Brain injury: personality, psychopathology and neuropsychology

A walk through the progression of resuscitation medicine

Cardiac arrest (CA) is a sudden and devastating disease process resulting in more deaths in the United States than many cancers, metabolic diseases, and even car accidents. Despite such a heavy mortality burden, effective treatments have remained elusive. The past century has been productive in establishing the guidelines for resuscitation, known as cardiopulmonary resuscitation (CPR), as well as developing a scientific field whose aim is to elucidate the underlying mechanisms of CA and develop therapies to save lives. CPR has been successful in reinitiating the heart after arrest, enabling a survival rate of approximately 10% in out-of-hospital CA. Although current advanced resuscitation methods, including hypothermia and extracorporeal membrane oxygenation, have improved survival in some patients, they are unlikely to significantly improve the national survival rate any further without a paradigm shift. Such a change is possible with sustained efforts in the basic and clinical sciences of resuscitation and their implementation. This review seeks to discuss the current landscape in resuscitation medicine-how we got here and where we are going.

Sleep disruption and the sequelae associated with traumatic brain injury

Sleep disruption, which includes a loss of sleep as well as poor quality fragmented sleep, frequently follows traumatic brain injury (TBI) impacting a large number of patients each year in the United States. Fragmented and/or disrupted sleep can worsen neuropsychiatric, behavioral, and physical symptoms of TBI. Additionally, sleep disruption impairs recovery and can lead to cognitive decline. The most common sleep disruption following TBI is insomnia, which is difficulty staying asleep. The consequences of disrupted sleep following injury range from deranged metabolomics and blood brain barrier compromise to altered neuroplasticity and degeneration. There are several theories for why sleep is necessary (e.g., glymphatic clearance and metabolic regulation) and these may help explain how sleep disruption contributes to degeneration within the brain. Experimental data indicate disrupted sleep allows hyperphosphorylated tau and amyloid β plaques to accumulate. As sleep disruption may act as a cellular stressor, target areas warranting further scientific investigation include the increase in endoplasmic reticulum and oxidative stress following acute periods of sleep deprivation. Potential treatment options for restoring the normal sleep cycle include melatonin derivatives and cognitive behavioral therapy.

Traumatic brain injury - modeling neuropsychiatric symptoms in rodents

Each year in the US, ∼1.5 million people sustain a traumatic brain injury (TBI). Victims of TBI can suffer from chronic post-TBI symptoms, such as sensory and motor deficits, cognitive impairments including problems with memory, learning, and attention, and neuropsychiatric symptoms such as depression, anxiety, irritability, aggression, and suicidal rumination. Although partially associated with the site and severity of injury, the biological mechanisms associated with many of these symptoms - and why some patients experience differing assortments of persistent maladies - are largely unknown. The use of animal models is a promising strategy for elucidation of the mechanisms of impairment and treatment, and learning, memory, sensory, and motor tests have widespread utility in rodent models of TBI and psychopharmacology. Comparatively, behavioral tests for the evaluation of neuropsychiatric symptomatology are rarely employed in animal models of TBI and, as determined in this review, the results have been inconsistent. Animal behavioral studies contribute to the understanding of the biological mechanisms by which TBI is associated with neurobehavioral symptoms and offer a powerful means for pre-clinical treatment validation. Therefore, further exploration of the utility of animal behavioral tests for the study of injury mechanisms and therapeutic strategies for the alleviation of emotional symptoms are relevant and essential.

Psychiatric disturbances after traumatic brain injury: neurobehavioral and personality changes

Traumatic brain injuries (TBI) are frequently accompanied by psychiatric disturbances, which can include striking to relatively minor alterations in personality, behavior, and emotional regulation. The persistence of these neurobehavioral syndromes often leads to deleterious effects on recovery and rehabilitation outcomes. A recent surge of studies has emerged in the past several years to quantify the extent of psychiatric disorders in TBI and to describe differential clinical presentations. Various pre- and post-injury factors also have been hypothesized to contribute to the development and maintenance of psychiatric symptoms in survivors of brain injuries. The identification of high-risk individuals with distinct neuropathophysiological and psychosocial features permits the development of multidisciplinary and tailored approaches to the assessment, prevention, and management of the negative effects of personality and behavioral changes in TBI. This article summarizes the most recent research in these areas and highlights the gaps that need to be filled in subsequent future.

Suicide after traumatic brain injury: a population study

OBJECTIVES

To determine the rates of suicide among patients who have had a traumatic brain injury.

METHODS

From a Danish population register of admissions to hospital covering the years 1979-93 patients were selected who had had either a concussion (n=126 114), a cranial fracture (n=7560), or a cerebral contusion or traumatic intracranial haemorrhage (n=11 766). All cases of deaths by the end of the study period were identified.

RESULTS

In the three diagnostic groups there had been 750 (0.59%), 46 (0.61%), and 99 (0.84%) cases of suicide respectively. Standardised mortality ratios, stratified by sex and age, showed that the incidence of suicide among the three diagnostic groups was increased relative to the general population (3.0, 2.7, and 4.1 respectively). In all diagnosis groups the ratios were higher for females than for males, and lower for patients injured before the age of 21 or after the age of 60. The presence of a codiagnosis relating to substance misuse was associated with increased suicide rates in all diagnosis groups. There was a tendency, among patients with cerebral contusions or traumatic intracranial haemorrhages, for suicide risk to increase with duration of stay in hospital. Cox regression analyses for proportional hazards confirmed that there was a significantly greater risk of suicide among patients with cerebral contusions or traumatic intracranial haemorrhages than among patients with concussion or cranial fractures (hazard ratios=1.42 and 1.50 respectively). There was, however, no evidence of a specific risk period for suicide after injury.

CONCLUSION

The increased risk of suicide among patients who had a mild traumatic brain injury may result from concomitant risk factors such as psychiatric conditions and psychosocial disadvantage. The greater risk among the more serious cases implicates additionally the physical, psychological, and social consequences of the injuries as directly contributing to the suicides.

A psychological assessment of adolescent and young adult inpatients after traumatic brain injury

The purpose of this study was to evaluate the cognitive, behavioural, depressive and self-awareness disorders, and their relationships, after severe traumatic brain injury (TBI) in adolescent and young adult inpatients. Two groups of patients with (n = 83) and without (n = 103) TBI, aged 14-25 years, hospitalized after severe traumatic pathology, were compared using the clinician's report and self-report. A higher frequency of depressive tendencies in TBI patients than in controls was shown in the clinician's therapeutic attitude (i.e. prescription of antidepressant drugs), the clinician's report and the self-report. The same difference between the two groups was observed for behavioural and schooling problems in the clinician's report, but not in the self-report. Discrepancies between self- and clinician's evaluation were in favour of a lack of self-awareness of behavioural and cognitive disorders among TBI patients. Correlations of depressive mood with anxiety and cognitive complaints were stronger in TBI than in non-TBI patients. Depression in TBI patients seems compatible with some degree of lack of self-awareness of cognitive and behavioural difficulties.

Executive dysfunction and characterological changes after traumatic brain injury: two sides of the same coin?

This study examined the capacity of neuropsychological variables indicative of dysfunction in the regulation of executive abilities (e.g. noncompliance with rules) to reflect changes in character associated with disturbances in regulatory abilities (e.g. impulsivity). A close relative of 30 participants with traumatic brain injury (TBI) was administered the Current Behaviour Scale (CBS) at admission (rating premorbid character) and six months posttrauma (rating current character). The TBI group was examined neuropsychologically at six months posttrauma, along with 30 nonbrain-damaged (NBD) participants. Significant increases in CBS factors, Loss of Emotional Control and Loss of Motivation, occurred in the TBI group posttrauma. Differences between TBI and NBD groups were found for most executive variables. Those TBI participants with impairments on the neuropsychological Rule Breaking variable showed significant posttrauma increases in Loss of Emotional Control. There was also a trend for individuals with frontal lesions to make rule-breaking and perseverative errors.

Conversational discourse abilities following severe traumatic brain injury: a follow-up study

The major aim of this study was to describe the conversational abilities of a group of severely injured TBI speakers, at a minimum of 2 years post-injury. The association between conversational impairment and (a) selected measures of executive function and (b) psychosocial handicap was also examined. Twenty-four members of the group of 26 severely injured TBI speakers who had initially been assessed between 3 and 6 months post-injury were reviewed at a minimum of 2 years post-injury (mean = 2 years, 10 months). At initial assessment, TBI speakers were compared with non-TBI orthopaedic patients and with a group of university students. At follow-up, however, they were compared only with the orthopaedic patients. Conversational assessment was carried out using a modified form of Damico's Clinical Discourse Analysis. As a group, the TBI speakers' conversational abilities did not improve over time. There was, however, a subgroup (n = 8) of speakers who did improve, and these could be distinguished by greater initial severity of injury and a significantly longer period of speech-language pathology intervention than the speakers who either remained the same or worsened over time. Modest associations between conversational discourse skills and measures of executive function and a measure of psychosocial handicap were identified. These findings indicate that disruptions in conversation persist into the longer term. More assiduous efforts may need to be made to (a) identify subtle discourse changes in the early months after injury and (b) engage TBI speakers in speech-language pathology services. Such services are also required over a longer time frame, in community-based models of service provision.

Depression following traumatic brain injury

OBJECTIVE

Review the existing literature on the incidence, neurobiological and psychosocial correlates, and methods of assessment and treatment of depression following traumatic brain injury (TBI).

DATA SOURCES

Computerized database searches of the English-language literature from Index Medicus, Psychological Abstracts, Excerpta Medica, and Cumulative Index of Nursing and Allied Health Literature.

STUDY SELECTION

Given the relatively small number of publications specifically related to TBI and depression, all studies appearing in the peer-reviewed literature were included in the review. In addition, studies examining depression and other neurologic diseases (eg, stroke) were also reviewed as to the potential applicability of the theoretical model or methodology used.

CONCLUSIONS

Depression occurs with sufficient frequency to be considered a significant consequence after TBI. Depression can impede the achievement of optimal functional outcome, whether in the acute or chronic stages of recovery. It appears that a combination of neuroanatomic, neurochemical, and psychosocial factors is responsible for the onset and maintenance of depression. Its treatment is typically psychopharmacologic, with best results obtained from nontricyclic antidepressants. These results have not been confirmed in double-blind clinical trials, however. Future research should use comprehensive, integrative models of depression that include demographic, biologic, and psychosocial factors; enhanced functional neuroimaging techniques; controlled studies of psychopharmacologic and other interventions; and prospective designs with long-term follow-up.