Acute and Subacute Clinical Markers After Sport-Related Concussion

ObjectiveThis study aimed to determine the association of a range of off-field symptoms reported by athletes retrospectively with on-field concussion signs and in-office symptoms among rugby union players.BackgroundPlayers with sports concussion experience multiple symptoms. Understanding the association between these symptoms and clinical markers of concussion would facilitate a targeted approach to symptom assessment and treatment.Design/MethodsCross-sectional study. We consecutively enrolled 92 adult rugby union players, within the first 72 hours after sport concussion. Ten symptoms assessed using a retrospective symptoms interview were examined for their association with observed concussion signs and post-concussion symptoms using the Post-Concussion Symptoms Scale (PCSS).ResultsOdds ratios revealed that athletes who was overtly symptomatic based on retrospective concussion interview at the time of the concussion were over 2.6 times more likely (p = 0.047) to have exhibited post-traumatic amnesia when compared with athletes who was asymptomatic. There were no differences between groups in terms of on-field loss of consciousness or confusion. Off-field symptoms reported by athlete were associated with symptoms reporting on the Beck Depression Inventory (OR 2.8; 95% CI 1.14–6.88), headache (OR 4.9; 95% CI 1.92–12.79), memory concerns (OR 3.15; 95% CI 1.06–9.34), pressure in head (OR 2.8; 95% CI 1.03–8.08), and visual disturbances (OR 3.9; 95% CI 1.05–14.50) within the first 72 hours after concussion.ConclusionsSymptomatic concussed rugby athletes have increased odds for sustaining on-field concussion signs that can be observed by others and persistent symptoms within the first 72 hours after concussion. Information from the on-field and off-field assessment is essential in understanding the severity of sports concussion.

Pathological slow-wave activity and impaired working memory binding in post-traumatic amnesia

The mechanism by which information is bound together in working memory is a central question for cognitive neuroscience. This binding is transiently disrupted during periods of post-traumatic amnesia following significant head injuries. The reason for this impairment is unclear but may be due to electrophysiological changes produced by head impacts. These are common and include pathological low frequency activity, which is associated with poorer neurological outcomes and may disrupt cortical communication. Here, we investigate associative memory binding during post-traumatic amnesia and test the hypothesis that misbinding is caused by a disruption in cortical communication produced by the pathological slowing of brain activity. Thirty acute moderate-severe traumatic brain injury patients (mean time since injury = 10 days) and 26 healthy controls were tested with a precision working memory paradigm that required the association of object and location information. A novel entropy ratio measure was calculated from behavioural performance. This provided a continuous measure of the degree of misbinding and the influence of distracting information. Resting state EEG was used to assess the electrophysiological effects of traumatic brain injury. Patients in post-traumatic amnesia showed abnormalities in working memory function and made significantly more misbinding errors than patients who were not in post-traumatic amnesia and controls. Patients showed a higher entropy ratio in the distribution of spatial responses, indicating that working memory recall was abnormally biased by the locations of non-target items suggesting a specific impairment of object and location binding. Slow wave activity was increased following traumatic brain injury. Increases in the delta-alpha ratio indicative of an increase in low frequency power specifically correlated with binding impairment in working memory. In contrast, although connectivity was increased in the theta band and decreased in the alpha band after traumatic brain injury, this did not correlate with working memory impairment. Working memory and electrophysiological abnormalities both normalised at six-month follow-up, in keeping with a transient increase in slow-wave activity causing post-traumatic amnesia that impaired working memory function. These results show that patients in post-traumatic amnesia show high rates of working memory misbinding that are associated with a pathological shift towards lower frequency oscillations.

Post-traumatic amnesia

Post-traumatic amnesia is the transient state of altered brain function that may follow a traumatic brain injury. At a practical level, an individual has emerged from post-traumatic amnesia when he or she is fully orientated and with return of continuous memory. However, the clinical manifestations are often more complex, with numerous cognitive domains commonly affected, as well as behaviour. In the acute setting, post-traumatic amnesia may easily go unrecognised; this is problematic as it has important implications for both immediate management and for longer-term prognosis. We therefore recommend its careful clinical assessment and prospective evaluation using validated tools. Patients in post-traumatic amnesia who have behavioural disturbance can be particularly challenging to manage. Behavioural and environmental measures form the mainstay of its treatment while avoiding pharmacological interventions where possible, as they may worsen agitation. Patients need assessing regularly to determine their need for further rehabilitation and to facilitate safe discharge planning.

Duration of post-traumatic amnesia is uniquely associated with memory functioning in chronic moderate-to-severe traumatic brain injury

BACKGROUND: Disrupted memory circuitry may contribute to post-traumatic amnesia (PTA) after traumatic brain injury (TBI). It is unclear whether duration of PTA (doPTA) uniquely impacts memory functioning in the chronic post-injury stage. OBJECTIVE: To examine the relationship between doPTA and memory functioning, independent of other cognitive abilities, in chronic moderate-to-severe TBI. METHODS: Participants were 82 individuals (median chronicity = 10.5 years) with available doPTA estimates and neuropsychological data. Composite memory, processing speed (PS), and executive functioning (EF) performance scores, as well as data on subjective memory (SM) beliefs, were extracted. DoPTA-memory associations were evaluated via linear modeling of doPTA with memory performance and clinical memory status (impaired/unimpaired), controlling for PS, EF and demographic covariates. Interrelationships between doPTA, objective memory functioning, and SM were assessed. RESULTS: DoPTA was significantly related to memory performance, even after covariate adjustment. Impairment in memory, but not PS or EF, was associated with a history of longer doPTA. SM was associated with memory performance, but unrelated to doPTA. CONCLUSIONS: Findings suggest a specific association between doPTA—an acute injury phenomenon—and chronic memory deficits after TBI. Prospective studies are needed to understand how underlying mechanisms of PTA shape distinct outcome trajectories, particularly functional abilities related to memory processing.

Aspects of Cognitive Impairment Associated with Agitated Behaviour during Post-traumatic Amnesia

Objectives: Post-traumatic amnesia (PTA) is a transient period of recovery following traumatic brain injury (TBI) characterised by disorientation, amnesia, and cognitive disturbance. Agitation is common during PTA and presents as a barrier to patient outcome. A relationship between cognitive impairment and agitation has been observed. This prospective study aimed to examine the different aspects of cognition associated with agitation. Methods: The sample comprised 82 participants (75.61% male) admitted to an inpatient rehabilitation hospital in PTA. All patients had sustained moderate to extremely severe brain injury as assessed using the Westmead Post-Traumatic Amnesia Scale (WPTAS) (mean duration = 42.30 days, SD = 35.10). Participants were assessed daily using the Agitated Behaviour Scale and WPTAS as part of routine clinical practice during PTA. The Confusion Assessment Protocol was administered two to three times per week until passed criterion was achieved (mean number assessments = 3.13, SD = 3.76). Multilevel mixed modelling was used to investigate the association between aspects of cognition and agitation using performance on items of mental control, orientation, memory free recall, memory recognition, vigilance, and auditory comprehension. Results: Findings showed that improvement in orientation was significantly associated with lower agitation levels. A nonsignificant trend was observed between improved recognition memory and lower agitation. Conclusions: Current findings suggest that the presence of disorientation in PTA may interfere with a patient’s ability to understand and engage with the environment, which in turn results in agitated behaviours. Interventions aimed at maximizing orientation may serve to minimize agitation during PTA.

Relationship between post-traumatic amnesia and white matter integrity in traumatic brain injury using tract-based spatial statistics

This study used tract-based spatial statistics to examine the relationship between post-traumatic amnesia (PTA) and white matter integrity in patients with a traumatic brain injury (TBI). Forty-seven patients with TBI in the chronic stage and 47 age- and sex-matched normal control subjects were recruited to the study. Correlation coefficients were calculated to observe the relationships among the PTA duration, white matter fractional anisotropy (FA) values, and mini-mental state examination (MMSE) results in the patient group. Both before and after Benjamini–Hochberg (BH) corrections, FA values of 46 of the 48 regions of interests of the patient group were lower than those of the control group. The FA values of column and body of fornix, left crus of fornix, left uncinate fasciculus, right hippocampus part of cingulum, left medial lemniscus, right superior cerebellar peduncle, left superior cerebellar peduncle, and left posterior thalamic radiation (after BH correction: the uncinate fasciculus and right hippocampus part of cingulum) in the patient group were negatively correlated with PTA duration. PTA duration was related to the injury severity of eight neural structures, each of which is involved in the cognitive functioning of patients with TBI. Therefore, PTA duration can indicate injury severity of the above neural structures in TBI patients.

More than amnesia: prospective cohort study of an integrated novel assessment of the cognitive and behavioural features of PTA

Background and Objective: Post-traumatic amnesia (PTA) is an early significant stage of recovery from traumatic brain injury (TBI). Current prospective PTA scales do not assess the full range of PTA symptomatology. This study conducted a novel integrated assessment of cognition and behaviour during PTA. Method: Twenty-four moderate-to-severe TBI participants in PTA and 23 TBI controls emerged from PTA were matched for age, gender, and years of education. All completed PTA measures (Galveston Orientation and Amnesia Test: GOAT, Westmead Post-traumatic Amnesia Scale: WPTAS), a cognitive battery; and behaviour ratings scored by 2 independent raters (informant and staff). Results: Significantly poorer performance was found during PTA for attention, processing speed, delayed verbal free recall and recognition, and visual learning. A large effect size was found for category fluency only. Behaviour ratings were significantly higher during PTA. Five behaviours were rated as high frequency (>50%) by both raters: Inattention, Impulsivity, Sleep Disturbance, Daytime Arousal, and Self-Monitoring. Prospective PTA measures produced significantly different duration estimates from 2 days (GOAT vs. WPTAS 1st day) to 9 days (WPTAS 1st day vs. 3-day). The WPTAS correlated most highly with processing speed and language tasks; whilst the GOAT correlated most highly with language and executive control of verbal memory. Conclusion: New prospective measures are needed that integrate core cognitive and behavioural features are brief, easy to administer, and capable of measuring emergence. The term PTA is a misnomer that requires revision to better accommodate the clinical syndrome.

Cost of inpatient rehabilitation for children with moderate to severe traumatic brain injury

ABSTRACT Aim: To evaluate the cost of inpatient rehabilitation for children with moderate to severe traumatic brain injury (TBI). Secondary aim was to identify factors associated with high inpatient rehabilitation cost. Method: Retrospective review of a tertiary hospital’s trauma registry was performed from 2011–2017. All patients aged 16 years or younger who sustained TBI with Glasgow Coma Scale ≤13 were included. Data on patient demographics, mechanism and severity of injury, hospital duration and inpatient rehabilitation cost were collected. We performed a regression analysis to identify factors associated with high rehabilitation cost. Results: There were a total of 51 patients. The median duration of inpatient rehabilitation was 13.5 days (interquartile range [IQR] 4–35), amounting to a median cost of SGD8,361 (IQR 3,543–25,232). Daily ward costs contributed the most to total inpatient rehabilitation cost. Those with severe TBI had longer duration of inpatient rehabilitation that resulted in higher cost of inpatient rehabilitation. Presence of polytrauma, medical complications, post-traumatic amnesia and TBI post-non-accidental injury (NAI) were associated with higher cost of inpatient rehabilitation. Conclusion: The cost of inpatient rehabilitation for paediatric patients post-TBI is significant in Singapore. Patients with TBI secondary to NAI had significantly higher cost of inpatient rehabilitation. Ways to reduce duration of hospitalisation post-TBI and early step-down care or outpatient rehabilitation should be explored to reduce cost. Keywords: Duration, paediatrics, rehabilitative medicine