Musculocutaneous nerve variations. Meta-analysis of proportions and proposal for categorization

The musculocutaneous nerve (MCN) is one of the main terminal branches of the brachial plexus. It provides motor innervation to coracobrachialis, biceps brachii and brachialis muscles and sensory innervation to the skin of lateral side of the forearm. In the normal anatomical description, the MCN arises from lateral cord and don’t have communication with other terminal branches of brachial plexus. All motor branches arises from MCN, directly.[1] Despite these considerations, several variations of MCN have been reported. The most common are anomalous communications between MCN and median nerve. These communications could be relevant in clinical practice and could have several practical considerations that should be evaluated in different medical area, such as orthopedic surgery, traumatology or neurophysiology. Several classifications have been proposed but none of these is able to cover all aspects of this variation. Therefore, the aim of the present study are a systematic review of the available literature about MCN variations and a meta-analytic approach to define their prevalence.[2] At the same time, a new model of categorization with practical effects on clinical reasoning has been proposed. Several electronic databases have been searched. Articles have been screened and papers with anatomical description of MCN variations have been included. 43 out of 661 articles fulfilled inclusion criteria, with a description of 4695 brachial plexuses dissections. The random pooled prevalence of MCN variations is 18% (95%CI: 15-21%). The new categorization proposal is based on a 3 areas model: Area 1 (1A: absence of musculocutaneous nerve, 1B: variations before the division of the musculocutaneous nerve from lateral cord); Area 2: variations between origin of MCN from lateral cord and point of in coracobrachialis muscle (or same level if MCN does not pierce the muscle); Area 3: variations distal to point of entry in coracobrachialis muscle; Mixed areas: variations reported in more than a single area described above. Applying this model, the random pooled prevalence of reported variations is: Area 1A: 19% (95%CI: 11-28%), Area 1B: 26% (95%CI: 14-39%), Area 2: 46% (95%CI: 33- 59%), Area 3: 55% (95%CI: 40-70%), Mixed areas: 16 (95%CI: 8-25%). Therefore, MCN variations have a high prevalence. Among them, the most frequent are localized distal to coracobrachialis muscle. These results could be useful in clinical practice to point the attention at this anatomical region where variations in MCN are very common

Popliteal Artery Entrapment Syndrome (PAES) and Ankle-Brachial Index (ABI), any association?

Popliteal Artery Entrapment Syndrome (PAES) is an uncommon pathology. Often, it affects young athletic males, with symptoms like calf claudication, weakness, numbness, pain, coldness of the foot, cramps, foot drop and paresthesia. The etiology of this syndrome is related to anatomical variations determining an altered relationship between popliteal artery and the surrounding structures. Based on described anatomical variations, PAES has been classified in several types (type I to V). In other cases, the compression of the popliteal artery may be caused by the hypertrophic gastrocnemius muscle, without anatomical variations, defining a “functional popliteal entrapment” (type VI). [1]. The Ankle-Brachial Index (ABI) is the ratio of the systolic blood pressure measured at the ankle to that measured at the brachial artery. It’s a non-invasive measure of peripheral artery disease and can serve as a prognostic marker for cardiovascular events and functional impairment [2]. The ABI score is often pathological in patients affected by PAES. Nevertheless, to define diagnosis and type of PAES are often needed imaging studies and invasive procedures. The aim of the present study is to systematically review the available literature to define if ABI score could be useful to predict a specific type of PAES. Electronic databases have been searched using specific Keywords. Articles have been screened and full-texts of relevant papers have been retrieved. Case reports and case series with indications of symptoms, type of PAES, ABI score have been included. Results about ABI score (dependent variable) have been pooled and compared among types of PAES (independent variable). No statistical significance has been noted (ANOVA: F=1.9, p=0.09). The use of ABI is insufficient to predict the type of PAES and its prognosis. Nevertheless, this non-invasive method could be useful to suspect PAES and as a tool in follow up in these patients

Concussion Knowledge and Self-Reported Behaviors in Youth Rugby Players and Their Coaches: A Population-Wide Cross-Sectional Survey

Objective: To investigate concussion knowledge and self-reported behaviors in Italian youth rugby players and their coaches. To investigate predictors of lower concussion knowledge and association between athletes' self-reported knowledge and behavior. Design: Cross-sectional, population-wide, survey study. Setting: All rugby clubs (n = 52) of the Veneto region (Italy). Participants: Players and coaches of all under 15, 17 and 19 teams. Overall, 1719 athlete surveys (92.2% male; response rate, 71.1%) and 235 coach surveys (93.6% male; response rate, 93.2%) were eligible for analysis. Intervention: Surveys circulated from September 20 to December 13, 2021. Main outcome measures: Knowledge scores were reported as a percentage of correct answers. Descriptive statistics were reported for all answers. The primary outcomes were concussion knowledge and self-reported behaviors. The secondary outcomes were the association between knowledge and participant individual factors and self-reported behaviors. Results: Median knowledge score for athletes was 55% (IQR: 44-67) and for coaches was 60% (IQR: 52.5-69). Only 33.3% of athletes and 40% of coaches were aware of an increased risk of a second concussion after sustaining one. Athletes who had never heard of the word concussion (effect: -9.31; SE: 1.35, 95% CI: -12.0 to -6.7; P < 0.0001) and coaches with longer coaching experience (effect: -4.35; SE: 2.0, 95% CI: -8.29 to -0.41; P < 0.03) reported lower knowledge scores. There was no statistical association between knowledge scores and athlete self-reported behavior. Conclusion: Athletes and coaches had a similar level of concussion knowledge. Knowledge score of athletes did not predict self-reported behaviors. Although enhanced concussion education should be undertaken, interventions to ensure appropriate concussion reporting behaviors are also required

Can exercise test intensity and modality affect the prevalence of arrhythmic events in young athletes?

Pre-participation screening is performed to identify underlying cardiac conditions that may also lead to sudden cardiac death. Our aim is to compare submaximal Harvard Step Test (HST) with incremental Maximal Exercise Test (MET) on treadmill to induce and detect arrhythmias in younger athletes. A total of 1000 athletes (mean age 14.6 +/- 4.7 years) were evaluated, 500 with MET and 500 with HST, all with continuous ECG monitoring until three minutes of recovery. Pre-test evaluation includes medical history, clinical evaluation and resting electrocardiogram. Ventricular and/or supraventricular arrhythmias were observed in 2.6% of athletes performing HST and in 8.4% during MET (p < 0.001). Incidence of arrhythmias remained higher for MET also considering separately exercise phase (0.8% vs. 5.2%; p < 0.001) and recovery phase (2.0% vs. 6.0%; p < 0.01). No gender differences were observed. Results suggest that MET induces more arrhythmias than submaximal HST, regardless of test phase. Higher test intensity and longer exercise duration might influence test outcomes, making MET more arrhythmogenic

Head Injury Assessment in Italian rugby union: a two-seasons prospective analysis

Background: In Italy, to the best of our knowledge, there is no literature relating to injury and concussion epidemiology in rugby union. Therefore, the primary aim of this study is to describe the incidence of sport-related concussion in Italian rugby union and the associated management of Head Injury Assessment (HIA). Methods: This is an observational prospective study, analysing the Italian elite rugby championship (Top 12 and Coppa Italia) for two seasons (2018/2019 and 2019/2020). Twelve male teams of the Italian elite rugby championship were included. The diagnosis of traumatic brain injury was provided by a team doctor with HIA, while no match day doctor or video analysis was available. A concussion expert of Italian Rugby Federation reviewed all the HIAs. The outcome of interest were: incidence, playing situation and mechanism responsible for traumatic brain injury. Results: In the study period, 47 HIAs were performed during matches (45.3/1000 player-match-hours) and 7 concussions were diagnosed by team doctors (6.75/1000 player-match-hours). After the concussion expert HIAs' review, the thirty-three percent of 16 diagnoses were made later, during follow-up, or based on clinical suspicion. Most symptoms complained about by players were neck pain and headache, in 14.6% and 13.4% of HIA, respectively. Concussions were predominately the result of tackling (46.5%) for the tackler (90.9%). Conclusions: The incidence of concussion in Italian Rugby appears to be low compared to that of rugby outside Italy, which is likely due to the learning curve of HIA and the absence of video analysis and match day doctors during competitions. The implementation of educational projects may be fundamental to promoting HIA process

Prevalence of musculocutaneous nerve variations: systematic review and meta-analysis

We aimed to establish the prevalence of the musculocutaneous nerve (MCN) variations and the probability of the variation being pure or mixed in the same plexus. We applied the principles of evidence-based anatomy to find, appraise, and synthesize data through a meta-analysis of anatomical studies. The variations were grouped based on the presence and location of the communicating branch with the median nerve and the origin of branches to anterior arm muscles. Forty-three cadaveric studies met the inclusion criteria, providing data from 4124 plexuses. The overall pooled prevalence of plexuses with MCN variations was 20%. Based on the classification applied in our study, the pooled prevalence of variations was 17% in region 1A, 20% in region 1B, 36% in region 2 and 49% in region 3. Importantly, 64.58% of variations in region 1A and 74.14% of variations in region 1B were mixed, that is, associated with a variation in another region. The odds of finding another variation in the presence of a variation in region 2 or 3 were equal 0.37 and 0.52, respectively, demonstrating a significantly lower probability of finding mixed variations involving these regions, when compared with region 1A. Variations of the MCN are most common in the part distal to the exit from within or beneath the coracobrachialis muscle. Proximal variations are more often associated with another variation located along the nerve. These findings can assist health care professionals in the treatment of brachial plexus lesions. Clin. Anat., 2018. © 2018 Wiley Periodicals, Inc

Early repolarization in adolescent athletes: A gender comparison of ECG and echocardiographic characteristics

Background The early repolarization pattern (ERp) is an electrocardiographic finding previously associated with arrhythmic risk in adults. The purpose of this study is to evaluate the prevalence and characteristics of ERp in a group of adolescent athletes according to gender. Furthermore, potential associations with clinical, electrocardiographic, and echocardiographic parameters are explored. Methods In this cross-sectional study young athletes (age &lt; 18 years) were consecutively enrolled during the annual pre-participation evaluation, undergoing also transthoracic echocardiography assessment from January 2015 to March 2020. Results The prevalence of ERp was 27% in the whole population. Athletes with ERp were more frequently men practicing endurance sports. Women with ERp showed lower heart rate at rest, greater posterior, and relative ventricular wall thickness than those without ERp. Men with ERp presented higher systolic blood pressure at peak exercise, greater septal wall thickness, and indexed left ventricular mass than those without ERp. Both genders with ERp showed increased QRS voltage and narrower QRS duration. The ERp phenotype in men was more frequently notched with higher amplitude and ascending ST segment. Women's ERp presented more frequently a slurred morphology, especially in the inferior leads, and horizontal ST slope. No differences emerged in the occurrence of arrhythmias at rest and during maximal exercise test between groups, even considering higher risk phenotypes. Conclusions ERp is an ECG finding compatible with normal cardiac adaptations to training in young athletes. ERp demonstrated gender differences regarding phenotypes previously associated with increased cardiovascular risk, not showing any differences in arrhythmias during maximal exercise test

Ankle Brachial Index in Different Types of Popliteal Artery Entrapment Syndrome: A Systematic Review of Case Reports

Similar to other peripheral artery diseases, vessel narrowing in popliteal artery entrapment syndrome (PAES) reduces the ankle brachial index (ABI). Since the PAES is related to several anatomical or functional variations, we sought to determine if the ABI was correlated with the type of syndrome. Through a systematic review of literature, we identified case reports and series in which the diagnosis of PAES was accompanied by ABI measurement. Twenty-seven studies included in the qualitative synthesis described 87 limbs. The most common types of the syndrome were those caused by an abnormal medial head of the gastrocnemius (type II, n = 35, 40.23%) and aberrant course of the popliteal artery (type I, n = 20, 22.99%). The variation of plantaris muscle (n = 7, 8.05%) is currently not included in the classification system. The median value of ABI was 0.87 (interquartile range (IQR) = 0.6-1.0). There were no differences among types of syndrome (F = 0.13, p = 0.72). In conclusion, despite clinical recommendations, the ABI remains underused in PAES diagnosis. No correlation was detected between the index score and type of syndrome. The cases of PAES involving structures other than the gastrocnemius or popliteus muscle suggest the need to revisit the current clinical classification system

Strength and functional capacity in women with polycystic ovary syndrome

NTRODUCTION: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, with a prevalence in Europe of about 6.5%. It is known that women with PCOS have different hormonal pattern, with high variability through phenotypes. High levels of androgens may cause an increase in lean body mass. It is not yet clear whether patients with PCOS have greater muscle strength than women not suffering from this syndrome. Our aim was to investigate whether patients with PCOS have different lean mass, strength and aerobic capacity, respect to patients without the syndrome. METHODS: This is an observational study where patients underwent the following evaluations: - Functional tests, such as cardio-pulmonary exercise and handgrip test; - Evaluation of body composition with DEXA; - Blood analysis (testosterone, androstenedione). Statistic evaluation was made with SPSS. RESULTS: We evaluated 40 women (27 women with PCOS vs 13 women without PCOS). These two populations examined were comparable for BMI, age (18-46 years), total body composition and upper limbs Fat Free Mass (evaluated by DEXA). No differences were found in hormonal patterns too. The most interesting results were the observation in PCOS group of a greater handgrip strength, when related to kg of lean mass in arms (p=0,001). Also aerobic capacity, expressed as VO2 max per Kg (p=0,01) and VO2 per Kg of lean mass (p=0,02), was higher in the PCOS population. Similarly, OUES and maximal exercise capacity (expressed as METs) suggested the presence of a better fitness in the PCOS group. The analysis based on VO2 determinants (multivariate analysis) demonstrate that only having PCOS is an independent predictor of a better functional capacity (expressed as VO2max, VO2 max per Kg, VO2max per lean mass Kg and as OUES). Further, we demonstrated that VO2max per kg of lean mass is predicted by testosterone and lean mass too. CONCLUSION: In conclusion, our data could suggest the presence of greater muscle strength, higher aerobic and functional capacity in women with PCOS, despite the presence of a similar lean mass quantity and hormonal levels