Review of Awakening Agents

Amantadine for Traumatic Brain Injury-Supporting Evidence and Mode of Action

Traumatic brain injury (TBI) is an important global clinical issue, requiring not only prevention but also effective treatment. Following TBI, diverse parallel and intertwined pathological mechanisms affecting biochemical, neurochemical, and inflammatory pathways can have a severe impact on the patient's quality of life. The current review summarizes the evidence for the utility of amantadine in TBI in connection to its mechanism of action. Amantadine, the drug combining multiple mechanisms of action, may offer both neuroprotective and neuroactivating effects in TBI patients. Indeed, the use of amantadine in TBI has been encouraged by several clinical practice guidelines/recommendations. Amantadine is also available as an infusion, which may be of particular benefit in unconscious patients with TBI due to immediate delivery to the central nervous system and the possibility of precise dosing. In other situations, orally administered amantadine may be used. There are several questions that remain to be addressed: can amantadine be effective in disorders of consciousness requiring long-term treatment and in combination with drugs approved for the treatment of TBI? Do the observed beneficial effects of amantadine extend to disorders of consciousness due to factors other than TBI? Well-controlled clinical studies are warranted to ultimately confirm its utility in the TBI and provide answers to these questions.

Clinical Decision on Disorders of Consciousness After Acquired Brain Injury: Stepping Forward

Major advances have been made over the past few decades in identifying and managing disorders of consciousness (DOC) in patients with acquired brain injury (ABI), bringing the transformation from a conceptualized definition to a complex clinical scenario worthy of scientific exploration. Given the continuously-evolving framework of precision medicine that integrates valuable behavioral assessment tools, sophisticated neuroimaging, and electrophysiological techniques, a considerably higher diagnostic accuracy rate of DOC may now be reached. During the treatment of patients with DOC, a variety of intervention methods are available, including amantadine and transcranial direct current stimulation, which have both provided class II evidence, zolpidem, which is also of high quality, and non-invasive stimulation, which appears to be more encouraging than pharmacological therapy. However, heterogeneity is profoundly ingrained in study designs, and only rare schemes have been recommended by authoritative institutions. There is still a lack of an effective clinical protocol for managing patients with DOC following ABI. To advance future clinical studies on DOC, we present a comprehensive review of the progress in clinical identification and management as well as some challenges in the pathophysiology of DOC. We propose a preliminary clinical decision protocol, which could serve as an ideal reference tool for many medical institutions.

Nomogram for Early Prediction of Outcome in Coma Patients with Severe Traumatic Brain Injury Receiving Right Median Nerve Electrical Stimulation Treatment

BACKGROUND

Accurate outcome prediction can serve to approach, quantify and categorize severe traumatic brain injury (TBI) coma patients for right median electrical stimulation (RMNS) treatment, which can support rehabilitation plans. As a proof of concept for individual risk prediction, we created a novel nomogram model combining amplitude-integrated electroencephalography (AEEG) and clinically relevant parameters.

METHODS

This study retrospective collected and analyzed a total of 228 coma patients after severe TBI in two medical centers. According to the extended Glasgow Outcome Scale (GOSE), patients were divided into a good outcome (GOSE 3-8) or a poor outcome (GOSE 1-2) group. Their clinical and biochemical indicators, together with EEG features, were explored retrospectively. The risk factors connected to the outcome of coma patients receiving RMNS treatment were identified using Cox proportional hazards regression. The discriminative capability and calibration of the model to forecast outcome were assessed by C statistics, calibration plots, and Kaplan-Meier curves on a personalized nomogram forecasting model.

RESULTS

The study included 228 patients who received RMNS treatment for long-term coma after a severe TBI. The median age was 40 years, and 57.8% (132 of 228) of the patients were male. 67.0% (77 of 115) of coma patients in the high-risk group experienced a poor outcome after one year and the comparative data merely was 30.1% (34 of 113) in low-risk group patients. The following variables were integrated into the forecasting of outcome using the backward stepwise selection of Akaike information criterion: age, Glasgow Coma Scale (GCS) at admission, EEG reactivity (normal, absence, or the stimulus-induced rhythmic, periodic, or ictal discharges (SIRPIDs)), and AEEG background pattern (A mode, B mode, or C mode). The C statistics revealed that the nomograms' discriminative potential and calibration demonstrated good predictive ability (0.71).

CONCLUSION

Our findings show that the nomogram model using AEEG parameters has the potential to predict outcomes in severe TBI coma patients receiving RMNS treatment. The model could classify patients into prognostic groups and worked well in internal validation.

Role of the Dopaminergic System in the Striatum and Its Association With Functional Recovery or Rehabilitation After Brain Injury

Disabilities are estimated to occur in approximately 2% of survivors of traumatic brain injury (TBI) worldwide, and disability may persist even decades after brain injury. Facilitation or modulation of functional recovery is an important goal of rehabilitation in all patients who survive severe TBI. However, this recovery tends to vary among patients because it is affected by the biological and physical characteristics of the patients; the types, doses, and application regimens of the drugs used; and clinical indications. In clinical practice, diverse dopaminergic drugs with various dosing and application procedures are used for TBI. Previous studies have shown that dopamine (DA) neurotransmission is disrupted following moderate to severe TBI and have reported beneficial effects of drugs that affect the dopaminergic system. However, the mechanisms of action of dopaminergic drugs have not been completely clarified, partly because dopaminergic receptor activation can lead to restoration of the pathway of the corticobasal ganglia after injury in brain structures with high densities of these receptors. This review aims to provide an overview of the functionality of the dopaminergic system in the striatum and its roles in functional recovery or rehabilitation after TBI.

Amantadine: reappraisal of the timeless diamond-target updates and novel therapeutic potentials

The aim of the current review was to provide a new, in-depth insight into possible pharmacological targets of amantadine to pave the way to extending its therapeutic use to further indications beyond Parkinson's disease symptoms and viral infections. Considering amantadine's affinities in vitro and the expected concentration at targets at therapeutic doses in humans, the following primary targets seem to be most plausible: aromatic amino acids decarboxylase, glial-cell derived neurotrophic factor, sigma-1 receptors, phosphodiesterases, and nicotinic receptors. Further three targets could play a role to a lesser extent: NMDA receptors, 5-HT3 receptors, and potassium channels. Based on published clinical studies, traumatic brain injury, fatigue [e.g., in multiple sclerosis (MS)], and chorea in Huntington's disease should be regarded potential, encouraging indications. Preclinical investigations suggest amantadine's therapeutic potential in several further indications such as: depression, recovery after spinal cord injury, neuroprotection in MS, and cutaneous pain. Query in the database http://www.clinicaltrials.gov reveals research interest in several further indications: cancer, autism, cocaine abuse, MS, diabetes, attention deficit-hyperactivity disorder, obesity, and schizophrenia.

Role of bromocriptine in multi-spectral manifestations of traumatic brain injury

PURPOSE

Despite the prevalence and cost of traumatic brain injury related disabilities, there is paucity in the literature on modern approaches to pharmacotherapy. Medications may promote recovery by enhancing some neurological functions without impacting others. Herein we discussed the role of bromocriptine in neurorehabilitation for patients with traumatic brain injury.

METHODS

A cohort comprising of 36 selective nonsurgical cases of traumatic brain injury in minimally conscious state were enrolled in the study. After hemodynamic stability, bromocriptine was given at paediatric dose of 3.75 mg/d and adult dose of 7.5 mg/d. It was administered through a naso-gastric (NG) feeding tube in the patients with minimally conscious state, then changed to oral route after proper swallowing and good gag reflex were ensured in the patient. The drug was slowly reduced over three weeks after neurological improvement in the patients. Positive result was determined by improved GCS score of 2 and motor power by at least 1 British Medical Council (BMC) motor score. Improvement of deficits was evaluated in terms of fluency of speech for aphasia, task switching, digit span double tasking and trail-making test for cognition and attention, and functional independence measure score for motor functioning and self-independence.

RESULTS

Accelerated arousal was seen in 47.0% of cases (8/17) in 4-40 days. In 41.2% of cases (7/17), Glasgow outcome score (GOS) was improved to 4/5 in 90 days. Improvement in hemiparesis by at least 1 BMC score was seen in 55.6% of cases (5/9) in 40 days. Aphasia was improved in 80% of cases (4/5) in 7-30 days. Moderate improvement in cognitive impairment was seen in 66.7% of cases (2/3) in 14-20 days. Improvement in memory was observed in 50% of cases (1/2) in over 30 days. No cases were withdrawn from the study because of adverse reactions of the drug. There was no mortality in the study group.

CONCLUSION

Bromocriptine improves neurological sequelae of traumatic brain injury as well as the overall outcome in the patients. If medication is given to promote recovery and treat its associated disabilities, clinicians should thoroughly outline the goals and closely monitor adverse effects.

Amantadine Therapy in Traumatic Brain Injury Patients

Objective:

To review literature on amantadine therapy in patients with traumatic brain injury (TBI).

Data Sources:

MEDLINE (1966–March 2006), EMBASE (1974–March 2006), BIOSIS (1969–March 2006), and International Pharmaceutical Abstracts (1970–March 2006) were searched to identify papers on the clinical outcomes of patients with TBI treated with amantadine. A bibliographic search was also performed.

Study Selection and Data Extraction:

Papers were excluded if they were not published in English, if they included patients less than 16 years old, or if they included patients in whom the effects of multiple medications, rather than amantadine alone, were studied. Reports were categorized according to the time of initiation of amantadine following the injury.

Data Synthesis:

Reports examining early initiation of amantadine suggest a possible benefit for treatment of decreased responsiveness and functional recovery. One report examining late initiation of amantadine failed to demonstrate benefit in the treatment of motor impairment, while 2 reports suggested possible improvement of functional recovery. Finally, reports examining late initiation of amantadine in the treatment of cognitive and behavioral therapy demonstrated possible benefit.

Conclusions:

Further investigation is needed before either early or late initiation of amantadine can be recommended for treatment of decreased responsiveness and functional recovery. However, while additional research is conducted, late initiation of amantadine can be considered an option for the treatment of cognitive and behavioral impairments in patients with TBI.

Drugs for behavior disorders after traumatic brain injury: Systematic review and expert consensus leading to French recommendations for good practice

OBJECTIVE

There are no handbook or recommendations for the use of pharmacological agents to treat neurobehavioral disorders after traumatic brain injury (TBI). This work proposes a systematic review of the literature and a user guide on neuroleptics, antidepressants, beta-blockers, mood stabilizers and other medications for irritability, aggressiveness, agitation, impulsivity, depression, apathy…

METHOD

Steering, working and reading groups (62 people) were formed under the control of the French High Authority for Health (HAS) in collaboration with the SOFMER scientific society (French Society of Physical and Rehabilitation Medicine). Articles were searched by HAS officers in the Medline database from 1990 to 2012, crossing TBI and pharmacological agents. The HAS method to select, read and analyze papers is close to the PRISMA statements.

RESULTS

Out of 772 references, 89 were analyzed, covering a total of 1306 people with TBI. There is insufficient evidence to standardize drug treatments for these disorders. There are however some elements to establish consensus recommendations for good clinical practice. Propranolol can improve aggression (B grade). Carbamazepine and valproate seem effective on agitation and aggression and are recommended as first line treatment (Expert Consensus [EC]). There is no evidence of efficacy for neuroleptics. Their prescription is based on emergency situation for a crisis (loxapine) but not for long-term use (EC). Antidepressants are recommended to treat depression (EC) with a higher standard of proof for Selective Serotonin Reuptake Inhibitors (SSRI, grade B). Other products are described.

CONCLUSION

The choice of treatment depends on the level of evidence, target symptoms, custom objectives, clinical experience and caution strategies.

Right Median Nerve Electrical Stimulation for Acute Traumatic Coma Patients

The right median nerve as a peripheral portal to the central nervous system can be electrically stimulated to help coma arousal after traumatic brain injury (TBI). The present study set out to examine the efficacy and safety of right median nerve electrical stimulation (RMNS) in a cohort of 437 comatose patients after severe TBI from August 2005 to December 2011. The patients were enrolled 2 weeks after their injury and assigned to the RMNS group (n=221) receiving electrical stimulation for 2 weeks or the control group (n = 216) treated by standard management according to the date of birth in the month. The baseline data were similar. After the 2-week treatment, the RMNS-treated patients demonstrated a more rapid increase of the mean Glasgow Coma Score, although statistical significance was not reached (8.43 ± 4.98 vs. 7.47 ± 5.37, p = 0.0532). The follow-up data at 6-month post-injury showed a significantly higher proportion of patients who regained consciousness (59.8% vs. 46.2%, p = 0.0073). There was a lower proportion of vegetative persons in the RMNS group than in the control group (17.6% vs. 22.0%, p = 0.0012). For persons regaining consciousness, the functional independence measurement (FIM) score was higher among the RMNS group patients (91.45 ± 8.65 vs. 76.23 ± 11.02, p < 0.001). There were no unique complications associated with the RMNS treatment. The current study, although with some limitations, showed that RMNS may serve as an easy, effective, and noninvasive technique to promote the recovery of traumatic coma in the early phase.

Prescribing multiple neurostimulants during rehabilitation for severe brain injury

BACKGROUND

Despite a lack of clear evidence, multiple neurostimulants are commonly provided after severe brain injury (BI). The purpose of this study is to determine if the number of neurostimulants received during rehabilitation was associated with recovery of full consciousness or improved neurobehavioral function after severe BI.

METHOD

Data from 115 participants were extracted from a neurobehavioral observational study database for this exploratory, retrospective analysis. Univariate optimal data analysis was conducted to determine if the number of neurostimulants influenced classification of four outcomes: recovery of full consciousness during rehabilitation, recovery of full consciousness within one year of injury, and meaningful neurobehavioral improvement during rehabilitation defined as either at least a 4.7 unit (minimal detectable change) or 2.58 unit (minimal clinically important difference) gain on the Disorders of Consciousness Scale-25 (DOCS-25).

RESULTS

Number of neurostimulants was not significantly (P > 0.05) associated with recovery of full consciousness during rehabilitation, within one year of injury, or meaningful neurobehavioral improvement using the DOCS-25.

CONCLUSIONS

Receiving multiple neurostimulants during rehabilitation may not influence recovery of full consciousness or meaningful neurobehavioral improvement. Given costs associated with additional medication, future research is needed to guide physicians about the merits of prescribing multiple neurostimulants during rehabilitation after severe BI.

Pharmacotherapy for disorders of consciousness: are 'awakening' drugs really a possibility?

Disorders of consciousness, including the coma state, vegetative state and minimally conscious state, are among the least understood and least curable conditions in modern neurology. Structural or functional injuries may produce impairments in the neuronal circuits (the ascending reticular activating system and thalamocortical loops) responsible for maintaining the wakefulness state and awareness, associated with a change in neurotransmitter concentrations. Pharmacological agents that are able to restore the levels of neurotransmitters and, consequently, neural synaptic plasticity and functional connectivity of consciousness networks, may play an important role as drugs useful in improving the consciousness state. Currently, there is growing interest in the scientific community with regard to pharmacological agents that act on the gamma amino-butyric acid (GABA) system, such as zolpidem and baclofen, and monoamine systems, such as dopaminergic agents and some antidepressants. The purpose of this article is to provide a comprehensive overview of these potential 'awakening' drugs in patients with disorders of consciousness. The possible mechanisms by which these drugs may exert their effects in promoting recovery of consciousness are discussed, highlighting how many findings are often the result of sporadic events rather than prospective controlled trials or implementation of standard treatment guidelines.

Methylphenidate and amantadine to stimulate reawakening in comatose patients resuscitated from cardiac arrest

BACKGROUND

Despite critical-care packages including therapeutic hypothermia (TH), neurologic injury is common after cardiac arrest (CA) resuscitation. Methylphenidate and amantadine have treated coma in traumatically-brain-injured patients with mixed success, but have not been explored in post-arrest patients.

OBJECTIVE

Compare the outcome of comatose post-arrest patients treated with neurostimulants to a matched cohort.

METHODS

Retrospective cohort study from 6/2008 to 12/2011 in a tertiary university hospital. We included adult patients treated with methylphenidate or amantadine after resuscitation from in-hospital or out-of-hospital CA (OHCA) of any rhythm, excluding patients with traumatic/surgical etiology of arrest, terminal re-arrest within 6h, or withdrawal of care by family within 6h. Primary outcome was following commands; secondary outcomes included survival to hospital discharge, cerebral performance category (CPC), and modified Rankin scale (mRS). We compared characteristics and outcomes to a control cohort matched on TH and 72 h FOUR score ± 1.

RESULTS

Of 588 patients, 8 received methylphenidate, 6 received amantadine, and 2 both. Most were female suffering OHCA with median age 61 years. All received TH and a multi-modal neurological evaluation. Initial exam revealed median GCS 6 and FOUR 7, which was unchanged at 72 h. Six patients (38%) followed commands prior to discharge at median 2.5 days (range: 1-18 days) after treatment. Patients receiving neurostimulants trended toward improved rate of following commands, survival to hospital discharge, and distribution of CPC and mRS scores.

CONCLUSIONS

Neurostimulants may be considered to stimulate wakefulness in selected post-cardiac arrest patients, but a prospective trial is needed to evaluate this therapy.

Awakenings and awareness recovery in disorders of consciousness: is there a role for drugs?

Disorders of consciousness (DOC) include coma, vegetative state (VS) and minimally conscious state (MCS). Coma is a condition of unarousability with a complete absence of wakefulness and awareness, whereas VS is characterized by a lack of awareness despite a preserved wakefulness. Patients in coma are unconscious because they lack both wakefulness and awareness. Patients in a VS are unconscious because, although they are wakeful, they lack awareness. Patients in a MCS show minimal but definite behavioural evidence of self and environmental awareness. Coma results from diffuse bilateral hemispheric lesions or selective damage to the ascending reticular system (which is functionally connected to the cerebral cortex by intralaminar thalamic nuclei). VS is a syndrome that is considered to be the result of a disconnection of different cortical networks rather than a dysfunction of a single area or a global reduction in cortical metabolism. As revealed by functional imaging studies, clinical recovery is often associated with a functional restoration of cortico-thalamo-cortical connections. Depending on the amount of network restored, patients may regain full consciousness or remain in a MCS. Molecular and neural mediators may indirectly contribute to the above restoration processes owing to their role in the phenomenon of neural synaptic plasticity. Therefore, there is growing interest in the possible effects of drugs that act at the level of the CNS in promoting emergence from DOC. Sporadic cases of dramatic recovery from DOC after the administration of various pharmacological agents, such as baclofen, zolpidem and amantadine, have been recently supported by intriguing scientific observations. Analysis of the reported cases of recovery, with particular attention paid to the condition of the patients and to the association of their improvement with the start of drug administration, suggests that these treatments might have promoted the clinical improvement of some patients. These drugs are from various and diverging classes, but can be grouped into two main categories, CNS stimulants and CNS depressants. Some of these treatments seem to directly encourage a consciousness restoration, while others play a more determinant role in improving cognitive domains, especially in patients with residual cognitive impairment, than in the field of consciousness. Given the great interest recently generated in the scientific community by the increasing number of papers addressing this issue, further investigation of the above treatments, with particular attention paid to their mechanisms of action, the neurotransmitters involved and their effects on cortico-thalamo-cortical circuitry, is needed.

Effects of methylphenidate on cerebral glucose metabolism in patients with impaired consciousness after acquired brain injury

OBJECTIVES

To evaluate the effects of methylphenidate on cerebral glucose metabolism in patients with impaired consciousness after acquired brain injury.

METHODS

Fourteen patients with impaired consciousness after acquired brain injury were enrolled in our study. We evaluated the level of consciousness with the Glasgow Coma Scale upon initial evaluation and at the 6-week follow-up after methylphenidate medication (0.3 mg/kg per day, which was administered twice daily). Positron emission tomography was performed before and after 6 weeks of medication, and the effects of methylphenidate on cerebral glucose metabolism were analyzed using statistical parametric mapping.

RESULTS

The statistical parametric mapping analysis indicated that significant increases of the cerebral glucose metabolism after methylphenidate therapy, compared with the initial positron emission tomographic image, were most evident in the left precuneus, the right posterior cingulated and the right retrosplenial cortices, and the right inferior parietal cortex (P < 0.001). In addition, cerebral glucose metabolism was significantly increased in the right precuneus, the right superior and middle temporal gyri, and bilateral middle occipital gyri (P < 0.005). In the correlation analysis, improvement of the Glasgow Coma Scale scores after methylphenidate medication was significantly associated with increased cerebral glucose metabolism in the bilateral precuneus, the bilateral middle occipital gyri, and right middle frontal gyrus.

CONCLUSIONS

Our findings suggest that the posteromedial parietal cortex, which is part of the neural network for consciousness, may be the relevant structure for the pharmacological response to methylphenidate treatment in patients with impaired consciousness after acquired brain injury.

Amantadine for adynamic speech: possible benefit for aphasia?

OBJECTIVE

Dopaminergic agents may stimulate behavior and verbal expression after frontal lobe dysfunction. Although amantadine is used in neurorehabilitation of motivational disorders and head injury, it is not commonly prescribed to improve aphasia. This pilot study examined verbal fluency on and off amantadine for nonfluent speech.

DESIGN

Four participants undergoing inpatient rehabilitation, meeting criteria for transcortical motor aphasia had stroke (2), stroke postaneurysm surgery (1), or brain tumor resection (1). We administered 100 mg of amantadine twice a day in an open-label, on-off protocol, with multiple assessments per on-off period.

RESULTS

Off medication, subjects generated a mean 12.62 of words (abnormally few) on the Controlled Oral Word Association test. On medication, word generation significantly improved to 17.71 words (P = 0.04), although scores remained psychometrically in the abnormal range.

CONCLUSIONS

Further research on amantadine, specifically for nonfluent speech and nonfluent aphasia, including effects on functional communication and control conditions, may be warranted.

Sexual function in men and women with neurological disorders

The advent of non-invasive functional brain imaging has clarified which regions of the brain are recruited during sexual arousal. Injuries to those regions, and to the spinal cord and peripheral nerves that link genitalia to limbic and cognitive centres, can profoundly influence sexual wellbeing. In epilepsy, expressions of hypersexuality and hyposexuality interact with the location of epileptogenic foci in the temporolimbic circuitry, and are tempered by the sexual effects of drug treatments. We outline the sexual consequences of epilepsy, stroke, multiple sclerosis, Parkinson's disease, and other common neurological disorders. Management of sexual dysfunction from both disease and treatment is discussed. Nerve-sparing techniques could mitigate the substantial sexual dysfunction in both men and women through surgical disruption of the autonomic nerves during radical pelvic surgery.

Pharmacological enhancement of cognitive and behavioral deficits after traumatic brain injury

PURPOSE OF REVIEW

To provide the clinician with a reasonable overview of the modern pharmacological alternatives to treat the cognitive and behavioral sequels of traumatic brain injury.

RECENT FINDINGS

Original research in this area is sparse and more than half of the articles published on the subject recently have been reviews. Of the three randomized controlled trials, one studied methylphenidate (n = 18), one methylphenidate and sertraline (n = 30) and one amantadine (n = 27). All these studies reported beneficial effects on various cognitive measures, but because of the study protocols, the evidence provided may be questioned. The various reviews, uncontrolled studies and case reports suggest that at least psychostimulants, cholinergic agents, dopaminergic agents and antidepressants may be beneficial in treating the cognitive and behavioral symptoms of traumatic brain injury.

SUMMARY

The clinician trying to ameliorate the cognitive and behavioral symptoms of traumatic brain injury has to make decisions about pharmacotherapy that are still based mainly on clinical experience. Large randomized controlled trials giving high-quality evidence are so far missing. This review discusses the problems facing both the clinician and the scientist treating the cognitive and behavioral sequels of traumatic brain injury. A symptom-based approach is suggested for current practice.

Fatigue et traumatisme crânien

Fatigue is frequent and disabling in patients with traumatic brain injury (TBI). Its mechanisms are complex and multifactorial. We performed a literature review of reports of the condition using the following key words: brain injury, depression, neuroendocrine dysfunction, and treatment. Five scales have been used to evaluate fatigue in TBI patients: the Fatigue Severity Scale, the visual analog scale (VAS) for fatigue, the Fatigue Impact Scale, the Barrow Neurological Institute (BNI) Fatigue Scale and the Cause of Fatigue (COF) Questionnaire. The BNI Fatigue Scale and the COF Questionnaire have been designed specifically for brain-injured patients. Fatigue is present in 43-73% of patients and is one of the first symptoms for 7% of them. Fatigue does not seem to be significantly related to injury severity not to time since injury. It can be related to mental effort necessary to overcome attention deficit and slowed processing ("coping hypothesis"). It can also be related to sleeping disorders and depression, although the relation between fatigue and depression are debated. Finally, fatigue can also be related to infraclinical pituitary insufficiency (growth hormone insufficiency, hypocorticism). To date, no published study of treatment of fatigue after TBI exists.

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.