Detection of muscle gap by L-BIA in muscle injuries: clinical prognosis

Sport-related muscle injury classifications are based basically on imaging criteria such as ultrasound (US) and magnetic resonance imaging (MRI) without consensus because of a lack of clinical prognostics for return-to-play (RTP), which is conditioned upon the severity of the injury, and this in turn with the muscle gap (muscular fibers retraction). Recently, Futbol Club Barcelona's medical department proposed a new muscle injury classification in which muscle gap plays an important role, with the drawback that it is not always possible to identify by MRI. Localized bioimpedance measurement (L-BIA) has emerged as a non-invasive technique for supporting US and MRI to quantify the disrupted soft tissue structure in injured muscles.

OBJECTIVE

To correlate the severity of the injury according to the gap with the RTP, through the percent of change in resistance (R), reactance (Xc) and phase-angle (PA) by L-BIA measurements in 22 muscle injuries.

MAIN RESULTS

After grouping the data according to the muscle gap (by MRI exam), there were significant differences in R between grade 1 and grade 2f (myotendinous or myofascial muscle injury with feather-like appearance), as well as between grade 2f and grade 2g (myotendinous or myofascial muscle injury with feather and gap). The Xc and PA values decrease significantly between each grade (i.e. 1 versus 2f, 1 versus 2g and 2f versus 2g). In addition, the severity of the muscle gap adversely affected the RTP with significant differences observed between 1 and 2g as well as between 2f and 2g.

SIGNIFICANCE

These results show that L-BIA could aid MRI and US in identifying the severity of an injured muscle according to muscle gap and therefore to accurately predict the RTP.

Localized BIA identifies structural and pathophysiological changes in soft tissue after post-traumatic injuries in soccer players

Localized bioimpedance (BIA) was measured with a single frequency phase-sensitive analyzer at 50 kHz in three post-traumatic types of injuries on four professional soccer players: (1) myositis ossificans, (2) intramuscular seroma and (3) trochanteric (hip) bursitis. Normal reference value (no injury) was obtained from the contra lateral not injured limb at a mirror-like location of the injury. The relative variations resistance (R) and reactance (Xc) at the time of injury was confronted with the not injured values. Relative variations between acute measurements and post medication ones on intramuscular seroma and bursitis have been computed. In intramuscular seroma and trochanteric bursitis we have obtained a percent of change between injury data and after medical intervention. On myositis ossificans, localized BIA showed a 7-8 % decrease in Xc whereas the percent of change of R was negligible (1 %). These percent of changes are in concordance with histological evidence. In the case of a presence of seroma or the lower thigh and trochanteric bursitis, the soft tissue cavity accumulates fluid. Post-injury localized BIA, relative with respect to non-injured side, confirmed sizeable soft tissue destruction evidenced by 50 % decrease of Xc and 24-31 % decrease of R due to interstitial fluid accumulation. Once the seroma and the blood in the bursitis was removed the localized the immediate post-injury BIA parameters increased as follows: a) intramuscular seroma + 10 % on R and + 74 % of Xc; b) trochanteric bursitis + 20 % of R and +24 % of Xc. Localized BIA other than classifying soft tissue injuries, can be useful to understand the pathophysiology and structural impairments of other kind of injuries and to understand their behavior.

[The validity and reliability of the Spanish version of the Severe Cognitive Impairment Profile (SCIP) for the cognitive assessment of persons with advanced stages of Alzheimer's disease]

INTRODUCTION

Few validated tools exist in Spanish for conducting a precise assessment of the cognitive functioning of persons with advanced dementia. This population is a challenge due to the large number of persons who reach these states and owing to the complexity of the care that they require. This study presents a validated Spanish version of an instrument, the Severe Cognitive Impairment Profile (SCIP), which allows assessment of the cognitive functioning of persons with advanced Alzheimer's disease.

PATIENTS AND METHODS

We conducted a cross-sectional study with 133 subjects (29 males and 104 females; mean age: 81.61 ± 7.41 years) diagnosed with Alzheimer's disease in moderate to very severe stages, according to the Global Deterioration Scale (GDS 5-7). The following were performed: discrimination analyses of the items, a study of the internal consistency and interrater reliability and test-retest. Likewise, the factorial structure and the validity of the instrument were also tested.

RESULTS

Only 1% of the 160 items on the scale were found to be non-discriminatory. The internal consistency of the scale is adequate, as is the interrater and the test-retest reliability. As regards the validity of the construct, the correlation with the mini-mental state examination is 0.74 (p < 0.01) and significant differences are found between the SCIP and the three levels of the GDS that were analysed. The factorial structure of the scales shows the existence of a single factor that accounts for 66.12% of the variance.

CONCLUSIONS

The SCIP scale is a useful, reliable and valid instrument for the exhaustive evaluation in Spanish of the cognitive functions of persons with dementia in moderate to very severe states.

Effects of muscle injury severity on localized bioimpedance measurements

Muscle injuries in the lower limb are common among professional football players. Classification is made according to severity and is diagnosed with radiological assessment as: grade I (minor strain or minor injury), grade II (partial rupture, moderate injury) and grade III (complete rupture, severe injury). Tetrapolar localized bioimpedance analysis (BIA) at 50 kHz made with a phase-sensitive analyzer was used to assess damage to the integrity of muscle structures and the fluid accumulation 24 h after injury in 21 injuries in the quadriceps, hamstring and calf, and was diagnosed with magnetic resonance imaging (MRI). The aim of this study was to identify the pattern of change in BIA variables as indicators of fluid [resistance (R)] and cell structure integrity [reactance (Xc) and phase angle (PA)] according to the severity of the MRI-defined injury. The % difference compared to the non-injured contralateral muscle also measured 24-h after injury of R, Xc and PA were respectively: grade I (n = 11; -10.4, -17.5 and -9.0%), grade II (n = 8; -18.4, -32.9 and -16.6%) and grade III (n = 2; -14.1, -52.9 and -43.1%), showing a greater significant decrease in Xc (p < 0.001). The greatest relative changes were in grade III injuries. However, decreases in R, that indicate fluid distribution, were not proportional to the severity of the injury. Disruption of the muscle structure, demonstrated by the localized determination of Xc, increased with the severity of muscle injury. The most significant changes 24 h after injury was the sizeable decrease in Xc that indicates a pattern of disrupted soft tissue structure, proportional to the severity of the injury.

Localized bioimpedance to assess muscle injury

Injuries to lower limb muscles are common among football players. Localized bioimpedance analysis (BIA) utilizes electrical measurements to assess soft tissue hydration and cell membrane integrity non-invasively. This study reports the effects of the severity of muscle injury and recovery on BIA variables. We made serial tetra-polar, phase-sensitive 50 kHz localized BIA measurements of quadriceps, hamstring and calf muscles of three male football players before and after injury and during recovery until return-to-play, to determine changes in BIA variables (resistance (R), reactance (Xc) and phase angle (PA)) in different degrees of muscle injury. Compared to non-injury values, R, Xc and PA decreased with increasing muscle injury severity: grade III (23.1%, 45.1% and 27.6%), grade II (20.6%, 31.6% and 13.3%) and grade I (11.9%, 23.5% and 12.1%). These findings indicate that decreases in R reflect localized fluid accumulation, and reductions in Xc and PA highlight disruption of cellular membrane integrity and injury. Localized BIA measurements of muscle groups enable the practical detection of soft tissue injury and its severity.

Assessment and follow-up of muscle injuries in athletes by bioimpedance: preliminary results

Mono-frequency (50 kHz) whole-body and segmental bioimpedance is measured before sport training in 14 high performance athletes. The athletes are classified in two groups according to the team sport: football and basketball. Bioelectrical impedance vector analysis (BIVA) method is used to obtain the individual whole-body impedance and 6 segmental impedance vectors in the main muscular groups in the lower-limbs. The whole-body vector is analyzed in the tolerance ellipses of the reference population. Individual impedance vector components are standardized by the height H of the subject, (R/H and Xc/H) to obtain the impedance vector (Z/H) of each segment. The hypotheses of the study are: 1) Not all the sports have the same pattern of bioimpedance vector by muscle group. 2) In elite well trained athletes their muscle groups are symmetrical (right and left sides), thus each athlete is its own reference for future comparisons. 3) We expect a change in the two components of bioimpedance vector (R/H and Xc/H) in front of a muscle injury. In order to compare the differences between the complex Z/H vector (R/H, Xc/H) we use Hotelling's T2 test. Preliminary results show a significant difference (P < 0.05) in bioimpedance vectors between groups according to the team sport, and also between normal muscle condition and after muscle injury producing hyper-hydration.

Genes related to iron metabolism and susceptibility to Alzheimer's disease in Basque population

Alzheimer's disease (AD) is the most common dementing disorder and presents with a progressive and irreversible cognitive decline of gradual onset. To date, several reports have involved iron in AD physiopathology. In this study, we have analysed TFC2 variant and HFE mutations (H63D and C282Y) in 211 AD patients and 167 controls recruited from an area of the Basque Country. Furthermore, we have studied APOE genotype as it is a well-known risk factor for AD. APOE epsilon 4 allele was associated with an increased risk of AD and an earlier age at onset, whereas no association was found between TFC2 or HFE C282Y mutation and disease susceptibility. The frequency of H63D mutation was higher in control population (29.9%) than in AD patients (18%), suggesting a protective role of this allele on AD either due to the presence of the mutation itself or through the effect of other related genes in the ancestral haplotype in which it is included.