A novel estimate of biological aging by multiple fitness tests is associated with risk scores for age-related diseases.

Introduction: Recent research highlights the need for a correct instrument for monitoring the individual health status, especially in the elderly. Different definitions of biological aging have been proposed, with a consistent positive association of physical activity and physical fitness with decelerated aging trajectories. The six-minute walking test is considered the current gold standard for estimating the individual fitness status in the elderly. Methods: In this study, we investigated the possibility of overcoming the main limitations of assessing fitness status based on a single measure. As a result, we developed a novel measure of fitness status based on multiple fitness tests. In 176 Sardinian individuals aged 51-80 years we collected the results of eight fitness tests to measure participants' functional mobility, gait, aerobic condition, endurance, upper and lower limb strength, and static and dynamic balance. In addition, the participants' state of health was estimated through validated risk scores for cardiovascular diseases, diabetes, mortality, and a comorbidity index. Results: Six measures contributing to fitness age were extracted, with TUG showing the largest contribution (beta = 2.23 SDs), followed by handgrip strength (beta = -1.98 SDs) and 6MWT distance (beta = -1.11 SDs). Based on fitness age estimates, we developed a biological aging measure using an elastic net model regression as a linear combination of the results of the fitness tests described above. Our newly developed biomarker was significantly associated with risk scores for cardiovascular events (ACC-AHA: r = 0.61; p = 0.0006; MESA: r = 0.21; p = 0.002) and mortality (Levine mortality score: r = 0.90; p = 0.0002) and outperformed the previous definition of fitness status based on the six-minute walking test in predicting an individual health status. Discussion: Our results indicate that a composite measure of biological age based on multiple fitness tests may be helpful for screening and monitoring strategies in clinical practice. However, additional studies are needed to test standardisation and to calibrate and validate the present results.

Vestibulo masseteric reflex and acoustic masseteric Reflex. Normative data and effects of age and gender.

OBJECTIVE: To provide normative data for the Vestibulo-Masseteric Reflex (VMR) and Acoustic-Masseteric Reflex (AMR) in healthy subjects, stratified for age and gender. METHODS: A total of 82 healthy subjects (M:F 43:39, mean age 39.3 ±â€¯18.4 years, range 13-79 years) underwent recording of click-evoked VMR and AMR (0.1 ms duration, 5 Hz frequency) from active masseter muscles. Masseter responses to uni- and bilateral stimulation were recorded in a zygomatic and a mandibular configuration, according to the position of the reference electrode. Stimulation intensity curves were recorded for each reflex in ten subjects (mean age 20.7 ±â€¯8.1 years). Gender effect was investigated in 62 subjects and age effect was analyzed in six 10-subject groups aged from <25 to >65 years. Onset and peak latencies, interpeak intervals, raw and corrected amplitudes, latency and amplitude asymmetries were analyzed. RESULTS: VMR had a higher elicitation rate than AMR. For both reflexes, rates of elicitation, and corrected amplitudes were higher in the zygomatic configuration, and bilateral stimulation elicited larger responses. Best acoustic ranges of elicitation were 98-113 dB for AMR and 128-138 dB for VMR. Reflex latencies were shorter in females than males. Frequency and amplitude of VMR and AMR decreased substantially over 55 year olds. CONCLUSIONS: VMR and AMR can be easily performed in any clinical neurophysiology laboratory. SIGNIFICANCE: These reflexes can find application in the investigation of brainstem function in central neurological disorders.

No evidence of neural adaptations following chronic unilateral isometric training of the intrinsic muscles of the hand: a randomized controlled study.

PURPOSE: To test whether long-term cortical adaptations occur bilaterally following chronic unilateral training with a simple motor task. METHODS: Participants (n = 34) were randomly allocated to a training or control groups. Only the former completed a 4-week maximal-intensity isometric training of the right first dorsal interosseus muscle through key pinching. Maximal strength was assessed bilaterally in four different movements progressively less similar to the training task: key, tip and tripod pinches, and handgrip. Transcranial magnetic stimulation was used to probe, in the left and right primary hand motor cortices, a number of standard tests of cortical excitability, including thresholds, intra-cortical inhibition and facilitation, transcallosal inhibition, and sensory-motor integration. RESULTS: Training increased strength in the trained hand, but only for the tasks specifically involving the trained muscle (key +8.5 %; p < 0.0005; tip +7.2 %; p = 0.02). However, the effect size was small and below the cutoff for meaningful change. Handgrip and tripod pinch were instead unaffected. There was a similar improvement in strength in the untrained hand, i.e., a cross-education effect (key +6.4 %; p = 0.02; tip +4.7 %; p = 0.007). Despite these changes in strength, no significant variation was observed in any of the neurophysiological parameters describing cortico-spinal and intra-cortical excitability, inter-hemispheric inhibition, and cortical sensory-motor integration. CONCLUSIONS: A 4-week maximal-intensity unilateral training induced bilaterally spatial- and task-specific strength gains, which were not associated to direct or crossed cortical adaptations. The observed long-term stability of neurophysiological parameters might result from homeostatic plasticity phenomena, aimed at restoring the physiological inter-hemispheric balance of neural activity levels perturbed by the exercise. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier NCT02010398.

Trigeminal nerve stimulation modulates brainstem more than cortical excitability in healthy humans.

Multiple sites in the central nervous system (CNS) have been hypothesized to explain the beneficial effects of transcutaneous trigeminal nerve stimulation (TNS) on several disorders. This work investigated the acute effects of TNS on the excitability of brainstem and intracortical circuits, as well as on sensorimotor integration processes at cortical level in physiological conditions. Brainstem excitability was evaluated in seventeen healthy subjects measuring the R1 and R2 areas of the blink reflex (BR) and its recovery cycle, with cortical excitability and sensorimotor integration assessed by probing short-interval (SICI) and long-interval (LICI) intracortical inhibition, with short-interval (SICF), intracortical facilitation (ICF), short-latency (SAI) and long-latency (LAI) inhibition measuring motor potentials evoked in the first dorsal interosseous muscle by TMS of the contralateral motor cortex. Neurophysiological parameters were assessed, in seventeen healthy subjects, before and after cyclic 20-min TNS delivered bilaterally to the infraorbital nerve. After TNS, the area of the R2 was significantly reduced (p = 0.018). By contrast, R1 area and R2 recovery cycle were unaffected. Similarly, SICI, ICF, LICI, SICF, SAI and LAI appeared unaltered after TNS. These data suggest that, in normal subjects, TNS mainly acts on brainstem polysynaptic circuits mediating the R2 component of the BR and plays a minor role in modifying the activity of higher-level structures involved in the R2 recovery cycle and in modulation of cortical excitability. A further investigation of a chronic TNS-induced effect may disclose a higher potential for TNS in producing measurable after effects on its CNS targets.

Paired neurophysiological and clinical study of the brainstem at different stages of Parkinson's Disease.

OBJECTIVE: To study brainstem function in Parkinson's Disease (PD) at different stages, through a battery of vestibular-evoked myogenic potentials (VEMPs) and compare the results with scores on clinical scales assessing the presence of symptoms linked to brainstem involvement. METHODS: Cervical, masseter and ocular VEMPs were recorded in patients with early PD (n=14, disease duration 1.42±0.7years), advanced PD (n=19, disease duration 7.26±2.9years) and in 27 age-matched controls. In PD, the following clinical scales were administered: Mini-BESTest, REM sleep Behavior Disorder Screening Questionnaire (RBD-SQ), PD Sleep Scale, Epworth Sleepiness Scale and Geriatric Depression Scale. RESULTS: Rate of VEMPs alterations was higher (p<0.001) in PD than controls, but similar within PD groups. However, early and advanced PD showed a different pattern of abnormalities (p=0.02), being latency delay prevalent in the former and absence in the latter. VEMP impairment correlated directly with RBD-SQ scores in both PD cohorts and inversely with Mini-BESTest scores in advanced PD. CONCLUSIONS: VEMPs displayed progressive severity of alterations at different stages of PD, with remarkable correlations with presence of postural instability and RBD. SIGNIFICANCE: The combined use of VEMPs may provide interesting insights into the pathophysiological mechanisms of PD at the earliest and prodromal stage of the disease.

Ultrasound and laser as stand-alone therapies for myofascial trigger points: a randomized, double-blind, placebo-controlled study.

BACKGROUND AND PURPOSE: Ultrasound (US) and low-level laser therapy (LLLT) are commonly employed for myofascial trigger points (MTP) despite lack of evidence for usage as stand-alone treatments. The aim of the study was to determine, on MTP of the upper trapezius muscle (uTM), the effects of US and LLLT per se, as delivered in accordance with the procedures reported by surveys about their usage among physiotherapists. METHODS: Design was set as a double-blind, randomized, placebo-controlled study. Sixty participants with at least one active MTP in uTM (28 women and 32 men; mean age 24.5 ± 1.44 years) were recruited and randomly assigned to one out of five groups: active US (n = 12), placebo US (n = 12), active LLLT (n = 11), placebo LLLT (n = 11) and no therapy (control, n = 14). The participants and outcome assessor were blinded to the group assignment and therapy delivered. Three outcome measures were assessed at baseline, after a 2-week treatment and 12 weeks after the end of the intervention (follow-up): pressure pain threshold, subjective pain on a numerical rating scale and muscle extensibility performing a cervical lateral flexion. All subjects assigned to the intervention groups were treated five times weekly for overall 10 treatments given. Two-way ANOVA was used to compare differences before and after intervention and among groups at each time-point. RESULTS: After the 2-week intervention, all groups showed pressure pain threshold, numerical rating scale and cervical lateral flexion significant improvements (p < 0.05), which were confirmed at the follow-up. When performing multiple comparisons, controls scored significantly less than both the active therapies and placebos, whereas no differences were detected between active therapies and placebos. CONCLUSIONS: Ultrasound and LLLT provided significant improvements in pain and muscle extensibility, which were superior to no therapy but not to placebos, thus raising concerns about the suitability, both economically and ethically, of administering such common physical modalities as stand-alone treatments in active MTP of the uTM.