Transverse Ultrasound Assessment of the Displacement of the Median Nerve in the Carpal Tunnel during Wrist and Finger Motion in Healthy Volunteers

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.

Median nerve versus flexor tendons: visualization of median nerve level changes in the proximal carpal tunnel during wrist movement with dynamic high-resolution ultrasound

Aim

The purpose of this prospective ultrasound study was to document dorso-palmar (vertical) displacement of the median nerve in relation to the superficial flexor tendons at the level of the carpal tunnel. Furthermore, the gliding patterns of the median nerve were characterized. The presence of vertical gliding was intended to serve as an additional bio-kinematic parameter of median nerve movement, and will be referred to as a 'level change'.

Material and methods

In this study, a total of 32 healthy young individuals underwent dynamic high-resolution ultrasound examinations of both wrists. The neutral position, and maximum flexion and extension of the wrist had to be reached in active and passive movement. The gliding patterns were determined in relation to the superficial flexor tendons. When no vertical nerve gliding was observed, it was characterized as 'no level change'.

Results

The presence of a level change prevailed in the healthy young cohort and was observed in 84% (27/32) of individuals during wrist flexion. The following gliding pattern was distinctively the most common: gliding of the entire nerve in between the flexor tendons in active but not in passive movement of the right and left wrists (13/27; 48%). The extent of vertical displacement was found to be associated with the gliding pattern (Kruskal-Wallis test).

Conclusions

Movement in the carpal tunnel allows the median nerve to adapt to biomechanical stress. Dynamic ultrasound can demonstrate median nerve level changes in response to wrist movements. Furthermore, a typical gliding pattern was characterized. The presence of level change and gliding patterns were proposed as additional movement parameters during wrist flexion in healthy individuals.

Effects of wrist extension on median nerve and flexor tendon excursions in patients with carpal tunnel syndrome: a case control study

Background

Reduced gliding ability of the median nerve in the carpal tunnel has been observed in patients with carpal tunnel syndrome (CTS). The purpose of this study was to evaluate the gliding abilities of the median nerve and flexor tendon in patients with CTS and healthy participants in the neutral and 30° extended positions of the wrist and to compare the gliding between the finger flexion and extension phases.

Methods

Patients with CTS and healthy participants were consecutively recruited in a community hospital. All the subjects received the Boston CTS questionnaire, physical examinations, nerve conduction study (NCS), and ultrasonography of the upper extremities. Duplex Doppler ultrasonography was performed to evaluate the gliding abilities of the median nerve and flexor tendon when the subjects continuously moved their index finger in the neutral and 30° extension positions of the wrist.

Results

Forty-nine patients with CTS and 48 healthy volunteers were consecutively recruited. Significant differences in the Boston CTS questionnaire, physical examination and NCS results and the cross-sectional area of the median nerve were found between the patients and the healthy controls. The degree of median nerve gliding and the ratio of median nerve excursion to flexor tendon excursion in the CTS group were significantly lower than those in the healthy control group in both the neutral and 30° wrist extension positions. Significantly increased excursion of both the median nerve and flexor tendon from the neutral to the extended positions were found in the CTS group. The ratio of median nerve excursion to flexor tendon excursion was significantly higher in the finger flexion phase than in the extended phase in both groups, and this ratio had mild to moderate correlations with answers on the Boston CTS Questionnaire and with the NCS results.

Conclusions

Reduced excursion of the median nerve was found in the patients with CTS. The ratio of median nerve excursion to flexor tendon excursion was significantly lower in the patients with CTS than in the healthy volunteers. The median nerve excursion was increased while the wrist joint was extended to 30° in the patients with CTS. Wrist extension may be applied as part of the gliding exercise regimen for patients with CTS to improve median nerve mobilization.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04349-8.

Median nerve travel and deformation in the transverse carpal tunnel increases with chuck grip force and deviated wrist position

Background

We assessed median nerve travel and deformation concurrently to better understand the influence of occupational risk factors on carpal tunnel dynamics, including forceful chuck gripping and deviated wrist positions.

Methods

Fourteen healthy right-hand dominant participants performed a chuck grip in 6 experimental conditions: two relative force levels (10% and 40% of maximum voluntary effort); three wrist positions (15° radial deviation, 0° neutral, 30° ulnar deviation). Chuck grip forces were measured with a load cell while the transverse cross-section of the carpal tunnel was imaged via ultrasound at the distal wrist crease. Images of the median nerve were analyzed in ImageJ to assess cross-sectional area, circularity, width, and height as well as travel in the anterior-posterior and medial-lateral axes.

Results

We found a main effect of deviated wrist position on both anterior-posterior and medial-lateral travel, with the greatest nerve travel occurring in 30° ulnar deviation. There was also a significant interaction between chuck grip force and deviated wrist position on cross-sectional area. Specifically, the area decreased with 40% vs. 10% chuck grip force when the wrist was in 30° ulnar deviation; however, there were no changes in 0° neutral and 15° radial deviation.

Discussion

Overall, we demonstrated that forceful chuck gripping in deviated wrist positions influenced carpal tunnel dynamics, resulting in both migratory and morphological changes to the median nerve. These changes may, in turn, increase local strain and stress with adjacent structures in the carpal tunnel. Future studies mapping contact stress between structures may further elucidate injury development of work-related carpal tunnel syndrome.

A systematic review of the methodology of sonographic assessment of upper limb activities-associated carpal tunnel syndrome

BACKGROUND

Various upper limb activities were speculated to be associated with the development of carpal tunnel syndrome (CTS). Nonetheless, there are currently no standardization on the uses of parameters in CTS assessments, nor are there any conclusive findings regarding the usefulness of various sonographic measurements in studies of different upper limb activities. In this review, we intend to evaluate the methodology of assessing CTS induced by upper limb activities with ultrasonographic technique and provide corresponding suggestions.

METHODS

Clinical studies on the association between upper limb activities and prevalence of CTS using ultrasonography were recruited in a database research on the basis of a procedural selection criteria and reviewed. The following qualitative items were extracted: characteristics of studies, scanning methods, selection of sonographic parameters, and related article findings.

RESULTS

Eleven studies were qualified for this review. Three studies were computer keyboard typing related, five studies were electronic device related, and three studies were wheelchair-related. All sampled articles included cross-sectional area (CSA) at the pisiform level. The swelling ratio (SR) and flattening ratio (FR) at the hamate level are also used in most studies in addition to the CSA at the pisiform level. The effectiveness of such parameters is subjected to various confounding factors such as age, weight, body mass index, and wrist anthropometrics, suggesting CSA and SR with sufficient levels had significant values as sonographic parameters. Values of parameters were found affecting symptomatic signs and hand dominance.

CONCLUSION

Ultrasound scan is a suitable tool to assess the relationship between upper limb activity and CTS. CSA at the pisiform level and SR and the FR at the hamate levels are generally suitable in upper limb-associated CTS investigations. Specific study designs are required to eliminate different confounding factors accordingly.

Median Nerve Transverse Mobility and Outcome after Carpal Tunnel Release

Nerve movement is decreased in patients with carpal tunnel syndrome and can be assessed with ultrasound. In addition to morphologic features, this study describes a novel approach in which nerve movement and the association with short-term patient-reported outcome are assessed. Ultrasound images at the carpal tunnel inlet were acquired during finger and wrist flexion. Linear regression models were used with the Boston Carpal Tunnel Questionnaire as main outcome. Eighty-five patients were included; 93% completed the 3-mo follow-up. Pre-surgical mean nerve area was 14.5 ± 4.2 mm2 and decreased to 13.3 ± 3.8 mm2 (p < 0.001). Displacement in dorsal direction with wrist flexion increased from 1.9 ± 1.3 to 2.4 ± 1.3 mm (p < 0.01). A pre-surgical larger nerve area was associated with more functional improvement (β = -0.024, p = 0.02), but baseline mobility was not. Change in excursion with finger flexion was associated with symptomatic improvement, but with a small effect (β = -0.05, p = 0.01). This indicates that there is limited prognostic potential for dynamic transverse ultrasound in carpal tunnel syndrome.

Median nerve movement in the carpal tunnel before and after carpal tunnel release using transverse ultrasound

PURPOSE

We aimed to compare the movement of the median nerve within the carpal tunnel during wrist and finger motions between before and after carpal tunnel release (CTR) using transverse ultrasound in carpal tunnel syndrome (CTS) patients and to evaluate the biomechanical efficacy of CTR for CTS.

METHODS

Twenty-four patients with CTS were examined by transverse ultrasound. The location of the median nerve within the carpal tunnel was examined quantitatively as a coordinate at varied wrist positions with finger extension and flexion, respectively, before and after CTR.

RESULTS

We found that the median nerve moved statistically significantly more palmarly after CTR than before at all wrist positions during finger motion. The average median nerve displacement toward the palmar side at the palmar flexion position in finger flexion was the greatest among all positions. Additionally, the displacement amounts of the median nerve during finger motion at all wrist positions were statistically significantly smaller after CTR than before.

CONCLUSIONS

The current study demonstrated the movement patterns of the median nerve in the carpal tunnel during wrist and finger motions compared before and after CTR using transverse ultrasound in CTS patients. The findings suggested that as the median nerve shifted greatly palmarly away from the tendons after CTR, the nerve avoids compression or shearing stress from the tendons. This ultrasound information could offer further understanding of the pathomechanics of CTS and provide a more accurate diagnosis of CTS and better treatment by CTR.

Neurodynamic Techniques Versus "Sham" Therapy in the Treatment of Carpal Tunnel Syndrome: A Randomized Placebo-Controlled Trial

OBJECTIVE

To evaluate the efficacy of neurodynamic techniques used as the sole therapeutic component compared with sham therapy in the treatment of mild and moderate carpal tunnel syndromes (CTS).

DESIGN

Single-blinded, randomized placebo-controlled trial.

SETTING

Several medical clinics.

PARTICIPANTS

Volunteer sample of patients (N=250) diagnosed with CTS (n=150).

INTERVENTIONS

Neurodynamic techniques were used in the neurodynamic techniques group, and sham therapy was used in the sham therapy group. In the neurodynamic techniques group, neurodynamic sequences were used, and sliding and tension techniques were also used. In the sham therapy group, no neurodynamic sequences were used, and therapeutic procedures were performed in an intermediate position. Therapy was conducted twice weekly for a total of 20 therapy sessions.

MAIN OUTCOME MEASURES

Symptom severity (symptom severity scale) and functional status (functional status scale) of the Boston Carpal Tunnel Questionnaire.

RESULTS

A baseline assessment revealed no intergroup differences in all examined parameters (P>.05). After therapy, there was statistically significant intragroup improvement in nerve conduction study (sensory and motor conduction velocity and motor latency) only for the neurodynamic techniques group (P<.01). After therapy, intragroup statistically significant changes also occurred for the neurodynamic techniques group in pain assessment, 2-point discrimination sense, symptom severity scale, and functional status scale (in all cases P<.01). There were no group differences in assessment of grip and pinch strength (P>.05).

CONCLUSIONS

The use of neurodynamic techniques has a better therapeutic effect than sham therapy in the treatment of mild and moderate forms of CTS.