Neuropsychiatric symptoms after moderate-to-severe traumatic brain injury in Vietnam: Assessment, prevalence, and impact on caregivers.

OBJECTIVE: Neuropsychiatric symptoms (NPSs) after moderate-to-severe traumatic brain injury (TBI) have been well documented in WEIRD (Western, educated, industrialized, rich, and democratic) populations. In non-WEIRD populations, such as Vietnam, however, patients with TBI clinically remain uninvestigated with potential neuropsychiatric disorders, limiting on-time critical interventions. This study aims to (1) adapt the Vietnamese Neuropsychiatric Inventory (V-NPI), (2) examine NPSs after moderate-to-severe TBI and (3) evaluate their impact on caregiver burden and well-being in Vietnam. METHOD: Caregivers of seventy-five patients with TBI completed the V-NPI, and other behavior, mood, and caregiver burden scales. RESULTS: Our findings demonstrated good internal consistency, convergent validity, and structural validity of the V-NPI. Caregivers reported that 78.7% of patients with TBI had at least three symptoms and 16.0% had more than seven. Behavioral and mood symptoms were more prevalent (ranging from 44.00% to 82.67% and from 46.67% to 66.67%, respectively) and severe in the TBI group. Importantly, NPSs in patients with TBI uniquely predicted 55.95% and 33.98% of caregiver burden and psychological well-being, respectively. CONCLUSION: This study reveals the first evidence for the presence and severity of NPSs after TBI in Vietnam, highlighting an urgent need for greater awareness and clinical assessment of these symptoms in clinical practice. The adapted V-NPI can serve as a useful tool to facilitate such assessments and interventions. In addition, given the significant impact of NPS on caregiver burden and well-being, psychosocial support for caregivers should be established.

Reduced Sensitivity to Background Reward Underlies Apathy After Traumatic Brain Injury: Insights From an Ecological Foraging Framework.

BACKGROUND: Altered reward processing is increasingly recognised as a crucial mechanism underpinning apathy in many brain disorders. However despite its clinical relevance, little is known about the mechanisms of apathy following moderate-to-severe traumatic brain injury (TBI). In real-life situations, reward representations encompass both foreground (gains from current activity) and background (potential gains from the broader environment) elements. This latter variable provides a crucial set-point for switching behaviour in many naturalistic settings. We hypothesised apathy post-TBI would be associated with disrupted background reward sensitivity. METHODS: We administered a computer-based foraging task to 45 people with moderate-to-severe TBI (20 with apathy, 39 males) and 37 matched controls. Participants decided when to leave locations (patches) where foreground reward rates depleted at differing rates, to pursue greater rewards from other patches in the environment, which had either a high or low background reward rate. Primary analysis was performed using linear mixed effects models, with patch leaving time the dependent variable. RESULTS: Findings showed a significant interaction between apathy and background reward sensitivity, driven by apathetic TBI participants not altering patch-leaving decisions as environmental reward rate changed. In contrast, although TBI was associated with reduced sensitivity to changing foreground rewards, this did not vary as a function of apathy. CONCLUSIONS: These results provide the first evidence directly linking disrupted background reward processing to apathy in any brain disorder. They identify a novel mechanism for apathy following moderate-to-severe TBI, and point towards novel interventions to improve this debilitating complication of head injury.

Contributions of intrinsic and extrinsic reward sensitivity to apathy: Evidence from traumatic brain injury.

OBJECTIVE: Apathy is a key feature of traumatic brain injury (TBI). However, mechanisms underlying apathy are poorly understood. Evidence suggests that changes in reward may be a crucial factor. Rewards can come from two important sources: extrinsic reward (e.g., money) and intrinsic reward (e.g., enjoyment). Here, we used an experimental paradigm to examine the contributions of intrinsic-extrinsic reward sensitivity to apathy post-TBI and neurocognitive processes associated with these reward processing components. METHOD: Fifty-seven patients with TBI (TBI with clinical/severe apathy [TBI + sA], TBI with subclinical/moderate apathy [TBI + mA] and TBI without apathy [TBI-A] groups), and 30 healthy individuals completed the "birthday-gift task." In the "intrinsic reward" condition, participants chose to "go" to collect the gift or "wait" for the same gift to be delivered. In the "extrinsic reward" condition, the task was identical, however, participants received monetary incentives when choosing "going" instead of "waiting." The Montreal Cognitive Assessment was utilized for cognitive examination. RESULTS: A smaller proportion of people in the TBI + sA group had high sensitivity to both intrinsic and extrinsic rewards than the TBI + mA, TBI-A and healthy comparison groups. The TBI+sA group also perceived the "go" option on the intrinsic reward condition as more effortful and made fewer "go" decisions on the extrinsic condition. Attention was the only predictor of intrinsic reward sensitivity, whereas executive functioning, attention and group predicted extrinsic reward. CONCLUSION: This study demonstrates the relationship between intrinsic-extrinsic reward hyposensitivity and apathy post-TBI. These results may be integrated into future trials to improve apathy in clinical practice. (PsycInfo Database Record (c) 2022 APA, all rights reserved).