Carpal tunnel decompression in spite of normal electromyography

Characteristics of Patients with Clinical Signs and Symptoms of Carpal Tunnel Syndrome but Negative Diagnostic Testing

Background

Carpal tunnel syndrome (CTS) is a clinical diagnosis involving numerous confirmatory diagnostic tools, including patient questionnaires, ultrasound (US), and electrodiagnostic studies (EDX.) Patients may experience clinical symptoms of CTS with false negative diagnostic testing. The purpose of this study was to identify characteristics of patients with clinical symptoms of CTS with negative diagnostic testing.

Methods

An existing database of 295 hands containing the six-item CTS-6, US of the median nerve, and EDX was queried. Patients with symptoms of carpal tunnel scoring 12.5 or higher on CTS-6 were sorted into those with all positive testing or negative testing.

Results

In 60 patients, 103 hands had both positive US and EDX and a CTS-6 of 12.5 or higher. Twenty-nine hands in 25 patients had a CTS-6 of 12.5 or higher and both negative ultrasound and EDX. There was a significantly younger average age of 43 (P = 0.007) and lower average BMI of 28 (P < 0.0001) of patients in the negative diagnostic study group, compared with the average age of 53, and a body mass index (BMI) of 34 in the positive diagnostic study.

Conclusions

In this series, patients with symptoms of carpal tunnel syndrome and negative diagnostic studies were on average younger and had a lower BMI. These patients may warrant more careful consideration of CTS clinical diagnosis and counseling regarding a higher risk of false-negative confirmatory testing. Further studies are needed to determine possible effects of age and BMI on electrodiagnostic studies and ultrasound testing in CTS.

Correlation of Carpal Tunnel Syndrome 6 Score and Physical Exam Maneuvers With Electrodiagnostic Test Severity in Carpal Tunnel Syndrome: A Blinded Prospective Cohort Study

PURPOSE

Although carpal tunnel syndrome (CTS) can be diagnosed clinically with the Carpal Tunnel Syndrome 6 (CTS-6) evaluation tool, the relationship between disease severity and CTS-6 score has not been elucidated. The purpose of our study was to determine the correlation of the CTS-6 score and other physical examination maneuvers with the carpal tunnel severity grade by electrodiagnostic testing (EDT). We hypothesized that the CTS-6 score, Durkan test, and Semmes Weinstein Monofilament Testing (SWMT) positively correlate with EDT severity.

METHODS

We prospectively enrolled 105 consecutive patients who presented to the office with suspected CTS, excluding those with previous surgery, previous EDT from an outside facility, or concomitant neuropathy. Four fellowship-trained hand surgeons obtained the CTS-6 score, time to obtain a positive Durkan compression test, and SWMT of the thumb, index, and middle fingers. All patients were sent for EDT. Hand surgeons were blinded to the results of the EDT, and the electrodiagnosticians were blinded to the clinical data. We used the Bland criteria (0-6) to grade CTS severity on EDT. This grade was compared with the CTS-6 score, Durkan time, and SWMT results.

RESULTS

Using Spearman correlation coefficients, we found a weakly positive correlation between a higher CTS-6 score and a higher severity grade on EDT. The mean CTS-6 score based on EDT grading were the following: (1) 14.8 (grade 0), (2) 16.0 (grade 1), (3) 14.8 (grade 2), (4) 16.7 (grade 3), (5) 18.7 (grade 4), (6) 18.3 (grade 5), and (7) 22.4 (grade 6). We also found a statistically significant association between the SWMT and a higher CTS-6 score as well as a higher severity grade on EDT. Durkan compression test did not appear to correlate with the EDT grade.

CONCLUSIONS

The CTS-6 and SWMT show a positive correlation with EDT severity in CTS on the basis of the Bland criteria. The time to a positive Durkan test did not show any correlation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Diagnostic Value of a Carpal Tunnel Corticosteroid Injection in Patients with Negative Electrodiagnostic Studies

Introduction  There is a known false negative rate when using electrodiagnostic studies (EDS) to diagnose carpal tunnel syndrome (CTS). This can pose a management dilemma for patients with signs and symptoms that correlate with CTS but normal EDS. While corticosteroid injection into the carpal tunnel has been used in this setting for diagnostic purposes, there is little data in the literature supporting this practice. The purpose of this study is to evaluate the prognostic value of a carpal tunnel corticosteroid injection in patients with a normal electrodiagnostic study but exhibiting signs and symptoms suggestive of carpal tunnel, who proceed with a carpal tunnel release. Materials and Methods  The group included 34 patients presenting to an academic orthopedic practice over the years 2010 to 2019 who had negative EDS, a carpal tunnel corticosteroid injection, and a carpal tunnel release. One patient (2.9%), where the response to the corticosteroid injection was not documented, was excluded from the study, yielding a study cohort of 33 patients. Three patients had bilateral disease, yielding 36 hands for evaluation. Statistical analysis was performed using Chi-square analysis for nonparametric data. Results  Thirty-two hands (88.9%) demonstrated complete or partial relief of neuropathic symptoms after the corticosteroid injection, while four (11.1%) did not experience any improvement. Thirty-one hands (86.1%) had symptom improvement following surgery, compared with five (13.9%) which did not. Of the 32 hands that demonstrated relief following the injection, 29 hands (90.6%) improved after surgery. Of the four hands that did not demonstrate relief after the injection, two (50%) improved after surgery. This difference was statistically significant ( p  = 0.03). Conclusion  Patients diagnosed with a high index of suspicion for CTS do well with operative intervention despite a normal electrodiagnostic test if they have had a positive response to a preoperative injection. The injection can provide reassurance to both the patient and surgeon before proceeding to surgery. Although patients with a normal electrodiagnostic test and no response to cortisone can still do well with surgical intervention, the surgeon should carefully review both the history and physical examination as surgical success may decrease when both diagnostic tests are negative. Performing a corticosteroid injection is an additional diagnostic tool to consider in the management of patients with CTS and normal electrodiagnostic testing.

The Utility of the Carpal Tunnel Syndrome-6 for Predicting the Outcomes of Carpal Tunnel Release

PURPOSE

Considering the cost of, discomfort with, and time required for nerve conduction testing, the Carpal Tunnel Syndrome-6 (CTS-6) is often used to determine the likelihood of the presence of carpal tunnel syndrome. We sought to determine whether the CTS-6, designed as a diagnostic instrument, could serve a dual purpose and predict the outcome of carpal tunnel release (CTR) based on postoperative changes in the Boston Carpal Tunnel Questionnaire (BCTQ) score.

METHODS

This prospective observational study enrolled 118 adults before they underwent open CTR at a tertiary center. A primary regression analysis was used to determine the association between preoperative CTS-6 scores and changes in the BCTQ score at ≥6 months after surgery. Additional demographic, social, electrodiagnostic, and mental health variables were assessed for associations with changes in the BCTQ score. The secondary outcomes included single questions rating satisfaction with the result of CTR as well as symptom changes and the Decision Regret Scale. Noneffective CTR was defined as a BCTQ score change of <1.0 point or reported dissatisfaction.

RESULTS

Postoperatively, the BCTQ score improvement averaged 1.38 ± 0.77. Although 102 of 109 patients (94%) noted symptom improvement, 94 of 109 (86%) were satisfied with the result of CTR, and 78 of 109 patients (72%) demonstrated a meaningful change in the BCTQ score. Preoperative CTS-6 scores were not correlated with changes in BCTQ scores. CTS-6 scores were not associated with Decision Regret Scale scores, reported satisfaction, or the single-question assessment of symptom changes. Satisfaction, decision regret, and the single symptom change question were correlated with changes in the BCTQ score and each other. Dissatisfied patients were distinguished by a differential improvement in the BCTQ score (1.5 vs 0.7), but no preoperative variable consistently predicted noneffective CTR.

CONCLUSIONS

The CTS-6 score does not predict changes in BCTQ scores after CTR. Patient satisfaction with surgical results is associated with postoperative changes in carpal tunnel symptoms but is not predictable using preoperative information. A single question of symptom change may offer an efficient assessment of CTR outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Ultrasonographical Evaluation of the Median Nerve Mobility in Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis

Diagnostic ultrasound is widely used for evaluating carpal tunnel syndrome (CTS), an entrapment neuropathy of the median nerve (MN). Decreased mobility of the MN inside the carpal tunnel has been reported in CTS, and various methods have been used to evaluate MN mobility; however, there is still no conclusive understanding of its connection with CTS. The purpose of this study is to conduct a systematic review and meta-analysis of the current published literature on ultrasonographic evaluations of transverse and longitudinal MN displacement and to identify the relationship between MN mobility and CTS. This study was conducted in accordance with the 2020 PRISMA statement and the Cochrane Collaboration Handbook. Comparative studies that investigated differences in MN displacement between CTS patients and healthy controls were retrieved by searching the Cochrane Library, Embase and PubMed. A total of 15 case–control studies were included. Nine of 12 studies evaluating transverse MN displacement and 4 of 5 studies evaluating longitudinal MN gliding showed that the MN was less mobile in CTS patients than in healthy subjects. Despite the large heterogeneity among the 15 included studies, this systematic review and meta-analysis provide evidence that the mobility of the MN is significantly reduced in both transverse and longitudinal planes in CTS patients compared to healthy controls. Five of the 15 included studies reported that a decrease in transverse or longitudinal MN displacement in CTS was correlated with clinical symptoms or with severity as measured by a nerve conduction study (NCS).

Surgeon Ratings of the Severity of Idiopathic Median Neuropathy at the Carpal Tunnel Are Not Influenced by Magnitude of Incapability

BACKGROUND

Accurately distinguishing the severity of pathophysiology from the level of symptom intensity and incapability is a foundation of effective treatment strategies under the biopsychosocial paradigm of illness. With respect to idiopathic median neuropathy at the carpal tunnel (the symptoms and signs of which are referred to as carpal tunnel syndrome), surgeons who are more likely to recommend surgery based on the magnitude of symptoms and incapability rather than the severity of neuropathy may be underappreciating and undertreating mental health opportunities and overtreating mild, and on occasion unmeasurable, disease. A survey-based experiment that randomizes elements of the patient presentation can help determine the relative influence of magnitude of incapability on ratings of pathology severity.

QUESTION/PURPOSE

What factors are associated with severity rating of idiopathic median neuropathy at the carpal tunnel on an 11-point ordinal scale?

METHODS

One hundred eight hand and wrist members of the Science of Variation Group (among approximately 200 participants who complete at least one survey-experiment a year related to the upper extremity on average) reviewed seven scenarios of fictional median neuropathy with seven randomized variables: age, gender, limitations of daily activity (incapability), Tinel and Phalen test results, duration of numbness episodes, prevention of numbness with nocturnal splint immobilization, constant numbness, and weakness of palmar abduction. Participants had a mean age of 51 ± 10 years, 90% (97 of 108) were men, and 74% (80 of 108) were subspecialized in hand surgery. Surgeons were asked to rate the severity of idiopathic median neuropathy at the carpal tunnel on a on an 11-point ordinal scale. Factors associated with rated severity were sought in multilevel ordered logistic regression models. Fifteen surgeons did not complete all of their assigned randomized scenarios, resulting in a total of 675 ratings.

RESULTS

After controlling for potentially confounding variables such as magnitude of incapability, factors associated with severity rating on the 11-point ordinal scale included palmar abduction weakness (odds ratio 11 [95% confidence interval 7.7 to 15]), longer duration of symptom episodes (OR 4.5 [95% CI 3.3 to 6.2]), nocturnal numbness in spite of splint immobilization (OR 3.2 [95% CI 2.3 to 4.3]), constant numbness (OR 2.5 [95% CI 1.9 to 3.4]), positive Tinel and positive Phalen test results (OR 2.2 [95% CI 1.6 to 2.9]), and older age (OR 1.6 [95% CI 1.2 to 2.1]).

CONCLUSION

Our results suggest that surgeons rate the severity of idiopathic median neuropathy at the carpal tunnel based on evidence of worse pathophysiology and are not distracted by greater incapability.

CLINICAL RELEVANCE

Surgeons who consider greater incapability as an indication of more severe pathology seem to be practicing outside the norm and may be underappreciating and undertreating the unhelpful thoughts and feelings of worry or despair that consistently account for a notable amount of the variation in symptom intensity and magnitude of incapability.

Difference and ratio of the cross-sectional area of median nerve at the carpal tunnel and the pronator quadratus muscle in diagnosing carpal tunnel syndrome: a cross-sectional study

Background

At present, the most commonly used diagnostic method of carpal tunnel syndrome (CTS) is based on clinical manifestations and electrophysiology, but the electrophysiology is not cheap, invasive, and lacks the presentation of peripheral nerve conditions, which is exactly the advantage of ultrasound (US). The purpose of this study was to evaluate the accuracy and effectiveness of US in the diagnosis of CTS by calculating the cross-sectional area (CSA) at the carpal tunnel and proximally at the level of the pronator quadratus muscle., and to find an appropriate index that can be used to achieve the diagnosis in a more cost-effective manner.

Methods

Forty-three wrists from 35 symptomatic CTS patients and 23 wrists from 18 asymptomatic volunteers were evaluated. Diagnosis in the CTS group was based on the American Academy of Neurology clinical diagnostic criteria. The ultrasonic probe was placed at the carpal tunnel and the distal 1/3 of the pronator muscle respectively, and the carpal tunnel cross-sectional area (CSAC) and the proximal cross-sectional area (CSAP) was calculated, with a further calculation of their difference (ΔCSA) and ratio (R-CSA).

Results

There was a significant difference between the 2 groups regarding mean ± standard deviation (SD) of CSAC, CSAP, ΔCSA, and R-CSA (P<0.01). The cutoff value of 12.14 mm² for CSAC had a sensitivity and specificity of 90.7% and 100%, respectively; the cutoff value of 1.235 mm² for R-CSA had a sensitivity and specificity of 97.67% and 95.65%, respectively; and the cutoff value of 2.035 mm² for ΔCSA had a sensitivity and specificity of 100% and 100%, respectively. Therefore, US was found to be an effective method for the diagnosis of CTS. Receiver operating characteristic curve (ROC) analysis of all patients showed area under the curve (AUC) was 0.9778 for CSAC, 0.9949 for R-CSA and 1.000 for ΔCSA.

Conclusions

US can provide reference values for the diagnosis of CTS. CSAC, ΔCSA, and R-CSA can be used for CTS diagnosis and evaluation. The ROC curve analysis showed that among the 3 values, ΔCSA was the most useful in the diagnosis of patients with CTS. ΔCSA is considered a valid diagnostic value for CTS, as its threshold of 2.04 mm² showed the highest sensitivity and specificity.

Electrodiagnostic, Sonographic, and Clinical Features of Carpal Tunnel Syndrome with Bifid Median Nerve

Purpose

A bifid median nerve (BMN) is not a rare variant. This study aimed to investigate the features of carpal tunnel syndrome (CTS) accompanied by BMN.

Patients and Methods

In this retrospective study, we defined a BMN group as CTS with BMN and a non-bifid median nerve (NMN) group as CTS without BMN. All hands were assigned to four severity grades according to the findings of electrodiagnosis (EDx): very mild, mild, moderate, and severe. The cross-sectional area (CSA) of the median nerve, palmar bowing of the flexor retinaculum, and persistent median artery (PMA) were assessed by ultrasonography. Numerical pain rating scale (NRS) and symptom duration were assessed as clinical variables.

Results

Sixty-four hands (57 patients) and 442 hands (341 patients) were enrolled in the BMN and the NMN groups, respectively. BMN was prevalent in 12.6% of all CTS hands. The distribution of EDx severity grade was milder in the BMN group than in the NMN group (P<0.001). The CSA of the BMN group was 16.2±4.1 mm², slightly larger than 15.1±4.2 mm² in the NMN group (P=0.056). The BMN group showed higher NRS than the NMN group (5.5±1.5 and 4.4±1.7, respectively; P<0.001). In the subgroup analysis, NRS was significantly higher in the BMN group than in the NMN group at all EDx severity grades. In the BMN group, the PMA group showed greater EDx severity (P=0.037) and higher NRS (6.0 and 5.0, respectively; P=0.012) than the non-PMA group. The radial side branch's CSA was larger than that of the ulnar side branch (10.0 mm² and 6.0 mm², respectively; P<0.001).

Conclusion

CTS with BMN presented more severe symptoms and relatively milder EDx severity. When assessing the severity of CTS with BMN, the clinical symptoms should primarily be considered, as well as we should complementarily evaluate the EDx and ultrasonography.

Carpal Tunnel Release Despite Normal Nerve Conduction Studies in Carpal Tunnel Syndrome Patients

PURPOSE

Carpal tunnel syndrome (CTS) is a common entrapment neuropathy, often requiring carpal tunnel release (CTR) surgery. Often, a nerve conduction study (NCS) is performed before CTR; however, there are various reports questioning the sensitivity of NCS, and some patients do undergo CTR despite normal NCS results. We had the following purposes: (1) to report clinical outcome of CTS patients who undergo CTR despite normal NCS, (2) to identify the characteristics and compare those with abnormal NCS patients in terms of basic features and risk factors, and (3) to analyze and compare normal and abnormal NCS results.

MATERIALS AND METHODS

Medical records of 546 CTS (30 normal NCS and 516 abnormal NCS) patients were retrospectively reviewed. Of 30 normal NCS patients, 7 were excluded, leaving 23 patients in the experimental group. We investigated the influence of age, sex, operative arm, and body mass index, as well as medical conditions known to be risk factors for CTS. In normal NCS patients, as a functional score, we investigated Boston carpal tunnel scores before and after CTR. The NCS results were compared in terms of median motor and median sensory testing. In normal NCS patients, NCS data were compared with that of the contralateral nonoperated wrists.

RESULTS

There were 18 women and 5 men in the normal NCS group (mean age 43.7 years). On physical examination, 22 (94.7%) patients showed a positive Tinel test, 19 (82.6%) showed a positive Phalen test, 8 (34.8%) complained of nocturnal paresthesia, and only 1 (4.3%) presented with thenar atrophy. In 19 of 23 patients, the Boston CTS scores showed significant improvement after CTR. Normal NCS patients were significantly younger and significantly heavier and more likely to be a current smoker. In NCS analysis of normal NCS patients, the operated wrists were closer to the reference values than nonoperated wrists.

CONCLUSIONS

Surgeons should evaluate the possibility of other combined lesions before CTR in normal NCS patients. Normal NCS can be present with a CTS diagnosis, especially in younger patients. Nevertheless, CTR after failed conservative management, despite normal NCS, could relieve subjective symptoms and function.

Mimickers of Carpal Tunnel Syndrome

Carpal tunnel syndrome is the most common compression neuropathy. Despite the prevalence of carpal tunnel syndrome, many other conditions present with similar symptoms (numbness, tingling, thenar atrophy, and weakness). Carpal tunnel syndrome is differentiated from other etiologies through a detailed history and physical examination, aided by electrodiagnostic and adjunctive imaging studies. Misdiagnosis can lead to unnecessary operative procedures and persistent symptoms.

Carpal tunnel decompression in patients with normal nerve conduction studies

Some patients present with typical clinical features of carpal tunnel syndrome despite normal nerve conduction studies. This study compared the preoperative and 1-year postoperative QuickDASH scores in patients with normal and abnormal nerve conduction studies, who underwent carpal tunnel decompression. Of the 637 patients included in the study, 19 had clinical features of carpal tunnel syndrome but normal nerve conduction studies, and underwent decompression after failure of conservative management. Preoperative QuickDASH scores were comparable in both groups (58 vs 54.8). However, there were significant differences between the normal and abnormal nerve conduction study groups in the QuickDASH at 1 year (34.9 vs 21.5) and change in QuickDASH postoperatively (23.1 vs 33.4). Patients with normal nerve conduction studies had comparable preoperative disability scores compared with those with abnormal studies. Although they had a significant improvement in QuickDASH at 1 year, this was significantly less than those with abnormal nerve conduction studies. Level of evidence: III.

Median nerve ultrasound in carpal tunnel syndrome with normal electrodiagnostic tests

INTRODUCTION

To evaluate the ultrasound findings of the median nerve in patients with clinical assigned carpal tunnel syndrome but normal nerve conduction studies.

METHODS

This prospective, cross-sectional study involved 41 patients (51 hands) with clinically assigned CTS and normal nerve conduction studies and 20 healthy controls (30 hands). Ultrasonography was performed in all participants, and cross-sectional area (CSA), hypoechogenicity, and mobility of the median nerve were evaluated. All patients were assessed with Boston Carpal Tunnel Questionnaire (BCTQ).

RESULTS

CSA of the median nerve in the wrist was significantly higher in the patient group when compared to the control group. Echogenicity and mobility were significantly decreased in the patient group. Ultrasound abnormalities were positively correlated with clinical features. A significant correlation was observed among sensory loss, provocative tests, body mass index, BCTQ, and high CSA.

CONCLUSION

US can help the clinicians with the diagnosis of carpal tunnel syndrome in patients with clinical symptoms but negative nerve conduction study results.

Cold effect in median nerve conductions in clinical carpal tunnel syndrome with normal nerve conduction studies

Clinical diagnosis of carpal tunnel syndrome (CTS) is confirmed by nerve conduction studies (NCS). In some cases, NCS may be normal. We aimed to demonstrate changes of distal motor latency (DML) and nerve conduction velocity (NCV) pathology of demyelination in entrapment neuropathy with cold application in case of clinical CTS with normal NCS. This prospective, cross-sectional, randomise, case-control involved 15 patients (25 hands) with clinically definite unilateral or bilateral CTS and normal nerve conduction studies (NCS), and 11 controls (22 hands). Ice pack was applied to median nerve trasse at wirst with monitoring skin temperature. NCS of median nerve were examinated again. Increases of DML, decrease of velocity of median nerve were observed in two groups after post-cooling. The change in NCV was greater than the change in DML. Cold effect was evident in DML and NCV in the patient group. This could be sign of the demyelination pathology. We think that cold application is influential to determine electrophysiologic abnormalities in clinic CTS with normal NCS.

Medical Ultrasound in the Evaluation of the Carpal Tunnel: A Critical Review

The use of medical ultrasound as an imaging modality in the evaluation of the carpal tunnel syndrome has been growing. Technical progress and the introduction of new, high-quality devices and ultra-high frequency transducers with smaller dimensions have led to a better quality of acquired images and the development of new examination methodologies. The sonographic method has a number of advantages: available, non-invasive, cheaper, and allows an easier and faster evaluation and diagnosis of carpal tunnel syndrome, along with the possibility to assess various parameters of the median nerve, including its size, blood flow, and mobility. In addition, medical ultrasound may be used to detect anatomical variations and space-occupying lesions in the carpal tunnel to monitor the therapeutic response in patients suffering from carpal tunnel syndrome and to evaluate median nerve injuries. Herein, we present a review of the pertinent literature with regard to the diagnostic potential of medical ultrasound in the evaluation of pathological changes in the carpal tunnel.

Ultrasound elastography for carpal tunnel pressure measurement: A cadaveric validation study

Carpal tunnel pressure is a key factor in the etiology of carpal tunnel syndrome. Numerous approaches have been conducted to measure carpal tunnel pressure. However, most techniques are invasive and take time and effort. We have developed an innovative approach to noninvasively assess the tunnel pressure by using the ultrasound surface wave elastography (USWE) technique. In a previous study it was shown that the shear wave speed in a tendon increased linearly with increasing tunnel pressure enclosed the tendon in a simple tendon model. This study aimed to examine the relationship between the carpal tunnel pressure and the shear wave speeds inside and outside the carpal tunnel in a human cadaveric model. The result showed that the shear wave speed inside the carpal tunnel increased linearly with created carpal tunnel pressure, while the shear wave speed outside the carpal tunnel remained constant. These findings suggest that noninvasive measurement of carpal tunnel pressure is possible by measuring the shear wave speed in the tendon. After fully establishing this technology and being applicable in clinic, it would be useful in the diagnosis of carpal tunnel syndrome. For that reason, further validation with this technique in both healthy controls and patients with carpal tunnel syndrome is required. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:477-483, 2018.

Treatment outcome in patients with clinically defined carpal tunnel syndrome but normal electrodiagnostic test results: a randomized controlled trial

Little is known about treatment effect of carpal tunnel release in patients with clinically defined carpal tunnel syndrome (CTS), but normal electrodiagnostic test results (EDX). The aim of this study was to determine whether this category of patients will benefit from surgical treatment. 57 patients with clinically defined CTS and normal EDX were randomized for surgical treatment (n = 39) or non-surgical treatment (n = 18). A six-point scale for perceived improvement as well as the Boston Carpal Tunnel Questionnaire was completed at baseline and at follow-up after 6 months. A significant improvement of complaints was reported by 70.0% of the surgically treated patients and 39.4% reported full recovery 6 months after surgery. Furthermore, both Functional Status Score and Symptom Severity Score improved significantly more in the surgically treated group (p = 0.036 and p < 0.001, respectively). This study demonstrates that most patients with clinically defined CTS and normal EDX results will benefit from carpal tunnel release. Therefore, this group of CTS patients must not a priori be refrained from surgery.

Diagnostic Testing Requested Before Surgical Evaluation for Carpal Tunnel Syndrome

PURPOSE

We sought to evaluate how often physicians who perform carpal tunnel release in the state of Michigan routinely request electrodiagnostic studies (EDS) or other diagnostic tests prior to an initial consultation and whether provider or practice characteristics had an influence on requirements for preconsultation diagnostic tests.

METHODS

Through online data sources, we identified 356 providers in 261 practices throughout the state of Michigan with profiles confirming hand surgery practice or surgical treatment of carpal tunnel syndrome (CTS). We recorded American Society for Surgery of the Hand (ASSH) membership, teaching facility status, practice size, and primary specialty for each provider. Using a standardized telephone script, 219 providers were contacted by telephone to determine whether any diagnostic tests were needed before an appointment. Using multivariable logistic regression, we evaluated the relationship between the requirement for preconsultation testing and surgeon and practice characteristics.

RESULTS

Among the 134 providers who were confirmed to perform carpal tunnel release, 57% (n = 76) required and 9% (n = 12) recommended a diagnostic test prior to the initial consultation. Of the 88 physicians who required/recommended testing, 85% (n = 75) requested EDS, 22% (n = 19) requested magnetic resonance imaging, 13% (n = 11) requested a computed tomography scan, and 9% (n = 8) requested an x-ray. Patients were asked to have multiple studies by 19 (22%) of the 88 surgeons who requested/recommended testing. In the multivariable analysis, ASSH membership, size of practice, and teaching facility status did not have a significant relationship with the requirement for preconsultation testing.

CONCLUSIONS

Most surgeons who treat CTS in the state of Michigan routinely request EDS before evaluation, rather than reserving the test for cases in which the diagnosis is unclear.

CLINICAL RELEVANCE

In the quest for high-value care, providers must consider whether the benefit of diagnostic tests for CTS likely outweighs the costs, inconvenience, and potential for treatment delay.

Neuromuscular ultrasound in patients with carpal tunnel syndrome and normal nerve conduction studies

INTRODUCTION

Nerve conduction studies (NCS) are sensitive for carpal tunnel syndrome (CTS), but a small proportion of patients with clinical CTS have normal NCS. This retrospective study was designed to assess the neuromuscular ultrasound findings in a group of CTS patients.

METHODS

The electronic medical record was reviewed by a neurologist to identify patients who had a diagnosis of CTS with normal NCS, including either mixed median-ulnar comparison or transcarpal sensory studies, and complete neuromuscular ultrasound evaluation for CTS.

RESULTS

Fourteen individuals (22 wrists) met all criteria. A total of 92.3% had median nerve cross-sectional area enlargement at the wrist (mean 16.3 mm² ), 100% had increased wrist-to-forearm median nerve area ratio (mean 2.4), 82.4% had decreased median nerve echogenicity, 75.0% had decreased median nerve mobility, and 7.1% had increased median nerve vascularity.

CONCLUSION

A large proportion of patients with clinical CTS but normal NCS have abnormal neuromuscular ultrasound findings. Muscle Nerve 55: 913-915, 2017.

The clinical relevance of complex regional pain syndrome type I: The Emperor's New Clothes

The management of patients with chronic pain is a nearly daily challenge to rheumatologists, neurologists, orthopedic surgeons, pain specialists and indeed a issue in nearly every clinical practice. Among the myriad of causes of pain are often included a unique syndrome, generally referred to as complex regional pain syndrome type I (CRPS). Unfortunately CRPS I has become a catch all phase and there are serious questions on whether it exists at all; this has led to an extraordinary number of poorly defined diagnostic criteria. It has also led to an etiologic quagmire that includes features as diverse as autoimmunity to simple trauma. These, in turn, have led to overdiagnosis and often overzealous use of pain medications, including narcotics. In a previous paper, we raised the issue of whether CRPS type I reflected a valid diagnosis. Indeed, the diagnostic criteria for CRPS I, and therefore the diagnosis itself, is unreliable for a number of reasons: 1) the underlying pathophysiology of the signs and symptoms of CPRS I are not biologically plausible; 2) there are no consistent laboratory or imaging testing available; 3) the signs and symptoms fluctuate over time without a medical explanation; 4) the definitions of most studies are derived from statistical analysis with little consideration to required sample size, i.e. power calculations; 5) interobserver reliability in the assessment of the signs and symptoms are often only fair to moderate, and agreement on the diagnosis of "CRPS I" is poor. Even physicians who still believe in the concept of "CRPS I" admit that it is vastly overdiagnosed and has become a diagnosis of last resort, often without a complete differential diagnosis and an alternative explanation. Finally, one of the most convincing arguments that there is no clinical entity as "CRPS I" comes from the enormous heterogeneity in sign and symptom profiles and the heterogeneity of pathophysiological mechanisms postulated. This observation is underscored by the diversity of responses among "CRPS I" patients to essentially all treatment modalities. It has even led to the concept that the signs and symptoms of CRPS can spread throughout the body, as if it is an infectious disease, without any medical plausible explanation. If true progress is to be made in helping patients with pain, it will require entirely new and different concepts and abandoning CRPS I as a legitimate diagnosis.

The Effects of Oscillatory Biofield Therapy on Pain and Functional Limitations Associated with Carpal Tunnel Syndrome: Randomized, Placebo-Controlled, Double-Blind Study

OBJECTIVES

Biofield treatments have been used for pain control in patients with cancer and chronic pain. However, research on the effect of biofield treatment on specific somatic disorders is lacking. This study intends to investigate the effect of oscillating biofield therapy (OBFT) on symptoms of carpal tunnel syndrome.

DESIGN

Randomized, placebo-controlled, double-blind study.

PARTICIPANTS

Thirty patients with chronic carpal tunnel syndrome participated in the study.

INTERVENTION

Patients were randomly assigned to active or placebo treatment groups. Those in the treatment group received six sessions of OBFT with intention to treat during a period of 2 weeks. Patients in the placebo group had the same number of treatment sessions with mock OBFT treatment.

OUTCOME MEASURE

The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire; Symptom Severity Scale (SSS); and Functional Status Scale (FSS) were used for outcome assessment.

RESULTS

Both clinically and statistically significant changes in intensity of pain with activity (95% confidence interval [CI], 2.5-4.2; p = 0.000), night pain (p = 0.000, 95% CI, 3.2-5.7), DASH questionnaire (95% CI, 12.0-21.9; p = 0.000), SSS (95% CI, 0.64-1.15; p = 0.003), and FSS (95% CI, 0.41-0.97; p = 0.029) were found between the treatment and placebo groups. Statistically significant reduction in number of patients with positive results on the Phalen test (87%; p = 0.000), Tinel sign (73%; p = 0.000), and hand paresthesia (80%; p = 0.000) was noted in the treatment group. During 6-month follow-up, 86% of patients in the treatment group remained pain free and had no functional limitations.

CONCLUSION

OBFT can be a viable and effective treatment for improving symptoms and functional limitations associated with chronic carpal tunnel syndrome.

Immediate and durable clinical improvement in the non-operated hand after contralateral surgery for patients with bilateral Carpal Tunnel Syndrome

BACKGROUND

Little is known about clinical improvement in the non-operated hand after unilateral surgery for patients who present with bilateral carpal tunnel syndrome (CTS). In this prospective study of patients with bilateral CTS, we evaluated the clinical effects on the non-operated hand following unilateral contralateral carpal tunnel surgical release.

MATERIAL AND METHODS

During a consecutive period of 22 months, 69 patients with bilateral CTS underwent unilateral open carpal tunnel release. Bilateral subjective and objective evaluations were performed pre-operatively, at days 2, 15 and 180 after surgery. Subjective evaluations, analysed with Student t test, included the Boston-Levine symptom severity score and a visual analogue scale including pain, nocturnal symptoms and numbness. A telephone survey was conducted 12 months after surgery.

RESULTS

The Boston-Levine severity score of the contralateral non-operated hand decreased from 2.70 pre-operatively to 1.70 at 2 days (p < 0.001). The visual analogue pain score decreased at 2 days for 61 patients (88 %), whereas the nocturnal symptoms decreased or disappeared in 63 cases (91 %) and the paresthesia in 52 cases (75 %) (ps < 0.001). These beneficial effects were stable in time with no statistically significant change at 180 days. Overall, 58 patients (84 %) observed a total resolution or a significant improvement in their symptoms at 6 months. At 12 months, 100 % of patients responded to a telephone survey. Fifty one of them (74 %) reported minimal or no symptoms on the non-operated hand. Linear regression (analysis of variance [ANOVA]) showed that gender, age, professional status, duration of pre-operative symptoms and severity of electrophysiological disturbances were not predictive of post-operative evolution in the non-operated hand after unilateral surgery for CTS.

Carpal tunnel syndrome and work

Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome, and it frequently presents in working-aged adults. Its mild form causes 'nuisance' symptoms including dysaesthesia and nocturnal waking. At its most severe, CTS can significantly impair motor function and weaken pinch grip. This review discusses the anatomy of the carpal tunnel and the clinical presentation of the syndrome as well as the classification and diagnosis of the condition. CTS has a profile of well-established risk factors including individual factors and predisposing co-morbidities, which are briefly discussed. There is a growing body of evidence for an association between CTS and various occupational factors, which is also explored. Management of CTS, conservative and surgical, is described. Finally, the issue of safe return to work post carpal tunnel release surgery and the lack of evidence-based guidelines are discussed.

Value of ultrasonography in the diagnosis of carpal tunnel syndrome: correlation with electrophysiological abnormalities and clinical severity

OBJECTIVE

To investigate a diagnostic value of ultrasonography in carpal tunnel syndrome (CTS) patients and to evaluate a correlation of sonographic measurements with the degree of electrodiagnostic abnormalities and clinical severity.

METHODS

Two-hundred-forty-six symptomatic hands in 135 patients and 30 asymptomatic hands in 19 healthy individuals as control group were included. In ultrasonographic study, we measured the cross-sectional area (CSA) and flattening ratio (FR) of the median nerve at the pisiform as well as palmar bowing (PB) of the flexor retinaculum. Sensitivity and specificity of ultrasonographic measurements were evaluated and ultrasonographic data from the symptomatic and control hands were compared to the grade of electrodiagnostic and clinical severity.

RESULTS

The mean CSA was 13.7±4.2 mm(2) in symptomatic hands and 7.9±1.3 mm(2) in asymptomatic hands. The mean FR was 4.2±1.0 in symptomatic hands and 3.4±0.4 in asymptomatic hands. The mean PB was 3.5±0.5 mm in symptomatic hands and 2.6±0.3 mm in asymptomatic hands. Statistical analysis showed differences of the mean CSA, FR and PB between groups were significant. A cut-off value of 10 mm(2) for the mean CSA was found to be the upper limit for normal value. Both the mean CSA and PB are correlated with the grade of electrophysiological abnormalities and clinical severity, respectively.

CONCLUSION

Ultrasographic measurement of the CSA and PB is helpful to diagnose CTS as a non-invasive and an alternative modality for the evaluation of CTS. In addition, ultrasonography also provides a reliable correlation with the grade of electrodiagnostic abnormalities and clinical severity.

Evaluation of the scratch collapse test for the diagnosis of carpal tunnel syndrome

This prospective study measured and compared the diagnostic performance characteristics of various clinical signs and physical examination manoeuvres for carpal tunnel syndrome (CTS), including the scratch collapse test. Eighty-eight adult patients that were prescribed electrophysiological testing to diagnose CTS were enrolled in the study. Attending surgeons documented symptoms and results of standard clinical manoeuvres. The scratch collapse test had a sensitivity of 31%, which was significantly lower than the sensitivity of Phalen's test (67%), Durkan's test (77%), Tinel's test (43%), CTS-6 lax (88%), and CTS-6 stringent (54%). The scratch test had a specificity of 61%, which was significantly lower than the specificity of thenar atrophy (96%) and significantly higher than the specificity of Durkan's test (18%) and CTS-6 lax (13%). The sensitivity of the scratch collapse test was not superior to other clinical signs and physical examination manoeuvers for CTS, and the specificity of the scratch collapse test was superior to that of Durkan's test and CTS-6 lax. Further studies should seek to limit the influence of a patient's clinical presentation on scratch test performance and assess the scratch test's inter-rater reliability.

The 100 top-cited classic papers in hand surgery

The number of citations that a published article has received reflects the importance that paper has on that area of practice. In hand surgery, it is unknown which journal articles are cited most frequently. The purpose of this study was to identify and analyze the characteristics of the top 100 papers in the field of hand surgery. The 100 most cited papers were identified in the following journals; the Journal of Hand Surgery (American volume), the Journal of Hand Surgery (European volume), the Journal of Hand Surgery (British and European volume), The Scandinavian Journal of Plastic and Reconstructive and Hand Surgery, Hand Clinics, and the Journal of Plastic Surgery and Hand Surgery. The articles were ranked in order of the number of citations received. These classic 100 papers were analyzed for article type, their journal distribution, as well as geographic and institutional origin.

A comparison of the results of carpal tunnel release in patients in different age groups

BACKGROUND AND PURPOSE

The age of the patient at the onset of the disease may influence its course and outcome of the treatment. The objective of this study was to compare outcomes of carpal tunnel release in patients in different age ranges.

MATERIAL AND METHODS

The records from the register of patients with carpal tunnel syndrome who were operated on in the authors' department over a period of two years (between 2009 and 2011) were analyzed. A total of 386 patients with carpal tunnel syndrome, 322 female (83%) and 64 male (17%) with a mean age of 57 (range: 30-81) years were divided into three sub-groups according to their age: 40 years or less (n = 28), 41-65 years (n = 248) and over 65 years (n = 73). All patients received mini-open carpal tunnel release. The results were assessed at 6 months after the operation by the Levine questionnaire and measurements of grip and pinch strengths as well as sensation of a light touch by the filament test.

RESULTS

At the six-month follow-up, all patients showed significant resolution of symptoms as assessed by the Levine symptom score (from 3.3 to 1.4) and significant improvement of the dexterity of the hand, as assessed by the Levine function score (from 3.0-3.2 to 1.6-1.8). All patients showed significant improvement of sensation of a light touch and in-crease of grip and pinch strengths. However, patients older than 60 years showed less improvement of the total grip strength of the hand.

CONCLUSION

Patients with carpal tunnel syndrome at any age may expect a similar benefit from surgery.

Comprehensive musculoskeletal sonographic evaluation of the hand and wrist

Sonography is widely used for evaluation of hand and wrist lesions. The easy accessibility, cost-effectiveness, and good diagnostic accuracy of sonography coupled with the numerous benefits of real-time imaging make it desirable. The aim of this article is to describe the typical sonographic appearances of lesions in the hand and wrist that are encountered frequently in routine clinical practice, such as inflammatory arthropathies, tumors, traumatic injuries, foreign bodies, and nerve entrapment syndromes. Relevant anatomy, scanning methods, and recent developments in musculoskeletal sonography are also discussed.

Correspondence between clinical presentation and electrophysiological testing for potential carpal tunnel syndrome

The diagnosis of carpal tunnel syndrome (CTS) is often applied in the absence of objectively verifiable pathophysiology (i.e. electrophysiologically normal carpal tunnel syndrome). The primary purpose of this study was to determine whether depressive symptoms, heightened illness concern, and pain catastrophizing are associated with an absence of electrophysiological abnormalities. The secondary purpose was to examine the correspondence between the Levine scale, the CTS-6, and electrophysiological abnormalities. Ninety-eight participants completed validated questionnaires assessing psychosocial factors at the initial visit, and surgeons recorded clinical data and their confidence that the diagnosis was carpal tunnel syndrome. Symptoms and signs that are characteristic of carpal tunnel syndrome (e.g. the CTS-6 and Levine scale) significantly, but incompletely coincided with electrophysiological testing. Psychological factors did not help distinguish patients with normal and abnormal objective testing and it remains unclear if symptoms that do not coincide with abnormal tests represent very mild, immeasurable median nerve dysfunction or a different illness altogether. Future studies should address whether outcomes are superior and resource utilization is optimized when surgery is offered based on symptoms and signs (e.g. the CTS-6) or when surgery is offered on the basis of measurable pathophysiology.

Ultrasound as a first-line test in the diagnosis of carpal tunnel syndrome: a cost-effectiveness analysis

BACKGROUND

The American Academy of Orthopaedic Surgeons (AAOS) recommends that surgeons obtain a confirmatory test in patients for whom carpal tunnel surgery is being considered. The AAOS, however, does not specify a preferred test. Ultrasound reportedly causes less patient discomfort and takes less time to perform, while maintaining comparable sensitivity and specificity to electrodiagnostic testing (EDX).

QUESTIONS/PURPOSES

We determined whether ultrasound as a first-line diagnostic test is more cost-effective than using EDX alone or using ultrasound alone: (1) when used by a general practitioner; and (2) when used by a specialist.

METHODS

A fictional population of patients was created and each patient was randomly assigned a probability of having true-positive, false-positive, true-negative, and true-positive ultrasound and EDX tests over an expected range of sensitivity and specificity values using Monte Carlo methods. Charges were assigned based on Medicare charges for diagnostic tests and estimates of missed time from work.

RESULTS

The average charge for the use of ultrasound as a first-line diagnostic test followed by EDX for confirmation of a negative ultrasound test was $562.90 per patient in the general practitioner scenario and $369.50 per patient in the specialist scenario, compared with $400.30 and $428.30 for EDX alone, respectively.

CONCLUSIONS

The use of diagnostic ultrasound as a first-line test for confirmation of a clinical diagnosis of carpal tunnel syndrome is a more cost-effective strategy in the specialist population and results in improved false-negative rates in the generalist population despite increased cost.

LEVEL OF EVIDENCE

Level III, economic and decision analyses. See the Guidelines for Authors for a complete description of levels of evidence.

The results of carpal tunnel release for carpal tunnel syndrome diagnosed on clinical grounds, with or without electrophysiological investigations: a randomized study

We compared the results of carpal tunnel release in patients with the diagnosis of carpal tunnel syndrome based on only clinical grounds and those diagnosed on clinical and electrophysiological grounds. Ninety-three patients, 83 women (89%) and ten men (11%), meeting the criteria of 'typical' carpal tunnel syndrome, were randomly assigned to receive carpal tunnel release with (n = 45, 48%) or without (n = 48, 52%) nerve conduction studies. Patients were followed-up at 1 and 6 months, by assessments that included the Levine scores, filament tests, grip and pinch strength. No significant differences in Levine scores were found at the 1 and 6 months assessments. Statistically significant differences were noted in three-point pinch strength and sensation; however, they were not of clinical importance. The results of the study show that the results of carpal tunnel release in patients with typical symptoms are no better after nerve conduction studies and, therefore, nerve conduction studies can be omitted.

The diagnostic assessment of hand elevation test in carpal tunnel syndrome

Objective

The aim of this study is to establish the value of hand elevation test as a reproducible provocative test for the diagnosis of carpal tunnel syndrome (CTS).

Methods

We had a prospective study of 45 hands of 38 patients diagnosed with CTS between April 2005 and February 2009. The diagnosis of CTS was based on the American Academy of Neurology clinical diagnostic criteria. Experimental and control group patients underwent Tinel's test, Phalen's test, carpal compression test and hand elevation test as provocative tests for CTS.

Results

We used chi-square analysis to compare Tinel's test and Phalen's test, carpal compression test with hand elevation test. The sensitivity and specificity of the hand elevation test is 86.7% and 88.9% each. Tinel's test had 82.2% sensitivity and 88.9% specificity. Phalen's test had 84.4% sensitivity and 86.7% specificity. Carpal compression test had 84.4% sensitivity 82.2% specificity. Comparisons of sensitivity and specificity between hand elevation test and Tinel's test, Phalen's test, and carpal compression test had no statistically significant differences. To compare the diagnostic accuracies of four tests, the area under the non-parametric receiver operating character curve was applied.

Conclusion

The hand elevation test has higher sensitivity and specificity than Tinel's test, Phalen's test, and carpal compression test. Chi-square statistical analysis confirms the hand elevation test is not ineffective campared with Tinel's test, Phalen's test, and carpal compression test.

Surface electromyography features in manual workers affected by carpal tunnel syndrome

INTRODUCTION

Alterations in surface electromyographic (sEMG) signals of the abductor pollicis brevis muscle were evaluated in 24 non-manual workers and 40 manual workers (25 asymptomatic and 15 reporting CTS symptoms).

METHODS

The initial value (IV) and the normalized rate of change (NRC) of average rectified value (ARV), mean frequency of the power spectrum (MNF), and muscle fiber conduction velocity (MFCV) were calculated during contractions at 20% and 50% of maximal voluntary contraction (MVC). Neuromuscular efficiency (NME) and kurtosis of the sEMG amplitude distribution were estimated.

RESULTS

With respect to controls, manual workers showed higher NME, lower ARV IV, and reduced myoelectric manifestations of fatigue (lower MNF NRC for both contraction levels, and lower MFCV NRC at 50% MVC). Kurtosis at 20% MVC showed higher values in symptomatic manual workers than in the other two groups.

CONCLUSIONS

Kurtosis seems to be a promising parameter for use in monitoring individuals who develop CTS.

Hyperventilation provokes symptoms of carpal tunnel syndrome

Hyperventilation causes respiratory alkalosis. The nervous system is more excitable in alkalosis. This phenomenon can be observed as paraesthesia in fingers and toes as well as around the lips in anxious patients breathing rapidly. We wanted to test this phenomenon on already irritable nerves like the median nerve in carpal tunnel syndrome (CTS). We deployed 50 patients who came in to the day case unit for carpal tunnel decompression with electro-physiologically proven diagnosis. We devised a test whereby patients were made to hyperventilate under prescribed conditions and repeated Phalen's test and Tinel's sign for comparison. These were compared with a control group chosen randomly among hospital staff. 86% patients had a positive result which was just behind Phalen's test in sensitivity. It was also 100% specific as there were no false positives. Hyperventilation is a phenomenon which provokes carpal tunnel syndrome. Its clinical value remains to be seen due to cumbersome method and probable patient non-compliance but it is a new discovery. It may be useful in other irritable-nerve-syndromes as a test to add to our available armament. It may be an additional factor or a primary reason for nocturnal paraesthesias in CTS patients.

Comparison of the Diagnostic Utility of Electromyography, Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging in Idiopathic Carpal Tunnel Syndrome Determined by Clinical Findings

Background:

Carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome. It is sometimes difficult to diagnose, and a late diagnosis may result in permanent nerve damage. Electromyography (EMG), ultrasonography (US), magnetic resonance imaging (MRI), and computed tomography (CT) may be performed for the diagnosis. The diagnostic accuracy of these tests is well documented, but most of these studies accept EMG as the gold standard.

Objective:

To evaluate the diagnostic accuracy of EMG, MRI, CT, and US for the diagnosis of carpal tunnel syndrome with the use of clinical findings as the gold standard.

Methods:

Patients suspected to have CTS on presentation to the outpatient clinic were evaluated. The tests were performed after a detailed physical examination. Both wrists of the 69 patients in the study were investigated.

Results:

The diagnostic accuracies of all the tests were found to be sufficient. Although EMG seemed to have the highest sensitivity and specificity, there was no statistically significant difference between the tests.

Conclusion:

EMG or US could be used as the first-step test in most cases. If they are both available, EMG should be the first choice. They may be performed together when diagnosis is challenging. CT may especially be preferred for bone-related pathological conditions, whereas MRI may be preferred for soft tissue-related pathological conditions. Even though imaging studies have been proven to be powerful diagnostic tools for CTS, no conclusive information currently exists to support replacing EMG with imaging studies.

Predictors of normal electrodiagnostic testing in the evaluation of suspected carpal tunnel syndrome

Electrodiagnostic studies (electromyography and nerve conduction velocity; EMG/NCV) are used to confirm the diagnosis of carpal tunnel syndrome (CTS) and to evaluate its severity. We investigated the hypothesis that normal electrodiagnostic median nerve testing is predicted by 1) Physician pre-test confidence in the diagnosis of CTS, and 2) Puzzling patient factors. One hundred and forty consecutive patients who underwent electrodiagnostic testing to evaluate for possible CTS were reviewed retrospectively. Both physician confidence in the diagnosis of CTS and puzzling patient factors (heightened illness concern, disproportionate complaints, and vague/nonanatomical/noncharacteristic symptoms) were recorded. Electrodiagnostic testing was used as the reference standard for diagnosis of CTS. Electrodiagnostic testing confirmed CTS in 115 patients and was within normal limits in 25 patients. Low physician confidence in the diagnosis of CTS was highly predictive of a normal electrodiagnostic test (p < 0.001), with high sensitivity (97%), moderate specificity (40%), and high overall accuracy (87%). Puzzling patient factors were moderately predictive of normal electrodiagnostic testing (p < 0.001), with low sensitivity (16%), high specificity (96%), and high overall accuracy (81%). The best multivariable model retained younger age, negative Phalen's test, and low physician confidence as the best predictors of normal electrodiagnostic testing and explained 35% of the variation in test results. A model with low confidence alone explained 19% of the variation in test results. Physician intuition as recorded in the medical record in terms of puzzlement and low confidence are very specific and accurate predictors of normal electrodiagnostic testing in the setting of suspected carpal tunnel syndrome.

CARPAL TUNNEL RELEASE IN PATIENTS WITH NEGATIVE NEUROPHYSIOLOGICAL EXAMINATIONS

OBJECTIVE

In 16% to 34% of patients with classic symptoms of carpal tunnel syndrome (CTS), neurophysiology is negative. Few studies have concentrated on patients with symptoms compatible with CTS with normal examinations. The purpose of our study was to examine the clinical and surgical characteristics of this subtype of CTS in order to clarify a correct approach toward these patients.

METHODS

We studied a subpopulation of 25 patients (31 hands) with typical CTS symptoms despite normal neurophysiological examinations. All of the patients were initially treated with conservative therapy, and patients with work-related symptoms were advised to change their duties. In patients with persistent symptoms, wrist ultrasound and radiographic and blood examinations with rheumatic screenings were performed. Cervical magnetic resonance imaging was performed in some cases to exclude cervical radiculopathy. Other pathologies were found in 5 cases. Nine patients improved with nonsurgical therapy. Six months later, electric examinations were repeated and 3 patients with a confirmed median nerve injury underwent surgery. Eight patients with negative examinations underwent surgery (10 hands). All patients were advised of the possibility of incomplete pain remission after surgery.

RESULTS

All patients improved after surgery. Median nerve injury was confirmed by operative findings according to Tuncali grading.

CONCLUSION

A combination of clinical findings and instrumental procedures is required when selecting patients for successful surgery.

Factors affecting willingness to undergo carpal tunnel release

BACKGROUND

Factors regarding patient willingness to undergo or avoid joint replacement have been studied; however, these factors have not been studied in patients with carpal tunnel syndrome. To further understand the aspects that are important for a patient with carpal tunnel syndrome in deciding whether to have surgery, we identified factors that affect this decision in women and that are not related to Workers' Compensation status.

METHODS

We retrospectively reviewed 282 female patients with electrophysiologically confirmed carpal tunnel syndrome without a known cause who were recommended for carpal tunnel release by a single hand surgeon in a tertiary medical setting. Of those, thirty-six female patients who were not entitled to Workers' Compensation canceled the operation during the waiting period, which averaged four weeks. Thirty-three of them were surveyed with a questionnaire sent by mail, and eighteen completed surveys were reviewed at a mean follow-up of thirty-two months. Furthermore, seventy female patients who underwent carpal tunnel release were randomly sampled, and thirty-eight patients completed the survey. The operation and cancellation groups were compared with regard to the reasons for choosing or canceling surgery.

RESULTS

The groups were similar with regard to age, sociodemographic variables, follow-up length, initial electrophysiological findings, and functional status. The highest-ranked reason for choosing surgery was symptom severity rather than fear of progression or a positive electrodiagnostic result. Those who canceled the operation rated symptom improvement during the waiting period as the leading reason for doing so, but they were also concerned about transient weakness, the financial burden, and a scar or pillar pain. Disease persistence or recurrence was the issue of most concern in both groups. At the time of the final review, the functional status was significantly improved in both groups and no significant difference between the groups was detected.

CONCLUSIONS

Women with carpal tunnel syndrome report that subjective symptom severity is the most important reason for undergoing surgery. Understanding this and other patient concerns may help physicians during patient-oriented consultation and decision-making. In particular, recommendations for carpal tunnel release on the basis of symptoms are reasonable from the perspective of the patient who has carpal tunnel syndrome without a known cause.

Incidence of carpal tunnel syndrome in the US military population

Carpal tunnel syndrome (CTS) is a common disease. Its epidemiology has been evaluated previously, mostly in regional populations or in working groups, with an incidence between 1.5 and 3.5 per 1,000 person-years. We studied this diagnosis in the US military population, with the hypothesis that this young population would have a lower incidence of CTS than previously reported in general populations. The Defense Medical Epidemiology Database notes all medical encounters for all US military personnel and maintains the number of all personnel on active duty each year. We queried the database using the International Classification of Diseases, ninth revision, code 354.0 (CTS) and analyzed the personnel presenting for initial visits for the years 1998-2006. Multivariate Poisson analysis was performed, controlling for rank, gender, age, and race. The raw incidence of CTS in the US military was 3.98 per 1,000 person-years, in a population of 12,298,088 person-years. Females had a significantly higher incidence of CTS than males, with an adjusted incidence rate ratio of 3.29. CTS incidence increased by age, with the age group > or = 40 years having a significantly higher incidence. Additionally, military rank was found to be an independent risk factor for CTS, with rates higher in senior officer and enlisted groups. This suggests that occupational requirements have an effect on CTS within the military. We showed a comparable incidence of CTS between the US military and general population, with a significantly higher female cohort with a diagnosis of CTS. Increased age and advanced rank were risk factors for CTS.

Sonographic measurement of cross-sectional area of the median nerve in the diagnosis of carpal tunnel syndrome: correlation with nerve conduction studies

PURPOSE

To assess the usefulness of sonographic measurement of the median nerve cross-sectional area (CSA) in the diagnosis of carpal tunnel syndrome (CTS) and grading of its severity using nerve conduction (NC) studies as the standard.

METHOD

The CSA of the median nerve was measured at the tunnel inlet and outlet using the ellipse formula and automatic tracing in 72 hands with suspicion of CTS.

RESULT

The lack of inter-reader reliability led to excluding CSA measurements obtained at the tunnel outlet. Based on the receiver operating characteristic curves, the following cut-off points for the CSA of the median nerve at the tunnel inlet was selected: 9.8 mm and 12.3 mm(2) for the ellipse formula and 11 and 13 mm(2) for automatic tracing. For the ellipse formula, a CSA less than or equal to 9.8 mm(2) excluded CTS whereas a CSA greater than or equal to 12.3 mm(2) was diagnostic of CTS with measurements between 9.8 and 12.3 mm(2) being indeterminate and requiring NC studies. For automatic tracing, the cutoff value of 11 mm(2) was excluded because of the high percentage of false negatives, whereas CSAs greater than or equal to 13 mm(2) were diagnostic of CTS. There were no statistically significant differences in CSA measurements between the various degrees of CTS severity determined by NC studies.

CONCLUSION

Sonographic measurement of median nerve CSA at the tunnel inlet is a good alternative to NC studies as the initial diagnostic test for CTS, but it cannot grade the severity of CTS as well as NC studies.

Carpal tunnel syndrome assessment with US: value of additional cross-sectional area measurements of the median nerve in patients versus healthy volunteers

PURPOSE

To improve accuracy in the diagnosis of carpal tunnel syndrome (CTS) by comparing cross-sectional area (CSA) measurements of the median nerve obtained at the level of the carpal tunnel (CSAc) with those obtained more proximally (CSAp), at the level of the pronator quadratus muscle.

MATERIALS AND METHODS

The study protocol was approved by the institutional review board, and all subjects gave written informed consent. One hundred wrists of 68 consecutive patients with CTS (16 men, 52 women; mean age, 57.9 years; range, 25-85 years) and 93 wrists of 58 healthy volunteers (16 male, 42 female; mean age, 55.1 years; range, 17-85 years) were examined with ultrasonography (US). Electrodiagnostic test results confirmed the diagnosis of CTS in all 68 patients. The US examiner was blinded to these test results. The CSA of the median nerve was measured at the carpal tunnel and proximal levels, and the difference between CSAc and CSAp (Delta CSA) was calculated for each wrist.

RESULTS

The mean CSAc in healthy volunteers (9.0 mm(2)) was smaller than that in patients (16.8 mm(2), P < .01). The mean Delta CSA was smaller in asymptomatic wrists (0.25 mm(2)) than in CTS-affected wrists (7.4 mm(2), P < .01). Receiver operating characteristic analysis revealed a diagnostic advantage to using the Delta CSA rather than the CSAc (P = .036). Use of a Delta CSA threshold of 2 mm(2) yielded the greatest sensitivity (99%) and specificity (100%) for the diagnosis of CTS.

CONCLUSION

Receiver operating characteristic analysis revealed improved accuracy in the diagnosis of CTS determined with the Delta CSA compared with the accuracy of the diagnosis determined with the CSAc.

The value added by electrodiagnostic testing in the diagnosis of carpal tunnel syndrome

BACKGROUND

There is no clear-cut consensus on the best diagnostic criteria for carpal tunnel syndrome. The objective of this study was to compare the probability of carpal tunnel syndrome being present following electrodiagnostic testing with the probability of it being present after the diagnosis was established on the basis of a clinical evaluation alone.

METHODS

The study sample included patients with any peripheral nerve diagnosis who had been referred to the electrodiagnostic laboratory of an academic health-care center. The probability of carpal tunnel syndrome before electrodiagnostic testing (pretest probability) was estimated with use of the CTS-6, a validated clinical diagnostic aid that is used to estimate the probability of carpal tunnel syndrome on the basis of the presence or absence of six clinical findings recorded as part of the history or noted on physical examination. All patients then underwent a standard electrodiagnostic assessment of the median nerve by a neurologist blinded to the result of the CTS-6 evaluation. Sensory nerve conduction velocity was used to classify the result of the electrodiagnostic testing as either positive or negative for carpal tunnel syndrome with use of two different criteria (one stringent and one lax) derived from the literature. The main outcome measure was the difference between the pretest and posttest probabilities of carpal tunnel syndrome.

RESULTS

One hundred and forty-three patients were studied. The pretest probability of carpal tunnel syndrome ranged between 0.10 and 0.99 (mean [and standard deviation], 0.81 +/- 0.22). Seventy-three percent of the patients had a pretest probability of at least 0.80. The average change in probability for these patients was -0.02 when the stringent electrodiagnostic criterion was used and -0.06 when the lax criterion was used. With either electrodiagnostic criterion, the majority of the large changes in probability were for patients for whom the pretest probability was < or =0.50. The probability of carpal tunnel syndrome was lowered after the electrodiagnostic testing in most of these cases.

CONCLUSIONS

For the majority of patients who are considered to have carpal tunnel syndrome on the basis of their history and physical examination alone, electrodiagnostic tests do not change the probability of diagnosing this condition to an extent that is clinically relevant.

Comparison of sonography and electrodiagnostic testing in the diagnosis of carpal tunnel syndrome

PURPOSE

To determine whether sonography can be an alternative method to nerve conduction study (NCS) in the diagnosis of carpal tunnel syndrome (CTS), by comparing sonography with nerve conduction study using clinical diagnosis as the reference standard.

METHODS

Forty-one wrists of 29 patients were enrolled, along with the same number of age- and gender-matched controls. All patients had sonographic measurement of the cross-sectional area (CSA) of the median nerve and NCS. Sensitivity and specificity were obtained and compared between sonography and NCS.

RESULTS

There were no significant differences in age, gender, body mass index and involved side between patients and controls (p<.05). The CSA at the tunnel inlet was significantly larger in patients than in controls (p=.03). The best cutoff value of CSA at the tunnel inlet was 10.7 mm(2), which had a sensitivity of 66% and a specificity of 63%. NCS showed a sensitivity of 78% and a specificity of 83%. Sensitivity was similar between sonography and NCS (p=0.27), whereas specificity was significantly lower in sonography than in NCS (p=0.02).

CONCLUSIONS

Sonography is not accurate enough to replace NCS for the diagnosis of CTS.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.