Small-Town Doctor Provides Big-Time Care

In brief: Two related studies were conducted to determine whether fast walking is intense enough to elicit a training heart rate (THR), which is defined as ≥ 70% of maximal heart rate. In one study, 343 subjects (165 men, 178 women) walked a mile as fast as possible. Ninety-one percent of all the women and 83% of men aged 50 and older reached a THR. In the second study, ten men with high V o₂ max values were instructed to achieve and maintain a THR and were provided with visual feedback of their heart rate (HR) during a 30-minute walk. These subjects maintained a THR for an average of 25 minutes during the walk. Thus, it seems that fast walking may indeed offer an adequate aerobic training stimulus for most adults.     

Neuropsychological Test Performance of Hawai‘i High School Athletes: Updated Hawai‘i Immediate Post-Concussion Assessment and Cognitive Testing Data

The present study reviewed the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) baseline test scores of 247 high school athletes ages 13 to 18 from a private school in Hawai‘i. The aim of the research was to update a prior exploratory investigation conducted in 2008 that compared the test scores of Hawai‘i public high school athletes with the normative data provided by the ImPACT publishers. The results of this study provide assurance that the present ImPACT scores of the Hawai‘i high school athletes are similar to the general ImPACT norms. The present study is a rare effort to compare the ImPACT scores of high school athletes from an ethnically diverse region with the ImPACT norms. The findings offer further support for the use of the ImPACT norms when evaluating high school athletes from Hawai‘i. Future research in various regions of the United States and with other sociocultural backgrounds is encouraged.     

Sports concussion assessment: the effect of exercise on dynamic and static balance

This study determined the effect of exercise on measures of static and dynamic balance used in the assessment of sports‐related concussion (SRC). A balanced three‐group cross‐over randomized design was used with three levels of exercise verified by blood‐lactate, heart rate and “perceived‐exertion”: no exercise/rest (NE), moderate‐intensity exercise (ME), and high‐intensity exercise (HE). Participants performed two timed balance tasks: tandem gait (TG) and single‐leg stance (SLS); pre‐ and post‐exercise and 15 min after exercise. Linear mixed‐models with adjusted means and contrasts compared exercise effects. Ninety asymptomatic participants (45♂:45♀) were recruited. When times were contrasted with NE; HE resulted in a significant decrease in SLS (P<0.001) and TG (P<0.001) performance immediately following exercise. Fifteen minutes of recovery improved SLS (P<0.001) and TG (P=0.011) from post‐exercise performance. ME caused a significant decrease in performance in SLS (P=0.038) but not TG (P=0.428). No statistically significant change occurred following ME in any tasks after 15‐min recovery (SLS P=0.064; TG P=0.495). Test–retest reliability was considerably higher for the dynamic task compared with the static task. The reliability of static and dynamic balance tasks, and the change in performance following exercise, have implications for the immediate assessment of SRC, as these measures are utilized in concussion assessment instruments.     

The Diagnosis of Concussion in Pediatric Emergency Departments: A Prospective Multicenter Study

Background

The accurate identification of children with a concussion by emergency physicians is important to initiate appropriate anticipatory guidance and management.

Mapping default mode connectivity alterations following a single season of subconcussive impact exposure in youth football

Repetitive head impact (RHI) exposure in collision sports may contribute to adverse neurological outcomes in former players. In contrast to a concussion, or mild traumatic brain injury, “subconcussive” RHIs represent a more frequent and asymptomatic form of exposure. The neural network‐level signatures characterizing subconcussive RHIs in youth collision‐sport cohorts such as American Football are not known. Here, we used resting‐state functional MRI to examine default mode network (DMN) functional connectivity (FC) following a single football season in youth players (n = 50, ages 8–14) without concussion. Football players demonstrated reduced FC across widespread DMN regions compared with non‐collision sport controls at postseason but not preseason. In a subsample from the original cohort (n = 17), players revealed a negative change in FC between preseason and postseason and a positive and compensatory change in FC during the offseason across the majority of DMN regions. Lastly, significant FC changes, including between preseason and postseason and between in‐ and off‐season, were specific to players at the upper end of the head impact frequency distribution. These findings represent initial evidence of network‐level FC abnormalities following repetitive, non‐concussive RHIs in youth football. Furthermore, the number of subconcussive RHIs proved to be a key factor influencing DMN FC.