A systematic review and meta-analysis of factors influencing ImPACT concussion testing in high school and collegiate athletes with self-reported ADHD and/or LD.

OBJECTIVE: Sport concussion is a common injury, and athletes with attention-deficit/hyperactivity disorder (ADHD) and/or learning disorder (LD) are at increased risk and require specialized attention in clinical settings. Although systematic reviews of the relationship between ADHD/LD and concussion are reported in the literature, these reviews do not include quantitative syntheses. Additionally, no reviews have focused on the most commonly utilized concussion assessment, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). The current review provides an update of sport concussion assessment in athletes with ADHD and/or LD from 2000 to 2021 on these topics: baseline and postconcussion performance on ImPACT, baseline and postconcussion symptom reporting using the Postconcussion Symptom Scale, invalid baseline classification on ImPACT, and self-reported history of concussion. METHOD: Meta-analyses were conducted on baseline ImPACT performance, symptom reporting, invalid baseline classification, and concussion rates. Thirty-four studies were included in systematic review and 19 were included in meta-analyses. RESULTS: Decreased baseline performance was found for athletes with ADHD (trivial to small effects), LD (small-to-medium effects), and ADHD/LD (small-to-medium effects). Increased baseline symptom reporting was found for athletes with ADHD (small effect). Increased odds of invalid baseline performance (trivial effect) and self-reported concussion history (small effect) were found in ADHD. CONCLUSIONS: These results provide the first quantitative synthesis of the literature in this area. It is recommended that future research further examines these topics in athletes with LD and co-occurring ADHD/LD (given the focus on ADHD), as well as the effects that all of these conditions may have on concussion recovery and return-to-play decision-making. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Potential for intranasal drug delivery to alter cerebrospinal fluid outflow via the nasal turbinate lymphatics.

BACKGROUND: Cerebrospinal fluid absorption (CSF) at the cribriform plate is mediated by direct extracranial connections to the lymphatic system. Given the accessibility of these pharmacologically responsive vessels we hypothesized that the rate of CSF outflow can be modulated via the intranasal delivery of drugs known to affect lymphatic contractile activity. FINDINGS: Fluid was infused into the lateral ventricle of anesthetized sheep and inflow rate and CSF pressure measured during intranasal administration of pharmacological agents. CSF absorption was calculated at steady-state CSF pressures. The ability of a pharmacological agent to alter CSF absorption was related to the steady-state intracranial pressure (ICP), the concentration and the class of pharmacological agent delivered. An increase in drug concentration correlated with an increase in CSF absorption at high ICP (45 cm H2O, r = 0.42, p = 0.0058). Specifically, the delivery of NG-monomethyl L-arginine (L-NMMA) significantly increased CSF absorption by 2.29 fold over no treatment (2.29 ± 0.34 mL/min), while the thromboxane A2 analogue U46619 resulted in a 2.44 fold increase in CSF absorption over no treatment (2.44 ± 0.55 mL/min). Saline delivery did not significantly increase CSF absorption (0.88 ± 0.097 mL/min). A trend of increased CSF absorption upon noradrenaline delivery was observed: however, this did not reach statistical significance. Increasing drug concentrations inversely correlated with CSF outflow resistance across all drug classes (r = -0.26, p = 0.046). CONCLUSIONS: The administration of nebulized pharmacological agents intranasally has the potential to provide an alternate method to non-invasively modulate CSF absorption and outflow resistance.