The prevalence, predictors, associated symptoms, and outcomes of social disinhibition following moderate-to-severe TBI: A scoping review of quantitative evidence

Behavioral disinhibition in stroke

Background

Post-stroke behavioral disinhibition (PSBD) is common in stroke survivors and often presents as impulsive, tactless or vulgar behavior. However, it often remains undiagnosed and thus untreated, even though it can lead to a longer length of stay in a rehabilitation facility. The proposed study will aim to evaluate the clinical, neuropsychological and magnetic resonance imaging (MRI) correlates of PSBD in a cohort of stroke survivors and describe its 12-month course.

Methods

This prospective cohort study will recruit 237 patients and will be conducted at the Neurology Unit of the Prince of Wales Hospital. The project duration will be 24 months. The patients will be examined by multiple MRI methods, including diffusion-weighted imaging, within 1 week after stroke onset. The patients and their caregivers will receive a detailed assessment at a research clinic at 3, 9 and 15 months after stroke onset (T1, T2 and T3, respectively). The disinhibition subscale of the Frontal Systems Behavior Scale (FrSBe) will be completed by each subject and caregiver, and scores ≥65 will be considered to indicate PSBD.A stepwise logistic regression will be performed to assess the importance of lesions in the regions of interest (ROIs), together with other significant variables identified in the univariate analyses. For patients with PSBD at T1, the FrSBe disinhibition scores will be compared between the groups of patients with and without ROI infarcts, using covariance analysis. The demographic, clinical and MRI variables of remitters and non-remitters will be examined again at T2 and T3 by logistic regression.

Discussion

This project will be the first MRI study on PSBD in stroke survivors. The results will shed light on the associations of lesions in the orbitofrontal cortex, anterior temporal lobe and subcortical brain structures with the risk of PSBD. The obtained data will advance our understanding of the pathogenesis and clinical course of PSBD in stroke, as well as other neurological conditions. The findings are thus likely to be applicable to the large population of patients with neurological disorders at risk of PSBD and are expected to stimulate further research in this field.

Exploring neuropsychological underpinnings of poor communication after traumatic brain injury: The role of apathy, disinhibition and social cognition

BACKGROUND

Dysarthria, aphasia and executive processes have been examined for their role in producing impaired communicative competence post traumatic brain injury (TBI). Less understood is the role of emotional dysregulation, that is, apathy and disinhibition, and social cognition, that is, reading and interpreting social cues.

METHODS & PROCEDURES

In this study, we examined 49 adults with moderate to severe TBI and 18 neurologically healthy adults. We hypothesised that apathy and disinhibition would predict communication outcomes as would social cognition. We also predicted that apathy and disinhibition would influence social cognition. Communication outcomes were measured by the La Trobe Communication Questionnaire (LCQ) and the Social Skills Questionnaire-TBI (SSQ-TBI). Apathy and disinhibition were measured by the Frontal Systems Behavior Scale (FrSBe). We measured four aspects of social cognition: emotion perception and theory of mind using The Awareness of Social Inference Test (TASIT) and the Complex Audio-Visual Evaluation of Affect Test (CAVEAT), empathy using the Questionnaire of Cognitive and Affective Empathy (QCAE) and the Balanced Emotional Empathy Scale (BEES), and alexithymia using the Toronto Alexithymia Scale (TAS-20) and the Bermond-Vorst Alexithymia Questionnaire.

OUTCOMES & RESULTS

Consistent with predictions, the LCQ and SSQ-TBI were associated with disinhibition and the LCQ was also associated with apathy. The LCQ was associated with the full range of social cognition constructs although the SSQ-TBI was not. Finally, apathy and disinhibition predicted a number of social cognition measures.

CONCLUSIONS AND IMPLICATIONS

These results are discussed in relation to understanding the nature of communication disorders following TBI and how they are measured, as well as the interrelation between emotion dysregulation and social cognition.

WHAT THIS STUDY ADDS

What is already known on this subject The role of emotional dysregulation and social cognition in producing impaired communicative competence post traumatic brain injury (TBI) is not well understood. Although most adults with severe TBI have minimal or possibly no language impairment, they often struggle with functional communication in everyday situations. Many have been reported to be overtalkative, insensitive, childish and self-centred, displaying an inappropriate level of self-disclosure and making tangential and irrelevant comments. Conversely, some speakers with TBI have been noted to have impoverished communication, producing little language either spontaneously or in response to the speaker's questions and prompts. What this paper adds to existing knowledge We found that both apathy and disinhibition were strongly associated with the Latrobe Communication Questionnaire both empirically and conceptually, despite the LCQ being developed from a different, pragmatic orientation. Disinhibition was also associated with the Social Skills Questionnaire for TBI. We also found that poor social cognition scores predicted communication difficulties. Finally, we found that behavioural dysregulation itself, i.e., both apathy and disinhibition, predicted poor social cognition. What are the potential or actual clinical implications of this work? Our findings highlight the central role that apathy and disinhibition play in both communication and social cognition. These insights point to the importance of remediation to target behavioural and autonomic dysregulation as a means to improve everyday social function.

Action control and selection in social disinhibition following severe TBI: a pavlovian-to-instrumental transfer and outcome devaluation study

INTRODUCTION

Social disinhibition is a significant sequela of severe traumatic brain injury (TBI). Some research suggests that it could reflect a deficiency in goal-directed behavior. The current study aimed to test whether these inappropriate behaviors tend to be deficient in goal-directed control, that is, triggered more by environmental stimuli than by the known consequences of their actions.

METHOD

We used a between-group design with 25 adult participants with severe TBI, and 27 control participants. Social disinhibition was measured using Frontal Systems Behavior Scale and Social Disinhibition Interview. Changes in reward-related goal-directed behavior were evaluated using a computer-based task in which we assessed the influence of cues predicting reward and of reward devaluation on choice performance.

RESULTS

We found no difference in the levels of social disinhibition between the TBI and control groups and, using mixed two-way ANCOVAs, no overall effect of the stimuli or outcome devaluation. However, after combing these groups and splitting them based on their disinhibition levels, a significant interaction between group (High vs Low disinhibition) and reward type (Valued vs Devalued) in sensitivity to outcome devaluation test (F = 5.99, p = .01, ηp2 = .13) appeared. Comparing with the baseline rate of responding, the Low disinhibition group decreased their responding to devalued and increased their responding to still-valued outcomes. In contrast, the High disinhibition group showed the opposite pattern of choice performance.

CONCLUSIONS

It appears that people with clinical levels of social disinhibition are both prone to outcome-response priming effects and insensitive to changes in the value of the consequences of their actions, that is, despite evidence they were aware of the reduction in the value of their actions's outcomes, people with high-level disinhibition kept performing those actions. This pattern has the hallmarks of a habit suggesting their disinhibition reflects a loss of executive control.

How Subjective and Objective Factors in Research and Practice May Perpetuate Health Disparities Among Patients With Traumatic Brain Injury

ABSTRACT

Research shows disparities exist in traumatic brain injury (TBI)-related outcomes and are associated with objective and subjective factors. Objective factors (e.g., age, sex, race/ethnicity, health insurance status, and socioeconomic status) are defined as variables that are frequently measured, not easily modifiable, and not easily influenced by individual perceptions, opinions, or experiences. Conversely, subjective factors (e.g., personal health literacy, cultural competence, patient/family-clinician communication, implicit bias, and trust) are defined as variables that may be less frequently measured, more easily modifiable, and more easily influenced by individual perceptions, opinions, or experiences. The purpose of this analysis and perspective is to provide recommendations for further examination of subjective factors within TBI research and practice, with the overarching goal of reducing TBI-related disparities. Establishing reliable and valid measures of subjective factors is recommended to allow for further examination of the influence of both objective factors and subjective factors in the TBI population. Providers and researchers must also engage in education and training to recognize their biases and how bias influences decision making. The influence of subjective factors in practice and research must also be considered to ensure that knowledge needed to advance health equity is generated and disparities in outcomes for patients with TBI are reduced.

The Pathogenesis of Disinhibition in Patients with Traumatic Brain Injury: A Two Patient Case Report

Higher brain dysfunction commonly occurs following traumatic brain injury (TBI), and may manifest in a social behavioral impairment which can significantly impede active social participation. We report two cases, one of voyeurism and the second of alcohol abuse, which might have been caused by TBI resulting in disinhibition, a type of social behavioral impairment. We discuss the underlying pathophysiological mechanisms to raise awareness of such cases and aid the development of effective interventions. Patient 1 suffered a TBI at 18 years of age, 2 years after which he presented repeated episodes of sexually deviant behavior (voyeurism). At 28, he committed suicide, since he was unable to control his aberrant behavior. Patient 2 suffered a TBI at the age of 13. He first displayed problematic behavior 7 years later, which included drinking excessive amounts of alcohol and stealing while inebriated. Despite both patients having sound moral judgment, they had irrational and uncontrollable impulses of desire. Imaging findings could explain the possible causes of impulse control impairments. Damage to the basal ganglia and limbic system, which are involved in social behavior, presumably led to desire-dominated behavior, leading to the patients conducting unlawful acts despite intact moral judgment. It is crucial to educate society about the prevalence of these disorders, explain how these disinhibitions start, and develop effective interventions.

Calling on clinicians to get social and emotional

OBJECTIVE

Disorders of social cognition, such as difficulties with emotion perception, alexithymia, Theory of Mind (ToM), empathy and disorders of emotion regulation, are prevalent and pervasive problems across many neurological, neurodevelopmental and neuropsychiatric conditions. Clinicians are familiar with how these difficulties present but assessment and treatment has lagged behind other traditional cognitive domains, such as memory, language and executive functioning.

METHOD

In this paper, we review the prevalence and degree of impairment associated with disorders of social cognition and emotion regulation across a range of clinical conditions, with particular emphasis on their relationship to cognitive deficits and also real-world functioning. We reported effects sizes from published meta-analyses for a range of clinical disorders and also review test usage and available tests.

RESULTS

In general, many clinical conditions are associated with impairments in social cognition and emotion regulation. Effect sizes range from small to very large and are comparable to effect sizes for impairments in nonsocial cognition. Socio-emotional impairments are also associated with social and adaptive functioning. In reviewing prior research, it is apparent that the standardized assessment of social cognition, in particular, is not routine in clinical practice. This is despite the fact that there are a range of tools available and accruing evidence for the efficacy of interventions for social cognitive impairments.

CONCLUSION

We are using this information to urge and call for clinicians to factor social cognition into their clinical assessments and treatment planning, as to provide rigorous, holistic and comprehensive person-centred care.