Carpal Tunnel Syndrome Subjects Research Articles

Electrophysiological assessment of radial shock wave therapy for carpal tunnel syndrome.

This study presents an electrophysiological assessment of radial extracorporeal shock wave therapy on patients with carpal tunnel syndrome (CTS). Sixteen CTS subjects received radial extracorporeal shock wave therapy once a week for five consecutive weeks. Outcome performance was assessed using the Boston Carpal Tunnel Questionnaire (BCTQ) and electrodiagnostic measurements including a nerve conduction study of the median nerve and a compound muscle action potential (CMAP) scan of the abductor pollicis brevis muscle. The BCTQ and the sensory conduction test measurements were all statistically improved after the treatment. However, the motor conduction test measurements were not significantly different before and after the treatment. The CMAP scan examination revealed MScanFit motor unit number estimation (MUNE) was significantly higher after the treatment, while no significant change was found in StairFit MUNE and step index. These results confirmed the effectiveness of shock wave therapy for treating CTS symptoms and the associated sensory property changes. The reasons for the inconsistencies from different CMAP scan processing methods are worthwhile targets for further investigation.

The Diagnostic Value of the Median Nerve Sonography in Chronic Phase Carpal Tunnel Syndrome Cases in Indonesia

Background. Ultrasound evaluation on the median nerve in carpal tunnel syndrome (CTS) patients by measuring cross-sectional area (CSA) is widely known. However, studies have shown that CSA of the median nerve could vary in different demographical factors. Therefore, the cut-off CSA value for CTS in the Indonesian population could be significantly different. Purpose. To compare mean CSA of the median nerve between normal and CTS populations and establish a cut-off point of CSA to diagnose CTS. Materials and Methods. A comparative cross-sectional study was conducted involving 40 people divided equally into CTS and normal groups. Normal and CTS subjects are determined by Electrodiagnostic study (EDx) using EMG and Nerve Conduction Study (NCS). The CSA measurement was performed at the level of the carpal tunnel inlet. Results. The mean CSA value at the level of tunnel inlet of the normal group was 8.3 ± 1.4 mm2 and for the CTS group is 15.4 ± 4.4 mm2. The receiver operating characteristics (ROC) analysis showed 10.6 mm2 as the cut-off point with 95% sensitivity and 95% specificity (P<0.001). Conclusion. The median nerve CSA at the tunnel inlet is significantly larger in the CTS population and the cut-off point can be recommended in detecting CTS in the Indonesian population.

Dysfunction in the Interaction of Information Between and Within the Bilateral Primary Sensory Cortex.

BackgroundInterhemispheric and intrahemispheric long-range synchronization and information communication are crucial features of functional integration between the bilateral hemispheres. Previous studies have demonstrated that disrupted functional connectivity (FC) exists in the bilateral hemispheres of patients with carpal tunnel syndrome (CTS), but they did not clearly clarify the phenomenon of central dysfunctional connectivity. This study aimed to further investigate the potential mechanism of the weakened connectivity of primary somatosensory cortex (S1) based on a precise template.MethodsPatients with CTS (n = 53) and healthy control subjects (HCs) (n = 23) participated and underwent resting-state functional magnetic resonance imaging (rs-fMRI) scanning. We used FC to investigate the statistical dependency of the whole brain, effective connectivity (EC) to analyze time-dependent effects, and voxel-mirrored homotopic connectivity (VMHC) to examine the coordination of FC, all of which were adopted to explore the change in interhemispheric and intrahemispheric S1.ResultsCompared to the healthy controls, we significantly found a decreased strength of the two connectivities in the interhemispheric S1hand, and the results of EC and VMHC were basically consistent with FC in the CTS. The EC revealed that the information output from the dominant hemisphere to the contralateral hemisphere was weakened.ConclusionThis study found that maladjusted connections between and within the bilateral S1 revealed by these methods are present in patients with CTS. The dominant hemisphere with deafferentation weakens its effect on the contralateral hemisphere. The disturbance in the bilateral S1 provides reliable evidence to understand the neuropathophysiological mechanisms of decreased functional integration in the brains of patients with CTS.

Innovative Quantitative Assessment of Hand Function in Carpal Tunnel Syndrome.

Carpal tunnel syndrome (CTS) compromises fine sensorimotor function during activities of daily living and affects a large number of individuals with high burden costs for society. The purpose of this study was to quantitatively characterize fine movement skills in CTS patients preoperatively and at 1 month postoperatively by means of a sensor-engineered glove, in order to provide new insights for evaluative and finally therapeutic purposes. Forty-one CTS patients and 41 age- and gender-matched healthy controls (HC) were analyzed by adopting the engineered glove Hand Test System (HTS), which previously demonstrated its reliability and sensitivity to detect hands dysfunction in several neurological diseases. A sub-group of 11 CTS subjects was re-tested 1 month after surgery. Three parameters-touch duration (TD), inter-tapping interval (ITI), and movement rate (MR)-were considered to characterize hand function. The affected hand of CTS patients generally showed worst finger opposition performances than HC. Comparing the dominant hand, all parameters were able to significantly discriminate CTS patients from HC. Considering the nondominant hand, the best performing parameter in discriminating CTS from HC was TD. The follow-up assessment at 1 month after surgery showed that considered parameters were able to monitor patients' recovery. In particular, the TD parameter recorded at the 3 different assigned task modalities resulted significantly enhanced. Results of this pilot study proved the validity of the parameters obtained through the sensor-engineered glove to assess objectively hand functional status and surgical outcomes in CTS.

Effects of Additional Radial Shockwave Therapy to Median Nerve Gliding Exercises on Hand Grip Strength in Carpal Tunnel Syndrome Patients

ABSTRACTIntroduction: Carpal Tunnel Syndrome (CTS) is one of the most common entrapment neuropathies found in the upper extremities. Patients with moderate and severe CTS usually experience disturbances in motor strength. A non-invasive therapeutic method that has recently emerged in the treatment of CTSis Radial Shock Wave Therapy (RSWT). RSWT is a therapy using shock waves and can be added to other forms of exercise. The addition of RSWT in CTS is expected to increase the grip strength. Research that directly assesses the effect of adding RSWT and median nerve gliding exercises on hand grip strength inCTS patients has not been conducted.Methods: This study was a pre-test/post-test control group design. There were 22 moderate grade CTS subjects divided into 2 groups, the control group was received median nerve gliding exercise (n=11) and the treatment group was received additional RSWT on median nerve gliding exercise (n=11). Assessmentof grip strength by Jamar hand dynamometer was performed before and after 4 weeks of treatment. The mean differences before and after treatment, as well as between groups was compared statistically using an unpaired t-test.Results: There was no significant difference in the handgrip strength of the control group (p = 0.094), and a significant difference in the treatment group (p = 0.009) before and after the intervention. However, there were no significant differences in grip strength between the two groups (p=0.065).Conclusion: There was no significant effect of adding RSWT on improving handgrip strength in CTS patients who received a median nerve gliding exercise.Keywords: carpal tunnel syndrome, entrapment neuropathies, grip strength, nerve gliding exercise,radial shockwave therapy

Can Carpal Tunnel Syndrome be Appropriately Diagnosed in a Cold Hand?

INTRODUCTIONThe diagnosis of carpal tunnel syndrome (CTS) with nerve conduction studies traditionally involves warming the hand to avoid misleading prolongation of distal latency (DL). Comparing the median nerve DL to the ulnar and radial nerves using the combined sensory index (CSI) has been reported to improve the accuracy of CTS diagnosis. During this study, the authors examined the effect of hand temperature on the CSI and diagnosis of CTS.METHODSThe authors conducted a prospective, controlled, cohort study with 20 asymptomatic control patients and 21 symptomatic patients with confirmed CTS. Symptomatic patients underwent nerve conduction studies with the CSI calculated under both cold and warm conditions.RESULTSControl subjects with warm hands had an average CSI of 0.0 milliseconds (ms), and -0.3ms with cold hands. CTS subjects with warm hands had an average CSI of 3.2ms, and 3.7ms with cold hands. Although hand temperature was shown to slow sample latencies, differences calculated with the CSI did not misclassify any of the 41 sample subjects.CONCLUSIONSDuring this study, cold temperature did not result in misclassification of either control patients or CTS patients when CSI was diagnostically used. Based on these results, peak latency comparisons in cold hands can be considered as diagnostically reliable as under standard hand temperature ranges for the diagnosis of CTS, with caution warranted in borderline cases. This diagnostic technique can save time for the patient, physician, and care team without compromising quality of care. Future larger sample blinded studies at multiple electrodiagnostic sites are indicated.

Withdrawal: “Efficacy of cervical manual therapy plus conventional physical therapy on clinical outcomes in patients with carpal tunnel syndrome: A double blind randomized controlled trial” Milad Zarrin, Maryam Saadat, Mohammad Jafar Shaterzadeh Yazdi, Davood Shalil Ahmadi

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. Current physical therapy treatment options show limited effects or low-quality evidence, especially in the long-term. To date, there has been little research to look at the effects of treating the cervical spine for decreasing symptoms distally to the carpal tunnel. So the aim of this study was to compare the effects of cervical manual therapy plus conventional physical therapy with conventional physiotherapy only in Carpal Tunnel Syndrome Subjects. A group of 46 patients with CTS was randomly allocated into two groups: Cervical manual therapy plus conventional physiotherapy (n = 23), and conventional physiotherapy (n = 22). All patients received 10 sessions of supervised intervention treatment for 2 weeks. The efficacy of the therapies was assessed before initiation of therapy and after completion of therapy using a visual analog scale (VAS), a symptom severity scale, the functional capacity scale of the Boston Carpal Tunnel Questionnaire (BCTQ), functional status of DASH questionnaire, measurement of median nerve motor distal latency (mMDL) and median sensory nerve conduction velocity (mSNCV). Cervical manual therapy plus conventional physiotherapy group showed significantly greater improvement in VAS, DASH score, mMDL and mSNCV (p < 0.05) compared to the conventional group. There was no significant difference in BCTQ for two groups (p > 0.05). The analysis of the results showed that conventional physiotherapy combined with Cervical manual therapy could be more effective in improving the pain, functional abilities, median nerve motor distal latency and median sensory nerve conduction velocity of patients with CTS compared with conventional physiotherapy only.

P-NJ003. Sonographic pattern of median nerve enlargement in hansen’s neuropathy

Introduction . Median nerve enlargement in leprosy using high-resolution ultrasound seems to be more proximal than in carpal tunnel syndrome (CTS), which might be an important discriminating sign, but has not been studied systematically. The aim of this study is to compare the sites of median nerve enlargement in patients with leprosy with that of patients with CTS. Methods . Transverse sections of the median nerve were recorded from wrist until the forearm (at distal wrist crease, and at 2-cm: M1, 4-cm: M2, 6-cm: M3, 8-cm: M4 and 10-cm: M5, proximal to the distal wrist crease in the forearm) and at mid arm and forearm in patients with leprosy, CTS and healthy subjects. Results . Twenty-six patients each with leprosy and CTS were compared with healthy controls. Patients with leprosy included 6 (23%), 7 (26.9%), 7 (26.9%) and 6 (23.1%) patients with borderline-tuberculoid, borderline-borderline, borderline-lepromatous and lepromatous leprosy respectively. Cross-sectional area (CSA) of median nerve was increased in all patients with leprosy as compared to healthy controls at all points of measurement. CSA was higher among patients with leprosy as compared to CTS at all points except at the wrist. In patients with leprosy, the maximal enlargement was noted 2-cm (M1) proximal to the wrist crease with gradual tapering of the CSA proximally (p < 0.05). In contrast, in patients with CTS the median nerve was maximally enlarged at the distal wrist crease (p < 0.05). Conclusion . Enlargement of median nerve 2-cm proximal to the distal wrist crease is a characteristic feature that distinguishes leprosy from CTS. This important finding can be used at point-of-care ultrasound to identify patients with leprosy.

Sonographic pattern of median nerve enlargement in Hansen's neuropathy.

Median nerve enlargement in leprosy seems to be more proximal than in carpal tunnel syndrome (CTS), but this feature has not been studied systematically. The aim of the study was to compare the sites of median nerve enlargement in patients with leprosy with that of patients with CTS. Transverse sections of the median nerve were recorded from wrist to the mid-forearm (at distal wrist crease and at 2-cm: M1, 4-cm: M2, 6-cm: M3, 8-cm: M4 and 10-cm: M5, proximal to the distal wrist crease in the forearm) in patients with leprosy, CTS and healthy subjects using high-resolution ultrasound. Twenty-six patients each with leprosy and CTS were compared with healthy controls. Patients with leprosy included 6 (23.1%), 7 (26.9%), 7 (26.9%) and 6 (23.1%) patients with borderline tuberculoid, borderline-borderline, borderline lepromatous and lepromatous leprosy, respectively. Cross-sectional area (CSA) of median nerve was increased in all patients with leprosy as compared to healthy controls at all points of measurement. CSA was higher among patients with leprosy as compared to CTS at all points except at the wrist. In patients with leprosy, the maximal enlargement was noted 2-cm (M1) proximal to the wrist crease with gradual tapering of the CSA proximally (p<.05). In contrast, in patients with CTS the median nerve was maximally enlarged at the distal wrist crease (p<.05). Median nerve enlargement 2-cm proximal to the distal wrist crease distinguishes leprosy from CTS. This important discriminating sign can be used at point-of-care to identify patients with leprosy.

Quantitative Evaluation of the Echo Intensity of Paraneural Area and Myofascial Structure around Median Nerve in Carpal Tunnel Syndrome.

The aim of this study was to investigate whether the echo intensity (EI) of the paraneural area (PA), the median nerve (MN) at the carpal tunnel, the EI of the myofascial structure (MS) around MN, the ‘PA and MN’ at the mid-forearm, and the MN transversal displacement at both sites differs between persons with carpal tunnel syndrome (CTS) and control subjects. Methods: In total, 16 CTS patients and 16 controls, age- and gender-matched, were recruited. Cross-sectional ultrasound images of MN were obtained to evaluate the EI of the PA, the MN at carpal tunnel, the EI of MS, and the ‘PA and MN’ at the mid-forearm in a natural position, then images were taken after a whole-hand grasp movement, to evaluate MN transversal displacement. Inter-rater and intra-rater reliability in control, and differences in the EI and MN displacement between CTS and control, were analyzed. In addition, the correlations between ultrasound parameters and MN displacement were evaluated. Results: The quantitative EI of PA, MN, EI of MS, ‘PA and MN’ had high inter-rater and intra-rater reliability in the control. The EI of PA, MS and ‘PA and MN’ were significantly higher in CTS subjects (p < 0.01), whilst there was no significant difference in the EI of MN at the carpal tunnel. MN displacement was significantly decreased both at the carpal tunnel and the mid-forearm in CTS subjects (p < 0.01). In addition, there were negative correlations among the EI of PA (rs = −0.484, p = 0.004), EI of MS (rs = −0.479, p = 0.002), EI of ‘PA and MN’ (rs = −0.605, p < 0.001) and MN transversal displacement. Conclusions: The higher EI of PA and MS around MN in CTS may indicate greater fibrosis along the course of MN, reducing fascial adaptability, influencing the synergy and coordination of the MS, and increasing the shear stress between MS and MN, and it may further increase the abnormal pressure on the MN not only at the carpal tunnel, but also at the mid-forearm. These results may partly explain the role of PA and MS in CTS pathogenesis.

Diagnosis and grading of carpal tunnel syndrome with quantitative ultrasound: Is it possible?

The recent diagnostic tools for carpal tunnel syndrome (CTS) include nerve conduction studies (NCS) and ultrasound (US). Quantitative US (QUS) can be used for demonstrating muscle changes according to denervation. The aim of this study was to evaluate if QUS can diagnose and grade the severity of CTS. In this single blinded cross-sectional study, female patients diagnosed with CTS and age-matched healthy female subjects were included in the study. Median and ulnar nerve conduction studies (NCS) were performed for CTS diagnosis. Median and ulnar nerve cross-sectional area (CSA) was measured, and the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles were longitudinally and transversally visualised. Axial images were analysed for echo intensity (EI) via computer-assisted, grayscale analysis. Intra-rater and inter-rater reliability analysis was performed. The Boston questionnaire was used for the evaluation of symptom severity and functional status. Forty-two patients (42 hands) and 32 controls were included. In the CTS group, 17 patients had mild, 13 patients had moderate, and 12 patients had severe CTS. CSA of the median nerve and APB echo intensity was significantly higher in patients with CTS. However, according to the CTS grade, no significant difference was detected for APB EI. The intraclass correlation coefficient (ICC) was calculated as 0.928 for intra-rater reliability and 0.768 for inter-rater reliability. QUS evaluation is helpful for the diagnosis of CTS, but not for grading. Further studies are needed with a larger population including both genders.

Role of fasciae around the median nerve in pathogenesis of carpal tunnel syndrome: microscopic and ultrasound study.

This study investigated the connections between the median nerve paraneural sheath and myofascial structures near it, from both macroscopic and microscopic points of view. Four samples of median nerve and surrounding tissues were excised from nine non-embalmed upper limbs for microscopic analysis. Ultrasound images were analysed in 21 healthy subjects and 16 carpal tunnel syndrome patients to evaluate median nerve transversal displacement during finger motion at carpal tunnel and forearm levels. An anatomical continuity between epimysium and paraneural sheath and a reduction of paraneural fat tissue from proximal to distal was found in all samples. Median nerve displacements at both levels were significantly reduced in carpal tunnel syndrome subjects (P<0.001). It was observed that the median nerve is not an isolated structure but is entirely connected to myofascial structures. Therefore, unbalanced tension of epimysial fasciae can affect the paraneural sheath, limiting nerve displacement, and consequently this must be included in carpal tunnel syndrome pathogenesis.

Can serum C-Reactive Protein and Procalcitonin levels associate with carpal tunnel syndrome?

Objective: The purpose of this study was to examine whether an increase occurs in serum C-reactive protein (CRP) and procalcitonin (PCT) levels in patients with carpal tunnel syndrome (CTS). Material and Methods: Thirty-six patients who have CTS due to electrophysiological tests and 40 healthy individuals were included the study. Boston Questionnaire (BQ) was used to assess the functional and clinical status of the patients. Also, CRP and PCT levels were investigated. Correlations between such parameters (electrophysiological findings, BQ results, and clinical findings) were evaluated. Results: CTS and control subjects had similar CRP levels, whereas there was significant elevation in PCT among CTS patients. Serum PCT activity did not correlate with subunits of BQ (p> 0.05). Conclusion: The results of this small study showed significant PCT increases in patients with CTS. Further studies in this regard may help to clarify the diagnostic and or follow-up value of PCT in patients with CTS.

Pre-operative grip force as clinical predictor for weakness after transversal carpal ligament release

Temporary or long-lasting loss of grip force after open carpal tunnel release (CTR) in carpal tunnel syndrome (CTS) patients is well known and caused by changes in biomechanical conditions through sectioning of the transverse carpal ligament. We hypothesize to find predicting factors for loss of grip strength. We performed dynamometer testing of overall hand grip, tip pinch, and key pinch grip prior, 3 and 6 months after open CTR in 42 CTS subjects. Changes in these three main variables related to pre-operative grip, tip pinch and key pinch forces as well as gender and age were analyzed for significant results (t test, Pearson and Spearman correlations, descriptive statistics; 2-tailed p = .05). At 3-month post-CTR, overall hand grip force decreased significantly by 11.7% (p = .006), whereas key pinch and tip pinch only decreased by 5.6 and 3.5% (p < .0004). At 6-month post-CTR our subjects showed, compared to pre-operative level, an increase of overall grip force to 94.6% (p = .242) and an improvement of tip pinch to even 107% (p = .169) and key pinch to 102% (p = .675). Further investigation showed that subjects with a strong grip prior to the operation seem to lose more strength 3 and 6 months after operation than subjects with average or low strength results (3 months: Spearman −.522.; 6 months: Spearman −.569, p = .000). Pre-operative dynamometer assessment can predict loss of grip force and therefore create realistic post-operative expectations. Patients at risk for prolonged weakness after surgery (especially male subjects with high pre-operative grip force), could, instead of early surgical transversal carpal ligament release, profit from enrolling into an extended conservative therapy (immobilization and anti-inflammatory medication). Additionally, these patients undergoing CTR could enroll into an intensive post-operative occupational therapy with focus on grip force training to improve their recovery. Level of Evidence: Level III, risk / prognostic study

Overall health status in patients with mild to moderate carpal tunnel syndrome: A case-control study

Study DesignA case-control study. IntroductionThere are no reports in the literature that evaluate the overall health status (OHS) of patients with mild to moderate forms of carpal tunnel syndrome (CTS) using 36-Item Short Form Health Survey (SF-36). Purpose of the StudyTo assess OHS in patients with mild to moderate CTS, in comparison with healthy subjects. MethodsThe study involved 273 healthy people and 140 people diagnosed with CTS. The CTS diagnosis was made on the basis of clinical examinations and nerve conduction studies. OHS was assessed using the SF-36. ResultsIn the assessment of physical components of OHS, in the CTS group (compared with healthy subjects), the results show significantly lower values in physical functioning, role limitations because of physical health problems, bodily pain, and general health perceptions by 7.44, 23.2, 18.9, and 4.1, respectively. Mental components were lower (in CTS group) only in relation to vitality and social functioning by 4.1 and 5.5, respectively. In the assessment of physical component summary (PCS) and mental component summary (MCS), the results show significantly lower values of PCS (by 13 in CTS group) and no significant differences in the assessment of MCS between patients with CTS and healthy subjects. DiscussionThe perception of the OHS in CTS patients is diminished. Hence, when evaluating the effects of the therapy, not only disease-specific scales should be used, but also the OHS. This will allow an assessment of the impact of CTS on OHS and the impact of applied therapy, not only in terms of a reduction in the main symptoms of the condition. ConclusionsMild and moderate forms of CTS significantly affected the PCS of the OHS and all its subcomponents (physical functioning, role limitations because of physical health problems, bodily pain, and general health perceptions) but did not affect the MCS of OHS evaluated as a whole. There were significant differences in the mental component in the evaluation of vitality and social functioning. Level of Evidence3.

Electrophysiologic and Ultrasonographic Assessment of Carpal Tunnel Syndrome in Wheelchair Basketball Athletes.

ObjectiveTo investigate the contributing factors of carpal tunnel syndrome (CTS), electrodiagnostic and ultrasonographic findings of median nerve, and median nerve change after exercise in wheelchair basketball (WCB) players.MethodsFifteen WCB players with manual wheelchairs were enrolled in the study. Medical history of the subjects was taken. Electrodiagnosis and ultrasonography of both median nerves were performed to assess CTS in WCB players. Ultrasonographic median nerves evaluation was conducted after wheelchair propulsion for 20 minutes.ResultsAverage body mass index (BMI) and period of wheelchair use of CTS subjects were greater than those of normal subjects. Electrodiagnosis revealed CTS in 14 of 30 hands (47%). Cross-sectional area (CSA) of median nerve was greater in CTS subjects than in normal subjects at 0.5 cm and 1 cm proximal to distal wrist crease (DWC), DWC, 1 cm, 2 cm, 3 cm, and 3.5 cm distal to DWC. After exercising, median nerve CSAs at 0.5 cm and 1 cm proximal to DWC, DWC, and 3 cm and 3.5 cm distal to DWC were greater than baseline CSAs in CTS subjects; and median nerve CSAs at 1 cm proximal to DWC and DWC were greater than baseline CSAs in normal subjects. The changes in median nerve CSA after exercise in CTS subjects were greater than in normal subjects at 0.5 cm proximal to DWC and 3 cm and 3.5 cm distal to DWC.ConclusionBMI and total period of wheelchair use contributed to developing CTS in WCB players. The experimental exercise might be related to the median nerve swelling around the inlet and outlet of carpal tunnel in WCB athletes with CTS.

Reappraisal of the F/M amplitude ratio in carpal tunnel syndrome.

The F-wave/M-wave amplitude (F/M-amp) ratio has been shown to be increased in peripheral neuropathies, provided the maximum M-wave is relatively preserved. Reduced M-wave amplitudes and central facilitation of antidromically-induced reactivation of the anterior horn cells' axon hillocks (F-wave) are believed to contribute to higher F/M-amp ratios. The present study was undertaken to re-evaluate mechanisms responsible for higher F/M-amp ratios in carpal tunnel syndrome (CTS). We enrolled 232 cases affected by CTS and 108 controls. Fand M-wave amplitudes and F-wave chronodispersion were analyzed for the median and ulnar nerves. The F/M-amp ratio of the median nerve in CTS subjects with moderate-severe nerve damage was significantly higher than that of mild CTS subjects and controls. Chronodispersion of the median nerve F-wave increased with increasing CTS severity. We conclude that the relative preservation of the median nerve F-wave is due to damage to the large diameter muscle afferent fibers responsible for the monosynaptic response. Absence of the monosynaptic response makes the small motoneurons, usually inaccessible to the antidromic volley because of its collision with the orthodromic reflex volley, able to fire in the F-wave.

Diagnosis of carpal tunnel syndrome assessed using high-frequency ultrasonography: cross-section areas of 8-site median nerve.

This study aimed to determine the most suitable site for diagnosis of carpal tunnel syndrome (CTS) by examining an 8-site measurement of the median nerve's cross-sectional area (CSA). A total of 36 wrists of 26 patients with nerve conduction study (NCS) proven CTS, along with 34 wrists of 23 controls whose age and gender were matched with the patients, were evaluated with ultrasonography. The CSAs of the median nerve at eight predetermined sites including at the sites of 3, 2, and 1cm proximal to the wrist crease, wrist crease, as well as at the sites of 1, 2, 3. and 4cm distal to the wrist crease were obtained. The correlation between CSA and NCS severity, and duration of clinical CTS symptoms was analyzed. Receiver operating characteristic (ROC) curves was applied to determine the optimum cut-off point and to evaluate the diagnostic sensitivity and specificity of sonographic measurements. The CSAs of the median nerves at the eight sites were significantly higher in the CTS subjects, relative to the controls. Moreover, anatomical variation of the median nerve was found in the CTS group. ROC results indicated the areas under curve (AUC) at the site of 4cm distal to the wrist crease were the largest with 0.874cm(2), and an optimal cut-off value of 0.095 yielded a sensitivity of 88.9% and a specificity of 76.5%. The CSAs of "CTS-wrists" positively correlated with NCS severities and the CTS symptoms duration. Using 8-site CSAs measurement of the median nerve from inlet to outlet has positive correlations with NCS severity and duration of CTS symptoms.

Quantitative Muscle Ultrasonography in Carpal Tunnel Syndrome.

ObjectiveTo assess the reliability of quantitative muscle ultrasonography (US) in healthy subjects and to evaluate the correlation between quantitative muscle US findings and electrodiagnostic study results in patients with carpal tunnel syndrome (CTS). The clinical significance of quantitative muscle US in CTS was also assessed.MethodsTwenty patients with CTS and 20 age-matched healthy volunteers were recruited. All control and CTS subjects underwent a bilateral median and ulnar nerve conduction study (NCS) and quantitative muscle US. Transverse US images of the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) were obtained to measure muscle cross-sectional area (CSA), thickness, and echo intensity (EI). EI was determined using computer-assisted, grayscale analysis. Inter-rater and intra-rater reliability for quantitative muscle US in control subjects, and differences in muscle thickness, CSA, and EI between the CTS patient and control groups were analyzed. Relationships between quantitative US parameters and electrodiagnostic study results were evaluated.ResultsQuantitative muscle US had high inter-rater and intra-rater reliability in the control group. Muscle thickness and CSA were significantly decreased, and EI was significantly increased in the APB of the CTS group (all p<0.05). EI demonstrated a significant positive correlation with latency of the median motor and sensory NCS in CTS patients (p<0.05).ConclusionThese findings suggest that quantitative muscle US parameters may be useful for detecting muscle changes in CTS. Further study involving patients with other neuromuscular diseases is needed to evaluate peripheral muscle change using quantitative muscle US.

Anthropometric measurements as a screening test for carpal tunnel syndrome: receiver operating characteristic curves and accuracy.

To identify optimal cutoff values for body, hand, and wrist measurements in order to correctly identify individuals with carpal tunnel syndrome (CTS), using receiver operating characteristic (ROC) curves. We enrolled patients with CTS and control subjects at a 1:2 ratio, regardless of age and sex. The diagnosis of CTS was based on clinical findings and delayed distal conduction velocity of the median nerve. The anthropometric measurements included weight, height, waist circumference, hip circumferences, wrist depth/width, third digit length, and palm length/width. Obesity indicators and hand/wrist ratios were calculated. Area under the ROC curve (AUC), sensitivity, specificity, and likelihood ratios were calculated separately according to sex. To assess the role of multiple anthropometric measurements, we fit multivariable logistic regression models including age, wrist ratio, shape index, body mass index, and waist-to-hip ratio. The study group comprised 1,117 subjects (250 female patients and 474 female controls; 120 male patients and 273 male controls). In women, the accuracy of all anthropometric measures was low (AUC ≤0.64). In men, the accuracy of the hand ratio, shape index, and wrist-to-palm ratio was moderate (AUC = 0.75). The estimates from the multivariable models confirmed the well-known associations between the selected variables and the risk of CTS, but the use of multiple predictors did not dramatically improve the diagnostic performance observed for single anthropometric indexes. In clinical practice, the cutoff values for many anthropometric measurements have limited value as tools for the diagnosis of CTS.