Enlarged median nerve in idiopathic carpal tunnel syndrome

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.

Comparison of the Effects of Volar-Assisted and Elastic Wrist Splints on Edema, Pain, Grip Strength, and Functionality in Pregnant Women With Carpal Tunnel Syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is a common musculoskeletal problem in pregnancy. The aim of this study is to compare the effects of rigid and elastic wrist splints on edema, pain levels, grip strength, and upper-extremity functionality in pregnant women with CTS.

METHODS

Forty-one pregnant women in the last trimester of pregnancy who were diagnosed with CTS were included in the study. The grip strength was evaluated with the Jamar hand dynamometer, functionality with the Quick Disabilities of the Arm, Shoulder, and Hand and Boston Carpal Tunnel Syndrome Questionnaire, pain with the Visual Analog Scale (VAS), and edema with the water overflow method.

RESULTS

The mean age of the participants was 31.71 ± 5.78 years, body mass index was 28.85 ± 3.63 kg/m2, duration of pain was 2.24 ± 0.79 months, and their pain intensity was 6.63 ± 1.69 according to the VAS. As a result of the study, reductions in pain (P = .001), increases in functionality values (P = .001), increases in grip strength (P = .001), and decreases in edema (P = .001) were observed in both groups after the treatment. However, there was no significant difference in pain, functionality, or grip strength values between the groups after the treatment (P > .05).

CONCLUSION

In this study comparing the effects of a wrist splint to those of an elastic splint, both treatment methods for pregnant women with CTS decreased pain and edema, increased grip strength, and improved upper-extremity functionality. Considering individual needs, characteristics, and living conditions, both splints can be recommended for pregnant women with CTS.

Diagnostic utility of anteroposterior measurements of the median nerve on sagittal ultrasonographic images and their correlation with clinical findings in carpal tunnel syndrome

PURPOSE

To investigate the efficacy of sagittal ultrasonography of the median nerve in diagnosing carpal tunnel syndrome (CTS).

METHODS

Seventy-six hands with idiopathic CTS and 80 hands of asymptomatic subjects were included. All patients with CTS underwent ultrasonographic examination, electrodiagnostic testing, and CTS-6 assessment. In the sagittal ultrasonographic examination, the maximum and minimum median nerve diameters (MNDs) were measured at the proximal and distal ends of the carpal tunnel, respectively. The median nerve stenosis rate (MNSR) was computed as (1 - minimum MND/maximum MND) × 100 (%). The cross-sectional area (CSA) of the median nerve at the level of the pisiform was measured.

RESULTS

In the sagittal ultrasonographic examination, the mean maximum MNDs were 0.252 cm and 0.202 cm, mean minimum MNDs were 0.145 cm and 0.165 cm, and mean MNSRs were 41.83% and 17.35% in the CTS and control groups, respectively; the mean maximum MND and MNSR were considerably larger in the CTS group. The maximum MND and MNSR were correlated with the electrodiagnostic testing results and CTS-6 score. The MNSR with a cut-off value of 34.0% had a higher sensitivity and specificity than the CSA in diagnosing CTS.

CONCLUSIONS

Sagittal ultrasonographic examination is useful in diagnosing CTS.

Ultrasonographic Measurement of Median Nerve Cross-Sectional Area in Evaluating Carpal Tunnel Release Outcomes

PURPOSE

Earlier research has explored carpal tunnel release (CTR) surgery outcomes using electrodiagnostic tests (EDX). However, evaluation of the median nerve before and after CTR by ultrasound (US) is understudied. This study aimed to establish the outcomes of CTR by EDX and US, and examine the correlation between the clinical improvement and US after CTR.

METHODS

The sample consisted of 172 wrists that underwent CTR. Pain was assessed using the visual analog scale (VAS). The Boston Carpal Tunnel Syndrome Questionnaire (BCTQ), including the symptom severity and function subscales, was applied before and 3 months after CTR. The proximal and distal cross-sectional areas (CSAs) of the median nerve were measured using US, and EDX was performed before and 3 months after CTR.

RESULTS

Patients had mean preoperative and postoperative VAS scores of 7.7 ± 1.2 and 1.7 ± 1.2, respectively. The mean preoperative and postoperative proximal CSA measurements were 16.4 ± 4.5 mm2 and 12.1 ± 3.9 mm2, respectively. The mean preoperative and postoperative distal CSA measurements were 13.6 ± 3.7 mm2 and 11.0 ± 3.1 mm2, respectively. A significant improvement was observed in VAS, BCTQ, and EDX 3 months after CTR. A weak, positive correlation was observed between the improvement in the BCTQ symptom severity and function subscales and CSAs following CTR.

CONCLUSIONS

The results of this study demonstrate that preoperative median nerve CSA values may be used in evaluating CTR outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The cross-sectional morphology of median nerve in carpal tunnel of healthy, adult population: A systematic review and meta-analysis

The cross-section area is a crucial parameter to assess peripheral neuropathy. The ultrasonographic evaluation of cross-section area of median nerve is a low-cost and readily available tool for diagnosis and assessment. However, the intra-nerve dimensional variability and its normative reference value in a healthy subject are missing. The current meta-analysis aims to capture the median nerve cross-section area for healthy subjects and generate a comprehensive ultrasonographic reference data set for each population.

METHODS

The full text of manuscripts were collected after short-listing the abstracts collected from search strategy. A quality assurance tool was used to capture the risk of bias of each study after reviewing the included manuscripts. The pooled estimate of cross-section area was stratified according to anatomical landmarks, sex, and ancestry.

RESULTS

A total of 97 observational studies dealt with 6679 wrists of healthy subjects were included. The pooled estimate of the cross-section area of median nerve at carpal tunnel inlet was 8.54mm² [95% CI: 8.34-8.74mm²]. The same pooled estimate at carpal tunnel outlet was 8.03mm² [95% CI: 7.46-8.60mm²]. Both these pooled estimates have significant correlation with mean age of population. Age and sex were two primary predictors of the cross-section of median nerve. The flattening ratio, circularity, and wrist-forearm ratio of median nerve were also computed.

CONCLUSION

These normative data could serve as a reference for assessing median nerve pathologies, including carpal tunnel syndrome. The ethnic variation of pooled estimate and heterogeneity will guide clinician set up the reference value for diagnostic criteria.

Mnemonics and Metaphorical Videos for Detecting/Diagnosing Musculoskeletal Sonopathologies

ABSTRACT

Musculoskeletal ultrasound identifies a broad range of pathologies. Typical sonographic images of certain pathological/abnormal conditions can be rendered and "highlighted" for the daily practice/language of musculoskeletal sonographers. The following text and accompanying figures/videos represent a collection of findings pertaining to commonplace pathological conditions. This article is the second part of a series-after the characteristic/metaphoric descriptions of normal musculoskeletal structures.

Carpal tunnel mechanics and its relevance to carpal tunnel syndrome

The carpal tunnel is an elaborate biomechanical structure whose pathomechanics plays an essential role in the development of carpal tunnel syndrome. The purpose of this article is to review the movement related biomechanics of the carpal tunnel together with its anatomical and morphological features, and to describe the pathomechanics and pathophysiology associated with carpal tunnel syndrome. Topics of discussion include biomechanics of the median nerve, flexor tendons, subsynovial tissue, transverse carpal ligament, carpal tunnel pressure, and morphological properties, as well as mechanisms for biomechanical improvement and physiological restoration. It is our hope that the biomechanical knowledge of the carpal tunnel will improve the understanding and management of carpal tunnel syndrome.

Clinical Relevance of Ultrasonographic and Electrophysiological Findings of the Median Nerve in Unilateral Carpal Tunnel Syndrome Patients

Few studies have compared the unaffected and affected sides in the same carpal tunnel syndrome (CTS) patients using ultrasonography and electrophysiological tests. We focused on unilateral idiopathic CTS patients to investigate whether clinical test results differ between the unaffected and affected sides. The bilateral wrist joints of 61 unilateral idiopathic CTS patients were evaluated. The median nerve cross-sectional area of ultrasound image, and latencies of the compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) were measured. The values obtained were compared between the affected and unaffected sides. The diagnostic accuracies of each parameter were assessed, and cut-off values were defined. Significant differences were observed in all parameters between the affected and unaffected sides (p < 0.01). Area under the curve (AUC) values were 0.74, 0.88, and 0.73 for the cross-sectional area, CMAP distal latency, and SNAP distal latency, respectively. Cut-off values were 11.9 mm2, 5.1 ms, and 3.1 ms for the cross-sectional area, CMAP distal latency, and SNAP distal latency, respectively. The most reliable parameter that reflected clinical symptoms was the distal latency of CMAP. Cut-off values for each parameter are considered to be an index for the onset of the clinical symptoms of CTS.

Use of Ultrasound in Patients With Carpal Tunnel Syndrome: A Cost-Effective Solution to Reduce Delays in Surgical Care

PURPOSE

Currently, electrodiagnostic testing, which comprises electromyogram (EMG) and nerve conduction studies (NCS), is the most commonly used method for confirming the clinical diagnosis of carpal tunnel syndrome (CTS). Electromyogram and NCS can be costly, can require multiple visits, may induce anxiety, and may be painful for patients. The purpose of this study was to determine whether replacing EMG/NCS with ultrasound (US), performed by the treating surgeon, to diagnose CTS decreases time to surgery and the number of office visits.

METHODS

We retrospectively reviewed a database that consisted of patients who presented to our department with numbness and/or tingling in the hand(s). We assessed the patients' histories for any subsequent carpal tunnel release, dates of diagnosis, dates of surgery, the number of CTS-related medical visits, and diagnostic methods employed. A fellowship-trained hand surgeon performed US examination, and the patients were referred for EMG/NCS testing. We collected data prior to surgery using the Boston Carpal Tunnel Questionnaire to evaluate symptom severity scale and functional status scale scores. We performed linear regression to assess differences in the time to surgery and the number of medical visits prior to carpal tunnel release.

RESULTS

Patients who had the diagnosis confirmed by the surgeon using US (n = 34) underwent surgical intervention 3-4 weeks earlier, with 1.8 fewer medical visits on average than the number of medical visits for those who had their diagnosis confirmed using EMG/NCS (n = 98).

CONCLUSIONS

If a confirmatory method for the diagnosis of CTS is required or desired by the treating surgeon, surgeon-conducted US might have an impact on the efficiency of care for patients with CTS.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Normative Value of the Cross-Sectional Area of the Median Nerve at the Carpal Tunnel Inlet and Distal Forearm in the Singapore Population

Background: Ultrasonography is often used in the diagnosis of carpal tunnel syndrome (CTS). However, we were unable to find normative data regarding the cross-sectional area (CSA) of the median nerve in the Singapore population as measured by ultrasound. The aims of this study were to establish normative values of the CSA of the median nerve at the carpal tunnel inlet in a healthy population, 5 cm proximal to the carpal tunnel inlet, and to determine if the CSA correlated with side, age, gender or race.

Methods: Sixty-nine wrists of 36 healthy subjects with no history of wrist injury or any signs and symptoms of CTS were examined. The CSA of the median nerve at the carpal tunnel inlet and 5 cm proximal to the carpal tunnel inlet was determined using ultrasound by a trained operator.

Results: The mean CSA of the median nerve at the carpal tunnel inlet was 6.41 mm2 (SD 2.18 mm2). These were not significantly different from the values for mean CSA obtained 5 cm proximal to the carpal tunnel inlet. We did not find any correlation between the CSA of the median nerve and age, gender or race.

Conclusions: The mean CSA of the median nerve at the carpal tunnel inlet in normal subjects in Singapore was found to be lower than other Asian populations. Wide variations of the median nerve CSA at the carpal tunnel inlet exists in the literature, and this is probably due to the heterogeneity of the study methodology and population.

Level of Evidence: Level III (Diagnostic)

Sonographic Changes in the Median Nerve Predict Conversion to Surgery after Corticosteroid Injection of the Carpal Tunnel

BACKGROUND

Risk factors for conversion to surgical management of moderate severity carpal tunnel syndrome (CTS) are poorly understood. We hypothesized that sonographic findings along the carpal tunnel could predict failure of conservative management for CTS.

METHODS

We report on 96 wrists with moderate clinical signs and symptoms of CTS. Sonographic evaluation with measurement of median nerve cross-sectional area (CSA) was performed at 3 consistent anatomic locations. We recorded median nerve morphology, inlet/outlet dimensions of the carpal tunnel, and maximal thickness of the transverse carpal ligament. Subsequently, steroid injection was performed. Patients were followed for a minimum of one year after injection and progression to surgical management was recorded.

RESULTS

54% (n = 52) patients converted to surgical management within 1 year following injection. Median nerve CSA decreased over the course of the carpal tunnel from proximal to distal in 81 of 96 wrists. A greater decrease in CSA of the median nerve between the pisiform and the hamate was associated with conversion to operative intervention for CTS with the average decrease in median nerve CSA among those who failed conservative treatment being 5.01 mm2 compared to 2.97 mm2 among those who did not progress to surgical treatment.

CONCLUSIONS

Our study demonstrates that ultrasound may be one additional tool used by clinicians in order to better counsel patients about the severity and progression of their disease. Patients who demonstrate a decrease in cross-sectional area of the median nerve along the carpal tunnel demonstrate a higher likelihood of progression to operative management.

Thirty Minutes of Sub-diastolic Blood Flow Occlusion Alters Carpal Tunnel Tissue Function and Mechanics

There is evidence that carpal tunnel syndrome (CTS) development is driven by vascular factors, specifically those resulting from ischemia and edema. The purpose of this study was to investigate the vascular hypothesis of CTS development by quantifying the temporal effects of 30 min of sub-diastolic brachial blood flow occlusion on median nerve edema, intraneural blood flow velocity, nerve function as measured through nerve conduction study (NCS), tendon-connective tissue mechanics and carpal tunnel tissue stiffness. Forty healthy volunteers underwent 30 min of sub-diastolic brachial occlusion while an NCS and ultrasound examination were performed consecutively every 5 min. Motor latency (p < 0.001), sensory conduction velocity (p < 0.001), sensory amplitude (p = 0.04), nerve blood flow (p < 0.001), peak relative flexor digitorum superficialis tendon-sub-synovial connective tissue displacement (p = 0.02) and shear strain (p = 0.04) were significantly affected by partial ischemia. Our results highlight the dependency of carpal tunnel tissue function on adequate blood flow.

High-resolution ultrasound in the diagnosis of failed carpal tunnel decompression: a study of 35 cases

We used high-resolution ultrasound to examine 35 median nerves (35 patients) with failed carpal tunnel decompression to identify the cause of failure. The carpal tunnel was examined before revision surgery, and the results were correlated with surgical findings. The cross-sectional area was measured, and nerve morphology was analysed at the sites of compression. We found persistent median nerve compression in 30 out of 35 patients. In 20 patients, the compression was caused by a residual transverse carpal ligament, in four by perineural fibrosis, in five by both of these causes and in one by tenosynovitis. In four patients, evidence of median nerve injury with an epineural/fascicular lesion was detected; and in one, no abnormalities were found. Surgical findings were consistent with the ultrasound findings except in one patient where tenosynovitis was associated with a giant cell tumour, which was missed by ultrasound. High-resolution ultrasound can provide helpful information in preoperative diagnosis of failed carpal tunnel decompression with good correlation between the ultrasound and surgical findings.Level of evidence: IV.

Utility of shear wave elastography and high-definition color for diagnosing carpal tunnel syndrome

OBJECTIVE

The diagnostic values of measuring median nerve (MN) stiffness and vascularity with shear wave elastography (SWE) and high-definition (HD) color were investigated in carpal tunnel syndrome (CTS).

METHODS

Seventy patients (123 wrists) with CTS and thirty-five healthy volunteers (70 wrists) were enrolled. Based on nerve conduction studies (NCS), the patients were subdivided into NCS-negative, mild-to-moderate, and severe CTS groups. MN and abductor pollicis brevis (APB) SWE and MN HD color were performed on a longitudinal plane.

RESULTS

The mild-to-moderate and severe CTS groups showed increased MN stiffness at the wrist and MN stiffness ratio (wrist-to forearm) compared with the control (p < 0.001). The NCS-negative CTS group showed increased MN stiffness at the wrist (p = 0.022) and MN stiffness ratio (p = 0.032) compared with the control. The severe CTS group showed increased MN stiffness at the wrist compared with the mild-to-moderate CTS group (p = 0.034). The cutoff-values in diagnosing NCS-confirmed CTS were 50.12 kPa for MN stiffness at the wrist, 1.91 for MN stiffness ratio, and grade 1 for HD color.

CONCLUSIONS

SWE and HD color are good supportive tools in diagnosing and assessing severity in CTS.

SIGNIFICANCE

SWE and HD color demonstrated that MN in CTS was associated with increased stiffness and hypervascularity.

Does Patient Sex Affect Ultrasound Cutoff Values for Severity Grading of Carpal Tunnel Syndrome?

PURPOSE

A growing body of evidence supports ultrasound (US) as an alternative first-line confirmatory test for carpal tunnel syndrome (CTS). Recent studies have demonstrated a correlation of US cross-sectional area with electrodiagnostic (EDX)-determined severity; however, it is unclear whether patient sex affects the cutoff values used for determining severity. The purpose of this study was to determine if patient sex affects US graded severity when using EDX as the reference standard.

METHODS

A cohort of 367 women and 46 men, aged 18-90 years, from 1 orthopedic hand surgeon's practice underwent EDX and US. Distal motor latency and distal sensory latency of the median nerve were recorded. Severity was classified using a modified Bland severity scale. The US measurements of the cross-sectional area of the median nerve at the wrist crease were acquired by a fellowship-trained hand surgeon. Separate receiver operator characteristic curve analyses of the male and female groups were performed for US cutoff values.

RESULTS

The cutoff value in both the female (F) and male (M) patients was 11 mm² for mild (area under the curve = 0.76 F; 0.78 M), 12 mm² for moderate (area under the curve = 0.75 F; 0.73 M), and 13 mm² for severe (area under the curve = 0.75 F; 0.71 M) CTS. The sensitivity of the cutoffs for mild, moderate, and severe CTS in the female and male groups was 49% and 56%, 44% and 50%, and 49% and 44%, respectively. The specificity of the cutoffs for mild, moderate, and severe CTS in the female and male groups was 75% and 79%, 74% and 82%, and 83% and 78%, respectively.

CONCLUSIONS

Patient sex does not appear to have a significant impact on the determination of CTS severity graded using US cutoff values. Ultrasound can be used to grade the severity of CTS with a 75% to 85% specificity but low sensitivity. A cutoff value of 13 mm² can be used to classify CTS as severe.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

[Entrapment neuropathies: a contemporary approach to pathophysiology, clinical assessment, and management : German version]

Entrapment neuropathies such as carpal tunnel syndrome, radiculopathies, or radicular pain are the most common peripheral neuropathies and also the most common cause for neuropathic pain. Despite their high prevalence, they often remain challenging to diagnose and manage in a clinical setting. Summarising the evidence from both preclinical and clinical studies, this review provides an update on the aetiology and pathophysiology of entrapment neuropathies. Potenzial mechanisms are put in perspective with clinical findings. The contemporary assessment is discussed and diagnostic pitfalls highlighted. The evidence for the noninvasive and surgical management of common entrapment neuropathies is summarised and future areas of research are identified.

MRI of carpal tunnel syndrome: before and after carpal tunnel release

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Magnetic resonance imaging (MRI) is increasingly used to diagnose CTS, exclude secondary causes of CTS, and investigate patients with persistent symptoms after carpal tunnel release. Median nerve compression may also be either subclinical in the early stages or present with atypical symptoms. Radiologists are therefore not infrequently the first to alert clinicians as to the possibly of subclinical or atypical CTS. This review shows the normal and abnormal appearances of the carpal tunnel before and after CTR.

Ultrasonography Findings of the Carpal Tunnel after Endoscopic Carpal Tunnel Release for Carpal Tunnel Syndrome

Objective

To investigate changes in the median nerve, retinaculum, and carpal tunnel on ultrasound after successful endoscopic carpal tunnel release (ECTR).

Materials and Methods

This prospective study involved 37 wrists in 35 patients (5 male, 30 female; mean age ± standard deviation [SD], 56.9 ± 6.7 years) with primary carpal tunnel syndrome (CTS). An in-house developed scoring system (0–3) was used to gauge the clinical improvement after ECTR. Ultrasound was performed before ECTR, and at 1, 3, and 12 months post-ECTR. Changes in the median nerve, flexor retinaculum, and carpal tunnel morphology on ultrasound after ECTR were analyzed. Ultrasound parameters for different clinical improvement groups were compared.

Results

All patients improved clinically after ECTR. The average clinical improvement score ± SD at 12 months post-ECTR was 2.2 ± 0.7. The median nerve cross-sectional area proximal and distal to the tunnel decreased at all time intervals post-ECTR but remained swollen compared to normal values. Serial changes in the median nerve caliber and retinacular bowing after ECTR were more pronounced at the tunnel outlet than at the tunnel inlet. The flexor retinaculum had reformed in 25 (68%) of 37 wrists after 12 months.

Conclusion

Postoperative changes in median nerve and retinaculum parameters were most pronounced at the tunnel outlet. Even in patients with clinical improvement after ECTR, nearly all ultrasound parameters remain abnormal at one year post-ECTR. These ultrasound parameters should not necessarily be relied upon to diagnose persistent CTS after ECTR.

Wrist Circumference-Dependent Upper Limit of Normal for the Cross-Sectional Area Is Superior Over a Fixed Cut-Off Value in Confirming the Clinical Diagnosis of Carpal Tunnel Syndrome

Introduction: In confirming the clinical diagnosis of carpal tunnel syndrome (CTS), ultrasonography (US) is the recommended first diagnostic test in The Netherlands. One of the most important parameters for an abnormal US result is an increase of the CSA of the median nerve at the carpal tunnel inlet. An earlier study showed that a wrist-circumference dependent cut-off for the upper limit of normal of this CSA might be superior to a fixed cut-off of 11 mm². In this study we compared three ultrasonography (US) parameters in three large Dutch hospitals.

Methods: Patients with a clinical suspicion of CTS and with reasonable exclusion of other causes of their symptoms were prospectively included. A total number of 175 patients were analysed. The primary goal was to compare the number of wrists with an abnormal US result while using a fixed cut-off of 11 mm² (FC), a wrist circumference-dependent cut-off (y = 0.88 ^* x−4, where y = ULN and x = wrist circumference in centimetres; abbreviated as WDC), and an intraneural flow related cut-off (IFC).

Results: The WDC considered more US examinations to be abnormal (55.4%) than the FC (50.3%) did, as well as the IFC (46.9%), with a statistically significant difference of p = 0.035 and p = 0.001, respectively. The WDC detected 12 abnormal median nerves while the FC did not, and 18 while the IFC did not. The wrist circumference of the patients of these subgroups turned out to be significantly smaller (p < 0.001) when compared with the rest of the group.

Conclusion: According to these study results, the wrist-circumference dependent cut-off value for the CSA of the median nerve at the wrist appears to have a higher sensitivity than either a fixed cut-off value of 11 mm² or cut-off values based on intraneural flow, and may add most value in patients with a smaller wrist circumference.

Ligament and Bone Arch Partition of the Carpal Tunnel by Three-Dimensional Ultrasonography

The carpal tunnel is geometrically irregular due to the complex composition of many carpal bones intercalated by numerous intercarpal ligaments. The purpose of the study was to investigate the relative contributions of the ligament and bone arches to carpal tunnel space at the proximal, middle, and distal tunnel regions. A catheter ultrasound probe acquired fan-like images inside cadaveric carpal tunnels for three-dimensional reconstruction of the tunnel. The total tunnel volume was 5367.6 ± 940.1 mm3 with contributions of 12.0%, 6.9%, and 4.1% by proximal, middle, and distal ligament arches, respectively, and 27.0%, 25.3%, and 24.7% by proximal, middle, and distal bone arches, respectively. The bone arch occupied more tunnel space than the ligament arch at all regions (p < 0.05). The ligament arch was largest at the proximal region of the tunnel and significantly decreased toward the distal region (p < 0.05). However, the bone arch significantly decreased only from the proximal to middle region (p < 0.05) but not from the middle to distal region (p = 0.311). Consequently, it was observed that the ligament arch was the key contributor to the unequal carpal tunnel space across regions. Partitional and regional tunnel morphometric information may provide a better understanding of tunnel abnormality associated with various wrist pathological conditions. The developed framework of ultrasonography and data processing can be applied to other areas of interest in the musculoskeletal system.

Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome

With the widespread use of high-resolution ultrasonography, ultrasonic examination has been shown to be useful as a diagnostic method for carpal tunnel syndrome. The main advantages of ultrasonography are that it is simple, quick, non-invasive, and economical. Another advantage is that tissue dynamics can be observed with real-time imaging. In recent reports, it has been shown that ultrasonic examination can provide similar diagnostic accuracy as nerve conduction study in the diagnosis of carpal tunnel syndrome. It has been expected that ultrasound demand in daily medical care will continue to increase. Ultrasonography in carpal tunnel syndrome shows an enlarged median nerve in proximal carpal tunnel, thickening of the flexor retinaculum, and edema around flexor tendons in cross-sectional images. In addition, with the introduction of new technologies such as ultrasonic elastography and speckle tracking, it has become possible to quantify dynamics and material property changes of nerves, tendons, and their surrounding structures. In this review, we describe recent advancements of carpal tunnel syndrome diagnosis based on ultrasound dynamic images, and discuss its pathology.

Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome

With the widespread use of high-resolution ultrasonography, ultrasonic examination has been shown to be useful as a diagnostic method for carpal tunnel syndrome. The main advantages of ultrasonography are that it is simple, quick, non-invasive, and economical. Another advantage is that tissue dynamics can be observed with real-time imaging. In recent reports, it has been shown that ultrasonic examination can provide similar diagnostic accuracy as nerve conduction study in the diagnosis of carpal tunnel syndrome. It has been expected that ultrasound demand in daily medical care will continue to increase. Ultrasonography in carpal tunnel syndrome shows an enlarged median nerve in proximal carpal tunnel, thickening of the flexor retinaculum, and edema around flexor tendons in cross-sectional images. In addition, with the introduction of new technologies such as ultrasonic elastography and speckle tracking, it has become possible to quantify dynamics and material property changes of nerves, tendons, and their surrounding structures. In this review, we describe recent advancements of carpal tunnel syndrome diagnosis based on ultrasound dynamic images, and discuss its pathology.

Recent Advances in Ultrasound Diagnosis of Carpal Tunnel Syndrome

With the widespread use of high-resolution ultrasonography, ultrasonic examination has been shown to be useful as a diagnostic method for carpal tunnel syndrome. The main advantages of ultrasonography are that it is simple, quick, non-invasive, and economical. Another advantage is that tissue dynamics can be observed with real-time imaging. In recent reports, it has been shown that ultrasonic examination can provide similar diagnostic accuracy as nerve conduction study in the diagnosis of carpal tunnel syndrome. It has been expected that ultrasound demand in daily medical care will continue to increase. Ultrasonography in carpal tunnel syndrome shows an enlarged median nerve in proximal carpal tunnel, thickening of the flexor retinaculum, and edema around flexor tendons in cross-sectional images. In addition, with the introduction of new technologies such as ultrasonic elastography and speckle tracking, it has become possible to quantify dynamics and material property changes of nerves, tendons, and their surrounding structures. In this review, we describe recent advancements of carpal tunnel syndrome diagnosis based on ultrasound dynamic images, and discuss its pathology.

Entrapment neuropathies: a contemporary approach to pathophysiology, clinical assessment, and management

Entrapment neuropathies such as carpal tunnel syndrome, radiculopathies, or radicular pain are the most common peripheral neuropathies and also the most common cause for neuropathic pain. Despite their high prevalence, they often remain challenging to diagnose and manage in a clinical setting. Summarising the evidence from both preclinical and clinical studies, this review provides an update on the aetiology and pathophysiology of entrapment neuropathies. Potential mechanisms are put in perspective with clinical findings. The contemporary assessment is discussed and diagnostic pitfalls highlighted. The evidence for the noninvasive and surgical management of common entrapment neuropathies is summarised and future areas of research are identified.

Electrodiagnostic Studies and Ultrasound Cross-Sectional Area of the Median Nerve in Patients With Isolated Cervical Radiculopathy

Purpose

Although the literature has shown that the cross-sectional area (CSA) of the carpal tunnel on ultrasound is enlarged in patients with carpal tunnel syndrome, it does not provide information regarding whether proximal nerve pathology, such as that seen in cervical radiculopathy, increases the CSA of the median nerve.

Methods

In this study, 15 patients were enrolled who had a clinical diagnosis of cervical radiculopathy but not carpal tunnel syndrome. All patients underwent electrodiagnostic studies and ultrasound measurement of the CSA of the median nerve.

Results

Increased median nerve CSA was seen in 1 of 15 patients (7%). Positive findings of cervical radiculopathy were found in 7 patients (47%) by electrodiagnostic studies.

Conclusions

In patients clinically diagnosed with isolated cervical radiculopathy, the vast majority have normal median nerve CSA measured on ultrasound.

Type of study/level of evidence

Prognostic IV.

Carpal tunnel sonography

Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy of peripheral nerves, with an incidence of 1-3 patients in 1000. CTS typically occurs between 45 and 60 years of age, and it is more frequent in women than in men. The main cause of CTS is chronic compression of the median nerve and ischemic suffering secondary to increased pressure in the carpal tunnel. There are many possible causes of CTS, which can be differentiated into idiopathic causes, which include most cases, and secondary causes. Classical CTS diagnosis is based on the patient's clinical examination and electrophysiological tests, such as electromyography and nerve conduction studies. The latter are helpful for determining the site of nerve compression, assessing its severity, monitoring the course of the disease after therapy, and excluding other causes of median nerve pain, such as cervical radiculopathies, brachial plexopathies, polyneuropathy, or other forms of mononeuropathies. However, clinical examination and electrophysiological tests are not able to differentiate idiopathic forms from secondary forms of CTS, and discrepancies are possible between clinical examination and electrophysiological tests (false negatives). Ultrasound examination is able to recognize most of the secondary forms of CTS. It can evaluate the morphological alterations of the nerve and correlate them with the severity of nerve suffering in all cases, even idiopathic ones, with a sensitivity and specificity equal to those of electrophysiological tests. It can also highlight some anatomical predisposing variants or conditions that may represent contraindications to minimally invasive treatments. Ultrasound examination also plays a fundamental role in evaluating patients with an unfavorable outcome after surgical treatment.

Blood flow velocity but not tendon mechanics relates to nerve function in carpal tunnel syndrome patients

Carpal tunnel syndrome (CTS) develops from chronic compression of the median nerve. Chronic compression results in a number of vascular, structural and functional changes to the carpal tunnel tissues which ultimately manifest in the characteristic symptoms of CTS. The purpose of this study was to investigate the interplay of median nerve function, median nerve hemodynamics, and finger flexor tendon and subsynovial connective tissue (SSCT) mechanics in CTS patients. Thirty-five patients were recruited following nerve conduction study for this double-blinded imaging study. Ultrasound B-mode, pulse-wave Doppler, and colour Doppler images and videos were collected at the proximal carpal tunnel to quantify: (1) median nerve cross-sectional area, (2) intraneural blood flow velocity in 3 wrist postures (neutral (0°), flexion (15°), extension (30°)), and (3) flexor digitorum superficialis and SSCT displacement. Results demonstrate that intraneural blood flow velocity is dependent on median nerve function and wrist posture such that patients with mild CTS are more susceptible to the effects of non-neutral wrist postures. Tendon-SSCT mechanics do not appear to differ based on severity. This study stresses the importance of limiting exposure to non-neutral wrist postures in patients with early signs of the condition.

Short-term clinical outcome of orthosis alone vs combination of orthosis, nerve, and tendon gliding exercises and ultrasound therapy for treatment of carpal tunnel syndrome

STUDY DESIGN

Prospective randomized study.

INTRODUCTION

Carpal tunnel syndrome (CTS) has been described as the most common compression neuropathy. Many modalities exist for conservative treatment. Efficacy of each modality has been described in the literature. However, the effectiveness of combination of these modalities is not well established. The purpose of this study is to assess the short-term clinical outcome of conservative treatment for CTS comparing orthosis alone with combination of orthosis, nerve/tendon gliding exercises, and ultrasound therapy.

METHODS

Forty-one patients who presented to Upper Limb Reconstructive and Microsurgery Clinic, University Malaya Medical Centre with CTS and positive electrodiagnostic study were recruited. Fifteen patients had bilateral CTS. Fifty-six wrists were equally randomized to orthosis alone and a combined therapy of orthosis, nerve/tendon gliding exercise, and ultrasound therapy. All patients were required to complete the Boston Carpal Tunnel Questionnaire during the first visit and 2 months after treatment.

RESULTS

Both the orthosis and combined therapy groups showed a significant improvement in symptoms and function after treatment. The mean difference of symptoms in the orthosis group was 0.53; 95% confidence interval [CI]: 0.23-0.83 (P = .001) and in the combined therapy group was 0.48; 95% CI: 0.24-0.72 (P < .001). Mean difference of function in the orthosis group was 0.59; 95% CI: 0.28-0.91 (P = .001) and combined group was 0.69; 95% CI: 0.49-0.89 (P < .001). However, there was no significant difference in symptom severity and functional status scores between the groups.

DISCUSSION

Our findings support other findings where orthosis and exercises improved symptom severity and functional status scores, however, there was no significant difference between orthosis alone and combined treatment.

CONCLUSION

Patients who underwent conservative management for CTS showed improvement in symptoms and function. However, the combination of orthosis, nerve/tendon gliding exercises, and ultrasound therapy did not offer additional benefit compared to orthosis alone.

Ultrasound measurements of the median nerve at the carpal tunnel in ambulant chronic stroke patients: comparison between paretic and non-paretic sides

[Purpose] The purpose of this study was to examine the cross-sectional area (CSA) and longitudinal sliding length (LSL) of the median nerve bilaterally in patients with ambulant chronic hemiplegia and to compare these measurements with those in healthy controls using ultrasound. [Participants and Methods] Forty patients with hemiplegia who developed a non-functional hand on the paretic side after one year or more of stroke and 25 asymptomatic controls were included. To obtain the CSA of the median nerve at the wrist in the neutral position and the LSL of the median nerve during wrist extension, the participants underwent bilateral ultrasound examination. [Results] The non-paretic side of stroke patients had the largest median nerve CSA, followed by the paretic side and then the controls; the median nerve CSA in the non-paretic side and the controls differed significantly. The CSA of the median nerve was significantly larger in the non-paretic sides of patients, evaluated at more than 5.5 years post-stroke relative to those evaluated at less than 5.5 years. The LSL of the paretic side was significantly shorter than the non-paretic side and the controls. [Conclusion] Compared to the controls, the CSA of the median nerve was enlarged in the non-paretic hand of ambulant chronic stroke patients and the LSL were identical. As such, entrapment neuropathy of the median nerve may follow long-term chronic stroke due to overuse. This study indicates the usefulness of ultrasound in the potential identification of such cases.

Ultrasonography Findings in Severe Carpal Tunnel Syndrome

Background: Increasing severity of carpal tunnel syndrome (CTS), as graded by nerve conduction studies (NCS), has been demonstrated to predict the speed and completeness of recovery after carpal tunnel release (CTR). The purpose of this study is to compare the cross-sectional area (CSA) of the median nerve in patients with severe and nonsevere CTS as defined by NCS. Methods: Ultrasound CSA measurements were taken at the carpal tunnel inlet at the level of the pisiform bone by a hand fellowship-trained orthopedic surgeon. Severe CTS on NCS was defined as no response for the distal motor latency (DML) and/or distal sensory latency (DSL). Results: A total of 274 wrists were enrolled in the study. The median age was 51 years (range: 18-90 years), and 72.6% of wrists were from female patients. CSA of median nerve and age were comparatively the best predictors of severity using a linear regression model and receiver operator curves. Using cutoff of 12 mm² for severe CTS, the sensitivity and specificity are 37.5% and 81.9%, respectively. Conclusions: Ultrasound can be used to grade severity in younger patients (<65 years) with a CTS-6 score of >12.

Ultrasound elastography in the evaluation of peripheral neuropathies: a systematic review of the literature

Peripheral neuropathy is associated with an increase in intraneural pressure, and hence ultrasound elastography seems to be an ideal method to detect early stages of this condition based on changes in the affected nerve stiffness. The aim of this systematic review was to analyse the applicability of strain elastography (SE) and shear wave elastography (SWE) in the evaluation of peripheral nerves in patients with neuropathy of various aetiologies. Published evidence shows clearly that ultrasound elastography can accurately diagnose many types of peripheral neuropathies (carpal tunnel syndrome and other entrapment neuropathies, diabetic peripheral neuropathy and peripheral neuropathy associated with other systemic diseases), sometimes at the stages at which the condition is still asymptomatic. However, it is still unclear whether elastographic changes within the nerves precede functional anomalies detectable on nerve conduction studies. Also, relatively little is known about the relationship between the stiffness of peripheral nerves and the severity of peripheral neuropathy and its underlying condition. Based on the reproducibility data, SWE seems to be superior to SE. Nevertheless, the sources of heterogeneity in the peripheral nerve stiffness in healthy persons need to be identified, and the sets of reference values for specific peripheral nerves need to be determined. Finally, the potential confounding effect of hardening artefacts, such as bones, on the stiffness of peripheral nerves needs to be verified. After addressing all these issues, elastographic evaluation of peripheral nerve stiffness might become a reliable, easily accessible, and convenient diagnostic test performed routinely in patients with various peripheral neuropathies.

A Comparison of Ultrasound and MRI Measurements of the Cross-Sectional Area of the Median Nerve at the Wrist

Background: Ultrasound (US) measurement of cross-sectional area (CSA) of the median nerve has emerged as a viable alternative to electromyography/nerve conduction studies (EMG/NCS) for diagnosis of carpal tunnel syndrome (CTS). The purpose of this study is to compare CSA of the median nerve between US and MRI using current MRI and US technology. The null hypothesis is there is no difference between US and MRI CSA measurements. Methods: The study design was an observational cohort, enrolling patients presenting to clinic with MRI of the wrist. Participants with clinical signs and symptoms of CTS were excluded. The CSA measurements of the median nerve on MRI T1-weighted axial images were performed by a hand fellow blinded to results of US measurements, and US measurement of median nerve CSA was performed by a hand fellowship trained surgeon blinded to results of the MRI measurements. Results were analyzed via percent error, Pearson correlation, and t tests. Results: Twenty participants were enrolled with mean age of 29.4 years. Four left wrists and 16 right wrists were measured. The US mean CSA of the median nerve was 6.8 mm² (±2.330 mm²). The MRI mean CSA of the median nerve was 6.8 mm² (±2.153 mm²), P = .442. Pearson correlation between modalities was 0.93, suggesting near-perfect correlation. Mean percent error was 8.8%. Conclusions: Results of this study suggest that US is an accurate method to measure CSA of the median nerve at the carpal tunnel inlet. The mean difference between US and MRI was unlikely to be clinically significant.

Value of cross-sectional area of median nerve by MRI in carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome is diagnosed based on history, physical examination, and nerve conduction testing; however, there are no clear criteria for the diagnosis of carpal tunnel syndrome. Recently, studies have aimed to diagnose carpal tunnel syndrome through ultrasound or MRI. The purpose of this study was to compare and analyze the cross-sectional area of the median nerve between patients with carpal tunnel syndrome and a control group.

METHODS

From July 2015 to August 2017, we retrospectively analyzed fishery and white-collar workers (164 people, 37 men, 127 women). Carpal tunnel syndrome was diagnosed on the basis of both physical examination and nerve conduction testing. A negative result in either test led to exclusion from the study.

RESULTS

In total, 164 wrist MRI were retrieved, with 67 patients diagnosed with carpal tunnel syndrome and 97 patients allocated to the control group. The mean value of cross-sectional area at the pisiform was 18.8 mm² in the MRI of the carpal tunnel syndrome patients and 12.1 mm² (p-value <0.05) in the control group. The mean value of cross-sectional area at the hook of hamate was 11.70 mm² and that at the control group was 11.67 mm² (p-value 0.055).

CONCLUSION

Cross-sectional area at pisiform in MRI is a valuable factor in the diagnosis of carpal tunnel syndrome and in predicting the duration of pain.

Sonographic Findings Associated With Carpal Tunnel Syndrome

PURPOSE

The purpose of this study was to identify associations between the clinical manifestations of carpal tunnel syndrome (CTS) and the sonographic measurements of the median nerve in the carpal tunnel. We hypothesized that sonographic changes in the median nerve from proximal to distal along the carpal tunnel would be associated with symptom severity scores.

METHODS

We report on 38 patients with clinical signs and symptoms of CTS in a prospective investigation. Subjects underwent sonographic evaluation with measurement of median nerve cross-sectional area (CSA) at 3 locations: the level of the pronator quadratus, pisiform, and hamate. In addition, we measured dimensions of the carpal tunnel at the levels of the pisiform (inlet) and hamate (outlet). Finally, we recorded maximal thickness of the transverse carpal ligament (TCL). Patients underwent routine clinical evaluation and 31 patients had electrodiagnostic examination. Patients completed the Levine Katz Questionnaire (LKQ) to characterize severity of clinical symptoms. Each clinician was blinded to symptom severity scores. Pearson correlation coefficients were calculated to measure the relationship between LKQ score and sonographic measures.

RESULTS

Median nerve CSA decreased over the course of the carpal tunnel from proximal to distal in 30 of 38 wrists. A greater absolute change in CSA of the median nerve over the course of the carpal tunnel between the pisiform and the hamate as well as between the pronator quadratus and the hamate correlated with increased severity of clinical symptoms. Increased thickening of the TCL also correlated with greater symptom severity scores.

CONCLUSIONS

Changes in CSA of the median nerve as well as thickening of the TCL correlate with CTS severity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Estimating the most accurate sonographic measurement in the diagnosis of carpal tunnel syndrome: Which is the best?

Objectives

This study aims to identify the most accurate method or ultrasonographic measurement for the diagnosis of carpal tunnel syndrome (CTS).

Patients and methods

Between October 2010 and April 2011, a total of 160 hands of 87 patients (4 males, 83 females; mean age 54.5 years; range, 26 to 84 years) with clinically and electrodiagnostically proven CTS and 80 hands of 40 controls (3 males, 37 females; mean age 53.7 years; range, 32 to 77 years) were evaluated by sonographic examination. The diameters and cross-sectional areas (CSA) of the median nerve and longitudinal diameters of the median nerve were measured at the inlet, proximal carpal tunnel, and outlet of the carpal tunnel. Volar bulging and thickness of the retinaculum were also measured.

Results

The most optimal combination for the diagnosis of CTS was proximal CSA, volar bulging, and the proximal transverse diameter. The combination of proximal CSA with volar bulging increased the sensitivity and specificity of sonographic measurements.

Conclusion

Based on our study results, ultrasonography can be used as a practical modality to distinguish CTS patients from asymptomatic controls.

Comparison of median nerve stiffness with and without rheumatoid arthritis by ultrasound real-time tissue elastography: A propensity score matching study

Objectives: This study aimed to compare median nerve stiffness measured by ultrasound real-time tissue elastography in patients with and without rheumatoid arthritis (RA and non-RA groups, respectively).Methods: Altogether, 402 hands of 201 RA group and 222 hands of 111 non-RA group were included in the study. Ultrasonography was performed to evaluate the circumference, cross-sectional area (CSA) and strain ratio as an elasticity of the median nerve at the inlet level of the carpal tunnel and the proximal portion of the carpal tunnel inlet. Using propensity score matching, the difference between RA and non-RA group were analyzed.Results: After propensity score matching, 135 hands in 104 RA group and 70 non-RA group were finally analyzed. There were no significant differences in the circumference and CSA of the median nerve between the two groups. The strain ratio of the median nerve was significantly higher in RA group than in non-RA group only at the inlet of the carpal tunnel level.Conclusions: The nerve stiffness in patients with RA measured by ultrasound real-time tissue elastography was higher than without RA. Inflammatory condition of the flexor tendon and wrist joint in patients with RA may generate fibrotic changes in the median nerve.Trial registration: University Hospital Medical Information Network Clinical Trials Registry: UMIN000015314.

Reliability of ultrasound speckle tracking with singular value decomposition for quantifying displacement in the carpal tunnel

Inhibited movement patterns of carpal tunnel structures have been found in carpal tunnel syndrome (CTS) patients. Motion analysis on ultrasound images allows us to non-invasively study the (relative) movement of carpal tunnel structures and recently a speckle tracking method using singular value decomposition (SVD) has been proposed to optimize this tracking. This study aims to assess the reliability of longitudinal speckle tracking with SVD in both healthy volunteers and patients with CTS. Images from sixteen healthy volunteers and twenty-two CTS patients were used. Ultrasound clips of the third superficial flexor tendon and surrounding subsynovial connective tissue (SSCT) were acquired during finger flexion-extension. A custom made tracking algorithm was used for the analysis. Intra-class correlation coefficients (ICCs) were calculated using a single measure, two-way random model with absolute agreement and Bland-Altman plots were added for graphical representation. ICC values varied between 0.73 and 0.95 in the control group and 0.66-0.98 in the CTS patients, with the majority of the results classified as good to excellent. Tendon tracking showed higher reliability values compared to the SSCT, but values between the control and CTS groups were comparable. Speckle tracking with SVD can reliably be used to analyze longitudinal movement of anatomical structures with different sizes and compositions within the context of the carpal tunnel in both a healthy as well as a pathological state. Based on these results, this technique also holds relevant potential for areas where ultrasound based dynamic imaging requires quantification of motion.

Sonographic Measurement of Cross-sectional Area of the Median Nerve in Academic Dentists Without Symptoms or Signs of Carpal Tunnel Syndrome

The objective was to evaluate the distribution of the cross-sectional area (CSA) and flattening ratio (FR) of the median nerve (MN) in asymptomatic academic dentists using ultrasonography (US). Fifty academic dentists underwent US of the MN in transverse section at the pisiform bone level and the CSA (mm2) and FR were measured bilaterally. A CSA of <10 mm2 was considered normal. Paired t-test showed no statistical significance between either hand for CSA and FR ( P> .05). Two independent t-tests showed significant statistical differences ( P= .023) between males and females in the right dominant hand for CSA. Linear correlation analysis showed no significant correlation between CSA and FR for number of years of experience or number of working hours per day in either hand ( P>.05). The CSA was abnormal in the right dominant hand in 20 (40%) of the subjects. These male academic dentists were at increased risk of having an enlarged MN without symptoms.

The effectiveness of gabapentin and exercises in the treatment of carpal tunnel syndrome: a randomized clinical trial

Carpal tunnel syndrome (CTS) is one of the reasons for labor abandonment due to inability and pain. The aim of this study was to evaluate the effectiveness of gabapentin and exercise training in the treatment of CTS and compare their effects. This single-blind clinical trial was conducted on patients referred to the Imam Hossein hospital's electrodiagnostic (EDX) unit. The patients randomly assigned into four groups: using nocturnal splint as an approved treatment in the control group; taking 300-mg gabapentin per night and using nocturnal splint; nerve and tendon gliding exercises and using nocturnal splint; and taking 300-mg gabapentin per night, performing same exercise as group 3 and using nocturnal splint. At baseline, four indicators were assessed in all patients, including the Boston carpal tunnel questionnaire, visual analogue scale (VAS), pinch and grip strength of the affected hand. One month after the beginning of intervention, participants were reassessed and compared for each of the four indicators. Using nocturnal splint along with exercise and gabapentin significantly improved VAS, pinch and grip strength in moderate CTS compared to control group that only used nocturnal splint. However in mild CTS, grip strength was not significantly higher compared to control group (P=0.048). Results of this study showed that use of splint alone in mild CTS is an appropriate and sufficient treatment; however, in moderate CTS, receiving gabapentin along with exercise and splinting showed better treatment results compared to splinting alone.

Correlation of ultrasound cross-sectional area of the median nerve, nerve conduction studies and 2-point discrimination

INTRODUCTION

The purpose of this study was to determine the correlation between a measure of physical performance, a measure of physiology and a measure of anatomy in the setting of carpal tunnel syndrome (CTS).

METHODS

A retrospective review of 215 consecutive patients with suspected CTS was conducted. All patients were evaluated with static 2-point discrimination (2PD), ultrasound (US) measurement of the median nerve cross-sectional area (CSA), and nerve conduction studies (NCS). Correlations between 2PD and US and NCS parameters were calculated. The ability of US/NCS to predict 2PD was evaluated.

RESULTS

Analysis failed to prove a statistically significant correlation between 2PD and median nerve CSA. A weak correlation was detected between 2PD and NCS parameters. When 2PD was used as a reference standard, NCS parameters combined had the greatest sensitivity, followed by US.

CONCLUSIONS

Currently used diagnostic tests (NCS and US) correlate poorly with 2PD. Muscle Nerve 000: 000-000, 2018 Muscle Nerve 59:236-239, 2019.

A randomized, controlled trial of magnetic therapy for carpal tunnel syndrome

INTRODUCTION

Magnet therapy has been proposed as a treatment for neurologic conditions. In this this trial we assessed the feasibility and efficacy of a magnet inserted into a wristband for carpal tunnel syndrome (CTS).

METHODS

Twenty-two patients with mild to moderate CTS were randomized to wear a high-dose or low-dose "sham" magnetic wristband for 6 weeks. The primary outcome was the Symptom Severity Scale (SSS) of the Boston Carpal Tunnel Questionnaire. Secondary measures were nerve conduction studies (NCS), median nerve ultrasound, and compliance.

RESULTS

Compliance for both groups was >90%. Improvements in the mean SSS, NCS, and median nerve ultrasound did not reach statistical significance.

DISCUSSION

Magnet therapy via wristband is well-tolerated. Further investigations in larger populations are needed to determine efficacy. Muscle Nerve 58: 310-313, 2018.

Distortion-free diffusion tensor imaging for evaluation of lumbar nerve roots: Utility of direct coronal single-shot turbo spin-echo diffusion sequence

PURPOSE

Diffusion tensor imaging (DTI) based on a single-shot echo planer imaging (EPI-DTI) is an established method that has been used for evaluation of lumbar nerve disorders in previous studies, but EPI-DTI has problems such as a long acquisition time, due to a lot of axial slices, and geometric distortion. To solve these problems, we attempted to apply DTI based on a single-shot turbo spin echo (TSE-DTI) with direct coronal acquisition. Our purpose in this study was to investigate whether TSE-DTI may be more useful for evaluation of lumbar nerve disorders than EPI-DTI.

MATERIALS AND METHODS

First, lumbar nerve roots of five healthy volunteers were evaluated for optimization of imaging parameters with TSE-DTI including b-values and the number of motion proving gradient (MPG) directions. Subsequently, optimized TSE-DTI was quantitatively compared with conventional EPI-DTI by using fractional anisotropy (FA) values and visual scores in subjective visual evaluation of tractography. Lumbar nerve roots of six patients, who had unilateral neurologic symptoms in one leg, were evaluated by the optimized TSE-DTI.

RESULTS

TSE-DTI with b-value of 400 s/mm² and 32 diffusion-directions could reduce the image distortion compared with EPI-DTI, and showed that the average FA values on the symptomatic side for six patients were significantly lower than those on the non-symptomatic side (P < 0.05).

CONCLUSION

Tractography with TSE-DTI might show damaged areas of lumbar nerve roots without severe image distortion. TSE-DTI might improve the reproducibility in measurements of FA values for quantification of a nerve disorder, and would become a useful tool for diagnosis of low back pain.

Evolution of clinical, electrophysiological, and radiological aspects of the carpal tunnel syndrome before and after surgery

The aim of the study was to analyze the evolution of the clinical, electrophysiological, and ultrasound aspects of carpal tunnel syndrome (CTS) before and 4 and 8 weeks after surgery. A Boston Carpal Tunnel Questionnaire, an ultrasound scan, and an electrophysiological exam were performed in 14 patients the day of surgery, 4 and 8 weeks after. The nerve conduction study included: median nerve sensory conduction stimulating digit 3 and 4, median motor conduction from the abductor pollicis brevis, ulnar nerve sensory, and motor conduction. A significant improvement of the symptoms and a significant decrease of the median nerve proximal cross-sectional area on the ultrasound scan were observed 4 weeks after surgery. Distal motor latency (DML) was > 4.2 ms in six patients and decreased along the three visits. DML was ≤ 4.2 ms in the eight others and stayed stable after surgery. We observed a significant increase of the sensory median nerve amplitude response at the wrist stimulating the third digit 8 weeks after surgery. When operated patients are referred for control, we recommend to perform: (1) 4 weeks after surgery, an ultrasonography, and a measure of the DML of the median nerve; (2) 8 weeks after surgery, a measure of the sensory conduction velocity of the median nerve.

Pain and compression neuropathy in primary inguinal hernia

PURPOSE

Enlargement of the ilioinguinal nerve at the external inguinal ring is observed in 34% of patients undergoing primary open inguinal herniorrhaphy; in 88% of patients it occurs at the fascial edge where the hernia mushrooms with abdominal pressure. Compression neuropathy occurs near many anatomical nerve constriction sites and is associated with enlargement of the peripheral nerve accompanied by sensory changes.

METHODS

In this prospective study, Carolina Comfort Scale (CCS) questionnaire data was collected for 35 primary hernia repairs. Each patient underwent primary inguinal herniorrhaphy that included ilioinguinal neurectomy. All nerves were sampled proximal to the external inguinal ring. Any nerves with grossly increased overall diameter to any degree distal to the external ring were additionally sampled in the thickened portions. A neuropathologist performed histologic evaluation of the H&E-stained cross sections.

RESULTS

Paired comparison of proximal and distal nerves revealed a greater overall diameter and greater measured nerve-specific diameter in distal nerve segments. Nerves with increased overall diameter were also found to have a statistically significant positive correlation with four of eight pain measures. Additionally, increased nerve-specific diameter correlates with increased pain on four of eight pain values, but age effect on nerve diameter blunts this finding.

CONCLUSIONS

Increased preoperative CCS pain values in primary open inguinal hernia are significantly correlated with gross enlargement of the overall diameter and nerve-specific diameter of the ilioinguinal nerve beyond the external inguinal ring. This is consistent with a compression neuropathy.

Why do inguinal hernia patients have pain? Histology points to compression neuropathy

PURPOSE

The purpose of this study is to describe the known soft tissue neuro-histology factors associated with compression neuropathy in relation to the incidence of preoperative pain in primary inguinal hernia. Enlargement of the ilioinguinal nerve occurs in 63% of patients with primary inguinal hernia; compression neuropathy has similar gross features.

METHODS

Patients completed pain questionnaires pertaining to preoperative pain and the quality of pain experienced. During routine inguinal hernia repair, nerve segments were sampled for histologic evaluation.

RESULTS

Twenty-two thickened nerve segments (63% of total) with proximal and distal specimens were resected for examination and comparison. We quantified various histologic indicators including nerve diameter, fascicle count, myxoid content within the epineurium, perineurium and endoneurium. Increased preoperative patient pain scores correlate with increased nerve diameter, increased fascicle count and increased myxoid material both within the perineurium and endoneurium.

CONCLUSION

These findings support the concept that preoperative hernia pain is associated with compression neuropathy.

Sonographic Findings of Median Nerve and Prevalence of Carpal Tunnel Syndrome in Computer Mouse Users

The purpose of this study was to evaluate the median nerve sonographically and estimate the prevalence of carpal tunnel syndrome (CTS) in computer mouse users. Forty-nine right wrists of 49 employees who had used a computer mouse were included in the study. Thirty-three right wrists of 33 non-mouse user employees were studied as a control group. Both the mouse user and non-mouse user employees underwent sonography and electromyography (EMG). Axial sonograms of the median nerve were obtained proximally, in the middle and distally in the carpal tunnel. At each level, flattening ratio and the cross-sectional area of the median nerve were calculated. We found no significant difference in any parameters between mouse users and control group ( p>0.05). However, when we compared mouse users according to the presence of pain, there was a significant increase in the cross-sectional area of the median nerve proximally in the mouse users having pain ( p<0.05). Of all mouse users, eight (16.3%) were diagnosed as sensory CTS, four (8.2%) as motor CTS by EMG. We also found that four (50%) CTS patients had a proximal cross-sectional area of median nerve exceeding 10 mm2 and five (62.5%) had a distal flattening ratio over three. Prolonged use of a mouse may pose an occupational risk for employees. Sonography can serve as an initial step in symptomatic patients for diagnosis of CTS.