unidimensionality, acceptable item fit, and good reliability indices. A keyform plot was created to transform raw scores into linear measures of prosthesis embodiment, making it possible to compare the individual's item responses with those expected by the Rasch model, and to manage missing responses. CONCLUSIONS: The PEmbS is useful for assessing prosthesis embodiment in people with LLA, both for research and clinical purposes. We propose a revised version of the PEmbS for lower limb amputees; its appropriateness in other LLA contexts requires further investigation.

Prosthesis embodiment has been empirically related to positive clinical outcomes in limb amputees.The Prosthesis Embodiment Scale (PEmbS) is a patient-reported scale that has been recently recommended for use in research on prosthesis embodiment.Rasch analysis showed that the revised version of the German PEmbS is a psychometrically sound instrument for the assessment of prosthesis embodiment in lower limb amputees.The PEmbS thus also allows reliable and valid diagnosis of prosthesis embodiment in clinical and rehabilitation contexts.

Reduced tactile sensitivity is associated with mild cognitive impairment.

BACKGROUND: Sensory impairment has been related to age-associated cognitive decline. While these associations were investigated primarily in the auditory and visual domain, other senses such as touch have rarely been studied. Thus, it remains open whether these results are specific for particular sensory domains, or rather point to a fundamental role of sensory deficits in cognitive decline. METHODS: Data from 31 participants with mild cognitive impairment (MCI), 46 participants with frailty, and 23 non-clinical control participants (NCCs) were included. We assessed sensory function using visual acuity and contrast sensitivity, hearing threshold, and mechanical detection threshold. Cognitive function in participants with MCI was assessed using associative memory performance. Group differences on sensory thresholds were tested using analyses of covariance with age, sex, and years of education as covariates. Associations between measures within participants with MCI were evaluated using Spearman correlations. FINDINGS: We found a significant difference in mechanical detection threshold between the groups (p < 0.001, η2 = 0.18). Participants with MCI showed significantly reduced tactile sensitivity compared to participants with frailty and NCCs. In participants with MCI, lower associative memory performance was significantly related to reduced tactile sensitivity (rs = 0.39, p = 0.031) and auditory acuity (rs = 0.41, p = 0.022). INTERPRETATION: Our results indicate that reduced tactile sensitivity is related to cognitive decline. Prospective studies should investigate the age-related alterations of multimodal sensory processes and their contribution to dementia-related processes. FUNDING: Deutsche Forschungsgemeinschaft (FL 156/41-1) and a grant of the Hector-Stiftung II, Weinheim, Germany.

Effects of an app-based sensorimotor training in promoting neuroplasticity and neuropsychological functioning in frailty: A randomized controlled trial.

BACKGROUND: Loss of sensorimotor stimulation and maladaptive plastic changes of the brain may play a major role in problematic aging phenomena such as frailty. However, it is not clear if interventions specifically targeting neuroplasticity can reverse or slow the development of frailty. OBJECTIVES: We compared the effect of a tablet-based neuroplasticity-oriented sensorimotor training (experimental group, EG) and a tablet-based relaxation training (control group, CG) on frailty and sensorimotor brain function. METHODS: Interventions consisted of daily 30 min sessions distributed over 90 days. Assessments took place at baseline, after 60 days, and after 90 days. A total of N = 48 frail older adults (EG: n = 24; CG: n = 24) were assigned to the two groups and reassessed after 60 days. Primary outcomes included frailty phenotype (FP) and frailty index (FI). Sensorimotor brain activity was evaluated using functional magnetic resonance imaging and single-pulse transcranial magnetic stimulation. RESULTS: After 60 days of training, both groups showed a reduction in the number of FP criteria (p < 0.001) with a trend towards a significant time-by-group interaction (p = 0.058) indicating a stronger reduction of frailty in the EG (p < 0.001) compared to the CG (p = 0.039). In addition, pain was significantly reduced in the EG but not the CG. No significant effects were found for measures of brain function. DISCUSSION: We provided initial evidence that a neuroplasticity-oriented sensorimotor training could be beneficial in counteracting frailty as well as chronic pain. Further studies are needed to determine the potentially underlying neuroplastic mechanisms and the influence of plasticity-related biomarkers as well as their clinical significance. TRIAL REGISTRATION: ClinicalTrials.gov NCT03666039 (registered 11 September 2018).

Rasch validation of the German translation of the Prosthetic Limb Users Survey of Mobility short forms in people with lower limb amputation.

BACKGROUND: Prostheses are a primary rehabilitative intervention for people after lower limb amputation. To appropriately measure the effectiveness of prosthetic interventions, valid and reliable measures of prosthetic mobility are required. The Prosthetic Limb Users Survey of Mobility (PLUS-M) is a promising instrument for measuring prosthesis users' mobility. However, German translations of the PLUS-M short forms have not yet been validated. OBJECTIVES: Rasch validation of the German translation of the PLUS-M short forms in people with lower limb amputation. STUDY DESIGN: This study is based on a cross-sectional survey of prosthesis-using lower limb amputees from a nation-wide cohort. METHODS: PLUS-M data (the 7-item and the 12-item shortforms; PLUS-M-7 and PLUS-M-12, respectively) from 194 lower limb prosthesis users were subjected to Rasch analysis, an advanced statistical method for assessing if the measurement properties of a questionnaire comply with a wide spectrum of psychometric requirements. RESULTS: Analysis showed appropriate rating scale functioning, good internal construct validity (item fit), unidimensionality, and good targeting of the PLUS-M-7 and PLUS-M-12 short forms. Moreover, the greater conditional measurement precision of PLUS-M-12 (regarding higher test information and lower standard error of mobility estimates) was quantified. CONCLUSIONS: Rasch analysis of the German translation of both PLUS-M short forms showed good psychometric qualities. In addition, our study showed that test scores from the PLUS-M-12 are more accurate. Therefore, the PLUS-M-12 is recommended for individual-level clinical applications (e.g., classification or change assessment).

Prevalence of Phantom Phenomena in Congenital and Early-Life Amputees.

Phantom limb pain (PLP) is a common consequence of the amputation of a limb. Persons with congenital limb absence (congenital amputees) or an acquired limb amputation at an early age seem to rarely experience PLP. However, the number of available studies and their sample sizes are low. In the present cross-sectional study, we assessed the presence of several phantom phenomena in a sample of 99 adult unilateral congenital amputees (con) of whom 34 had a limb correction later in life (limbc) and 153 adult participants with a unilateral amputation before the age of 6 years (subgroups: amputation between birth and 2 years (0-2y; n = 48), 3-4 years (3-4y; n = 46), and 5 to 6 years (5-6y; n = 59)). We found a higher prevalence and intensity of PLP in the 5-6y group compared to the other groups. Residual limb pain (RLP) intensity was higher in the 3 to 4 y and 5 to 6 y groups compared to the con group. Non-painful phantom limb sensation (PLS) intensity and telescoping intensity were higher in the 5 to 6 y group compared to the con and 0 to 2 y groups. Our results indicate that PLP prevalence as well as intensity is low when the limb loss happened before the age of 5 years. PERSPECTIVE: The prevalence of phantom limb pain, residual limb pain, and non-painful phantom limb sensation in congenital amputees and participants with an amputation early in life is low. This might be due to the missing or reduced nociceptive input from the residual limb to the brain and higher development-associated adaptability of the somatosensory system.

Is It a Gut Feeling? Bodily Sensations Associated With the Experience of Valence and Arousal in Patients With Inflammatory Bowel Disease.

Background: Previous studies have shown dysfunctional emotion processing in patients with inflammatory bowel diseases (IBD), characterized by a hypersensitivity to negative emotions and a hyposensitivity to positive emotions. Models of emotion processing emphasize the importance of bodily sensations to the experience of emotions. Since there have been no studies on whether emotion-associated bodily sensations are changed in IBD, we investigated the experience of bodily sensations related to valence and arousal, together with their links to emotional awareness, as one domain of interoceptive sensibility relevant to emotion processing. Methods: Using a topographical self-report measure, 41 IBD patients in clinical remission and 44 healthy control (HC) participants were asked to indicate where and how intensely in their body they perceive changes when experiencing emotions of positive and negative valence, as well as relaxation and tension. Additionally, we used self-report questionnaires to assess emotional awareness as one domain of an individual's interoceptive sensibility, gastrointestinal-specific anxiety (GSA), and psychological distress. Results: Patients with IBD reported higher emotional awareness but lower intensities of perceived changes in their bodily sensations related to valence and arousal of emotional processing. IBD patients reported less intense bodily activation during positive emotions and less intense bodily deactivation during negative emotional states in comparison to HC participants. Higher emotional awareness and psychological distress were linked to stronger experiences of emotion-related bodily sensations in IBD patients. Conclusion: Inflammatory bowel diseases patients exhibited alterations in how they link bodily sensations to their emotional experience. Such persistent changes can affect a patient's wellbeing and are related to higher levels of anxiety and depression among IBD patients, even in remission.

Pleasant touch perception in borderline personality disorder and its relationship with disturbed body representation.

BACKGROUND: Borderline personality disorder (BPD) is characterized by altered perception of affective stimuli, including abnormal evaluation of nociceptive input. However, whether or not perceptual alterations are present for its positive counterpart, i.e. pleasant touch (PT), has not yet been examined. METHODS: In the present study, we applied standardized PT stimuli to the hands of 25 patients with BPD and 25 healthy controls (HC) and compared their perception. We used the affect-modulated acoustic startle response as a physiological correlate of affective processing. We further explored the effect of PT stimulation on dissociative experiences in BPD. RESULTS: Compared to HC, BPD perceived PT as less pleasant and less intense. The effect on perceived valence of touch was large even after controlling for the effect of reduced perceived intensity of touch (ƞ2 = .29). We further found qualitative alterations in touch perception in BPD, who rated the touch as significantly rougher and firmer compared to HC. There was a positive correlation between perceived valence of touch and changes in dissociative experiences in terms of body ownership of the stimulated body part from pre to post stimulation, suggesting that a more negative evaluation of touch is associated with an increase in body-related dissociative experiences, while a positive perception of touch might be related to a reduction of these dissociative experiences. CONCLUSIONS: Our results confirm BPD-associated disturbances in the processing of affective somatosensory stimuli and indicate that not only pain perception but also pleasant touch perception is diminished in BPD. We discuss the role of altered touch perception for BPD psychopathology and its potential role for new treatment approaches.

Mind over matter: Perceived phantom/prosthesis co-location contributes to prosthesis embodiment in lower limb amputees.

Prosthesis embodiment - the cognitive integration of a prosthesis into an amputees' body representation - has been identified as important for prosthetic rehabilitation. However, the underlying cognitive mechanisms remain unclear. There is reason to assume that phantom limbs that are experienced as part of the bodily self (phantom self-consciousness) can affect prosthesis embodiment, but only if the phantom and the prosthesis can be brought into perceived co-location (phantom prosthesis tolerance, PPT). In the present study, phantom-prosthesis interactions were examined in lower limb amputees, and a PPT component was psychometrically extracted. Mediation analysis revealed an indirect-only effect, where the relationship between phantom self-consciousness and prosthesis embodiment was mediated by PPT, indicating that phantom limbs can transfer their immanent vividness to the prosthesis. Subsequent analyses suggested that this effect can compensate for negative consequences on prosthesis embodiment that arise from phantom limb awareness. These results shape theoretical considerations about the cognitive processes contributing to the bodily self.

Phantom limb pain after unilateral arm amputation is associated with decreased heat pain thresholds in the face.

BACKGROUND: The mechanisms underlying chronic phantom limb pain (PLP) are complex and insufficiently understood. Altered sensory thresholds are often associated with chronic pain but quantitative sensory testing (QST) in PLP has so far been inconclusive due to large methodological variation between studies and small sample sizes. METHODS: In this study, we applied QST in 37 unilateral upper-limb amputees (23 with and 14 without PLP) and 19 healthy controls. We assessed heat pain (HPT), pressure pain, warmth detection and two-point discrimination thresholds at the residual limb, a homologous point and the thenar of the intact limb as well as both corners of the mouth. RESULTS: We did not find significant differences in any of the thresholds between the groups. However, PLP intensity was negatively associated with HPT at all measured body sites except for the residual limb, indicating lower pain thresholds with higher PLP levels. Correlations between HPT and PLP were strongest in the contralateral face (r = -0.65, p < 0.001). Facial HPT were specifically associated with PLP, independent of residual limb pain (RLP) and various other covariates. HPT at the residual limb, however, were significantly associated with RLP, but not with PLP. CONCLUSION: We conclude that the association between PLP and, especially facial, HPT could be related to central mechanisms. SIGNIFICANCE: Phantom limb pain (PLP) is still poorly understood. We show that PLP intensity is associated with lower heat pain thresholds, especially in the face. This finding could be related to central nervous changes in PLP.

The Prevalence and Characteristics of Phantom Limb Pain and Non-Painful Phantom Phenomena in a Nationwide Survey of 3,374 Unilateral Limb Amputees.

The experience of phantom limb pain (PLP) is a common consequence of limb amputation, resulting in severe impairments of the affected person. Previous studies have shown that several factors such as age at or site of amputation are associated with the emergence and maintenance of PLP. In this cross-sectional study we assessed the presence of several phantom phenomena including PLP and other amputation-related information in a sample of 3,374 unilateral upper and lower limb amputees. Clinical and demographic variables (age at amputation, level of amputation) explained 10.6% of the variance in PLP and perceptual variables (intensity of phantom limb sensation [PLS], referred sensations, intensity of telescoping, residual limb pain [RLP] intensity) explained 16.9% of the variance. These variables were specific for PLP and not for RLP. These results suggest that distinct variables are associated with PLP (age at amputation, level of amputation, PLS intensity, referred sensations, intensity of telescoping, RLP intensity) and RLP (PLP intensity) and point at partly different mechanisms for the emergence and maintenance of PLP and RLP. PERSPECTIVE: Clinical/demographic variables as well as perceptual variables are 2 major components related to PLP and explain ∼11% and ∼17% of the variance. These results could potentially help clinicians to understand which factors may contribute to chronic phantom limb pain.

Limb apparent motion perception: Modification by tDCS, and clinically or experimentally altered bodily states.

Limb apparent motion perception (LAMP) refers to the illusory visual perception of a moving limb upon observing two rapidly alternating photographs depicting the same limb in two different postures. Fast stimulus onset asynchronies (SOAs) induce the more visually guided perception of physically impossible movements. Slow SOAs induce the perception of physically possible movements. According to the motor theory of LAMP, the latter perception depends upon the observer's sensorimotor representations. Here, we tested this theory in two independent studies by performing a central (study 1) and peripheral (study 2) manipulation of the body's sensorimotor states during two LAMP tasks. In the first sham-controlled transcranial direct current stimulation between-subject designed study, we observed that the dampening of left sensorimotor cortex activity through cathodal stimulation biased LAMP towards the more visually guided perception of physically impossible movements for stimulus pairs at slow SOAs. In the second, online within-subject designed study, we tested three participant groups twice: (1) individuals with an acquired lower limb amputation, either while wearing or not wearing their prosthesis (2) individuals with body integrity dysphoria (i.e., with a desire for amputation of a healthy leg) while sitting in a regular position or binding up the undesired leg (to simulate the desired amputation); (3) able-bodied individuals while sitting in a normal position or sitting on one of their legs. We found that the momentary sensorimotor state crucially impacted LAMP in individuals with an amputation and able-bodied participants, but not in BID individuals. Taken together, the results of these two studies substantiate the motor theory of LAMP.

Body connection mediates the relationship between traumatic childhood experiences and impaired emotion regulation in borderline personality disorder.

BACKGROUND: Previous studies revealed an association between traumatic childhood experiences and emotional dysregulation in patients with borderline personality disorder (BPD). However, possible mediating pathways are still not fully understood. The aim of the present study was to investigate the potential mediating role of body connection, describing the awareness of the relationship of bodily and mental states, for the association between a history of traumatic childhood experiences and BPD core symptomatology. METHODS: One-hundred-twelve adult female individuals with BPD and 96 healthy female controls (HC) were included. Impaired emotion regulation, traumatic childhood experiences, and BPD symptomatology were assessed with self-report questionnaires. The Scale of Body Connection was used to assess two dimensions of body connection, that is body awareness, describing attendance to bodily information in daily life and noticing bodily responses to emotions and/or environment and body dissociation, describing a sense of separation from one's own body, due to avoidance or emotional disconnection. Mann-Whitney U tests were employed to test for group differences (BPD vs. HC) on the two SBC subscales and associations with clinical symptoms were analyzed with Spearman correlations. We performed mediation analyses in the BPD group to test the assumption that body connection could act as a mediator between a history of traumatic childhood experiences and emotion dysregulation. RESULTS: Individuals with BPD reported significantly lower levels of body awareness and significantly higher levels of body dissociation compared to HC. Body dissociation, traumatic childhood experiences, and emotion dysregulation were significantly positively associated. Further analyses revealed that body dissociation, but not body awareness, significantly and fully mediated the positive relationship between traumatic childhood experiences and impaired emotion regulation in the BPD sample. This mediation survived when trait dissociation, i.e., general dissociative experiences not necessarily related to the body, was statistically controlled for. CONCLUSION: Certain dimensions of body connection seem to be disturbed in BPD patients, with body dissociation being an important feature linking a history of traumatic childhood experiences to current deficits in emotion regulation.

Prosthesis embodiment and attenuation of prosthetic touch in upper limb amputees - A proof-of-concept study.

Sensory attenuation of self-touch, that is, the perceptual reduction of self-generated tactile stimuli, is considered a neurocognitive basis for self-other distinction. However, whether this effect can also be found in upper limb amputees using a prosthesis is unknown. Thirteen participants were asked to touch their foot sole with a) their intact hand (self-touch), b) their prosthesis (prosthesis-touch), or c) let it be touched by another person (other-touch). Intensity of touch was assessed with a questionnaire. In addition, prosthesis embodiment was assessed in nine participants. Self-touch as well as prosthesis-touch was characterized by significant perceptual attenuation compared to other-touch, while self- and prosthesis-touch did not differ. The more embodied the prosthesis was, the more similar was its elicited touch perception to actual self-touch. These findings - although preliminary - suggest that perceptually embodied prostheses can be represented as an actual limb by the users' sensorimotor system.

Relationship of prosthesis ownership and phantom limb pain: results of a survey in 2383 limb amputees.

ABSTRACT: Phantom limb pain (PLP) accounts for a significant reduction in quality of life and is difficult to treat. Prosthesis use has been shown to negatively covary with PLP. Recent research on body perception in amputees suggest that prosthesis ownership, defined as the extent to which a prosthesis is experienced as being part of the body rather than an artificial device foreign to the body, might interact with PLP. We used survey data from 2383 unilateral prosthesis-using upper-limb or lower-limb amputees and performed regression analyses to determine the relationship between prosthesis ownership and PLP. To test for specificity, we examined the role of prosthesis ownership also for residual limb pain (RLP) and nonpainful phantom limb sensations (npPLS). Prosthesis ownership was reduced in older participants and higher in lower-limb compared to upper-limb amputees. A longer residual limb and more frequent prosthesis use as well as a longer time since amputation also yielded higher values. Prostheses based on natural principles were associated with higher prosthesis ownership. Phantom limb pain and RLP were lower with higher prosthesis ownership, and RLP but not PLP was lower when prosthesis use was frequent. There were no significant associations for npPLS. The regression results differ in some aspects from those revealed by univariate analyses, emphasizing the importance of multivariate statistical approaches. Our findings provide insights into the interplay of body- and pain-related sensations after amputation, and could help to develop new treatment approaches for both PLP and RLP.

Cognitive Models of Limb Embodiment in Structurally Varying Bodies: A Theoretical Perspective.

Using the seminal rubber hand illusion and related paradigms, the last two decades unveiled the multisensory mechanisms underlying the sense of limb embodiment, that is, the cognitive integration of an artificial limb into one's body representation. Since also individuals with amputations can be induced to embody an artificial limb by multimodal sensory stimulation, it can be assumed that the involved computational mechanisms are universal and independent of the perceiver's physical integrity. This is anything but trivial, since experimentally induced embodiment has been related to the embodiment of prostheses in limb amputees, representing a crucial rehabilitative goal with clinical implications. However, until now there is no unified theoretical framework to explain limb embodiment in structurally varying bodies. In the present work, we suggest extensions of the existing Bayesian models on limb embodiment in normally-limbed persons in order to apply them to the specific situation in limb amputees lacking the limb as physical effector. We propose that adjusted weighting of included parameters of a unified modeling framework, rather than qualitatively different model structures for normally-limbed and amputated individuals, is capable of explaining embodiment in structurally varying bodies. Differences in the spatial representation of the close environment (peripersonal space) and the limb (phantom limb awareness) as well as sensorimotor learning processes associated with limb loss and the use of prostheses might be crucial modulators for embodiment of artificial limbs in individuals with limb amputation. We will discuss implications of our extended Bayesian model for basic research and clinical contexts.

Interoceptive Awareness Is Negatively Related to the Exteroceptive Manipulation of Bodily Self-Location.

The perception of being located within one's body (i.e., bodily self-location) is an essential feature of everyday self-experience. However, by manipulating exteroceptive input, healthy participants can easily be induced to perceive themselves as being spatially dislocated from their physical bodies. It has previously been suggested that interoception, i.e., the processing of inner physiological signals, contributes to the stability of body representations; however, this relationship has not previously been tested for different dimensions of interoception and bodily self-location. In the present study, using an advanced automatized setup, we systematically manipulated participants' perspective of their own body (first- vs third-person perspective) as well as the synchrony of visuotactile stimulation (synchronous vs asynchronous). The malleability of bodily self-location was assessed using a questionnaire targeting in-body and out-of-body experiences. Participants also performed a heartbeat discrimination task to assess their interoceptive accuracy (behavioral performance), interoceptive sensibility (confidence in their interoceptive abilities), and interoceptive awareness (meta-cognitive representation of interoceptive signals). Bodily self-location was significantly influenced by perspective, with third-person perspective being associated with stronger out-of-body experiences compared to first-person perspective. Furthermore, there was a significant perspective × stimulation interaction, with subsequent analyses showing that participants reported out-of-body experiences particularly under third-person perspective combined with synchronous visuotactile stimulation. Correlation and regression analyses revealed that meta-cognitive interoceptive awareness was specifically and negatively related to the exteroceptively mediated malleability of body experiences. These results indicate that the perception of the self being located within one's body relies on the interaction of exteroceptive input and higher-order interoceptive abilities. This has implications for theoretical considerations about the bodily self in health as well as for the understanding of disturbed bodily self-processing in clinical contexts.

Evaluation of the own body in women with current and remitted borderline personality disorder: evidence for long-lasting effects of childhood sexual abuse.

BACKGROUND: Evaluation of one's own body highly depends on psychopathology. In contrast to healthy women, body evaluation is negative in women from several diagnostic groups. Particularly negative ratings have been reported in disorders related to childhood sexual abuse (CSA) including borderline personality disorder (BPD). However, it is unknown whether this negative evaluation persists beyond symptomatic remission, whether it depends on the topography of body areas (sexually connoted versus neutral areas), and whether it depends on CSA. OBJECTIVE: First, we aimed at a quantitative comparison of body evaluation across three diagnostic groups: current BPD (cBPD), remitted BPD (rBPD), and healthy controls (HC). Second, we aimed at clarifying the potentially moderating role of a history of CSA and of the sexual connotation of body areas. METHODS: The study included 68 women from the diagnostic groups of interest (cBPD, rBPD, and HC). These diagnoses were established with the International Personality Disorder Examination. The participants used the Survey of Body Areas to quantify the evaluation of the own body and the Childhood Trauma Questionnaire for assessing CSA. RESULTS: While the evaluation of the own body was generally negative in women from the cBPD group it was positive in those who had remitted from BPD. However, their positive scores were strictly confined to neutral body areas, whereas the evaluation of sexually connoted body areas was negative, resembling the respective evaluation in cBPD patients and contrasting the positive evaluation of sexually connoted areas in healthy women. The negative evaluation of sexually connoted areas in remitted women was significantly related to a history of CSA. CONCLUSIONS: Women with BPD may require a specifically designed intervention to achieve a positive evaluation of their entire body. The evaluation of sexually connoted body areas seems to remain an issue even after remission from the disorder has been achieved.

Antecedentes: La evaluación del cuerpo propio depende en gran parte de la psicopatología. En contraste con mujeres sanas, la evaluación del cuerpo es negativa en mujeres de diferentes grupos diagnósticos. Evaluaciones particularmente negativas han sido reportadas en trastornos relacionados al abuso sexual infantil (CSA por sus siglas en inglés), incluyendo el trastorno de personalidad límite (BPD por sus siglas en inglés). Sin embargo, no se conoce si esta evaluación negativa persiste al alcanzar la remisión sintomática, si es que depende de la topografía de las áreas del cuerpo (áreas con connotación sexual versus neutras), y si depende del antecedente de CSA.Objetivo: Primero, dirigimos una comparación cuantitativa de la evaluación corporal en tres grupos diagnósticos: BPD actual (cBPD), BPD en remisión (rBPD) y controles sanos (HC por sus siglas en inglés). En segundo lugar, intentamos clarificar el potencial rol moderador de una historia de CSA y de la connotación sexual de las áreas corporales.Métodos: El estudio incluyó 68 mujeres de los grupos diagnósticos de interés (cBPD, rBPD y HC). Estos diagnósticos fueron establecidos con el Examen Internacional de Trastornos de Personalidad. Las participantes completaron la Encuesta de Áreas Corporales para cuantificar la evaluación del cuerpo propio y el Cuestionario de Trauma Infantil para evaluar CSA.Resultados: Mientras la evaluación del cuerpo propio fue generalmente negativa en mujeres del grupo cBPD, fue positiva en aquellas con BPD en remisión. Sin embargo, sus puntajes positivos fueron estrictamente circunscritos a las áreas del cuerpo neutrales, mientras que la evaluación de las áreas del cuerpo con connotación sexual fue negativa, y símiles a la evaluación de las pacientes del grupo cBPD, y contrastando con la evaluación positiva de las áreas con connotación sexual de las mujeres sanas. La evaluación negativa de áreas del cuerpo con connotación sexual en las mujeres en remisión fue relacionada significativamente con una historia de CSA.Conclusiones: Las mujeres con BPD pueden requerir una intervención específicamente diseñada para alcanzar una evaluación positiva de su cuerpo completo. La evaluación de áreas del cuerpo con connotación sexual parece permanecer problemática incuso posterior a que la remisión del trastorno ha sido alcanzada.

Perceptual correlates of successful body-prosthesis interaction in lower limb amputees: psychometric characterisation and development of the Prosthesis Embodiment Scale.

Prostheses are used to at least partly restore the body after limb amputation. Making the user accepting the prosthetic device as part of his or her body, i.e., inducing prosthesis embodiment, has been identified as major aim of prosthetic treatment. However, up to now, there is no consensus about the psychometric nature of prosthesis embodiment in limb amputees. In the present study, 118 unilateral lower limb amputees using a prosthesis were asked to complete an online questionnaire targeting prosthesis embodiment. Principal axis factoring revealed the factor structure of prosthesis embodiment, i.e., Ownership/Integrity, Agency, and Anatomical Plausibility, which resembles the embodiment structure previously identified for normally-limbed participants. The majority of amputees achieved prosthesis embodiment as assessed with the final version of the newly developed Prosthesis Embodiment Scale. Internal consistency was excellent, and test-retest reliability was satisfying, while the instrument was also sensitive for new prosthetic equipment. Validation on the basis of relationships to prosthesis satisfaction and adjustment to prosthesis use was performed. The Prosthesis Embodiment Scale could be a valuable tool for the assessment of perceptual correlates of successful body-prosthesis interaction in rehabilitative and research contexts, the latter which might further benefit from the comparability of psychometrically evaluated data.

Assessment of cortical reorganization and preserved function in phantom limb pain: a methodological perspective.

Phantom limb pain (PLP) has been associated with reorganization in primary somatosensory cortex (S1) and preserved S1 function. Here we examined if methodological differences in the assessment of cortical representations might explain these findings. We used functional magnetic resonance imaging during a virtual reality movement task, analogous to the classical mirror box task, in twenty amputees with and without PLP and twenty matched healthy controls. We assessed the relationship between task-related activation maxima and PLP intensity in S1 and motor cortex (M1) in individually-defined or group-conjoint regions of interest (ROI) (overlap of task-related activation between the groups). We also measured cortical distances between both locations and correlated them with PLP intensity. Amputees compared to controls showed significantly increased activation in M1, S1 and S1M1 unrelated to PLP. Neural activity in M1 was positively related to PLP intensity in amputees with PLP when a group-conjoint ROI was chosen. The location of activation maxima differed between groups in S1 and M1. Cortical distance measures were unrelated to PLP. These findings suggest that sensory and motor maps differentially relate to PLP and that methodological differences might explain discrepant findings in the literature.

Dissociation proneness and pain hyposensitivity in current and remitted borderline personality disorder.

BACKGROUND: Stress-related dissociation has been shown to negatively co-vary with pain perception in current borderline personality disorder (cBPD). While remission of the disorder (rBPD) is associated with normalized pain perception, it remains unclear whether dissociation proneness is still enhanced in this group and how this feature interacts with pain sensitivity. METHODS: Twenty-five cBPD patients, 20 rBPD patients and 24 healthy controls (HC) participated in an experiment using the script-driven imagery approach. We presented a personalized stressful and neutral narrative. After listening to the scripts, dissociation and heat pain thresholds (HPT) were assessed. RESULTS: Compared to HC, cBPD patients showed enhanced dissociation and exhibited significantly enhanced HPT in the neutral condition, whereas rBPD participants were in between. After listening to the stress script, both clinical groups exhibited enhanced dissociation scores. Current BPD participants responded with significantly higher HPT, whereas rBPD only showed a trend in the same direction. However, both BPD groups showed significantly increased HPT compared to the HC in the stress condition, but did not differ from each other. Dissociation proneness correlated significantly positively with pain hyposensitivity only in cBPD. CONCLUSION: Dissociation proneness is enhanced in both BPD groups. This feature is clearly positively related to pain hyposensitivity in cBPD, but not in rBPD. However, the data indicate that stress causes the pain perception in rBPD to drift away from that obtained in HC. These results highlight the volatile state of BPD remission and might have important implications for the care of BPD patients in the remitted stage. SIGNIFICANCE: Both current (cBPD) and remitted borderline personality disorder (rBPD) patients show enhanced proneness to dissociation. This feature is significantly linked with pain hyposensitivity in cBPD in a paradigm that induces stress using a script-driven imagery approach, whereas this connection cannot be observed in rBPD. However, in the stress compared to the neutral condition, rBPD participants also show pain hyposensitivity compared to healthy controls. This study provides new insights into the pain processing mechanisms of BPD and its remission.