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

Sleep Disturbance During Post-Traumatic Amnesia and Early Recovery After Traumatic Brain Injury

After moderate to severe traumatic brain injury (TBI), sleep disturbance commonly emerges during the confused post-traumatic amnesia (PTA) recovery stage. However, the evaluation of early sleep disturbance during PTA, its recovery trajectory, and influencing factors is limited. This study aimed to evaluate sleep outcomes in patients experiencing PTA using ambulatory gold-standard polysomnography (PSG) overnight and salivary endogenous melatonin (a hormone that influences the sleep-wake cycle) assessment at two time-points. The relationships between PSG-derived sleep-wake parameters and PTA symptoms (i.e., agitation and cognitive disturbance) were also evaluated. In a patient subset, PSG was repeated after PTA had resolved to assess the trajectory of sleep disturbance. Participants with PTA were recruited from Epworth HealthCare's inpatient TBI Rehabilitation Unit. Trained nurses administered overnight PSG at the patient bedside using the Compumedics Somté portable PSG device (Compumedics, Ltd., Australia). Two weeks after PTA had resolved, PSG was repeated. On a separate evening, two saliva specimens were collected (at 24:00 and 06:00) for melatonin testing. Results of routine daily hospital measures (i.e., Agitated Behavior Scale and Westmead PTA Scale) were also collected. Twenty-nine patients were monitored with PSG (mean: 41.6 days post-TBI; standard deviation [SD]: 28.3). Patients' mean sleep duration was reduced (5.6 h, SD: 1.2), and was fragmented with frequent awakenings (mean: 27.7, SD: 15.0). Deep, slow-wave restorative sleep was reduced, or completely absent (37.9% of patients). The use of PSG did not appear to exacerbate patient agitation or cognitive disturbance. Mean melatonin levels at both time-points were commonly outside of normal reference ranges. After PTA resolved, patients (n = 11) displayed significantly longer mean sleep time (5.3 h [PTA]; 6.5 h [out of PTA], difference between means: 1.2, p = 0.005). However, disturbances to other sleep-wake parameters (e.g., increased awakenings, wake time, and sleep latency) persisted after PTA resolved. This is the first study to evaluate sleep disturbance in a cohort of patients as they progressed through the early TBI recovery phases. There is a clear need for tailored assessment of sleep disturbance during PTA, which currently does not form part of routine hospital assessment, to suggest new treatment paradigms, enhance patient recovery, and reduce its long-term impacts.

Post-traumatic amnesia: a scoping review & content analysis of behavioral disturbances

OBJECTIVE

The aim of this scoping review was to identify behavioral disturbances exhibited by patients in post-traumatic amnesia (PTA). While behavioral disturbances are common in PTA, research into their presentation and standardized measures for their assessment are limited.

DESIGN

The study protocol was registered with PROSPERO (CRD42021268275). A scoping review of databases was performed according to pre-determined criteria on 29 July 2021 and updated on 13 July 2022. A conventional content analysis was used to examine and categorize behavioral disturbances.

RESULTS

Thirty papers met the inclusion criteria, of which 27 reported observations and/or scores obtained on behavioral scales, and 3 on clinician interviews and surveys. None focused exclusively on children. Agitation was the most frequently assessed behavior, and Agitated Behavior Scale was the most used instrument. Content analysis, however, bore eight broad behavioral categories: disinhibition, agitation, aggression, lability, lethargy/low mood, perceptual disturbances/psychotic symptoms, personality change and sleep disturbances.

CONCLUSION

Our study revealed that while standardized assessments of behavior of patients in PTA are often limited to agitation, clinical descriptions include a range of behavioral disturbances. Our study highlights a significant gap in the systematic assessment of a wide range of behavioral disturbances observed in PTA.

Prolonged duration of post-traumatic amnesia: A sensitive classification for predicting cognitive outcomes in children recovering from traumatic brain injury

OBJECTIVE

A paucity of data exists regarding the duration of post-traumatic amnesia (PTA) as a predictor of cognitive functioning among children after traumatic brain injury (TBI). The study aimed to assess the relationship between PTA duration and areas of neurocognitive function among the pediatric population in the sub-acute phase of recovery and rehabilitation.

METHODS

Data were collected from medical files on 103 children aged 5.5-16.5 hospitalized at a pediatric rehabilitation department with a diagnosis of moderate-severe TBI (msTBI) between the years 2004-2019. The Children Orientation and Amnesia Test was used to evaluate PTA duration. Measures of high-order cognitive abilities of attention and executive function were collected using the Test of Everyday Attention-Child version (TEA-Ch).

RESULTS

Three PTA duration groups were assembled out of a cluster analysis: "Long PTA" (M = 21 days), "Very Long PTA" (M = 47 days), and "Extremely Long PTA" (M = 94 days). Analyses revealed that the "Long PTA" group preformed significantly better than the "Very Long PTA" and "Extremely Long PTA" groups on all TEA-Ch measures, that is, Selective Attention, Attentional Control Switching, and Sustained Attention.

CONCLUSIONS

This study is the first to demonstrate that PTA duration is a useful predictor of high-order cognitive functions among children with msTBI in the sub-acute phase of recovery and rehabilitation. The findings emphasize the importance of using a more sensitive classification of prolonged PTA durations to improve outcome prediction and allocation of resources to those who can benefit most after severe brain injuries.

Co-administration of Nanowired Oxiracetam and Neprilysin with Monoclonal Antibodies to Amyloid Beta Peptide and p-Tau Thwarted Exacerbation of Brain Pathology in Concussive Head Injury at Hot Environment

Environmental temperature adversely affects the outcome of concussive head injury (CHI)-induced brain pathology. Studies from our laboratory showed that animals reared at either cold environment or at hot environment exacerbate brain pathology following CHI. Our previous experiments showed that nanowired delivery of oxiracetam significantly attenuated CHI-induced brain pathology and associated neurovascular changes. Military personnel are the most susceptible to CHI caused by explosion, blasts, missile or blunt head trauma leading to lifetime functional and cognitive impairments affecting the quality of life. Severe CHI leads to instant death and/or lifetime paralysis. Military personnel engaged in combat operations are often subjected to extreme high or low environmental temperature zones across the globe. Thus, further exploration of novel therapeutic agents at cold or hot ambient temperatures following CHI are the need of the hour. CHI is also a major risk factor for developing Alzheimer's disease by enhancing amyloid beta peptide deposits in the brain. In this review, effect of hot environment on CHI-induced brain pathology is discussed. In addition, whether nanodelivery of oxiracetam together with neprilysin and monoclonal antibodies (mAb) to amyloid beta peptide and p-tau could lead to superior neuroprotection in CHI is explored. Our results show that co-administration of oxiracetam with neprilysin and mAb to AβP and p-tau significantly induced superior neuroprotection following CHI in hot environment, not reported earlier.

Use of Olanzapine to Treat Agitation in Traumatic Brain Injury: A Series of N-of-One Trials

Agitation is common during post-traumatic amnesia (PTA) following traumatic brain injury (TBI) and is associated with risk of harm to patients and caregivers. Antipsychotics are frequently used to manage agitation in early TBI recovery despite limited evidence to support their efficacy, safety, and impact upon patient outcomes. The sedating and cognitive side effects of these agents are theorized to exacerbate confusion during PTA, leading to prolonged PTA duration and increased agitation. This study, conducted in a subacute inpatient rehabilitation setting, describes the results of a double-blind, randomized, placebo-controlled trial investigating the efficacy of olanzapine for agitation management during PTA, analyzed as an n-of-1 series. Group comparisons were additionally conducted, examining level of agitation; number of agitated days; agitation at discharge, duration, and depth of PTA; length of hospitalization; cognitive outcome; adverse events; and rescue medication use. Eleven agitated participants in PTA (mean [M] age = 39.82 years, standard deviation [SD] = 20.06; mean time post-injury = 46.09 days, SD = 32.75) received oral olanzapine (n = 5) or placebo (n = 6) for the duration of PTA, beginning at a dose of 5 mg/day and titrated every 3 to 4 days to a maximum dose of 20 mg/day. All participants received recommended environmental management for agitation. A significant decrease in agitation with moderate to very large effect (Tau-U effect size = 0.37-0.86) was observed for three of five participants receiving olanzapine, while no significant reduction in agitation over the PTA period was observed for any participant receiving placebo. Effective olanzapine dose ranged from 5-20 mg. Response to treatment was characterized by lower level of agitation and response to treatment within 3 days. In group analyses, participants receiving olanzapine demonstrated poorer orientation and memory during PTA with large effect size (olanzapine, mean = 9.32, SD = 0.69; placebo, M = 10.68, SD = 0.30; p = .009, d = -2.16), and a trend toward longer PTA duration with large effect size (olanzapine, M = 71.96 days, SD = 20.31; placebo, M = 47.50 days, SD = 11.27; p = 0.072, d = 1.26). No further group comparisons were statistically significant. These results suggest that olanzapine can be effective in reducing agitation during PTA, but not universally so. Importantly, administration of olanzapine during PTA may lead to increased patient confusion, possibly prolonging PTA. When utilizing olanzapine, physicians must therefore balance the possible advantages of agitation management with the possibility that the patient may never respond to the medication and may experience increased confusion, longer PTA and potentially poorer outcomes. Further high-quality research is required to support these findings and the efficacy and outcomes associated with the use of any pharmacological agent for the management of agitation during the PTA period.