Clive B. Beggs

Dirty-Appearing White Matter in the Brain is Associated with Altered Cerebrospinal Fluid Pulsatility and Hypertension in Individuals without Neurologic Disease.

Aging of the healthy brain is characterized by focal or nonfocal white matter (WM) signal abnormality (SA) changes, which are typically detected as leukoaraiosis (LA). Hypertension is a risk factor for WM lesion formation. This study investigated whether LA might be associated with increased cerebrospinal fluid (CSF) pulsatility linked to arterial hypertension.

Internal Jugular Vein Cross-Sectional Area Enlargement Is Associated with Aging in Healthy Individuals

Background Internal jugular vein (IJV) narrowing has been implicated in central nervous system pathologies, however normal physiological age- and gender-related IJV variance in healthy individuals (HIs) has not been adequately assessed. Objectives We assessed the relationship between IJV cross-sectional area (CSA) and aging. Materials and Methods This study involved 193 HIs (63 males and 130 females) who received 2-dimensional magnetic resonance venography at 3T. The minimum CSA of the IJVs at cervical levels C2/C3, C4, C5/C6, and C7/T1 was obtained using a semi-automated contouring-thresholding technique. Subjects were grouped by decade. Pearson and partial correlation (controlled for cardiovascular risk factors, including hypertension, heart disease, smoking and body mass index) and analysis of variance analyses were used, with paired t-tests comparing side differences. Results Mean right IJV CSA ranges were: in males, 41.6 mm2 (C2/C3) to 82.0 mm2 (C7/T1); in females, 38.0 mm2 (C2/C3) to 62.3 mm2 (C7/T1), while the equivalent left side ranges were: in males, 28.0 mm2 (C2/C3) to 52.2 mm2 (C7/T1); in females, 27.2 mm2 (C2/C3) to 47.8 mm2 (C7/T1). The CSA of the right IJVs was significantly larger (p<0.001) than the left at all cervical levels. Controlling for cardiovascular risk factors, the correlation between age and IJV CSA was more robust in males than in the females for all cervical levels. Conclusions In HIs age, gender, hand side and cervical location all affect IJV CSA. These findings suggest that any definition of IJV stenosis needs to account for these factors.

The Use of Accelerometers to Quantify Collisions and Running Demands of Rugby Union Match-Play

This study examined the relationship between accelerometer metrics and both collisions and running demands during rugby union match-play. Twelve under-18 forwards and 14 under-18 backs were recruited from a professional rugby union club. Six competitive matches were filmed during which players wore micro-technological units (Optimeye S5, Catapult Innovations, Melbourne, Australia). Video footage was analysed for total collisions, while GPS data was analysed for total distance. Accelerometer metrics analysed were Player load™ (PL), Player Load™ 2D (PL2D), and Player Load™ slow (PLslow). A total of 81 player observations were included in the final analysis. Data were analysed using ordinary least squares regression. A 10-fold cross validation analysis was used to validate the findings. All PL variables demonstrated very large relationships with collisions in the forwards, while PLslow demonstrated the largest relationship (large) with collisions in the backs. Therefore, based on the strong relationship in both forwards and backs, PLslow may provide the most useful metric for measuring collision-based activity in both positional groups during match-play. Additionally, nearly perfect and very large relationships were observed between PL and total distance for forwards and backs respectively, suggesting that PL can be successfully used to quantify running demands when other methods are unavailable, for example during indoor training.

Identifying Talent in Youth Sport: A Novel Methodology Using Higher-Dimensional Analysis

Prediction of adult performance from early age talent identification in sport remains difficult. Talent identification research has generally been performed using univariate analysis, which ignores multivariate relationships. To address this issue, this study used a novel higher-dimensional model to orthogonalize multivariate anthropometric and fitness data from junior rugby league players, with the aim of differentiating future career attainment. Anthropometric and fitness data from 257 Under-15 rugby league players was collected. Players were grouped retrospectively according to their future career attainment (i.e., amateur, academy, professional). Players were blindly and randomly divided into an exploratory (n = 165) and validation dataset (n = 92). The exploratory dataset was used to develop and optimize a novel higher-dimensional model, which combined singular value decomposition (SVD) with receiver operating characteristic analysis. Once optimized, the model was tested using the validation dataset. SVD analysis revealed 60 m sprint and agility 505 performance were the most influential characteristics in distinguishing future professional players from amateur and academy players. The exploratory dataset model was able to distinguish between future amateur and professional players with a high degree of accuracy (sensitivity = 85.7%, specificity = 71.1%; p<0.001), although it could not distinguish between future professional and academy players. The validation dataset model was able to distinguish future professionals from the rest with reasonable accuracy (sensitivity = 83.3%, specificity = 63.8%; p = 0.003). Through the use of SVD analysis it was possible to objectively identify criteria to distinguish future career attainment with a sensitivity over 80% using anthropometric and fitness data alone. As such, this suggests that SVD analysis may be a useful analysis tool for research and practice within talent identification.

Internal Jugular Vein Cross-Sectional Area and Cerebrospinal Fluid Pulsatility in the Aqueduct of Sylvius: A Comparative Study between Healthy Subjects and Multiple Sclerosis Patients

Objectives Constricted cerebral venous outflow has been linked with increased cerebrospinal fluid (CSF) pulsatility in the aqueduct of Sylvius in multiple sclerosis (MS) patients and healthy individuals. This study investigates the relationship between CSF pulsatility and internal jugular vein (IJV) cross-sectional area (CSA) in these two groups, something previously unknown. Methods 65 relapsing-remitting MS patients (50.8% female; mean age = 43.8 years) and 74 healthy controls (HCs) (54.1% female; mean age = 43.9 years) were investigated. CSF flow quantification was performed on cine phase-contrast MRI, while IJV-CSA was calculated using magnetic resonance venography. Statistical analysis involved correlation, and partial least squares correlation analysis (PLSCA). Results PLSCA revealed a significant difference (p<0.001; effect size = 1.072) between MS patients and HCs in the positive relationship between CSF pulsatility and IJV-CSA at C5-T1, something not detected at C2-C4. Controlling for age and cardiovascular risk factors, statistical trends were identified in HCs between: increased net positive CSF flow (NPF) and increased IJV-CSA at C5-C6 (left: r = 0.374, p = 0.016; right: r = 0.364, p = 0.019) and C4 (left: r = 0.361, p = 0.020); and increased net negative CSF flow and increased left IJV-CSA at C5-C6 (r = -0.348, p = 0.026) and C4 (r = -0.324, p = 0.039), whereas in MS patients a trend was only identified between increased NPF and increased left IJV-CSA at C5-C6 (r = 0.351, p = 0.021). Overall, correlations were weaker in MS patients (p = 0.015). Conclusions In healthy adults, increased CSF pulsatility is associated with increased IJV-CSA in the lower cervix (independent of age and cardiovascular risk factors), suggesting a biomechanical link between the two. This relationship is altered in MS patients.

Intracranial volumetric changes govern cerebrospinal fluid flow in the Aqueduct of Sylvius in healthy adults

Abstract Purpose To characterize the intracranial volumetric changes that influence the cerebrospinal fluid (CSF) pulse in the Aqueduct of Sylvius (AoS). Materials and methods Neck MRI data were acquired from 12 healthy adults (8 female and 4 males; mean agexa0=xa030.9xa0years), using a 1.5xa0T scanner. The intracranial arterial, venous and CSF volumes changes, together with the aqueductal CSF (aCSF) volume, were estimated from flow rate data acquired at C2/C3 level and in the AoS. The correlations and temporal relationships among these volumes were computed. Results The aCSF volumetric changes were strongly correlated (rxa0=xa00.967, pxa0 Conclusion The aCSF pulse is strongly correlated with intracranial venous volume, with expansion of the cortical veins occurring prior to aCSF flow towards the third ventricle. Both caudal-cranial aCSF flow and venous blood retention occur when arterial blood volume is at a minimum.

Age-related brain atrophy may be mitigated by internal jugular vein enlargement in male individuals without neurologic disease

Objectives To assess the relationship between cross-sectional area of internal jugular veins and brain volumes in healthy individuals without neurologic disease. Methods A total of 193 healthy individuals without neurologic disease (63 male and 130 female; ageu2009>u200920 tou2009<u200970 years) received magnetic resonance venography and structural brain magnetic resonance imaging at 3T. The internal jugular vein cross-sectional area was assessed at C2–C3, C4, C5–C6, and C7–T1. Normalized whole brain volume was assessed. Partial correlation analyses were used to determine associations. Results There was an inverse relationship between normalized whole brain volume and total internal jugular vein cross-sectional area (C7–T1: males ru2009=u2009−0.346, pu2009=u20090.029; females ru2009=u2009−0.301, pu2009=u20090.002). After age adjustment, association of normalized whole brain volume and normalized gray matter volume with internal jugular vein cross-sectional area became positive in males (normalized whole brain volume and right internal jugular vein cross-sectional area (C2–C3) changed from ru2009=u2009−0.163 to ru2009=u20090.384, pu2009=u20090.002), but not in the females. Conclusion Sex differences exist in the relationship between brain volume and internal jugular vein cross-sectional area in healthy individuals without neurologic disease.

Factors influencing the hemodynamic response to balloon angioplasty in the treatment of outflow anomalies of internal jugular veins

OBJECTIVEnPercutaneous transluminal angioplasty (PTA) of the internal jugular veins (IJVs) has been proposed in recent years to treat chronic cerebrovascular venous insufficiency, with discordant results. Moreover, very little is known about the efficacy of PTA in restoring a normal cerebral venous outflow. The aim of this study was to investigate the anatomic factors and patient characteristics that might influence the efficacy of PTA of the IJV.nnnMETHODSnThere were 797 consecutive patients with venous outflow anomalies who underwent standardized, operator-independent catheter venography and PTA of the IJVs. Before and after PTA, morphologic and hemodynamic anomalies of the IJVs were documented. The primary end point of the study was to evaluate the morphologic factors influencing the efficacy of angioplasty in improving IJV outflow.nnnRESULTSnPTA resulted in an increased outflow through the IJVs in most patients. However, younger individuals with transverse endoluminal defects and higher pre-PTA flows are more likely to respond well to PTA compared with those who exhibit hypoplasia, stenosis, or longitudinal endoluminal defects.nnnCONCLUSIONSnThis study identified the factors that influence and could predict the efficacy of PTA in the treatment of IJV anomalies.

A retrospective longitudinal analysis of anthropometric and physical qualities that associate with adult career attainment in junior rugby league players

OBJECTIVESnTo retrospectively compare the longitudinal physical development of junior rugby league players between the Under 13 and 15 age categories in relation to their adult career attainment outcome.nnnDESIGNnRetrospective longitudinal design.nnnMETHODSnFifty-one former junior rugby league players were retrospectively grouped according to their career attainment outcome as adults (i.e., amateur, academy or professional). As juniors, players undertook a physical testing battery on three consecutive annual occasions (Under 13s, 14s, 15s) including height, body mass, sum of four skinfolds, maturation, vertical jump, medicine ball chest throw, 10-60m sprint, agility 505 and estimated V˙O2max .nnnRESULTSnFuture professional players were younger than academy players with a greater estimated V˙O2max compared to amateur players. Between Under 13s and 15s, professional players (5.8±2.5cm) increased sitting height more than amateur (4.4±2.1cm) and academy (4.1±1.4cm) players. Logistic regression analyses demonstrated improvements in sitting height, 60m sprint, agility 505 and estimated V˙O2max between amateur and professional players with a high degree of accuracy (sensitivity=86.7%, specificity=91.7%).nnnCONCLUSIONSnFindings demonstrate that the development of anthropometric, maturational and physical qualities in junior rugby league players aged between 13 and 15 years contributed to adulthood career attainment outcomes. Results suggest that age, maturity and size advantages, commonly observed in adolescent focused talent identification research and practice, may not be sensitive to changes in later stages of development in order to correctly identify career attainment. Practitioners should identify, monitor and develop physical qualities of adolescent rugby league players with long-term athlete development in mind.

Hydration strategies of professional elite rugby league referees during super league matches

Due to the focus of research within athletic populations, little is known about the hydration strategies of rugby league referees. We observed all eight full-time professional referees, during 31 Super League matches to investigate the drinking strategies and magnitude of dehydration (body mass loss) experienced by referees during match play. Referees arrived and remained euhydrated (urine osmolality; pre and post-match 558u2009±u2009310 and 466u2009±u2009283 mOsmol·kg−1). Mean body mass change was −0.7u2009±u20090.8%, fluid loss was 890u2009±u2009435u2009g and fluid intake was 444u2009±u2009167, 438u2009±u2009190, 254u2009±u2009108 and 471u2009±u2009221u2009g during pre-match, first half, half-time and second half. This study suggests that elite referees adopt appropriate hydration strategies during match-play to prevent large reductions in body mass, although individual variability was observed. Future research should investigate dehydration in referees from other sports and the effects on refereeing performance.