Neurodynamics: is tension contentious?

Neurofascialvascular training for carpal tunnel syndrome as an evolution of neurodynamic treatment: A case report

INTRODUCTION

In this case report a new approach called neurofascialvascular training (NFVT) is described. NFVT consists of two mechanisms which improve mechanosensitivity in carpal tunnel syndrome (CTS). The first involves increased blood flow in the nerve microcirculation, while the second stimulates the reciprocal sliding between the thin sheets of connective tissue inside the nerve. The goal of these two actions is to squeeze, mobilize and reduce intraneural edema. The novelty of this approach is the simultaneous involvement of multiple physiological systems to reduce nerve mechanosensitivity. This case report describes the rehabilitation progress achieved by NFVT in a patient with CTS.

MAIN SYMPTOMS AND/OR IMPORTANT CLINICAL FINDINGS

A 64-year-old woman complaining of nocturnal pain and tingling with severe impairment of sleep quality for two years was diagnosed at CTS.

THERAPEUTIC INTERVENTIONS

The patient underwent nine 30-min exercise sessions of NFVT.

OUTCOMES

At each session and at the last follow-up 3 months after the end of treatment the following tests were performed: the upper limb neurodynamic test1 (ULNT1), the Hand Grip Meter and the Phdurkan test. Furthermore ultrasound, numerical rating scale and the Boston Carpal Tunnel Questionnaire (BCTQ) were also adopted.

CONCLUSION

NFVT can improve symptoms and motor dysfunction in a patient with CTS.

TAKE-AWAY LESSON

In the presence of mild carpal tunnel syndrome, active neurofascialvascular training that increases peripheral blood flow and targets fascial tissue within the peripheral nervous system can resolve symptoms and produce significant improvement within a few months of starting treatment.

Using ultrasound shear wave elastography to characterize peripheral nerve mechanics: a systematic review on the normative reference values in healthy individuals

Ultrasound shear wave elastography (SWE) is an emerging non-invasive imaging technique for peripheral nerve evaluation. Shear wave velocity (SWV), a surrogate measure of stiffness, holds promise as a biomarker for various peripheral nerve disorders. However, to maximize its clinical and biomechanical value, it is important to fully understand the factors that influence nerve SWV measurements. This systematic review aimed to identify the normal range of SWV for healthy sciatic and tibial nerves and to reveal the factors potentially affecting nerve SWV. An electronic search yielded 17 studies eligible for inclusion, involving 548 healthy individuals (age range, 17 to 72 years). Despite very good reliability metrics, the reported SWV values differed considerably across studies for the sciatic (1.9-9.9 m/s) and tibial (2.3-9.1 m/s) nerves. Factors such as measurement proximity to joint regions, limb postures inducing nerve axial stretching, and transducer alignment with nerve fiber orientation were associated with increased SWV. These findings suggest regional-specific nerve mechanical properties, non-linear elastic behaviour, and marked mechanical anisotropy. The impact of age and sex remains unclear and warrants further investigation. These results emphasize the importance of considering these factors when assessing and interpreting nerve SWE. While increased SWV has been linked to pathological changes affecting nerve tissue mechanics, the significant variability observed in healthy nerves highlights the need for standardized SWE assessment protocols. Developing guidelines for enhanced clinical utility and achieving a comprehensive understanding of the factors that influence nerve SWE assessments are critical in advancing the field.

Effectiveness of neural mobilisation for the treatment of nerve-related cervicobrachial pain: a systematic review with subgroup meta-analysis

ABSTRACT

Neural mobilisations (NM) have been advocated for the treatment of nerve-related cervicobrachial pain; however, it is unclear what types of patients with nerve-related cervicobrachial pain (if any) may benefit. Medline, Web of Science, Scopus, PeDro, Cinahl, and Cochrane databases were searched from inception until December 2022. Randomised controlled trials were included if they assessed the effectiveness of NM in nerve-related cervicobrachial pain, and outcome measures were pain intensity and/or disability. Studies were classified according to their inclusion/exclusion criteria as radiculopathy , Wainner cluster , Hall , and Elvey cluster or other . Meta-analyses with subgroup analyses were performed. Risk of bias was assessed using Cochrane Rob2 tool. Twenty-seven studies were included. For pain and disability reduction, NM was found to be more effective than no treatment (pooled pain mean difference [MD] = -2.81, 95% confidence interval [CI] = -3.81 to -1.81; pooled disability standardized mean difference = -1.55, 95% CI = -2.72 to -0.37), increased the effectiveness of standard physiotherapy as an adjuvant when compared with standard physiotherapy alone (pooled pain MD = -1.44, 95% CI = -1.98 to -0.89; pooled disability MD = -11.07, 95% CI = -16.38 to -5.75) but was no more effective than cervical traction (pooled pain MD = -0.33, 95% CI = -1.35 to 0.68; pooled disability MD = -10.09, 95% CI = -21.89 to 1.81). For disability reduction, NM was found to be more effective than exercise (pooled MD = -18.27, 95% CI = -20.29 to -17.44). In most comparisons, there were significant differences in the effectiveness of NM between the subgroups. Neural mobilisations was consistently more effective than all alternative interventions (no treatment, traction, exercise, and standard physiotherapy alone) in 13 studies classified as Wainner cluster . PROSPERO registration: CRD42022376087.

Impact of the Order of Movement on the Median Nerve Root Function: A Neurophysiological Study with Implications for Neurodynamic Exercise Sequencing

Background: Neurodynamic exercise is a common clinical practice used to restore neural dynamic balance. The order in which movements are performed during these exercises is believed to play a crucial role in their effectiveness. This study aimed to investigate the impact of different sequences of neurodynamic exercise on nerve root function, with a specific focus on the median nerve. Methods: Participants were assigned randomly to three experimental groups, each undergoing a different test sequence: standard, proximal-to-distal, and distal-to-proximal. Dermatomal somatosensory evoked potentials (DSSEPs) were recorded at key levels (C6, C7, C8, and T1). Results: The findings revealed a significant influence of the movement sequence on DSSEP amplitudes. The execution of neurodynamic exercise in the proximal-to-distal sequence was associated with a notable reduction in amplitudes (p < 0.05). Conversely, the distal-to-proximal sequence resulted in increased amplitudes compared to the standard sequence (p < 0.05). Conclusions: This study underscores the importance of carefully considering the order of movements during neurodynamic exercising, particularly when evaluating nerve roots that lack the protective perineurium. The choice of sequence appears to have a substantial impact on nerve function, with implications for optimizing clinical neurodynamic exercise techniques.

Specific Neurodynamic Exercises on Pain and Disability in Old Women with Chronic Mechanical Neck Pain: A Randomized Controlled Trial

Neurodynamic exercise is a specific type of exercise used as a neural treatment that focuses on restoring altered homeostasis in the neuroimmune system by mobilising the nervous system and other structures. A prospective, randomized clinical trial was performed to evaluate the effect of neurodynamic exercises on disability and neck pain in elderly women over four weeks. Participants were randomized into two groups: a neurodynamic (NM) group (n = 28) and a non-specific exercise (NSE) group (n = 28). Inclusion criteria were women over 65 years of age who subjectively admitted to having mechanical neck pain for more than six months. Results showed that specific neurodynamic exercises can improve pain and disability in older women with chronic mechanical neck pain. Improvements were observed in all variables (p < 0.05). Significant between-group differences in favour of the NM group were only found for neck pressure pain thresholds and both tibialis anterior muscles. Larger effect sizes were obtained in favour of the NM group, especially for pain, disability, neck extension and inclination and pressure pain thresholds. Neurodynamic exercises have been shown to be more clinically relevant in disability and neck pain in older women.

Neuromodulation Through Magnetic Fields Irradiation with AT-04 Improves Hyperalgesia in a Rat Model of Neuropathic Pain via Descending Pain Modulatory Systems and Opioid Analgesia

Neuromodulation through magnetic fields irradiation with ait® (AT-04), a device that irradiates a mixed alternating magnetic fields (2 kHz and 83.3 MHz), has been shown to have high efficacy for fibromyalgia and low back pain in our previous clinical trials. The aim of this study was to elucidate the underlying analgesic mechanism of the AT-04 using the partial sciatic nerve ligation (PSL) model as an animal model of neuropathic pain. AT-04 was applied to PSL model rats with hyperalgesia and its pain-improving effect was verified by examining mechanical allodynia using the von Frey method. The results demonstrated a significant improvement in hyperalgesia in PSL model rats. We also examined the involvement of descending pain modulatory systems in the analgesic effects of AT-04 using antagonism by serotonin and noradrenergic receptor antagonists. These antagonists significantly reduced the analgesic effect of AT-04 on pain in PSL model rats by approximately 50%. We also measured the amount of serotonin and noradrenaline in the spinal fluid of PSL model rats using microdialysis during AT-04 treatment. Both monoamines were significantly increased by magnetic fields irradiation with AT-04. Furthermore, we evaluated the involvement of opioid analgesia in the analgesic effects of AT-04 using naloxone, the main antagonist of the opioid receptor, and found that it significantly antagonized the effects by approximately 60%. Therefore, the analgesic effects of AT-04 in PSL model rats involve both the endogenous pain modulation systems, including the descending pain modulatory system and the opioid analgesic system.

Safety of Epidural Hyaluronic Acid Injections in Managing the Symptoms of Lumbar Foraminal Stenosis: A Prospective Preliminary Study

Lumbar foraminal stenosis (LFS) of degenerative origin is a common reason for distorted neurodynamics of nerve roots, causing radicular pain that is difficult to resolve with conservative treatments. A hyaluronic acid (HA), providing a sliding layer in the mechanical interface of a nerve root in a narrowed lateral recess, could potentially improve its neurodynamics and the trophic, leading to radicular pain reduction and improvement of function. This study aimed to assess the usefulness of ultrasound-guided HA epidural injections combined with neuromobilization in the conservative treatment of LFS. A group of 10 consecutively admitted patients with MRI-confirmed LFS and reduced straight leg raise (SLR) test results were qualified for a single HA epidural injection along with self-performed neuromobilization. Three measurement tools were used for primary outcomes: the numeric rating scale (NRS) for pain intensity, the Oswestry disability index (ODI) and the Roland-Morris questionnaire (RMQ) for disability level, and the angle of pain-free elevation in the SLR test as a functional assessment. The treatment was accomplished in all patients (100%). Overall, 60% of the patients completed all follow-up visits. There were no statistically significant differences regarding the results of the NRS, ODI, or RMQ; however, a statistically significant increase in the results of the SLR test was noted (p = 0.015). Three patients reported a flare-up of the symptoms shortly after injection but without neurological deficits. In conclusion, an epidural HA injection combined with a self-administered exercise program is a promising method and might be a beneficial way to enhance the neurodynamics of nerve roots in LFS and offer an option for steroid treatment. However, this method of epidural HA administration in LFS should be verified in further studies to confirm its efficiency and safety.

Effects of Different Intervertebral Space Heights on Nerve Root Tension during Posterior Lumbar Interbody Fusion

OBJECTIVE

There is no effective standard method to evaluate whether the nerve root tension is restored during lumbar decompression surgery, which is an important indicator for the recovery of nerve function. This study aimed to investigate the feasibility of intraoperative nerve root tension measurement and to confirm the correlation between nerve root tension and intervertebral space height.

METHODS

A total of 54 consecutive patients (mean age, 54.3 years; range, 25-68 years) received posterior lumbar interbody fusion (PLIF) for lumbar disc herniation (LDH) with lumbar spinal stenosis and instability. The 110%, 120%, 130%, 140% height values of each lesion were calculated based on preoperative measurements of the intervertebral space height. The heights were intraoperatively expanded after the intervertebral disc was removed using the interbody fusion cage model. The tension value of nerve root was measured by pulling the nerve root for 5 mm with a self-made measuring device. The nerve root tension value was measured before decompression, after discectomy at 100%, 110%, 120%, 130%, and 140% of the height of each intervertebral space, and after placement of the cage during intraoperative nerve root tension monitoring.

RESULTS

The nerve root tension values at 100%, 110%, 120%, and 130% heights were significantly lower than those before decompression, and there was no statistical significance among the four groups. The nerve root tension value was significantly higher at 140% height and was statistically significant compared with that of 130% height. The nerve root tension value after cage placement was significantly lower than that before decompression (1.32 ± 0.22 N vs. 0.61 ± 0.17 N, p < 0.01), and the postoperative VAS score was also significantly improved (7.0 ± 2.24 vs. 0.8 ± 0.84, p < 0.01). The nerve root tension was positively correlated with the VAS score (F = 85.19, p < 0.01; F = 78.65, p < 0.01).

CONCLUSION

This study demonstrates that nerve root tonometry can perform instant noninvasive intraoperative nerve root tension measurement. There is a correlation between nerve root tension value and VAS score. We found that when the height of the intervertebral space was increased to 140% of the original height, the nerve root tension increased the risk of injury significantly.

The Effect of Neurodynamic Techniques on the Dispersion of Intraneural Edema: A Systematic Review with Meta-Analysis

BACKGROUND

There is evidence for the positive effects of neurodynamic techniques in some peripheral entrapment neuropathies, but the rationale for these effects has not been validated. We aimed to estimate the direct effect of neurodynamic techniques on the dispersion of artificially induced intraneural edema measured by dye spread in cadavers.

METHODS

We systematically searched the MEDLINE, WOS, Scopus, and the Cochrane databases from inception to February 2020 for experimental studies addressing the efficacy of neurodynamic techniques on the dispersion of artificially induced intraneural edema. The DerSimonian and Laird method was used to compute pooled estimates of the mean differences (MDs) and its respective 95% confidence intervals (CIs). Subgroup analyses were conducted according to the type of neurodynamic technique. In addition, a 95% prediction interval was calculated to reflect the variation in true treatment effects in different settings, including the effect to be expected in future patients.

RESULTS

Pooled results showed a significant increase in fluid dispersion (MD = 2.57 mm; 95%CI: 1.13 to 4.01). Subgroup analysis showed increased dye spread in the tensioning techniques group (MD = 2.22 mm; 95%CI: 0.86 to 3.57).

CONCLUSION

Neurodynamic techniques improved the intraneural edema dispersion and should be considered for the management of peripheral compression neuropathies. Furthermore, tensioning techniques appear to be effective in helping to disperse intraneural edema.

Neurodynamic Treatment Promotes Mechanical Pain Modulation in Sensory Neurons and Nerve Regeneration in Rats

Background: Somatic nerve injuries are a rising problem leading to disability associated with neuropathic pain commonly reported as mechanical allodynia (MA) and hyperalgesia. These symptoms are strongly dependent on specific processes in the dorsal root ganglia (DRG). Neurodynamic treatment (NDT), consisting of selective uniaxial nerve repeated tension protocols, effectively reduces pain and disability in neuropathic pain patients even though the biological mechanisms remain poorly characterized. We aimed to define, both in vivo and ex vivo, how NDT could promote nerve regeneration and modulate some processes in the DRG linked to MA and hyperalgesia. Methods: We examined in Wistar rats, after unilateral median and ulnar nerve crush, the therapeutic effects of NDT and the possible protective effects of NDT administered for 10 days before the injury. We adopted an ex vivo model of DRG organotypic explant subjected to NDT to explore the selective effects on DRG cells. Results: Behavioural tests, morphological and morphometrical analyses, and gene and protein expression analyses were performed, and these tests revealed that NDT promotes nerve regeneration processes, speeds up sensory motor recovery, and modulates mechanical pain by affecting, in the DRG, the expression of TACAN, a mechanosensitive receptor shared between humans and rats responsible for MA and hyperalgesia. The ex vivo experiments have shown that NDT increases neurite regrowth and confirmed the modulation of TACAN. Conclusions: The results obtained in this study on the biological and molecular mechanisms induced by NDT will allow the exploration, in future clinical trials, of its efficacy in different conditions of neuropathic pain.

Neurodynamic Functions and Their Correlations with Postural Parameters in Adolescents with Idiopathic Scoliosis

Knowledge about neurodynamic functions of the nervous system (NS) in patients with idiopathic scoliosis (IS) is limited. This study aimed to assess the mechanosensitivity of the NS structures (MNS) in adolescents with IS. The study included 69 adolescents with IS and 57 healthy peers aged 10–15 years. The Upper Limb Neurodynamic Test 1 (ULNT1), straight leg raise (SLR) test, and slump test (SLUMP) were used to assess MNS. The spinal curvatures in the sagittal plane and selected ranges of motion were measured. The data were analysed using the Mann–Whitney U test and Spearman’s rank correlation. Increased MNS assessed by ULNT1 and SLUMP tests was observed in participants with IS. Values of the neurodynamic tests correlated significantly with the sagittal profile of the spine and the mobility of the spine and lower limbs in both groups. In conclusion, increased MNS occurs in adolescents with IS. Therefore, the examination of adolescents with IS should include an assessment of MNS with the neurodynamic tests. Future studies should investigate this issue to better understand the mechanisms that coexist with IS.