Discover the most talked about and latest scientific content & concepts.

Concept: Post-traumatic amnesia


Our aim was to assess risk of Parkinson disease (PD) following traumatic brain injury (TBI), including specifically mild TBI (mTBI), among care recipients in the Veterans Health Administration.

Concepts: Medicine, Traumatic brain injury, Injury, Focal and diffuse brain injury, Concussion, Neurotrauma, Dementia pugilistica, Post-traumatic amnesia


Primary Objective: The relationship between prior mild traumatic brain injury/injuries (MTBI) and recovery from a subsequent MTBI may be complex. The present study investigated three factors hypothesized to influence this relation: (i) the number of prior MTBIs, (ii) the interval between MTBIs, and (iii) the certainty level of prior MTBIs. Research Design: Retrospective cross-sectional. Methods and Procedure: Participants (N=105) were evaluated at a concussion clinic on average one month after sustaining an MTBI, defined by World Health Organization diagnostic criteria. Main Outcomes and Results: Approximately half the sample had at least one prior MTBI. Subgroups with 0, 1, or 2+ prior MTBIs did not differ in levels of current postconcussion symptom reporting on the British Columbia Postconcussion Symptom Inventory. Time since the most recent prior MTBI was significantly associated with current postconcussion symptom reporting. This relation was best characterized as logarithmic, i.e., the impact of prior MTBI(s) lessens exponentially as time elapses to a subsequent MTBI. Defining prior MTBIs with a higher certainty level (i.e., probable versus possible) was not consistently associated with greater postconcussion symptom reporting. Conclusions: Participants with prior MTBIs did not report more postconcussion symptoms than those with no history of prior MTBI. However, prior MTBI(s) were associated with increased symptom reporting from a subsequent MTBI to the extent they occurred closer in time. Having one or two prior remote MTBIs was not associated with worse outcome from subsequent MTBI in this sample.

Concepts: Traumatic brain injury, Injury, Post-concussion syndrome, World Health Organization, Focal and diffuse brain injury, Concussion, Dementia pugilistica, Post-traumatic amnesia



Few studies have examined the trajectory of recovery of executive function (EF) after mild TBI (mTBI). Therefore consensus has not been reached on the incidence and extent of EF impairment after mTBI. The present study investigated trajectory of change in executive memory over three months after mTBI on 59 right-handed participants with mTBI, as defined by Centers for Disease Control criteria, ages 14-30 years, recruited within 96 hours post-injury and tested

Concepts: Brain, Traumatic brain injury, Nuclear magnetic resonance, Magnetic resonance imaging, Injury, Post-concussion syndrome, Concussion, Post-traumatic amnesia


This study examined postconcussion symptom reporting within the first 5 years following mild traumatic brain injury (MTBI). Participants were 167 U.S. military service members (Mean Age = 27.6 years; 74.3% blast; 96.4% male) who were evaluated following injuries sustained in theater during Operations Iraqi and Enduring Freedom (92.8%), or from other combat-related operations. Participants completed the Neurobehavioral Symptom Inventory and PTSD Checklist within three months of injury, and at least one follow-up telephone interview at 6 (n = 46), 12 (n = 89), 24 (n = 54), 36 (n = 42), 48 (n = 30), and/or 60 months (n = 25) post-injury. Approximately half of the sample (49.7%) met DSM-IV symptom criteria for postconcussion disorder (PCD) at baseline. At all six follow-ups, 46.1% to 72.0% met DSM-IV criteria for PCD. However, only 20.4% to 48.0% reported persistent PCD from baseline to follow-up. A substantial minority had also improved (4.0-24.1%) or ‘developed’ new symptoms (16.9-27.8%). Using regression analyses, baseline symptoms were somewhat predictive of PCD symptom reporting at follow-up, though this was not always reliable. Follow-up for all service members who sustain a combat related MTBI in the context of polytrauma, regardless of the presence/absence of symptom reporting in the acute recovery stage, should be considered the rule, not the exception.

Concepts: Traumatic brain injury, Injury, Fatigue, Post-concussion syndrome, Concussion, Second-impact syndrome, Dementia pugilistica, Post-traumatic amnesia


Approximately 75% of traumatic brain injuries (TBI) are classified mild (mTBI). Despite the high frequency of mTBI, it is the least well studied. The prevalence of mTBI among service personnel returning from Operations Iraqi Freedom (OIF) and Enduring Freedom (OEF) and the recent reports of an association between repeated mTBI and the early onset of Alzheimer’s and other types of dementias in retired athletes has focused much attention on mTBI. The study of mTBI requires the development and validation of experimental models of mTBI and one of the most basic requirements for an experimental model is that it replicates important features of the injury or disease in humans. mTBI in humans is associated with acute symptoms such as loss of consciousness and pre- and/or posttraumatic amnesia. In addition, although the majority of patients recover within a few months after mTBI, a small but significant number (2.5 - 26%) had Glasgow Outcome Scores in the “moderate disability” range. These mTBI patients experienced long-term effects of mTBI including deficits in speed of information processing, attention and concentration, memory acquisition, retention and retrieval and reasoning and decision-making. Although methods for the diagnosis and evaluation of the acute and chronic effects of mTBI in humans are well established, the same is not the case for rodents, the most widely used animal for TBI studies. Despite the magnitude of the difficulties associated with adapting these methods for experimental mTBI research, they must be surmounted. The identification and testing of treatments for mTBI depends of the development, characterization and validation of reproducible, clinically relevant models of mTBI.

Concepts: Traumatic brain injury, Model organism, Dementia, Injury, Post-concussion syndrome, Subdural hematoma, Concussion, Post-traumatic amnesia


After traumatic brain injury (TBI) and emergence from coma, the majority of people experience posttraumatic amnesia (PTA), characterized by confusion, disorientation, retrograde and anterograde amnesia, poor attention, and sometimes agitation and delusions. An international team of researchers and clinicians developed recommendations for assessment and management of PTA.

Concepts: Psychology, Traumatic brain injury, Hippocampus, Anterograde amnesia, Amnesia, Post-traumatic amnesia, Retrograde amnesia, Memory disorders


Past and recent attempts at devising objective biomarkers for traumatic brain injury (TBI) in both blood and cerebrospinal fluid have focused on abundance measures of time-dependent proteins. Similar independent determinants would be most welcome in diagnosing the most common form of TBI, mild TBI (mTBI), which remains difficult to define and confirm based solely on clinical criteria. There are currently no consensus diagnostic measures that objectively define individuals as having sustained an acute mTBI. Plasma metabolomic analyses have recently evolved to offer an alternative to proteomic analyses, offering an orthogonal diagnostic measure to what is currently available. The purpose of this study was to determine whether a developed set of metabolomic biomarkers is able to objectively classify college athletes sustaining mTBI from non-injured teammates, within 6 hours of trauma and whether such a biomarker panel could be effectively applied to an independent cohort of TBI and control subjects. A 6-metabolite panel was developed from biomarkers that had their identities confirmed using tandem mass spectrometry (MS/MS) in our Athlete cohort. These biomarkers were defined at ≤6 hours following mTBI and objectively classified mTBI athletes from teammate controls, and provided similar classification of these groups at the 2, 3, and 7 days post-mTBI. The same 6-metabolite panel, when applied to a separate, independent cohort provided statistically similar results despite major differences between the two cohorts. Our confirmed plasma biomarker panel objectively classifies acute mTBI cases from controls within 6 hours of injury in our two independent cohorts. While encouraged by our initial results, we expect future studies to expand on these initial observations.

Concepts: Mass spectrometry, Traumatic brain injury, Proteomics, Post-concussion syndrome, Tandem mass spectrometry, Concussion, Post-traumatic amnesia


To examine the utility of the Abbreviated Westmead Post-traumatic Amnesia Scale (A-WPTAS), which includes the Glasgow Coma Scale (GCS) and three picture cards used to measure amnesia, in identifying the presence or absence of post-traumatic amnesia (PTA) in individuals with mild traumatic brain injury (mTBI).

Concepts: Traumatic brain injury, Amnesia, Glasgow Coma Scale, Coma, Concussion, Neurotrauma, Post-traumatic amnesia, Head injury


To assess the prevalence of visual dysfunctions and associated symptoms in war fighters at different stages after non-blast- or blast-induced mild traumatic brain injury (mTBI).

Concepts: Brain, Disease, Traumatic brain injury, Post-concussion syndrome, Concussion, Post-traumatic amnesia