Damage to the right insula disrupts the perception of affective touch

© 2020 Kirsch et al. This article is distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use and redistribution provided that the original author and source are credited.Specific, peripheral C-tactile afferents contribute to the perception of tactile pleasure, but the brain areas involved in their processing remain debated. We report the first human lesion study on the perception of C-tactile touch in right hemisphere stroke patients (N = 59), revealing that right posterior and anterior insula lesions reduce tactile, contralateral and ipsilateral pleasantness sensitivity, respectively. These findings corroborate previous imaging studies regarding the role of the posterior insula in the perception of affective touch. However, our findings about the crucial role of the anterior insula for ipsilateral affective touch perception open new avenues of enquiry regarding the cortical organization of this tactile system.Peer reviewe

Modulating anosognosia for hemiplegia: The role of dangerous actions in emergent awareness

Anosognosia for hemiplegia is a lack of awareness of motor deficits following a right hemisphere lesion. Residual forms of awareness co-occur with an explicit denial of hemiplegia. The term emergent awareness refers to a condition in which awareness of motor deficits is reported verbally during the actual performance of an action involving the affected body part. In this study, two tasks were used to explore the potential effects of i) attempting actions which are impossible for sufferers of hemiplegia and ii) attempting actions which are potentially dangerous. Sixteen hemiplegic patients (8 anosognosic, and 8 non-anosognosic) were asked to perform both potentially dangerous and neutral actions. Our results confirm an increase in emergent awareness in anosognosic patients during the execution of both of these types of action. Moreover, actions that are potentially dangerous improved the degree of awareness. However, lesions in the fronto-temporal areas appear to be associated with a reduced effect of action execution (emergent awareness) while lesions in the basal ganglia and amygdale and the white matter underlying the insula and fronto-temporal areas are associated with a lesser degree of improvement resulting from attempting to perform dangerous actions

Artroscopia in corso di artrite radiocarpica in una vitella

The clinical signs, diagnosis and successful surgical treatment of bacterial arthritis in a calf in Italy [date not given] are described

Out of plane fragility of infill walls with and without prior in-plane damage

The paper presents the results of a probabilistic assessment framework aimed at evaluating out-of-plane fragility curves of infill walls which have suffered (or not) prior in-plane damage. Out-of-plane incremental dynamic analyses are performed based on a suite of 22 ground motion records. A recently developed in-plane / out-of-plane macroelement model is used to model masonry infills within frames. The outcomes show fragility curves representing the probability of exceeding out-of-plane collapse at a given earthquake intensity as a function of a different combination of geometrical and mechanical parameters, in-plane damage level and supporting conditions

Illusory hand movements in the absence of asomatognosia, spatial neglect and anosognosia for hemiplegia

Neuropsychological and neuroanatomical evidence from a single case study support the possibility that illusory limb movements may arise as the consequence of damage involving the sensory-motor network and as a specific manifestation independent from disorders of body representations

Out-of-Plane fragility of infilled frames with and without prior damage

The paper presents the results of a probabilistic assessment framework aimed at evaluating out-of-plane fragility curves of infill walls which have suffered (or not) prior in-plane damage. Out-of-plane incremental dynamic analyses are performed based on a suite of 22 ground motion records. A recently developed in-plane / out-of-plane macroelement model is used to model masonry infills within frames. The outcomes show fragility curves representing the probability of exceeding out-of-plane collapse at a given earthquake intensity as a function of a different combination of geometrical and mechanical parameters, in-plane damage level and supporting conditions

Gesture errors in left and right hemisphere damaged patients: A behavioural and anatomical study

Objective: Erroneous gesture execution is at the core of motor cognition difficulties in apraxia. While a taxonomy of errors may provide important information about the nature of the disorder, classifications are currently often inconsistent. This study aims to identify the error categories which distinguish apraxic from non-apraxic patients. Method. Two groups of mixed (bucco-facial and limb) and bucco-facial apraxic patients suffering from stroke were compared to non-apraxic, left and right hemisphere damaged patients in tasks tapping the ability to perform limb and bucco-facial actions. The errors were analysed and classified into 6 categories relating to content, configuration or movement, spatial or temporal parameters and unrecognisable actions. Furthermore, an anatomical investigation (VLMS) was conducted in the whole group of left hemisphere damaged patients to investigate potential correlates of the various error categories. Results. Although all the above error typologies may be observed, the most indicative of mixed apraxia is the content-related one in all the typologies of actions (transitive and intransitive), and configuration errors in transitive ones. Configuration and content errors in mouth actions seem to be typical of bucco-facial apraxia. Spatial errors are similar in both apraxic and right brain damaged, non-apraxic patients. A lesion mapping analysis of left-brain damaged patients demonstrates that all but the spatial error category are associated with the fronto-parietal network. Moreover, content errors are also associated with fronto-insular lesions and movement errors with damage to the paracentral territory (precentral and postcentral gyri). Spatial errors are often associated to ventral frontal lesions. Conclusions. Bucco-facial and mixed apraxic patients make different types of errors in different types of actions. Not all errors are equally indicative of apraxia. In addition, the various error categories are associated with at least partially different neural correlates

Anosognosia for limb and bucco-facial apraxia as inferred from the recognition of gestural errors

Anosognosia is a multifaceted syndrome characterized by a lack of awareness of motor, cognitive, or emotional deficits. While most studies have focused on basic motor disorders such as hemiplegia, only recently, the issue of whether anosognosia also concerns higher-order motor disorders like apraxia has been addressed. Here, we explore the existence of a specific form of anosognosia for apraxia in forty patients with uni-hemispheric vascular lesions. The patients were requested to imitate actions involving upper limb or bucco-facial body parts and then judge their performance. Successively, they were also asked to observe video recordings of the same actions performed by themselves or by other patients and judge the accuracy of the displayed actions. The comparison of participants versus examiner judgement and between error recognition of others' versus self's actions was considered as an index of awareness deficit for the online and offline conditions, respectively. Evidence was found that awareness deficits occurred both immediately after action execution (online anosognosia) and in the video recording task (offline anosognosia). Moreover, bucco-facial and limb apraxic patients were specifically unaware of their errors in bucco-facial and limb actions, respectively, indicating for the first time a topographical organization of the syndrome. Our approach allowed us to distinguish awareness deficits from more general disorders in error recognition; indeed, anosognosic patients were able to identify errors when the same action was executed by another patient but not when the video showed their own actions. Finally, we provide evidence that anosognosia for apraxia might be associated with frontal cortical and subcortical networks

The role of white matter disconnections in Anosognosia for Hemiplegia

Anosognosia for Hemiplegia (AHP) is a disturbance in motor awareness, secondary to right brain hemisphere damage, in which patients are unaware of their limb paralysis (Babinski 1914). Decades of neuropsychological and neuroimaging studies revealed that AHP is unrelated to other co-occurring symptoms, such as neglect and memory impairments (Fotopoulou, 2014). Rather, some experimental evidences address AHP to the disruption of action monitoring (Berti et al., 2005) or error recognition processes (Moro et al., 2015). Others hypothesized an impairment in updating one’s beliefs about the self (Fotopoulou, 2008) that involves the failure of motivational/emotional (Vuilleumiere, 2004) and mnemonic (Mograbi & Morris, 2013) processes. Findings from lesion-based symptom-mapping studies revealed the multifaceted nature of the disease, by linking AHP to contradictory patterns of cortical areas. These inconsistencies are due to small sample sizes in most of these studies and to the lack of consideration of lesions remote effects that impact structurally connected circuits. We explored the probability of white matter disconnections in 174 patients (95 AHP patients), through an advanced lesion analysis software (Foulon et al.,2017), excluding clinical variables (motor impairment, lesion size, interval from lesion onset) and associated neuropsychological deficits of AHP (extra-personal and personal neglect, memory impairment). Our results indicated that AHP symptoms may be attributable to the disconnection of indirectly impaired areas. The involvement of three neural systems emerged: the limbic system, the pre-motor loop, and the ventral non spatial-attention network. The disconnection of the limbic system probably plays a role in the failure of updating the autobiographical representations of the self; the disconnection of some pre-motor loop structures contributes to the deficit in monitoring and error processing, and the ventral non-motor attention network disconnection is involved in the attention shifting from the self to the third person perspective. Together, these three systems contribute to the awareness of motor deficits

Neural Correlates of Anosognosia for Hemiplegia: A White Matter Disconnection Study

Anosognosia for Hemiplegia (AHP) refers to unawareness of contralesional motor deficits, typically occurring after right brain damage. Neuroanatomical investigations of AHP have reported the involvement of distributed cortical and subcortical structures (Moro et al., 2016), whilst neuropsychological studies suggest that failures in action monitoring (Berti et al., 2005), error recognition (Moro et al., 2015) or updating of self-beliefs (Fotopoulou, 2008; Vuilleumiere, 2004;) contribute to the symptoms observed. This multifaceted nature of AHP suggests that the condition may be consequent to a disconnection between brain regions rather the damage of a single localized area. We explore this possibility using an advanced lesion analysis (BCBToolKit, Foulon et al.,2018), which allowed us to map the white matter disconnections probability in 174 patients (95 AHP patients), whilst controlling for clinical variables and concomitant symptoms (extrapersonal/peripersonal neglect, memory impairment). Results indicate that disconnections of three neural systems are evident in AHP: (1) the limbic system, (2) pre-motor loop, and (3) ventral non-motor attention network. These disconnections may account for different presentations of AHP via their established roles in (1) updating autobiographical representations of the self; (2) monitoring and error processing; and (3) attentional processes and shifting from the first- to the third-person perspective