Identifying serious underlying diagnoses among patients with brief resolved unexplained events (BRUEs): a Canadian cohort study.

OBJECTIVE: To describe the demographics and clinical outcomes of infants with brief resolved unexplained events (BRUE). DESIGN: A retrospective cohort study. SETTING: 11 centres within the Canadian Paediatric Inpatient Research Network. PATIENTS: Patients presenting to the emergency department (ED) following a BRUE (2017-2021) were eligible, when no clinical cause identified after a thorough history and physical examination. MAIN OUTCOME MEASURES: Serious underlying diagnosis (requiring prompt identification) and event recurrence (within 90 days). RESULTS: Of 1042 eligible patients, 665 were hospitalised (63.8%), with a median stay of 1.73 days. Diagnostic tests were performed on 855 patients (82.1%), and 440 (42.2%) received specialist consultations. In total, 977 patients (93.8%) were categorised as higher risk BRUE per the American Academy of Pediatrics guidelines. Most patients (n=551, 52.9%) lacked an explanatory diagnosis; however, serious underlying diagnoses were identified in 7.6% (n=79). Epilepsy/infantile spasms were the most common serious underlying diagnoses (2.0%, n=21). Gastro-oesophageal reflux was the most common non-serious underlying diagnosis identified in 268 otherwise healthy and thriving infants (25.7%). No instances of invasive bacterial infections, arrhythmias or metabolic disorders were found. Recurrent events were observed in 113 patients (10.8%) during the index visit, and 65 patients had a return to ED visit related to a recurrent event (6.2%). One death occurred within 90 days. CONCLUSIONS: There is a low risk for a serious underlying diagnosis, where the majority of patients remain without a clear explanation. This study provides evidence-based risk for adverse outcomes, critical information to be used when engaging in shared decision-making with caregivers.

Impact of Experimental Tonic Pain on Corrective Motor Responses to Mechanical Perturbations.

Movement is altered by pain, but the underlying mechanisms remain unclear. Assessing corrective muscle responses following mechanical perturbations can help clarify these underlying mechanisms, as these responses involve spinal (short-latency response, 20-50 ms), transcortical (long-latency response, 50-100 ms), and cortical (early voluntary response, 100-150 ms) mechanisms. Pairing mechanical (proprioceptive) perturbations with different conditions of visual feedback can also offer insight into how pain impacts on sensorimotor integration. The general aim of this study was to examine the impact of experimental tonic pain on corrective muscle responses evoked by mechanical and/or visual perturbations in healthy adults. Two sessions (Pain (induced with capsaicin) and No pain) were performed using a robotic exoskeleton combined with a 2D virtual environment. Participants were instructed to maintain their index in a target despite the application of perturbations under four conditions of sensory feedback: (1) proprioceptive only, (2) visuoproprioceptive congruent, (3) visuoproprioceptive incongruent, and (4) visual only. Perturbations were induced in either flexion or extension, with an amplitude of 2 or 3 Nm. Surface electromyography was recorded from Biceps and Triceps muscles. Results demonstrated no significant effect of the type of sensory feedback on corrective muscle responses, no matter whether pain was present or not. When looking at the effect of pain on corrective responses across muscles, a significant interaction was found, but for the early voluntary responses only. These results suggest that the effect of cutaneous tonic pain on motor control arises mainly at the cortical (rather than spinal) level and that proprioception dominates vision for responses to perturbations, even in the presence of pain. The observation of a muscle-specific modulation using a cutaneous pain model highlights the fact that the impacts of pain on the motor system are not only driven by the need to unload structures from which the nociceptive signal is arising.