Traumatic brain injury and post-acute decline: what role does environmental enrichment play? A scoping review

Real-world environmental enrichment rehabilitation paradigm in people with severe traumatic brain injury: a pilot feasibility study

BACKGROUND

The use of Environmental Enrichment (EE) has been widely studied in animal models. However, the application of the same in humans is limited to rehabilitation settings.

OBJECTIVE

To investigate the feasibility of a community-based EE paradigm in adults with brain injury.

METHODS

Six individuals diagnosed with traumatic brain injury enrolled in the study. The Go Baby Go Café instrumented with a body weight harness system, provided physical and social enrichment as participants performed functional tasks for 2 hours, three times a week, for 2 months. Feasibility and safety outcomes were recorded throughout sessions. Clinical measures including 10-meter walk, timed up and go, jebsen hand function, 6-minute walk, and trail making tests were obtained pre and post intervention.

RESULTS

All participants completed the study. The attendance was 100% and adherence was 87%. Positive changes in clinical measures were statistically significant for the timed up and go (p = 0.0175), TUG-cognitive (p = 0.0064), 10-meter walk (p = 0.0428), six-minute walk (p = 0.0196), TMT-A (p = 0.034). Changes in JHFT were not significant (p = 0.0506), with one subject recording values counter to the trend.

CONCLUSION

The Café was a comprehensive EE-based intervention that was feasible, safe, and has the potential to enhance motor and cognitive function in individuals with brain injury.

Riding waves to improve functioning: a quantitative evaluation of a Surf Week in individuals with chronic phase brain injury with six months follow-up

PURPOSE

Environmental enrichment seems to enable people in the chronic phase of acquired brain injury (ABI) to experience new functional abilities and motor/coping strategies and consequently to become more adaptable which might prevent/reverse functional decline. This study describes the influence of a five-days Surf Week program on participants on physical function, self-efficacy, functional balance performance and self-perceived recovery.

MATERIALS AND METHODS

A multiple-baseline single-case design was used. Adults participating in the Surf Week in chronic phase of ABI were eligible to participate. Participants completed a battery of tests monitoring physical function, self-efficacy, functional balance performance and self-perceived recovery. This battery was repeated 5 times over a 1-year period, two times pre-Surf Week, three times post-Surf Week. Visual data inspection with two non-overlap methods were used to determine if patients showed sustained improvement in outcomes post-intervention.

RESULTS

A moderate to strong indication for improvements on physical function, functional balance performance and self-perceived recovery exists till six months follow-up. No indication was observed on self-efficacy till six months follow-up.

CONCLUSIONS

A five-days Surf Week is a physically, cognitively and socially intensive stimulating activity that can positively challenge individuals after ABI and seems to improve physical functioning, functional balance performance and self-perceived recovery.

International classification of functioning, disability and health with long-term consequences of cranio-brain injury

OBJECTIVE

Aim: To describe health status and related functioning of patients with different severity of traumatic brain injury (TBI) in past medical history in Ukraine and determining the feasibility of using the International Classification of Functioning, Disability and Health (ICF) Brief Core Set for TBI.

PATIENTS AND METHODS

Materials and Methods: A total of 102 patients, who were treated in the neurological department of Dnipropetrovsk regional clinical hospital and State Institution ≪Ukrainian State Scientific Research Institute of Medical and Social Problems of Disability of Health Ministry of Ukraine≫, had been examined. Patients were divided into three groups: mild, moderate and severe TBI in past history and evaluated using ICF Brief Core Set for TBI.

RESULTS

Results: Тhe most common problems in the functioning and health of patients in remote period of TBI, along with the influencing factors have been identified in the study. The most frequent categories from ≪Body Functions≫ and ≪Activity and Participation≫ sections in which patients had alterations were: memory functions, emotional functions, sensation of pain, functions of attention, brain structure, complex interpersonal interactions, family relationships. The increase in the amount and severity of disturbances with increasing severity of TBI had been established in all categories, except complex interpersonal interactions and family relationships.

CONCLUSION

Conclusions: Patients of all groups identified the family and close relatives, healthcare service and social welfare services, as the most frequent relieving factors of life activity. The use of the ICF Brief Core Set for assessing the subjects with TBI in past history provides a convenient procedure to standardize and structure functioning description. Information collected by the ICF Brief Core Set may be used for different purposes: clinical assessment, administration of medical services, planning and implementation of rehabilitation and evaluation of results, in scientific research, reports and health care statistics.

Environmental Enrichment for Stroke and Traumatic Brain Injury: Mechanisms and Translational Implications

Acquired brain injuries, such as ischemic stroke, intracerebral hemorrhage (ICH), and traumatic brain injury (TBI), can cause severe neurologic damage and even death. Unfortunately, currently, there are no effective and safe treatments to reduce the high disability and mortality rates associated with these brain injuries. However, environmental enrichment (EE) is an emerging approach to treating and rehabilitating acquired brain injuries by promoting motor, sensory, and social stimulation. Multiple preclinical studies have shown that EE benefits functional recovery, including improved motor and cognitive function and psychological benefits mediated by complex protective signaling pathways. This article provides an overview of the enriched environment protocols used in animal models of ischemic stroke, ICH, and TBI, as well as relevant clinical studies, with a particular focus on ischemic stroke. Additionally, we explored studies of animals with stroke and TBI exposed to EE alone or in combination with multiple drugs and other rehabilitation modalities. Finally, we discuss the potential clinical applications of EE in future brain rehabilitation therapy and the molecular and cellular changes caused by EE in rodents with stroke or TBI. This article aims to advance preclinical and clinical research on EE rehabilitation therapy for acquired brain injury. © 2024 American Physiological Society. Compr Physiol 14:5291-5323, 2024.

Moderate-Severe TBI as a Progressive Disorder: Patterns and Predictors of Cognitive Declines in the Chronic Stages of Injury

BACKGROUND

Moderate-severe traumatic brain injury (TBI) has been associated with progressive cognitive decline in the chronic injury stages in a small number of studies.

OBJECTIVE

This study aimed to (i) replicate our previous findings of decline from 1 to 3+ years post-injury in a larger, non-overlapping sample and (ii) extend these findings by examining the proportion of decliners in 2 earlier time windows, and by investigating novel predictors of decline.

METHODS

N = 48 patients with moderate-severe TBI underwent neuropsychological assessment at 2, 5, 12 months, and 30+ months post-injury. We employed the Reliable Change Index (RCI) to evaluate decline, stability and improvement across time and logistic regression to identify predictors of decline (demographic/cognitive reserve; injury-related).

RESULTS

The proportions of patients showing decline were: 12.5% (2-5 months post-injury), 17% (5-12 months post-injury), and 27% (12-30+ months post-injury). Measures of verbal retrieval were most sensitive to decline. Of the predictors, only left progressive hippocampal volume loss from 5 to 12 months post-injury significantly predicted cognitive decline from 12 to 30+ months post-injury.

CONCLUSIONS

Identical to our previous study, 27% of patients declined from 12 to 30+ months post-injury. Additionally, we found that the further from injury, the greater the proportion of patients declining. Importantly, earlier progressive hippocampal volume loss predicted later cognitive decline. Taken together, the findings highlight the need for ongoing research and treatment that target these deleterious mechanisms affecting patients in the chronic stages of moderate-severe TBI.

Efficacy of Multimodal Sensory Therapy in Adult Acquired Brain Injury: A Systematic Review

Adults who experience an acquired brain injury often experience disorders of consciousness, physical difficulties, and maladaptive behaviours. Multimodal sensory therapy may benefit brain injured patients, however the extent this therapy can facilitate rehabilitation is not well understood. This systematic review aimed to synthesize multimodal sensory therapy research for adults affected by acquired brain injury. PRISMA guidelines were followed and searches for work published up until July 2021 were undertaken in 5 databases, finding 1054 articles. 43 articles were included in the study. Results describe 29 studies related to coma following an acquired brain injury and 14 to no coma studies (mostly stroke). Multimodal sensory therapy was mostly used as a coma arousal technique following traumatic brain injury, finding positive effects. Multimodal sensory therapy was less applied in stroke, no coma rehabilitation, where most studies found improvement in somatosensory sensation and motor control in an affected limb. In several no coma studies, effects were maintained after several months. The most common senses stimulated in coma studies were audio (N = 30), tactile (N = 28), visual (N = 26), olfactory (N = 22), and gustatory (N = 17), while the most common senses stimulated in stroke, no coma studies were proprioception (N = 7), tactile (N = 8), and stereognosis (N = 4). Multimodal sensory therapy can be beneficial for patients, especially those in a minimally conscious state or attempting physical rehabilitation following stroke. Negative findings are infrequent in the current literature base. Multimodal sensory therapy appears to be a low-risk intervention with positive outcomes.

Acquired brain injury (ABI) survivors' experience of occupation and activity during their inpatient stay: a scoping review

PURPOSE

This review aimed to characterise and map: (1) what type of evidence and what dominant study characteristics are available regarding acquired brain injury (ABI) survivors' experience of occupation and activity in hospital? (2) How are occupation and activity conceptualised in the literature? (3) How are ABI survivors experiencing occupation and activity while in hospital? (4) What factors create barriers or opportunities for engagement in occupations or activity in hospital? (5) Are there any knowledge gaps identified?

MATERIALS AND METHODS

A scoping review was conducted examining literature published between 2017 and 2022. Relevant studies were systematically retrieved from electronic databases.

RESULTS

Thirty-four publications were included. There were more quantitative studies (n = 18). Much of the research has been conducted outside of the UK. The populations studied were principally stroke (n = 22). The concept of activity rather than occupation predominates. Patients spend their time alone and inactive. Structural and contextual barriers for engaging in activity are identified. Qualitative study designs exclude ABI survivors with communication or cognitive impairment.

CONCLUSIONS

There is a paucity of research with ABI survivors in hospitals in the UK. Alternative methodological approaches such as ethnography would ensure those with communication or cognitive impairment are not excluded from research. Implications for rehabilitationRehabilitation professionals, especially occupational therapists, need to lead acquired brain injury (ABI) research in acute hospital settings in the UK.Conceptualisation of meaningful activity and occupation needs a clearer focus in ABI research.Qualitative studies frequently exclude participants with cognitive or communication impairments so methodologies that are more inclusive and representative of brain injury survivors are needed.

Multi-Mechanistic Approaches to the Treatment of Traumatic Brain Injury: A Review

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Despite extensive research efforts, the majority of trialed monotherapies to date have failed to demonstrate significant benefit. It has been suggested that this is due to the complex pathophysiology of TBI, which may possibly be addressed by a combination of therapeutic interventions. In this article, we have reviewed combinations of different pharmacologic treatments, combinations of non-pharmacologic interventions, and combined pharmacologic and non-pharmacologic interventions for TBI. Both preclinical and clinical studies have been included. While promising results have been found in animal models, clinical trials of combination therapies have not yet shown clear benefit. This may possibly be due to their application without consideration of the evolving pathophysiology of TBI. Improvements of this paradigm may come from novel interventions guided by multimodal neuromonitoring and multimodal imaging techniques, as well as the application of multi-targeted non-pharmacologic and endogenous therapies. There also needs to be a greater representation of female subjects in preclinical and clinical studies.

Implementation of active injury management (AIM) in youth with acute concussion: A randomized controlled trial

BACKGROUND

Nearly 2 million youth seek acute medical care following concussion in the U.S. each year. Current standard of care recommends rest for the first 48 h after a concussion. However, research suggests that prolonged rest may lengthen recovery time especially for patients with certain risk profiles. Research indicates that physical activity and behavioral management interventions (sleep, stress management) may enhance recovery. To date, there is limited empirical evidence to inform acute (<72 h) concussion recommendations for physical activity and behavioral management in adolescents.

OBJECTIVE

To determine the effectiveness of physical activity and behavioral management for acute concussion in adolescents and young adults, and to evaluate the role of patient characteristics on treatment response.

METHODS

This multicenter prospective randomized controlled trial will determine which combination of physical activity and behavioral management is most effective for patients 11-24 years old who present to the emergency department or concussion clinic within 72 h of injury. Participants are randomized into: 1) rest, 2) physical activity, 3) mobile health application (mHealth) behavioral management, or 4) physical activity and mHealth app conditions. Assessments at enrollment, 3-5 days, 14 days, 1 month, and 2 months include: concussion symptoms, balance, vestibular-ocular and cognitive assessments, quality of life, and recovery time. Somatic symptoms and other risk factors are evaluated at enrollment. Compliance with treatment and symptoms are assessed daily using actigraph and daily self-report. The primary study outcome is symptoms at 14 days.

CONCLUSION

Prescribed physical activity and behavioral management may improve outcomes in youth following acute concussion.

Sex-dependent effects of postweaning exposure to an enriched environment on visceral pain and anxiety- and depression-like behaviors induced by neonatal maternal separation

BACKGROUND

Neonatal maternal separation (NMS) can lead to visceral pain and anxiety- and depression-like behaviors. An enriched environment (EE) can alleviate NMS-induced pain and mental disorders, but previous studies have mostly been performed in male animals. Therefore, the aim of this study was to investigate whether the effects of EE were sex dependent at different stages of development.

METHODS

Female and Male C57BL/6 J mice that had been subjected to NMS alone and those subjected to both NMS and exposed to EE were used in this study. The visceral pain threshold test (PTT), open field test (OFT), sucrose preference test (SPT), and forced swimming test (FST) were conducted to evaluate visceral pain, anxiety-like behavior, and depression-like behavior in mice, respectively.

RESULTS

Compared with the male mice in the NMS group without EE exposure, those exposed to EE from postnatal day (P)21 to 41 showed an increase of the visceral pain threshold in the PTT, an increase of the central time and central distance in the OFT, an increase of the sucrose preference rate in the SPT, and a decrease of the time of immobility in the FST. Compared with both female and male mice in the NMS group without EE exposure, those exposed to EE from P21 to P61 had an increase of the visceral pain threshold in the PTT, an increase of the central time and central distance in the OFT, an increase in the sucrose preference rate in the SPT, and a decrease of the time of immobility in the FST.

CONCLUSIONS

EE is more effective in male NMS mice, while longer EE is required in female NMS mice for positive effects.

After 55 Years of Neurorehabilitation, What Is the Plan?

Neurological disorders often cause severe long-term disabilities with substantial activity limitations and participation restrictions such as community integration, family functioning, employment, social interaction and participation. Increasing understanding of brain functioning has opened new perspectives for more integrative interventions, boosting the intrinsic central nervous system neuroplastic capabilities in order to achieve efficient behavioral restitution. Neurorehabilitation must take into account the many aspects of the individual through a comprehensive analysis of actual and potential cognitive, behavioral, emotional and physical skills, while increasing awareness and understanding of the new self of the person being dealt with. The exclusive adoption by the rehabilitator of objective functional measures often overlooks the values and goals of the disabled person. Indeed, each individual has their own rhythm, unique life history and personality construct. In this challenging context, it is essential to deepen the assessment through subjective measures, which more adequately reflect the patient’s perspective in order to shape genuinely tailored instead of standardized neurorehabilitation approaches. In this overly complex panorama, where confounding and prognostic factors also strongly influence potential functional recovery, the healthcare community needs to rethink neurorehabilitation formats.

Neurorehabilitation through Hippotherapy on Neurofunctional Sequels of Stroke: Effect on Patients' Functional Independence, Sensorimotor/Cognitive Capacities and Quality of Life, and the Quality of Life of Their Caregivers-A Study Protocol

BACKGROUND

Stroke is a high burden illness and the second leading cause of worldwide disability with generally poor recovery rates. Robust benefits of hippotherapy, a novel neurorehabilitation approach, in functional recovery following various severe neurological disabling conditions has been shown. In the present study, we will analyze the effect of a hippotherapy program on the outcome of post-stroke patients in the first year post-stroke.

METHOD

A randomized controlled clinical trial on the effectiveness of hippotherapy (4 weeks/18 weeks hippotherapy/conventional neurorehabilitation) versus conventional neurorehabilitation alone (22 weeks) will be conducted over 48 weeks. In the treated group, one-hour daily hippotherapy sessions will be exclusively conducted during the hippotherapy's cycles, alternated with periods of conventional neurorehabilitation. A test battery will measure both the functional and psychological outcomes. The primary endpoint will be the patient's functional independence. The secondary endpoints will measure the sensorimotor function, autonomy, and quality of life, as well as the caregivers' quality of life.

RESULTS AND CONCLUSION

Individual brain connectome, life history and personality construct influence the brain's functional connectivity and are central to developing optimal tailored neurorehabilitation strategies. According to our current practice, hippotherapy allows the enhancement of substantial neuroplastic changes in the injured brain with significant neurological recovery. The protocol aims to confirm those issues. Trial registration in ClinicalTrials.gov NCT04759326 accessed on 19 February 2021.

Environmental enrichment for stroke and other non-progressive brain injury

BACKGROUND

Rehabilitation is effective for recovery after stroke and other non-progressive brain injuries but it is unclear if the rehabilitation environment itself, outside of limited therapy hours, is maximally conducive to recovery. Environmental enrichment is a relatively new concept within rehabilitation for humans. In this review, this is defined as an intervention designed to facilitate physical (motor and sensory), cognitive and social activity by the provision of equipment and organisation of a structured, stimulating environment. The environment should be designed to encourage (but not force) activities without additional specialised rehabilitation input.

OBJECTIVES

To assess the effects of environmental enrichment on well-being, functional recovery, activity levels and quality of life in people who have stroke or non-progressive brain injury.

SEARCH METHODS

We conducted the search on 26 October 2020. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (from 1950); Embase (from 1980); the Cumulative Index to Nursing and Allied Health Literature (CINAHL; from 1982); the Allied and Complementary Medicine Database (AMED; from 1985); PsycINFO (from 1806); the Physiotherapy Evidence Database (PEDro; from 1999); and 10 additional bibliographic databases and ongoing trial registers.

SELECTION CRITERIA

We planned to include randomised controlled trials (RCTs) that compared environmental enrichment with standard services.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligible studies, extracted data, and assessed study quality. Any disagreements were resolved through discussion with a third review author. We determined the risk of bias for the included study and performed a 'best evidence' synthesis using the GRADE approach.

MAIN RESULTS

We identified one RCT, involving 53 participants with stroke, comparing environmental enrichment (which included physical, cognitive and social activities such as reading material, board and card games, gaming technology, music, artwork, and computer with Internet) with standard services in an inpatient rehabilitation setting. We excluded five studies, found two studies awaiting classification and one ongoing study which described environmental enrichment in their interventions. Of the excluded studies, three were non-RCTs and two described co-interventions with a significant component of rehabilitation. Based on the single small included RCT at high risk of bias, data are insufficient to provide any reliable indication of benefit or risk to guide clinical practice in terms of the provision of environmental enrichment.

AUTHORS' CONCLUSIONS

The gap in current research should not, however, be interpreted as proof that environmental enrichment is ineffective. Further research is needed with robust study designs, such as cluster RCTs, and consistent outcome measurement evaluating the effectiveness of environmental enrichment in different settings (inpatient versus outpatient), the relative effectiveness of various components of environmental enrichment, cost-effectiveness, and safety of the intervention in people following stroke or other non-progressive brain injuries. It should be noted, however, that it is challenging to randomise or double-blind trials of environmental enrichment given the nature of the intervention.

Regulating emotion following severe traumatic brain injury: a randomized controlled trial of heart-rate variability biofeedback training

BACKGROUND

While difficulties regulating emotions are almost ubiquitous after traumatic brain injury (TBI), remediation techniques are limited. Heart-rate variability (HRV) is a physiological measure of emotion regulation and can be modified using biofeedback training. The aim of the current study was to evaluate the efficacy of repeated biofeedback training for improving emotion regulation difficulties following TBI.

DESIGN

Fifty adults with severe TBI were allocated to either biofeedback or waitlist conditions. Treatment consisted of six biofeedback sessions whereby participants were taught to breathe at their resonant frequency. Outcomes included changes in physiological and subjective reactivity to anger-induction, emotional well-being, and physiology at rest, together with symptoms of psychological distress and sleep disturbances (ACTRN12618002031246).

RESULTS

While biofeedback led to reduced skin conductance, it did not affect any other objective or subjective response to the mood induction procedure. Biofeedback led to fewer sleep disturbances, and reduced negative mood valence and depression during follow-up.

CONCLUSIONS

HRV biofeedback training is a feasible technique following TBI that transfers to improved symptoms of general emotional well-being, psychological distress, and sleep. Biofeedback does not transfer to a laboratory-based emotional provocation task. HRV biofeedback training may represent a novel adjunct for generalized emotional difficulties following injury.

Progressive Neurodegeneration Across Chronic Stages of Severe Traumatic Brain Injury

OBJECTIVE

To examine the trajectory of structural gray matter changes across 2 chronic periods of recovery in individuals who have sustained severe traumatic brain injury (TBI), adding to the growing literature indicating that neurodegenerative processes occur in the months to years postinjury.

PARTICIPANTS

Patients who experienced posttraumatic amnesia of 1 hour or more, and/or scored 12 or less on the Glasgow Coma Scale at the emergency department or the scene of the accident, and/or had positive brain imaging findings were recruited while receiving inpatient care, resulting in 51 patients with severe TBI.

METHODS

Secondary analyses of gray matter changes across approximately 5 months, 1 year, and 2.5 years postinjury were undertaken, using an automated segmentation protocol with improved accuracy in populations with morphological anomalies. We compared patients and matched controls on regions implicated in poorer long-term clinical outcome (accumbens, amygdala, brainstem, hippocampus, thalamus). To model brain-wide patterns of change, we then conducted an exploratory principal component analysis (PCA) on the linear slopes of all regional volumes across the 3 time points. Finally, we assessed nonlinear trends across earlier (5 months-1 year) versus later (1-2.5 years) time-windows with PCA to compare degeneration rates across time. Chronic degeneration was predicted cortically and subcortically brain-wide, and within specific regions of interest.

RESULTS

(1) From 5 months to 1 year, patients showed significant degeneration in the accumbens, and marginal degeneration in the amygdala, brainstem, thalamus, and the left hippocampus when examined unilaterally, compared with controls. (2) PCA components representing subcortical and temporal regions, and regions from the basal ganglia, significantly differed from controls in the first time-window. (3) Progression occurred at the same rate across both time-windows, suggesting neither escalation nor attenuation of degeneration across time.

CONCLUSION

Localized yet progressive decline emphasizes the necessity of developing interventions to offset degeneration and improve long-term functioning.

How environmental enrichment balances out neuroinflammation in chronic pain and comorbid depression and anxiety disorders

Depression and anxiety commonly occur in chronic pain states and the coexistence of these diseases worsens outcomes for both disorders and may reduce treatment adherence and response. Despite the advances in the knowledge of chronic pain mechanisms, pharmacological treatment is still unsatisfactory. Research based on exposure to environmental enrichment is currently under investigation and seems to offer a promising low-cost strategy with no side effects. In this review, we discuss the role of inflammation as a major biological substrate and aetiological factor of chronic pain and depression/anxiety and report a collection of preclinical evidence of the effects and mechanisms of environmental enrichment. As microglia participates in the development of both conditions, we also discuss microglia as a potential target underlying the beneficial actions of environmental enrichment in chronic pain and comorbid depression/anxiety. We also discuss how alternative interventions under clinical guidelines, such as environmental enrichment, may improve treatment compliance and patient outcomes.

Hippocampal atrophy is associated with psychotic symptom severity following traumatic brain injury

Psychosis is a rare, but particularly serious sequela of traumatic brain injury. However, little is known as to the neurobiological processes that may contribute to its onset. Early evidence suggests that psychotic symptom development after traumatic brain injury may co-occur with hippocampal degeneration, invoking the possibility of a relationship. Particularly regarding the hippocampal head, these degenerative changes may lead to dysregulation in dopaminergic circuits, as is reported in psychoses due to schizophrenia, resulting in the positive symptom profile typically seen in post-injury psychosis. The objective of this study was to examine change in hippocampal volume and psychotic symptoms across time in a sample of moderate-to-severe traumatic brain injury patients. We hypothesized that hippocampal volume loss would be associated with increased psychotic symptom severity. From a database of n = 137 adult patients with prospectively collected, longitudinal imaging and neuropsychiatric outcomes, n = 24 had complete data at time points of interest (5 and 12 months post-traumatic brain injury) and showed increasing psychotic symptom severity on the Personality Assessment Inventory psychotic experiences subscale of the schizophrenia clinical scale across time. Secondary analysis employing stepwise regression with hippocampal volume change (independent variable) and Personality Assessment Inventory psychotic symptom change (dependent variable) from 5 to 12 months post-injury was conducted including age, sex, marijuana use, family history of schizophrenia, years of education and injury severity as control variables. Total right hippocampal volume loss predicted an increase in the Personality Assessment Inventory psychotic experiences subscale (F_{(1, 22)} = 5.396, adjusted R² = 0.161, P = 0.030; β = −0.017, 95% confidence interval = −0.018, −0.016) as did volume of the right hippocampal head (F_{(1, 22)} = 5.764, adjusted R² = 0.172, P = 0.025; β = −0.019, 95% confidence interval = −0.021, −0.017). Final model goodness-of-fit was confirmed using k-fold (k = 5) cross-validation. Consistent with our hypotheses, the current findings suggest that hippocampal degeneration in the chronic stages of moderate-to-severe traumatic brain injury may play a role in the delayed onset of psychotic symptoms after traumatic brain injury. These findings localized to the right hippocampal head are supportive of a proposed aetiological mechanism whereby atrophy of the hippocampal head may lead to the dysregulation of dopaminergic networks following traumatic brain injury; possibly accounting for observed clinical features of psychotic disorder after traumatic brain injury (including prolonged latency period to symptom onset and predominance of positive symptoms). If further validated, these findings may bear important clinical implications for neurorehabilitative therapies following traumatic brain injury.

Clinical Neurorehabilitation: Using Principles of Neurological Diagnosis, Prognosis, and Neuroplasticity in Assessment and Treatment Planning

Neurorehabilitation aspires to restore a person to his or her fullest potential after incurring neurological dysfunction. In medical rehabilitation, diagnosis involves assessment of medical conditions and their effects on functioning. It is usually a team effort that involves an amalgam of diagnostic assessments by multiple disciplines, leading to a collection of rehabilitative treatment plans and goals. This article discusses a clinical neurological paradigm, using rigorous clinical assessment of neuropathological and clinical diagnosis, along with prognostication of natural history and recovery. In the context of the role of neuroplasticity in recovery, this paradigm can add significant value to rehabilitation team management and planning. It contributes to enhanced understanding of neurological impairments and syndromes as they relate to functional disability, aiding in targeting deficits and setting treatment goals. Rehabilitation strategies and goals should be informed by natural history and prognosis, and viewed in the framework of the stage of recovery. Prognostic formulations should suggest an emphasis on restorative versus compensatory strategies for functional problems. Treatment planning should be informed by evidence on how interventions modulate brain reorganization in promoting recovery. Strategies that promote adaptive neuroplasticity should be favored, especially with restorative efforts, and evidence supporting optimal techniques, timing, and dosing of rehabilitation should be considered in treatment planning.

Feasibility of a home-based environmental enrichment paradigm to enhance purposeful activities in adults with traumatic brain injury: a case series

PURPOSE

To assess the feasibility, safety, and functional recovery of an Environmental Enrichment (EE) inspired paradigm for enhancing daily activities in people with traumatic brain injury.

METHODS

Two TBI-Caregiver dyads participated in the six-month study. A preinstalled harness provided the support structure that enabled the family to perform task-specific functional and cognitive goals. The pre- and post-intervention evaluations included the safety, feasibility, and clinical outcomes such as the 10-m walk test, the Timed Up and Go test, the Jebsen Hand Function test, the Six-Minute Walk test, and the Trail Making Test. The Actigraph GT9X recorded the Caregiver-TBI step count during days spent in harness and out of harness.

RESULTS

The study was feasible, safe, and both TBI subjects improved in functional outcomes. Analysis of Actigraph GT9X yielded mixed results.

CONCLUSION

A partnership with caregivers and adults with TBI to design an EE-focused community program could improve functional activities in real life. To optimize this intervention, caregivers will likely need an alternate approach to record time spent in the harness.IMPLICATIONS FOR REHABILITATIONThe complexities of the real world encourage meaningful activities and participation.Autonomy in everyday activities is an important long-term objective for adults with brain injury.Community-tailored harnesses designed to prevent falls encourages physical activity and social interaction.

Training the brain: could it improve multiple sclerosis treatment?

Multiple sclerosis (MS) is a neurological disease characterized by neuroinflammation, demyelination and axonal degeneration along with loss of function in the central nervous system. For many years, research in MS has focused on the efficacy of pharmacological treatments. However, during the last years, many publications have been dedicated to the study of the efficacy of non-pharmacological strategies, such as physical exercise and cognitive training. Beneficial effects of the combination of both strategies on cognitive function have been described in both ageing adults and patients with neurodegenerative diseases, such as MS. The analysis of combining both physical and cognitive stimulation can be summarized by the environmental enrichment (EE) experiments, which are more suitable for animal models. EE refers to housing conditions consisting of exercise and cognitive and social stimulation. In this review, we will summarize the available studies that describe the influence of EE in both MS patients and MS animal models.

Environmental enrichment improves cognitive symptoms and pathological features in a focal model of cortical damage of multiple sclerosis

Multiple Sclerosis (MS) is a neuroinflammatory disease affecting white and grey matter, it is characterized by demyelination, axonal degeneration along with loss of motor, sensitive and cognitive functions. MS is a heterogeneous disease that displays different clinical courses: relapsing/remitting MS (RRMS), and MS progressive forms: primary progressive (PPMS) and secondary progressive (SPMS). Cortical damage in the progressive MS forms has considerable clinical relevance due to its association with cognitive impairment and disability progression in patients. One treatment is available for the progressive forms of the disease, but none are specific for cognitive deficits. We developed an animal model that reflects most of the characteristics of the cortical damage, such as cortical neuroinflammation, demyelination, neurodegeneration and meningeal inflammation, which was associated with cognitive impairment. Cognitive rehabilitation, exercise and social support have begun to be evaluated in patients and animal models of neurodegenerative diseases. Environmental enrichment (EE) provides exercise as well as cognitive and social stimulation. EE has been demonstrated to exert positive effects on cognitive domains, such as learning and memory, and improving anxiety-like symptoms. We proposed to study the effect of EE on peripherally stimulated cortical lesion induced by the long term expression of interleukin IL-1β (IL-1β) in adult rats. Here, we demonstrated that EE: 1) reduces the peripheral inflammatory response to the stimulus, 2) ameliorates cognitive deficits and anxiety-like symptoms, 3) modulates neurodegeneration, demyelination and glial activation, 4) regulates neuroinflammation by reducing the expression of pro-inflammatory cytokines and enhancing the expression of anti-inflammatory ones. Our findings correlate with the fact that EE housing could be considered an effective non- pharmacological therapeutic agent that can synergistically aid in the rehabilitation of the disease.

Social integration and loneliness among long-term care home residents: protocol for a scoping review

INTRODUCTION

Social well-being is associated with better physical and mental health. It is also important for quality of life, including from the perspectives of those living in long-term care (LTC) homes. However, given the characteristics of the LTC home environment and the people who live there, the nature and influence of social integration and loneliness, and strategies to address them, may differ in this population compared with those living in the community. The objective of this scoping review is to provide an overview of the nature and extent of research on social integration and loneliness among LTC home residents, including a summary of how these concepts have been operationalised and any evidence from specific groups.

METHODS AND ANALYSIS

This study protocol describes the methods of a scoping review of peer-reviewed literature related to social integration and loneliness among LTC home residents. A literature search was developed by an Information Specialist and will be conducted in MEDLINE(R) ALL (in Ovid, including Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily) and then translated into CINAHL (EBSCO), PsycINFO (Ovid), Scopus, Sociological Abstracts (Proquest), Embase and Embase Classic (Ovid), Emcare Nursing (Ovid) and AgeLine (EBSCO). Two reviewers will independently screen titles and abstracts of articles identified in the search. Two reviewers will then independently review full text articles for inclusion. Data extraction will also be carried out in duplicate. We will engage LTC home community members, including residents, family and staff, to refine the review questions, assist in interpreting the results and participate in knowledge translation.

ETHICS AND DISSEMINATION

Ethics approval is not required. We will present findings at conferences and publish in a peer-reviewed journal. Ultimately, we hope to inform future observational and interventional research aimed at improving the health and quality of life of LTC home residents.

A retrospective study on the acceptability, feasibility, and effectiveness of LoveYourBrain Yoga for people with traumatic brain injury and caregivers

PURPOSE

To conduct a mixed methods, pre-post, retrospective study on the feasibility, acceptability, and effectiveness of the LoveYourBrain Yoga program.

MATERIALS AND METHODS

People were eligible if they were a traumatic brain injury survivor or caregiver, age 15-70, ambulatory, and capable of gentle exercise and group discussion. We analyzed attendance, satisfaction, and mean differences in scores on Quality of Life After Brain Injury Overall scale (QOLIBRI-OS) and four TBI-QOL/Neuro-QOL scales. Content analysis explored perceptions of benefits and areas of improvement.

RESULTS

1563 people (82.0%) participated ≥1 class in 156 programs across 18 states and 3 Canadian provinces. Mean satisfaction was 9.3 out of 10 (SD 1.0). Mixed effects linear regression found significant improvements in QOLIBRI-OS (B 9.70, 95% CI: 8.51, 10.90), Resilience (B 1.30, 95% CI: 0.60, 2.06), Positive Affect and Well-being (B 1.49, 95% CI: 1.14, 1.84), and Cognition (B 1.48, 95% CI: 0.78, 2.18) among traumatic brain injury survivors (n = 705). No improvement was found in Emotional and Behavioral Dysregulation, however, content analysis revealed better ability to regulate anxiety, anger, stress, and impulsivity. Caregivers perceived improvements in physical and psychological health.

CONCLUSIONS

LoveYourBrain Yoga is feasible and acceptable and may be an effective mode of community-based rehabilitation.IMPLICATIONS FOR REHABILITATIONPeople with traumatic brain injury and their caregivers often experience poor quality of life and difficulty accessing community-based rehabilitation services.Yoga is a holistic, mind-body therapy with many benefits to quality of life, yet is largely inaccessible to people affected by traumatic brain injury in community settings.Participants in LoveYourBrain Yoga, a six-session, community-based yoga with psychoeducation program in 18 states and 3 Canadian provinces, experienced significant improvements in quality of life, resilience, cognition, and positive affect.LoveYourBrain Yoga is feasible and acceptable when implemented on a large scale and may be an effective mode of, or adjunct to, community-based rehabilitation.

Enriching Communicative Environments: Leveraging Advances in Neuroplasticity for Improving Outcomes in Neurogenic Communication Disorders

Purpose Research manipulating the complexity of housing environments for healthy and brain-damaged animals has offered strong, well-replicated evidence for the positive impacts in animal models of enriched environments on neuroplasticity and behavioral outcomes across the lifespan. This article reviews foundational work on environmental enrichment from the animal literature and considers how it relates to a line of research examining rich communicative environments among adults with aphasia, amnesia, and related cognitive-communication disorders. Method Drawing on the authors' own research and the broader literature, this article first presents a critical review of environmental complexity from the animal literature. Building on that animal research, the second section begins by defining rich communicative environments for humans (highlighting the combined effects of complexity, voluntariness, and experiential quality). It then introduces key frameworks for analyzing and designing rich communicative environments: distributed communication and functional systems along with sociocultural theories of learning and development in humans that support them. The final section provides an overview of Hengst's and Duff's basic and translational research, which has been designed to exploit the insights of sociocultural theories and research on environmental complexity. In particular, this research has aimed to enrich communicative interactions in clinical settings, to trace specific communicative resources that characterize such interactions, and to marshal rich communicative environments for therapeutic goals for individuals with aphasia and amnesia. Conclusions This article concludes by arguing that enriching and optimizing environments and experiences offers a very promising approach to rehabilitation efforts designed to enhance the reorganization of cognitive-communicative abilities after brain injury. Such interventions would require clinicians to use the principles outlined here to enrich communicative environments and to target distributed communication in functional systems (not the isolated language of individuals).

Stroke survivors' experiences of occupation in hospital-based stroke rehabilitation: a qualitative exploration

Purpose: Studies highlighting the time spent in self-isolating and inactive activities during stroke rehabilitation have led to the introduction of group programs and environmental enrichment to improve activity levels. A less explored perspective is to understand how the introduced changes align with the occupational needs of the stroke survivors. Therefore, the aim of this study was to explore stroke survivors experiences of engagement in occupations during stroke rehabilitation.Methods: A descriptive phenomenological approach with semi-structured interviews explored stroke survivors experiences.Results: Eight participants (five male and three female, mean age 72 years) described their experiences with two themes emerging: (1) "I'm here for that reason:" which highlighted therapy as an occupation which participants wanted to perform and (2) "Celebration of quiet moments:" exploring the value of rest and recreation.Conclusion: This study provides a preliminary understanding of how stroke survivors experience occupational engagement during rehabilitation. There was an apparent shift in priorities with therapy considered the most important occupation and a strong need expressed for rest and relaxation to be factored into people's days. It appears the increasing activity levels may not always align with people's occupations and that due consideration of this malalignment may further enhance engagement and outcomes.Implications for rehabilitationDuring hospital-based stroke rehabilitation, stroke survivors prioritized the occupations of therapy, rest, and recreation.People with stroke are motivated to participate when the activities within and outside of, therapy align with their pre-stroke life and occupations.A daily stroke rehabilitation program should be balanced with opportunities for rest to support recovery time from therapy and possible consolidation of learning.

Effect of Telenursing on Outcomes of Provided Care by Caregivers of Patients With Head Trauma After Discharge

Telenursing is a suitable tool for increasing health-related awareness of the caregivers for a better home care. But its efficacy may be affected by several factors. Considering the important complications of head trauma injury and high rate of readmission, we aimed to assess the effect of telenursing on care provided by the family members of patients with head trauma.This randomized controlled trial investigated 72 patients with head trauma, who were randomly allocated to intervention and control groups (36 patients in each group). The caregivers in both groups were provided with 1-hr face-to-face training session on patients' home care and educational booklets. The patients in the intervention group were followed up every week through phone calls by the telenurse for 12 weeks, who recorded the patient's status, as well. Caregivers in the intervention group could call the telenurse any time they desired. The health status of the control group was followed once by a phone call after 12 weeks. Data on patients' readmission and pressure ulcer (based on Norton's scale) rate and time were compared between the groups and analyzed using SPSS software, version 19. Thirty-three patients with a mean ± SD age of 31.12 ± 10.83 years were studied in the control group and 35 patients with a mean ± SD age of 34.11 ± 12.34 years in the intervention group (p = .098). None of the patients in the intervention group were readmitted, whereas 2 patients in the control group were readmitted s(p = .139). Risk of pressure ulcer did not differ between the groups (p = .583). Telenursing had no significant effect in readmission and decubitus prevention for patients with head trauma. Considering the chronic nature of the illness, a longer follow-up period is deemed necessary for an accurate conclusion.

Enriched Environment and Effects on Neuropathic Pain: Experimental Findings and Mechanisms

Neuropathic pain inflicts tremendous biopsychosocial suffering for patients worldwide. However, safe and effective treatment of neuropathic pain is a prominent unmet clinical need. Environmental enrichment (EE) is an emerging cost-effective nonpharmacological approach to alleviate neuropathic pain and complement rehabilitation care. We present here a review of preclinical studies in ascertaining the efficacy of EE for neuropathic pain. Their proposed mechanisms, including the suppression of ascending nociceptive signaling to the brain, enhancement of the descending inhibitory system, and neuroprotection of the peripheral and central nervous systems, may collectively reduce pain perception and improve somatic and emotional functioning in neuropathic pain. The current evidence offers critical insights for future preclinical research and the translational application of EE in clinical pain management.

Statements of Agreement From the Targeted Evaluation and Active Management (TEAM) Approaches to Treating Concussion Meeting Held in Pittsburgh, October 15-16, 2015

BACKGROUND

Conventional management for concussion involves prescribed rest and progressive return to activity. Recent evidence challenges this notion and suggests that active approaches may be effective for some patients. Previous concussion consensus statements provide limited guidance regarding active treatment.

OBJECTIVE

To describe the current landscape of treatment for concussion and to provide summary agreements related to treatment to assist clinicians in the treatment of concussion.

METHODS

On October 14 to 16, 2015, the Targeted Evaluation and Active Management (TEAM) Approaches to Treating Concussion meeting was convened in Pittsburgh, Pennsylvania. Thirty-seven concussion experts from neuropsychology, neurology, neurosurgery, sports medicine, physical medicine and rehabilitation, physical therapy, athletic training, and research and 12 individuals representing sport, military, and public health organizations attended the meeting. The 37 experts indicated their agreement on a series of statements using an audience response system clicker device.

RESULTS

A total of 16 statements of agreement were supported covering (1) Summary of the Current Approach to Treating Concussion, (2) Heterogeneity and Evolving Clinical Profiles of Concussion, (3) TEAM Approach to Concussion Treatment: Specific Strategies, and (4) Future Directions: A Call to Research. Support (ie, response of agree or somewhat agree) for the statements ranged from to 97% to 100%.

CONCLUSION

Concussions are characterized by diverse symptoms and impairments and evolving clinical profiles; recovery varies on the basis of modifying factors, injury severity, and treatments. Active and targeted treatments may enhance recovery after concussion. Research is needed on concussion clinical profiles, biomarkers, and the effectiveness and timing of treatments.

ABBREVIATIONS

ARS, audience response systemCDC, Centers for Disease Control and PreventionDoD, Department of DefensemTBI, mild traumatic brain injuryNCAA, National Collegiate Athletic AssociationNFL, National Football LeagueNIH, National Institutes of HealthRCT, randomized controlled trialRTP, return to playSRC, sport- and recreation-related concussionTBI, traumatic brain injuryTEAM, Targeted Evaluation and Active Management.

Neurorehabilitation: applied neuroplasticity

The prevalence of disability due to neurological conditions is escalating worldwide. Neurological disorders have significant disability-burden with long-term functional and psychosocial issues, requiring specialized rehabilitation services for comprehensive management, especially treatments tapping into brain recovery 'neuroplastic' processes. Neurorehabilitation is interdisciplinary and cross-sectorial, requiring coordinated effort of diverse sectors, professions, patients and community to manage complex condition-related disability. This review provides evidence for a range of neurorehabilitation interventions for four common neurological conditions: multiple sclerosis (MS), stroke, traumatic brain injury and Parkinson's disease using the Grade of Recommendation, Assessment, Development and Evaluation tool for quality of evidence. Although, existing best-evidence for many interventions is still sparse, the overall findings suggest 'strong' evidence for physical therapy and psychological intervention for improved patient outcomes; and. 'moderate' evidence for multidisciplinary rehabilitation for longer term gains at the levels of activity (disability) and participation in MS and stroke population. The effect of other rehabilitation interventions is inconclusive, due to a paucity of methodologically robust studies. More research is needed to improve evidence-base for many promising rehabilitation interventions.

Feasibility of online self-administered cognitive training in moderate-severe brain injury

PURPOSE

Cognitive environmental enrichment (C-EE) offers promise for offsetting neural decline that is observed in chronic moderate-severe traumatic brain injury (TBI). Brain games are a delivery modality for C-EE that can be self-administered over the Internet without therapist oversight. To date, only one study has examined the feasibility of self-administered brain games in TBI, and the study focused predominantly on mild TBI. Therefore, the primary purpose of the current study was to examine the feasibility of self-administered brain games in moderate-severe TBI. A secondary and related purpose was to examine the feasibility of remote monitoring of any C-EE-induced adverse symptoms with a self-administered evaluation tool.

METHOD

Ten patients with moderate-severe TBI were asked to complete 12 weeks (60 min/day, five days/week) of online brain games with bi-weekly self-evaluation, intended to measure any adverse consequences of cognitive training (e.g., fatigue, eye strain).

RESULTS

There was modest weekly adherence (42.6% ± 4.4%, averaged across patients and weeks) and 70% patient retention; of the seven retained patients, six completed the self-evaluation questionnaire at least once/week for each week of the study.

CONCLUSIONS

Even patients with moderate-severe TBI can complete a demanding, online C-EE intervention and a self-administered symptom evaluation tool with limited therapist oversight, though at daily rate closer to 30 than 60 min per day. Further self-administered C-EE research is underway in our lab, with more extensive environmental support. Implications for Rehabilitation Online brain games (which may serve as a rehabilitation paradigm that can help offset the neurodegeneration observed in chronic TBI) can be feasibly self-administered by moderate-to-severe TBI patients. Brain games are a promising therapy modality, as they can be accessed by all moderate-to-severe TBI patients irrespective of geographic location, clinic and/or therapist availability, or impairments that limit mobility and access to rehabilitation services. Future efficacy trials that examine the effect of brain games for offsetting neurodegeneration in moderate-to-severe TBI patients are warranted.

Environmental enrichment: evidence for an unexpected therapeutic influence

Environmental enrichment produces wide-ranging effects in the brain at molecular, cellular, network, and behavioral levels. The changes in neuronal plasticity are driven by changes in neurotransmitters, neurotrophic factors, neuronal morphology, neurogenesis, network properties of the brain, and behavioral correlates of learning and memory. Exposure to an enriched environment has also demonstrated intriguing possibilities for treatment of a variety of neurodegenerative diseases including Huntington's disease, Alzheimer's disease, and Parkinson's disease. The effect of environmental enrichment in epilepsy, a neurodegenerative disorder with pathological neuronal plasticity, is of considerable interest. Recent reports of the effect of environmental enrichment in the Bassoon mutant mouse, a genetic model of early onset epilepsy, provides a significant addition to the literature in this area.

Negative neuroplasticity in chronic traumatic brain injury and implications for neurorehabilitation

Based on growing findings of brain volume loss and deleterious white matter alterations during the chronic stages of injury, researchers posit that moderate-severe traumatic brain injury (TBI) may act to “age” the brain by reducing reserve capacity and inducing neurodegeneration. Evidence that these changes correlate with poorer cognitive and functional outcomes corroborates this progressive characterization of chronic TBI. Borrowing from a framework developed to explain cognitive aging (Mahncke et al., Progress in Brain Research, 157, 81–109, 2006a; Mahncke et al., Proceedings of the National Academy of Sciences of the United States of America, 103(33), 12523–12528, 2006b), we suggest here that environmental factors (specifically environmental impoverishment and cognitive disuse) contribute to a downward spiral of negative neuroplastic change that may modulate the brain changes described above. In this context, we review new literature supporting the original aging framework, and its extrapolation to chronic TBI. We conclude that negative neuroplasticity may be one of the mechanisms underlying cognitive and neural decline in chronic TBI, but that there are a number of points of intervention that would permit mitigation of this decline and better long-term clinical outcomes.

Environmental enrichment and the sensory brain: the role of enrichment in remediating brain injury

The brain's life-long capacity for experience-dependent plasticity allows adaptation to new environments or to changes in the environment, and to changes in internal brain states such as occurs in brain damage. Since the initial discovery by Hebb (1947) that environmental enrichment (EE) was able to confer improvements in cognitive behavior, EE has been investigated as a powerful form of experience-dependent plasticity. Animal studies have shown that exposure to EE results in a number of molecular and morphological alterations, which are thought to underpin changes in neuronal function and ultimately, behavior. These consequences of EE make it ideally suited for investigation into its use as a potential therapy after neurological disorders, such as traumatic brain injury (TBI). In this review, we aim to first briefly discuss the effects of EE on behavior and neuronal function, followed by a review of the underlying molecular and structural changes that account for EE-dependent plasticity in the normal (uninjured) adult brain. We then extend this review to specifically address the role of EE in the treatment of experimental TBI, where we will discuss the demonstrated sensorimotor and cognitive benefits associated with exposure to EE, and their possible mechanisms. Finally, we will explore the use of EE-based rehabilitation in the treatment of human TBI patients, highlighting the remaining questions regarding the effects of EE.

Scale and pattern of atrophy in the chronic stages of moderate-severe TBI

BACKGROUND

Moderate-severe traumatic brain injury (TBI) is increasingly being understood as a progressive disorder, with growing evidence of reduced brain volume and white matter (WM) integrity as well as lesion expansion in the chronic phases of injury. The scale of these losses has yet to be investigated, and pattern of change across structures has received limited attention.

OBJECTIVES

(1) To measure the percentage of patients in our TBI sample showing atrophy from 5 to 20 months post-injury in the whole brain and in structures with known vulnerability to acute TBI, and (2) To examine relative vulnerability and patterns of volume loss across structures.

METHODS

Fifty-six TBI patients [complicated mild to severe, with mean Glasgow Coma Scale (GCS) in severe range] underwent MRI at, on average, 5 and 20 months post-injury; 12 healthy controls underwent MRI twice, with a mean gap between scans of 25.4 months. Mean monthly percent volume change was computed for whole brain (ventricle-to-brain ratio; VBR), corpus callosum (CC), and right and left hippocampi (HPC).

RESULTS

(1) Using a threshold of 2 z-scores below controls, 96% of patients showed atrophy across time points in at least one region; 75% showed atrophy in at least 3 of the 4 regions measured. (2) There were no significant differences in the proportion of patients who showed atrophy across structures. For those showing decline in VBR, there was a significant association with both the CC and the right HPC (P < 0.05 for both comparisons). There were also significant associations between those showing decline in (i) right and left HPC (P < 0.05); (ii) all combinations of genu, body and splenium of the CC (P < 0.05), and (iii) head and tail of the right HPC (P < 0.05 all sub-structure comparisons).

CONCLUSIONS

Atrophy in chronic TBI is robust, and the CC, right HPC and left HPC appear equally vulnerable. Significant associations between the right and left HPC, and within substructures of the CC and right HPC, raise the possibility of common mechanisms for these regions, including transneuronal degeneration. Given the 96% incidence rate of atrophy, a genetic explanation is unlikely to explain all findings. Multiple and possibly synergistic mechanisms may explain findings. Atrophy has been associated with poorer functional outcomes, but recent findings suggest there is potential to offset this. A better, understanding of the underlying mechanisms could permit targeted therapy enabling better long-term outcomes.

Environmental enrichment may protect against hippocampal atrophy in the chronic stages of traumatic brain injury

OBJECTIVE

To examine the relationship between environmental enrichment (EE) and hippocampal atrophy in the chronic stages of moderate to severe traumatic brain injury (TBI).

DESIGN

Retrospective analysis of prospectively collected data; observational, within-subjects.

PARTICIPANTS

Patients (N = 25) with moderate to severe TBI.

MEASURES

Primary predictors: (1) An aggregate of self-report rating of EE (comprising hours of cognitive, physical, and social activities) at 5 months post-injury; (2) pre-injury years of education as a proxy for pre-morbid EE (or cognitive reserve).

PRIMARY OUTCOME

bilateral hippocampal volume change from 5 to 28 months post-injury.

RESULTS

As predicted, self-reported EE was significantly negatively correlated with bilateral hippocampal atrophy (p < 0.05), with greater EE associated with less atrophy from 5 to 28 months. Contrary to prediction, years of education (a proxy for cognitive reserve) was not significantly associated with atrophy.

CONCLUSION

Post-injury EE may serve as a buffer against hippocampal atrophy in the chronic stages of moderate-severe TBI. Clinical application of EE should be considered for optimal maintenance of neurological functioning in the chronic stages of moderate-severe TBI.