Sleep Disruption Persists and Relates to Memory Disability After Traumatic Brain Injury: A Cross-Sectional Study of Adults in the Chronic Phase of Injury

OBJECTIVE

To examine sleep disruption in chronic traumatic brain injury (TBI) across 3 aims: (1) to examine differences in self-reported sleep disruption between adults with and without a chronic history of TBI; (2) to query reported changes in sleep after TBI; and (3) to explore the relationship between self-reported sleep disruption and memory failures in daily life.

SETTING

Community-dwelling participants completed self-report sleep and memory surveys as part of their participation in a larger patient registry.

PARTICIPANTS

This study included 258 participants, and half (n = 129) of them have a chronic history of moderate-severe TBI (mean time since injury is 5.1 [SD 6.5] years).

DESIGN

We report descriptive statistics from this matched cross-sectional study on sleep in the chronic phase of injury. We also used planned Wilcoxon ranked-sum tests and exploratory correlations to examine the relationships of sleep disruption with TBI diagnosis, injury chronicity, and memory.

MAIN MEASURES

We used the Pittsburgh Sleep Quality Index to measure sleep disruption and the Epworth Sleepiness Scale to measure daytime sleepiness. Participants answered questions about postinjury sleep and responded to the Everyday Memory Questionnaire as a measure of memory failures in daily life.

RESULTS

Individuals with TBI had significantly higher rates of sleep disruption than those without TBI, as measured by the Pittsburgh Sleep Quality Index but not on the Epworth Sleepiness Scale. Sleep disruption in TBI manifested more in sleep quality than quantity. Half of the participants with TBI reported a negative change in sleep postinjury. In an exploratory analysis, sleep disruption was related to memory failure in daily life in the TBI sample.

CONCLUSIONS

Sleep disruption persists long after TBI but may be under-recognized in people with chronic TBI. Given that sleep is critical for memory and rehabilitation outcomes well into the chronic phase of injury, steps to improve the identification and management of sleep disruption are needed. Key words:chronic, memory, sleep, traumatic brain injury.

Measurement of Sleep in Chronic Traumatic Brain Injury: Relationship Between Self-report and Actigraphy

OBJECTIVE

To examine the relationship between self-report and actigraphy measurement of sleep in people with and without traumatic brain injury (TBI) by addressing 2 aims: (1) to assess the relationship between self-report and actigraphy for sleep quantity in people with and without TBI; and (2) to explore how self-report and actigraphy capture sleep quality in TBI.

SETTING

Participants completed the study over 2 weeks in their own homes. They wore activity monitors, day and night, throughout the experiment and completed morning sleep diaries while interacting with an experimenter on videoconference.

PARTICIPANTS

This project was embedded in a larger study on sleep and word learning in 100 adults: 50 with chronic, moderate-severe TBI and 50 demographically matched noninjured peers. Of the 100 participants who completed the larger study, 92 participants (45 with TBI and 47 noninjured peers) had sufficient actigraphy data for inclusion in the current study.

DESIGN

We used multilevel linear regression models and correlation analyses to assess how well participants' self-report corresponded to actigraphy measurement of sleep.

MAIN MEASURES

Actigraphy measures included nightly sleep duration and nighttime wakeups. Sleep diary measures included self-reported nightly sleep duration, nighttime wakeups, sleep quality, and morning fatigue.

RESULTS

People with and without TBI did not differ in the relationship between self-reported and actigraphy measurement of sleep quantity. Performance on a neuropsychological memory assessment did not correlate with the difference in self-reported and actigraphy-measured sleep in the TBI group. Sleep characteristics that were measured by actigraphy did not predict subjective experiences of sleep quality or fatigue.

CONCLUSIONS

Short-term self-report diaries capture accurate information about sleep quantity in individuals with TBI and may support self-report of other daily habits. Future research is needed to identify reliable metrics of sleep quality, and how they relate to other domains such as memory and mood, in the chronic phase of TBI.

Does Facebook Use Provide Social Benefits to Adults with Traumatic Brain Injury?

Drawing on the social compensation hypothesis, this study investigates whether Facebook use facilitates social connectedness for individuals with traumatic brain injury (TBI), a common and debilitating medical condition that often results in social isolation. In a survey (N = 104 participants; n = 53 with TBI, n = 51 without TBI), individuals with TBI reported greater preference for self-disclosure on Facebook (vs. face-to-face) compared to noninjured individuals. For noninjured participants, a preference for Facebook self-disclosure was associated with the enactment of relational maintenance behaviors on Facebook, which was then associated with greater closeness with Facebook friends. However, no such benefits emerged for individuals with TBI, whose preference for Facebook self-disclosure was not associated with relationship maintenance behaviors on Facebook, and did not lead to greater closeness with Facebook friends. These findings show that the social compensation hypothesis has partial utility in the novel context of TBI, and suggest the need for developing technological supports to assist this vulnerable population on social media platforms.

Intact moral decision-making in adults with moderate-severe traumatic brain injury

Background and aim

Deficits in decision-making are a common consequence of moderate-severe traumatic brain injury (TBI). Less is known, however, about how individuals with TBI perform on moral decision-making tasks. To address this gap in the literature, the current study probed moral decision-making in a sample of individuals with TBI using a widely employed experimental measure.

Methods/hypothesis

We administered a set of 50 trolley-type dilemmas to 31 individuals with TBI and 31 demographically matched, neurotypical comparison participants. We hypothesized that individuals with TBI would be more likely to offer utilitarian responses to personal dilemmas than neurotypical peers.

Results

In contrast to our hypothesis, we observed that individuals with TBI were not more likely to offer utilitarian responses for personal dilemmas.

Conclusion

Our results suggest that moral decision-making ability is not uniformly impaired following TBI. Rather, neuroanatomical (lesion location) and demographic (age at injury) characteristics may be more predictive of a disruption in moral decision-making than TBI diagnosis or injury severity alone. These results inform the neurobiology of moral decision-making and have implications for characterizing patterns of spared and impaired cognitive abilities in TBI.

The growing gap: A study of sleep, encoding, and consolidation of new words in chronic traumatic brain injury

Word learning is an iterative and dynamic process supported by multiple neural and cognitive systems. Converging evidence from behavioral, cellular, and systems neuroscience highlights sleep as an important support for memory and word learning over time. In many lab-based word learning experiments, participants encode and subsequently retrieve newly learned words in a single session. These designs are inadequate to capture the full dynamic word learning process, making them less ecologically valid. Single timepoint studies also limit investigation of the role of behavioral and lifestyle factors, like sleep, in supporting word learning over time. Adults with a history of traumatic brain injury (TBI), who commonly exhibit deficits in the memory systems that support word learning and report concomitant sleep disturbance, provide a unique opportunity to examine the link between memory, sleep, and word learning. Here we examined word learning over time and the influence of sleep on short- and long-term word recall in 50 adults with chronic moderate-severe TBI and 50 demographically matched neurotypical peers. We used a randomized within-participant crossover design to assess immediate encoding of new words and the consolidation of those words over time across intervals that did or did not involve sleep. Participants completed this study over the course of two weeks in their own homes to capture the iterative, dynamic process of real-world word learning. We also measured sleep in free living conditions using actigraphy throughout the experiment. Participants with TBI exhibited a word learning deficit that began at encoding and persisted across time. Critically, this deficit grew over the course of the week. The performance gap between groups was larger at the 1-week post-test than the immediate post-test, suggesting deficits in both encoding and consolidation of new words in individuals with TBI. Participants with and without TBI remembered more words when they slept after learning. Ecologically valid research designs that examine the relationship between memory, sleep, and word learning over time promise to advance mechanistic accounts of word learning and improve the long-term retention of new words in individuals with and without brain injury.

Word Learning as a Window to Memory and Rehabilitation Outcomes in Traumatic Brain Injury

PURPOSE

The purpose of this viewpoint is to advocate for increased study of word learning abilities and word learning interventions in traumatic brain injury (TBI).

METHOD

We describe the word learning process and the unique opportunities afforded by studying each component and stage. Building on discussions at the 2022 International Cognitive-Communication Disorders Conference, we describe how word learning may underlie a variety of functional outcomes after TBI, making it a promising target for rehabilitation. Finally, we discuss principles that may guide study in this critical area to advance outcomes after TBI for children and adults.

RESULTS

Word learning is a dynamic and iterative process taking place over time and in multiple stages. Thus, studying word learning affords the opportunity to parse the relative contributions of multiple memory systems to different phases and components of the process. However, single-timepoint designs are insufficient to capture the full word learning process, which occurs over time and across contexts. Word learning also presents an opportunity to assess the contributions of behavioral and lifestyle factors (e.g., sleep and exercise) to different memory phases. Understanding these interactions could drive clinical interventions aimed at improving memory through manipulable external behaviors.

CONCLUSIONS

Word learning is key to success in functional spheres across the life span. The importance of words to daily life remains after TBI, even as the memory systems that support word learning are disrupted. The empirical study of word learning and rehabilitation of word learning deficits in TBI presents a promising new direction in understanding the breadth of neurogenic cognitive-communication disorders and an opportunity to explore a potential driver of functional outcome and impactful rehabilitation target.

Designing evidence-based support aids for social media access for individuals with moderate-severe traumatic brain injury: A preliminary acceptability study

Background

Adults with traumatic brain injury (TBI) report significant barriers to using current social media platforms, including cognitive overload and challenges in interpreting social cues. Rehabilitation providers may be tasked with helping to address these barriers.

Objectives

To develop technological supports to increase social media accessibility for people with TBI-related cognitive impairments and to obtain preliminary data on the perceived acceptability, ease of use, and utility of proposed technology aids.

Methods

We identified four major barriers to social media use among individuals with TBI: sensory overload, memory impairments, misreading of social cues, and a lack of confidence to actively engage on social media platforms. We describe the process of developing prototypes of support aids aimed at reducing these specific social media barriers. We created mock-ups of these prototypes and asked 46 community-dwelling adults with TBI (24 females) to rate the proposed aids in terms of their acceptability, ease of use, and utility.

Results

Across all aids, nearly one-third of respondents agreed they would use the proposed aids frequently, and the majority of respondents rated the proposed aids as easy to use. Respondents indicated that they would be more likely to use the memory and post-writing aids than the attention and social cue interpretation aids.

Conclusions

Findings provide initial support for social-media-specific technology aids to support social media access and social participation for adults with TBI. Results from this study have design implications for future development of evidence-based social media support aids. Future work should develop and deploy such aids and investigate user experience.

Mediators, Moderators, and Covariates: Matching Analysis Approach for Improved Precision in Cognitive-Communication Rehabilitation Research

PURPOSE

The dual goals of this tutorial are (a) to increase awareness and use of mediation and moderation models in cognitive-communication rehabilitation research by describing options, benefits, and attainable analytic approaches for researchers with limited resources and sample sizes and (b) to describe how these findings may be interpreted for clinicians consuming research to inform clinical care.

METHOD

We highlight key insights from the social sciences literature pointing to the risks of common approaches to linear modeling, which may slow progress in clinical-translational research and reduce the clinical utility of our work. We discuss the potential of mediation and moderation analyses to reduce the research-to-practice gap and describe how researchers may begin to implement these models, even in smaller sample sizes. We discuss how these preliminary analyses can help focus resources for larger trials to fully encapsulate the heterogeneity of individuals with cognitive-communication disorders.

RESULTS

In rehabilitation research, we study groups, but we use the findings from those studies to treat individuals. The most functional clinical research is about more than establishing only whether a given effect exists for an "average person" in the group of interest. It is critical to understand the active ingredients and mechanisms of action by which a given treatment works (mediation) and to know which circumstances, contexts, or individual characteristics might make that treatment most beneficial (moderation).

CONCLUSIONS

Increased adoption of mediation and moderation approaches, executed in appropriate steps, could accelerate progress in cognitive-communication rehabilitation research and lead to the development of targeted treatments that work for more clients. In a field that has made limited progress in developing successful interventions for the last several decades, it is critical that we harness new approaches to advance clinical-translational research results for complex, heterogeneous groups with cognitive-communication disorders.

The Value of Patient Registries to Advance Basic and Translational Research in the Area of Traumatic Brain Injury

The number of individuals affected by traumatic brain injury (TBI) is growing globally. TBIs may cause a range of physical, cognitive, and psychiatric deficits that can negatively impact employment, academic attainment, community independence, and interpersonal relationships. Although there has been a significant decrease in the number of injury related deaths over the past several decades, there has been no corresponding reduction in injury related disability over the same time period. We propose that patient registries with large, representative samples and rich multidimensional and longitudinal data have tremendous value in advancing basic and translational research and in capturing, characterizing, and predicting individual differences in deficit profile and outcomes. Patient registries, together with recent theoretical and methodological advances in analytic approaches and neuroscience, provide powerful tools for brain injury research and for leveraging the heterogeneity that has traditionally been cited as a barrier inhibiting progress in treatment research and clinical practice. We report on our experiences, and challenges, in developing and maintaining our own patient registry. We conclude by pointing to some future opportunities for discovery that are afforded by a registry model.

Temporal order memory impairments in individuals with moderate-severe traumatic brain injury

INTRODUCTION

Temporal order memory is a core cognitive function that underlies much of our behavior. The ability to bind together information within and across events, and to reconstruct that sequence of information, critically relies upon the hippocampal relational memory system. Recent work has suggested traumatic brain injury (TBI) may particularly impact hippocampally mediated relational memory. However, it is currently unclear whether such deficits extend to temporal order memory, and whether deficits only arise at large memory loads. The present study assessed temporal order memory in individuals with chronic, moderate-severe TBI across multiple set sizes.

METHOD

Individuals with TBI and Neurotypical Comparison participants studied sequences of three to nine objects, one a time. At test, all items were re-presented in pseudorandom order, and participants indicated the temporal position (i.e., first, second, etc.) in which each object had appeared. Critically, we assessed both the frequency and the magnitude of errors (i.e., how far from its studied position was an item remembered).

RESULTS

Individuals with TBI were not impaired for the smallest set size, but showed significant impairments at 5+ items. Group differences in the error frequency did not increase further with larger set sizes, but group differences in error magnitude did increase with larger memory loads. Individuals with TBI showed spared performance for the first object of each list (primacy) but were impaired on the last object (recency), though error frequency was better for last compared to middle items.

CONCLUSIONS

Our findings demonstrate that TBI results in impaired temporal order memory for lists as small as five items, and that impairments are exacerbated with increasing memory loads. Assessments that test only small set sizes may be insufficient to detect these deficits. Further, these data highlight the importance of additional, sensitive measures in the assessment of cognitive impairments in TBI.

Confidence and Training of Speech-Language Pathologists in Cognitive-Communication Disorders: Time to Rethink Graduate Education Models?

Purpose The purpose of this article is to highlight the need for increased focus on cognitive communication in North American speech-language pathology graduate education models. Method We describe key findings from a recent survey of acute care speech-language pathologists (SLPs) in the United States and expand upon the ensuing discussion at the 2020 International Cognitive-Communication Disorders Conference to consider some of the specific challenges of training for cognitive communication and make suggestions for rethinking how to prepare future clinicians to manage cognitive-communication disorders. Results Results from the survey of acute care SLPs indicated inconsistent confidence and training in managing cognitive-communication disorders. We discuss the pros and cons of several avenues for improving the consistency of cognitive-communication training, including a standalone cognitive-communication course, integrating cognitive communication in all courses across the speech-language pathology undergraduate and graduate curriculum, and using problem-based learning frameworks to better prepare students as independent thinkers in the area of cognitive communication and beyond. Conclusions Cognitive-communication disorders cut across clinical diagnoses and settings and are one of the largest and fastest growing parts of the SLP's scope of practice. Yet, surveys, including the one discussed here, have repeatedly indicated that SLPs do not feel prepared or confident to work with individuals with cognitive-communication disorders. We propose several avenues for increasing educational emphasis on cognitive communication. We hope these ideas will generate discussion and guide decision making to empower SLPs to think critically and step confidently into their roles as leaders in managing the heterogeneous and ever-growing populations of individuals with cognitive-communication disorders.

Disability and the COVID-19 Pandemic: A Survey of Individuals With Traumatic Brain Injury

Objectives

To identify the consequences of the coronavirus 2019 (COVID-19) pandemic for individuals with traumatic brain injury (TBI), with particular attention to unique effects for individuals with chronic disability.

Design

Individuals with and without a history of TBI completed a web-based survey.

Setting

Participants were recruited from the Vanderbilt Brain Injury Patient Registry in Nashville, TN, and completed the survey from their homes between May and June 2020, during social distancing related to the COVID-19 pandemic.

Participants

Participants (N=47) in the chronic phase of moderate-severe TBI (>6mo postinjury) and 51 noninjured comparison (NC) peers completed the survey.

Interventions

Not applicable.

Main Outcome Measures

Participants, or respondents, answered a mix of multiple choice and free text questions about how the COVID-19 pandemic has affected their work, education, medical care, social communication, sources of information and decision making, and mental and physical well-being. Individuals with TBI also answered questions about how TBI has affected their experiences of the pandemic.

Results

As a group, respondents with TBI reported less pandemic-related behavior change (eg, daily habits, virtual social visits, and masking) than NC peers. Both NCs and respondents with TBI identified health care providers as trusted sources of public health information. One-third of individuals with TBI indicated that brain injury has made coping with the pandemic more difficult, and respondents identified mental health challenges and social isolation as key barriers.

Conclusions

These results suggest that health care providers should look for ways to provide tailored education and reduce social isolation for individuals with disability during the ongoing COVID-19 pandemic. We discuss several direct suggestions from participant responses.

Traumatic brain injury in the acute care setting: assessment and management practices of speech-language pathologists

PRIMARY OBJECTIVE

To characterize current knowledge, beliefs, confidence, and practice patterns of acute care speech-language pathologists (SLPs) in assessing and managing cognitive-communication disorders following traumatic brain injury (TBI).

RESEARCH DESIGN

We developed an online survey to learn more about current TBI knowledge and practice patterns of acute care SLPs, with the goal of establishing a baseline upon which changes in SLP training and practice standards may be measured.

METHODS AND PROCEDURES

We distributed the survey to 1800 SLPs in 18 states via postal mail, in addition to posting it to relevant online groups. One hundred and eighty-two practicing acute care SLPs responded to the survey.

MAIN OUTCOMES AND RESULTS

Respondents were highly variable in their training and knowledge about TBI, their beliefs about cognitive-communication rehabilitation, and their practice patterns in assessing, managing, and communicating about TBI during the acute stage of injury.

CONCLUSIONS

These results highlight the need for more consistent training about cognitive-communication deficits during and after graduate school, as well as the development of sensitive, specific, and standardized assessment tools, education protocols, and shared language for describing patients with TBI along the continuum of care.

Relational Memory at Short and Long Delays in Individuals With Moderate-Severe Traumatic Brain Injury

Memory deficits are a common and frequently-cited consequence of moderate-severe traumatic brain injury (TBI). However, we know less about how TBI influences relational memory, which allows the binding of the arbitrary elements of experience and the flexible use and recombination of relational representations in novel situations. Relational memory is of special interest for individuals with TBI, given the vulnerability of the hippocampus to injury mechanisms, as well as a growing body of literature establishing the role of relational memory in flexible and goal-directed behavior. In this study, participants with and without a history of moderate-severe TBI completed a continuous relational memory task for face-scene pairings. Participants with TBI exhibited a disruption in relational memory not only when tested after a delay, but also when tested with no experimenter-imposed delay after stimulus presentation. Further, canonical assessments of working and episodic memory did not correspond with performance on the face-scene task, suggesting that this task may tap into relational memory differently and with greater sensitivity than standardized memory assessments. These results highlight the need for rigorous assessment of relational memory in TBI, which is likely to detect deficits that have specific consequences for community reintegration and long-term functional outcomes.

Sleep Supports Memory and Learning: Implications for Clinical Practice in Speech-Language Pathology

Purpose This tutorial aims to draw attention to the interactions among memory, sleep, and therapy potential and to increase awareness and knowledge in the field of speech-language pathology of the potential impact of sleep as a mediating or moderating factor in promoting therapeutic outcome. Method We highlight key findings from the literature on the cognitive neuroscience of memory, the neurophysiology of sleep, how sleep supports memory, and how sleep disruption affects memory and learning abilities in populations commonly served in speech-language pathology. Results Research increasingly points to the critical importance of sleep quality and quantity to memory and learning, and sleep disruption is linked to deficits in functional cognition that may limit our clients' ability to benefit from speech pathology interventions. Conclusions As a field dedicated to promoting memory, learning, and relearning through our interventions, any systemic factors that affect these abilities demand our attention. Although speech-language pathologists do not treat sleep disturbance, we play a critical role in recognizing the signs and symptoms of sleep disturbance and making appropriate referrals, as undiagnosed and untreated sleep disturbance can have serious impacts on success in therapeutic contexts. By considering how related factors affect memory and learning, we have the opportunity to take a whole client approach to maximizing our clients' therapy potential and functional progress.

Calcium differentially alters behavioral and electrophysiological responses to ethanol in selectively bred mouse lines

Sensitivity to the hypnotic action of ethanol has been found to increase in SS/Ibg (SS) but not in LS/Ibg (LS) mice after intracerebroventricular (icv) administration of calcium. In the present investigation, a correlation was found between calcium-induced changes in behavioral sensitivity and in the sensitivity of cerebellar Purkinje neurons to the depressant effects of locally applied ethanol. Cerebellar Purkinje neuron sensitivity was measured as the dose of ethanol pressure ejected from a multibarreled micropipette required to produce a 50% depression of spontaneous firing rate of single neurons. Administration of 0.2-0.4 mumol calcium chloride into the lateral ventricle of the brain increased the sensitivity of SS but not LS mice to the hypnotic behavioral effect of systemically administered ethanol. Similarly, Purkinje neuron sensitivity to locally applied ethanol was also enhanced in SS but not in LS mice 15 min following administration of calcium (0.25 mumol) icv. Furthermore, locally applied ethanol was more effective in depressing spontaneous Purkinje neuron discharge in SS mice when a 1 mM calcium solution was concomitantly pressure ejected with ethanol from the micropipette. Magnesium chloride did not mimic the effects of calcium on either behavioral or electrophysiological effects of ethanol, suggesting that the action of calcium is not a nonspecific effect of divalent cations. These data suggest that calcium-dependent processes may be involved in behavioral and electrophysiological effects associated with ethanol intoxication. Further research will be required to determine if the genetically selected difference in ethanol sensitivity expressed in LS and SS mice is regulated by calcium mechanisms.

Calcium influence on neuronal sensitivity to ethanol in selectively bred mouse lines

Sensitivity to ethanol, as measured by blood ethanol concentration at loss of righting reflex, was increased significantly in SS but not LS mice following intracerebroventricular (ICV) administration of calcium chloride or A23187, a calcium ionophore. Magnesium chloride or lanthanum chloride, ICV, did not alter sensitivity to ethanol in either SS or LS mice, further indicating a specificity for calcium cation. Calcium was without effect on sensitivity to halothane narcosis in LS or SS mice. Endogenous brain calcium content was similar in these mouse lines, and ethanol administration either in vivo or in vitro did not alter brain calcium concentration. These results indicate that differences in brain sensitivity to ethanol are mediated, in part, by genetic differences in calcium-related processes and support the hypothesis that ethanol-induced narcosis may be due to alterations in calcium metabolism in the CNS.

Effects of ethanol and pentobarbital on neuronal hexose uptake in inbred mice

The effect of ethanol and pentobarbital narcosis on 2-deoxyglucose uptake into brain synaptosomes prepared from inbred C57BL/6J and DBA/2J mice which exhibit differential central sensitivity to ethanol and heterogeneous ICR mice was examined. A reversible depression of synaptosomal uptake was exhibited in all strains administered ethanol acutely, occurring at 2 min in ICR and C57BL/6J mice and 15 min in DBA/2J. Uptake returned to control values in all strains at 30 min although the mice remained intoxicated. Brain glucose concentration was significantly elevated at this time. Pentobarbital administration was without effect on synaptosomal hexose transport in DBA/2J and C57BL/6J mice but increased it significantly in ICR mice at 30 min. Pentobarbital anesthesia did not alter brain glucose concentration. No correlation was apparent between synaptosomal 2-deoxyglucose uptake and differential CNS sensitivity to ethanol and pentobarbital. The effects of ethanol and pentobarbital on neuronal hexose transport is discussed with respect to reported changes in glycolytic metabolism produced by these agents.