The Effect of Sex, Sport Participation, and Concussion History on Baseline Concussion Balance Test Performance in Division-I Collegiate Athletes

ObjectiveExplore the effect of baseline characteristics such as sex, sport, and concussion history on the Concussion Balance Test (COBALT) performance in collegiate athletes.BackgroundThe COBALT is a recently developed clinical balance assessment specifically for athletic populations following concussion. The task conditions of the COBALT are designed to challenge sensory integration and reweighting processing underlying postural control. It has been documented that balance performance is influenced by factors such as sex and sport in collegiate athletes.Design/MethodsOne-hundred twenty seven collegiate athletes (77 male, 50 female; age: 19.81 ± 1.39; height: 68.77 ± 5.57 in; mass: 80.98 ± 26.15 kg), who participated in Division-I football, soccer, or cheerleading were included. Participants completed the 4 baseline conditions (Condition 3, 4, 7, 8) of the COBALT. Condition 3 (C3) included a side-to-side headshake with eyes closed. For Condition 4 (C4) the participant stood with hands clasped, elbows extended, and thumbs up while rotating their trunk side-to-side, visually focusing on their thumbs. Conditions 7 (C7) and 8 (C8) repeated C3 and C4 on a foam surface. Two 20-second trials of each condition were completed on a forceplate and the mean angular sway velocity (°/s) were calculated and number of errors were counted. ANOVAs and ANCOVAs were used to assess the potential effects on COBALT performance.ResultsThere were no significant differences in postural sway for any COBALT condition based on sex (p > 0.05). Females demonstrated more errors than males on C7 (p < 0.001). Cheerleaders had more balance errors compared to football athletes for C3 and C7 (p < 0.05) and soccer athletes for C7 (p < 0.05). Concussion history did not have an effect on COBALT performance (p > 0.05).ConclusionsUnderstanding factors that may influence COBALT performance at baseline may enhance concussion evaluation in collegiate athletes with suspected balance deficits following concussion. While concussion history had no effect, sex and sports participation may influence performance and should be considered when interpreting COBALT results post-concussion.

A Comparison of Balance Performance of the Sensory Organization Test to the Head Shake Sensory Organization Test in Healthy Adults

ObjectiveTo compare equilibrium scores between computerized dynamic posturography tests of the Sensory Organization Test (SOT) to the Head Shake-Sensory Organization Test (HS-SOT) in healthy adults.BackgroundApproximately 50% of the brain's pathways are related to vision and many of these pathways are susceptible to injury in concussion. Visual-motor disruptions occur in 65%–90% of concussed patients. These disruptions impair balance and can be measured. The SOT is a computerized postural test that evaluates balance by altering visual, proprioceptive, and vestibular cues. The HS-SOT modifies 2 of the standard SOT conditions by including dynamic head motions that stimulate the semicircular canals within the vestibular system.Design/MethodsParticipants completed the Dizziness Handicap Inventory, Activities of Balance Confidence Scale, SOT, and HS-SOT in one session.ResultsTwenty-five individuals (17 females, 8 males; mean age, 21.08 ± 4.10 years, range, 18–33 years) completed outcome measures and 3 trials of testing. There was a significant difference in mean values between the SOT and the HS-SOT for both condition 2 (t(16) = 3.034, p = 0.008) and 5 (t(16) = 5.706, p < 0.001). Additionally, there was a significant difference in mean values between the SOT and the foam HS-SOT for condition 2 (t(16) = 4.673, p < 0.001) and condition 5 (t(16) = 7.263, p < 0.001). There was not a significant difference in means between the foam and without foam for HS-SOT for condition 2 (t(16) = 1.77, p = 0.095) and condition 5 (t(16) = 1.825, p = 0.087).ConclusionsThe HS-SOT may quantify subtle balance deficits and enhance the clinical standard use of the SOT. Unlike the SOT where the head is static, the HS-SOT requires head movements, as if saying no repeatedly at approximately 100°/second as measured by an accelerometer. The HS-SOT may quantify subtle balance deficits and enhance the clinical standard use of the SOT.

Impact of Canal-Otolith Integration on Postural Control

Roll tilt vestibular perceptual thresholds, an assay of vestibular noise, have recently been shown to be associated with suboptimal balance performance in healthy older adults. However, despite the strength of this correlation, the use of a categorical (i.e., pass/fail) balance assessment limits insight into the impacts of vestibular noise on postural sway. As a result, an explanation for this correlation has yet to be determined. We hypothesized that the correlation between roll tilt vestibular thresholds and postural control reflects a shared influence of sensory noise. To address this hypothesis, we measured roll tilt perceptual thresholds at multiple frequencies (0.2 Hz, 0.5 Hz, 1 Hz) and compared each threshold to quantitative measures of quiet stance postural control in 33 healthy young adults (mean = 24.9 years, SD = 3.67). Our data showed a significant linear association between 0.5 Hz roll tilt thresholds and the root mean square distance (RMSD) of the center of pressure in the mediolateral (ML; β = 5.31, p = 0.002, 95% CI = 2.1–8.5) but not anteroposterior (AP; β = 5.13, p = 0.016, 95% CI = 1.03–9.23) direction (Bonferroni corrected α of 0.006). In contrast, vestibular thresholds measured at 0.2 Hz and 1 Hz did not show a significant correlation with ML or AP RMSD. In a multivariable regression model, controlling for both 0.2 Hz and 1 Hz thresholds, the significant effect of 0.5 Hz roll tilt thresholds persisted (β = 5.44, p = 0.029, CI = 0.60–10.28), suggesting that the effect cannot be explained by elements shared by vestibular thresholds measured at the three frequencies. These data suggest that vestibular noise is significantly associated with the temporospatial control of quiet stance in the mediolateral plane when visual and proprioceptive cues are degraded (i.e., eyes closed, standing on foam). Furthermore, the selective association of quiet-stance sway with 0.5 Hz roll tilt thresholds, but not thresholds measured at lower (0.2 Hz) or higher (1.0 Hz) frequencies, may reflect the influence of noise that results from the temporal integration of noisy canal and otolith cues.

Predictors of Future Walking Speed: A 12-Month Monitoring Program

The purpose of the current study was to identify significant predictors of walking speed (WS) among community-dwelling older adults, as it is one of the most representative measures of functioning in their daily lives. Seventy-seven (24 adult men, 26 adult women, and 27 older-adult women) community-dwelling older adults (73.7 ± 4.9 years) performed two assessments, over a 12-month period. Several physical, cognitive, and psychological tests were performed, as well as assessing the preferred WS. Multiple linear regression, stratified by gender, was used to identify significant predictors of future WS. For the adult men, walking and functional performances at the first assessment predicted 71.9%; for adult women, reaction time, walking, and balance performance predicted 64.4%; and, for the older-adult women, fast walking and reaction time predicted 48.2% of the variance of future WS. Clinicians should consider including different exercises for each group of older adults to evaluate and preserve functional abilities.

NMDAR1 autoantibodies amplify behavioral phenotypes of genetic white matter inflammation: a mild encephalitis model with neuropsychiatric relevance

Encephalitis has an estimated prevalence of ≤0.01%. Even with extensive diagnostic work-up, an infectious etiology is identified or suspected in <50% of cases, suggesting a role for etiologically unclear, noninfectious processes. Mild encephalitis runs frequently unnoticed, despite slight neuroinflammation detectable postmortem in many neuropsychiatric illnesses. A widely unexplored field in humans, though clearly documented in rodents, is genetic brain inflammation, particularly that associated with myelin abnormalities, inducing primary white matter encephalitis. We hypothesized that “autoimmune encephalitides” may result from any brain inflammation concurring with the presence of brain antigen-directed autoantibodies, e.g., against N-methyl-D-aspartate-receptor NR1 (NMDAR1-AB), which are not causal of, but may considerably shape the encephalitis phenotype. We therefore immunized young female Cnp−/− mice lacking the structural myelin protein 2′-3′-cyclic nucleotide 3′-phosphodiesterase (Cnp) with a “cocktail” of NMDAR1 peptides. Cnp−/− mice exhibit early low-grade inflammation of white matter tracts and blood–brain barrier disruption. Our novel mental-time-travel test disclosed that Cnp−/− mice are compromised in what–where–when orientation, but this episodic memory readout was not further deteriorated by NMDAR1-AB. In contrast, comparing wild-type and Cnp−/− mice without/with NMDAR1-AB regarding hippocampal learning/memory and motor balance/coordination revealed distinct stair patterns of behavioral pathology. To elucidate a potential contribution of oligodendroglial NMDAR downregulation to NMDAR1-AB effects, we generated conditional NR1 knockout mice. These mice displayed normal Morris water maze and mental-time-travel, but beam balance performance was similar to immunized Cnp−/−. Immunohistochemistry confirmed neuroinflammation/neurodegeneration in Cnp−/− mice, yet without add-on effect of NMDAR1-AB. To conclude, genetic brain inflammation may explain an encephalitic component underlying autoimmune conditions.

Association of blood pressure and postural control in older adults with hypertension: an observational study

The study investigated the association of orthostatic hypotension (OH) with functional position change and balance in older adults with hypertension. The presence of OH was assessed with intermittent (OH intermittent) and continuous blood pressure (OH continuous) monitoring. The change in functional position was tested with sitting to standing assessment, balance performance using activity specific balance confidence scale (ABC), and timed up and go test (TUG). Testing unilateral and bilateral standing with and without altered sensory inputs was tested using the Humac balance system. ABC, TUG, and standing up time showed no significant association with OH intermittent and OH continuous. A significant association was found between bilateral standing with eyes closed on foam surface for overall stability index and OH intermittent. Older people with hypertension may be routinely examined for OH and appropriate intervention strategies should be included for comprehensive care.