Assessment of motor unit loss in patients with spinal muscular atrophy.

OBJECTIVE: To assess motor unit (MU) changes in patients with spinal muscular atrophy (SMA) using compound muscle action potential (CMAP) scans. METHODS: We performed CMAP scan recordings in median nerves of 24 treatment-naïve patients (median age 39; range 12-75 years) with SMA types 2-4. From each scan, we determined maximum CMAP amplitude (CMAPmax), a motor unit number estimate (MUNE), and D50 which quantifies the largest discontinuities within CMAP scans. RESULTS: Median CMAPmax was 8.1 mV (range 0.9-14.6 mV), MUNE was 29 (range 6-131), and D50 was 25 (range 2-57). We found a reduced D50 (<25) in patients with normal CMAPmax (n = 12), indicating MU loss and enlarged MUs due to reinnervation. Lower D50 values were associated with decreased MUNE (P < 0.001, r = 0.68, n = 43). CMAPmax, MUNE and D50 values differed between SMA types (P < 0.001). Lower motor function scores were related to patients with lower CMAPmax, MUNE and D50 values (P < 0.001). CONCLUSIONS: The CMAP scan is an easily applicable technique that is superior to routine assessment of CMAPmax in SMA. SIGNIFICANCE: The detection of pathological MU changes across the spectrum of SMA may provide important biomarkers for evaluating disease course and monitoring treatment efficacy.

Sonographic assessment of nerve blood flow in diabetic neuropathy.

AIMS: To undertake sonographic assessment of nerve blood flow in people with Type 2 diabetes and correlate the findings with neuropathy severity scores and electrophysiological measurements. METHODS: Median and tibial nerve ultrasound scans were undertaken in 75 people with diabetes and 30 aged-matched controls without diabetes, using a high-resolution linear probe at non-entrapment sites. Nerve blood flow was quantified using power Doppler techniques to obtain the vessel score and the maximum perfusion intensity. Neuropathy severity was assessed using a total neuropathy score. RESULTS: Diabetic nerves had higher rates of nerve blood flow detection (28%) compared to the control group (P < 0.0001). Significant correlations were found between nerve blood flow measurements and nerve size (P <0.001), reported sensory symptoms (P < 0.05) and neuropathy severity scores (P < 0.001). The cohort with diabetes had significantly larger median (8.5 ± 0.3 mm2 vs 7.2 ± 0.1 mm2 ; P < 0.05) and tibial nerves (18.0 ± 0.9 mm2 vs 12.8 ± 0.5 mm2 ; P < 0.05) compared with controls. CONCLUSION: Peripheral nerve hypervascularity is detectable by ultrasonography in moderate to severe diabetic neuropathy with prominent sensory dysfunction.

Quantitative assessment of cortical somatosensory digit representations after median and ulnar nerve injury in rats.

Incomplete recovery of sensory function is common after peripheral nerve injury (PNI). Despite reinnervation following injury, disorganized cortical representations persist and may contribute to functional deficits. There is a dearth of literature characterizing cortical responses after PNI in rodent models. Here we develop a quantitative electrophysiological method for mapping forepaw digit responses in primary somatosensory cortex (S1) of rats. We tested the hypothesis that PNI in the forelimb would generate significant, long lasting sensory deficits, and corresponding disorganization in S1. Rats underwent a transection of the proximal segment of the median and ulnar nerves in the forelimb followed by tubular repair. 4-12 months after nerve injury, we tested mechanosensory withdrawal thresholds and mapped S1 responses to mechanical stimulation of the digits. PNI produces persistent elevation of mechanical withdrawal thresholds, consistent with an impairment in sensory function. Assessment of cortical neurophysiology reveals a substantial disorganization of S1 somatotopy. Additionally, we document degraded timing and digit specificity of cortical responses. This quantitative measurement of long-term changes in S1 digit representations after forelimb nerve injury in rodents provides a framework for further studies focused on the development of therapeutic strategies to restore cortical and sensory function.

Stimulated grip strength measurement: Validation of a novel method for functional assessment.

BACKGROUND: Reliable measurement of functional recovery is critical in translational peripheral nerve regeneration research. Behavioral functional assessments such as volitional grip strength testing (vGST) are limited by inherent behavioral variability. Isometric tetanic force testing (ITFT) is highly reliable but precludes serial measurements. Combining elements of vGST and ITFT, stimulated grip strength testing (sGST) involves percutaneous median nerve stimulation to elicit maximal tetanic contraction of digital flexors, thereby allowing for consistent measurement of maximal grip strength. METHODS: We measured side-to-side equivalence of force using sGST, vGST, and ITFT to determine relative reliability and repeatability. We also performed weekly force measurements following median nerve repair. RESULTS: sGST demonstrated greater reliability and inter-trial repeatability than vGST and similar reliability to ITFT, with the added benefit of serial measurements. CONCLUSIONS: sGST is a valid method for assessing functional recovery that addresses the limitations of the currently available modalities used in translational peripheral nerve regeneration research.

Assessment of Peripheral Nerves With Shear Wave Elastography in Type 1 Diabetic Adolescents Without Diabetic Peripheral Neuropathy.

OBJECTIVES: To investigate the utility of shear wave elastography (SWE) in detecting morphologic abnormalities of the median nerve and posterior tibial nerve in transverse and longitudinal axes in adolescents with type 1 diabetes mellitus (DM) without diabetic peripheral neuropathy (DPN). METHODS: The median nerves and posterior tibial nerves of 25 adolescents with diagnosis and follow-up of type 1 DM without DPN and 32 healthy volunteers were evaluated with SWE by 2 observers on the transverse and longitudinal axes. The cross-sectional area and thickness of the nerves and disease duration were noted, and probable associations of these parameters with SWE features were analyzed. Interobserver and intraobserver correlations were also examined. The statistical significance level was set at P < .05. RESULTS: Both the median nerve and posterior tibial nerve were smaller, thinner, and stiffer in the patient group for both observers on both axes. The disease duration weakly correlated with median nerve SWE features (r = 0.245-0391). The thickness and cross-sectional area had no correlations with SWE features. CONCLUSIONS: The median nerve and posterior tibial nerve in adolescents with type 1 DM without DPN have morphologic abnormalities that can be displayed by SWE regardless of the imaging axis. Shear wave elastography may have a potential role in subclinical DPN, but the reliability of the findings is not as high as desirable.

Usefulness of ultrasound assessment of median nerve mobility in carpal tunnel syndrome.

BACKGROUND: Carpal tunnel syndrome (CTS) is the most common peripheral compression neuropathy of the upper extremity. Recently, dynamic ultrasound (US) imaging has shown differences in median nerve mobility between the affected and unaffected sides in CTS. PURPOSE: The present study was performed to compare the median nerve mobility between patients with CTS and healthy individuals, and to correlate median nerve mobility with the severity of CTS. MATERIAL AND METHODS: A total of 101 patients (128 wrists) with CTS and 43 healthy individuals (70 wrists) were evaluated. Electrodiagnostic studies were initially conducted to determine the neurophysiological grading scale (NGS). The cross-sectional area (CSA) of the median nerve and the grade of median nerve mobility were measured using US. RESULTS: The mean grade of median nerve mobility in the CTS group (1.9) was significantly lower than that in the control group (2.6; P < 0.001). There were significant negative correlations between the grade of median nerve mobility and distal motor latency of the median nerve (r = -0.218, P = 0.015), NGS (r = -0.207, P = 0.020) and CSA of the median nerve (r = -0.196, P = 0.028). CONCLUSION: The grade of median nerve mobility was negatively correlated with the severity of CTS. US assessment of median nerve mobility may be useful in diagnosing and determining the severity of CTS.

Electrophysiological Assessment for Splinting in the Treatment of Carpal Tunnel Syndrome.

An electrophysiological study is commonly used to decide a therapeutic strategy for carpal tunnel syndrome (CTS). In this study, the electrophysiological parameter measurement as a prognostic indicator for CTS after wrist splinting was assessed to identify appropriate candidates for wrist splinting for CTS. One hundred and six hands in 78 patients with CTS were treated by wrist splinting, and three electrophysiological parameters; median distal motor latency (DML) of the abductor pollicis brevis (APB) muscle, median distal sensory latency (DSL) of the index finger, and second lumbrical-interossei latency difference (2L-INT LD); were statistically analyzed to compare with clinical results by Kelly's evaluation respectively. Clinical results were excellent in 15 hands, good in 51 hands, fair in 19 hands, and poor in 21 hands. The recordable rate in 2L-INT LD (99.1%) was higher than DML (96.2%) and DSL (79.2%). Patients with DML less than 6.5 ms, DSL less than 5.7 ms, or 2L-INT LD less than 2.5 ms had significantly excellent or good clinical results. The odds ratios of the DML, DSL, and the 2L-INT LD were 7.93, 8.81, and 12.8, respectively. This study demonstrated that CTS patients with DML less than 6.5 ms, DSL less than 5.7 ms, or 2L-INT less than 2.5 ms were good candidates for wrist splinting. Especially, the 2L-INT LD could be the most reliable indicator to predict clinical results for all grades of CTS. This electrophysiological information could be useful in further improvement of accurate diagnosis of CTS, and may help in the assessment of appropriate treatment for CTS with wrist splinting.

Motor unit number estimation in the quantitative assessment of severity and progression of motor unit loss in Hirayama disease.

OBJECTIVE: To investigate motor unit number estimation (MUNE) as a method to quantitatively evaluate severity and progression of motor unit loss in Hirayama disease (HD). METHODS: Multipoint incremental MUNE was performed bilaterally on both abductor digiti minimi and abductor pollicis brevis muscles in 46 patients with HD and 32 controls, along with handgrip strength examination. MUNE was re-evaluated approximately 1year after initial examination in 17 patients with HD. RESULTS: The MUNE values were significantly lower in all the tested muscles in the HD group (P<0.05). Despite abnormally low MUNE values, 54.3% (25/46) of patients with HD had normal ipsilateral grip power. There was a significant inverse correlation between MUNE values and disease duration (P<0.05). A longitudinal follow-up MUNE analysis demonstrated slow progression of motor unit loss in patients with HD within approximately 1year (P<0.05), even in patients with an illness duration >4years. CONCLUSIONS: A reduction in the functioning motor units was found in patients with HD compared with that in controls, even in the early asymptomatic stages. Moreover, the motor unit loss in HD progresses gradually as the disease advances. SIGNIFICANCE: These results have provided evidence for the application of MUNE in estimating the reduction of motor unit in HD and confirming the validity of MUNE for tracking the progression of HD in a clinical setting.

Ultrasound elastography assessment of the median nerve in leprosy patients.

INTRODUCTION: We sought to compare median nerve elasticity between leprosy patients (LPs) and healthy volunteers (HVs) using ultrasound elastography (UE). METHODS: Two radiologists independently measured the strain ratio of the median nerve/flexor digitorum superficialis muscle (MN/FDSM) of 18 LP and 18 HV using real-time freehand UE. Statistical analysis included intra-class correlation coefficients (ICC) and Mann-Whitney test. RESULTS: The MN/FDSM strain ratios of the LP and HV were 2.66 ± 1.30 and 3.52 ± 0.93, respectively (P < 0.05). We observed a significantly lower MN/FDSM strain ratio in LP with reactions (types 1 and 2 cutaneous reactions associated with or without neuritis) (2.30 ± 0.91) compared with LP without reactions (3.60 ± 1.70). We found no significant differences between HV and LP without reactions. The intra- and inter-observer ICCs were 0.50 (95% confidence interval [CI], 0.11-0.72) and 0.34 (95% CI, 0.28-0.52), respectively. CONCLUSIONS: MN/FDSM strain ratios were significantly lower in LP with reactions. UE may be useful for nerve elasticity evaluation in leprosy. Muscle Nerve 56: 393-398, 2017.

High-Resolution Axonal Bundle (Fascicle) Assessment and Triple-Echo Steady-State T2 Mapping of the Median Nerve at 7 T: Preliminary Experience.

OBJECTIVES: The aims of this preliminary study were to determine the number of axonal bundles (fascicles) in the median nerve, using a high-resolution, proton density (PD)-turbo spin echo (TSE) fat suppression sequence, and to determine normative T2 values, measured by triple-echo steady state, of the median nerve in healthy volunteers and in patients with idiopathic carpal tunnel syndrome (CTS), at 7 T. MATERIALS AND METHODS: This prospective study was approved by the local ethics committee and conducted between March 2014 and January 2015. All study participants gave written informed consent. Six healthy volunteers (30 ± 12 years) and 5 patients with CTS (44 ± 16 years) were included. Measurements were performed on both wrists in all volunteers and on the affected wrist in patients (3 right, 2 left). Based on 5-point scales, 2 readers assessed image quality (1, very poor; 5, very good) and the presence of artifacts that might have a possible influence on fascicle determination (1, severe artifacts; 5, no artifacts) and counted the number of fascicles independently on the PD-TSE sequences. Furthermore, T2 values by region of interest analysis were assessed. Student t tests, a hierarchic linear model, and intraclass correlation coefficients (ICCs) were used for statistical analysis. RESULTS: Proton density-TSE image quality and artifacts revealed a median of 5 in healthy volunteers and 4 in patients with CTS for both readers. Fascicle count of the median nerve ranged from 13 to 23 in all subjects, with an ICC of 0.87 (95% confidence interval [CI], 0.67-0.95). T2 values were significantly higher (P = 0.023) in patients (24.27 ± 0.97 milliseconds [95% CI, 22.19-26.38]) compared with healthy volunteers (21.01 ± 0.65 milliseconds [95% CI, 19.61-22.41]). The ICC for all T2 values was 0.97 (95% CI, 0.96-0.98). CONCLUSIONS: This study shows the possibility of fascicle determination of the median nerve in healthy volunteers and patients with CTS (although probably less accurately) with high-resolution 7 T magnetic resonance imaging, as well as significantly higher T2 values in patients with CTS, which seems to be associated with pathophysiological nerve changes.

Assessment of Median Nerve Mobility by Ultrasound Dynamic Imaging for Diagnosing Carpal Tunnel Syndrome.

Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy and is characterized by median nerve entrapment at the wrist and the resulting median nerve dysfunction. CTS is diagnosed clinically as the gold standard and confirmed with nerve conduction studies (NCS). Complementing NCS, ultrasound imaging could provide additional anatomical information on pathological and motion changes of the median nerve. The purpose of this study was to estimate the transverse sliding patterns of the median nerve during finger movements by analyzing ultrasound dynamic images to distinguish between normal subjects and CTS patients. Transverse ultrasound images were acquired, and a speckle-tracking algorithm was used to determine the lateral displacements of the median nerve in radial-ulnar plane in B-mode images utilizing the multilevel block-sum pyramid algorithm and averaging. All of the averaged lateral displacements at separate acquisition times within a single flexion-extension cycle were accumulated to obtain the cumulative lateral displacements, which were curve-fitted with a second-order polynomial function. The fitted curve was regarded as the transverse sliding pattern of the median nerve. The R2 value, curvature, and amplitude of the fitted curves were computed to evaluate the goodness, variation and maximum value of the fit, respectively. Box plots, the receiver operating characteristic (ROC) curve, and a fuzzy c-means clustering algorithm were utilized for statistical analysis. The transverse sliding of the median nerve during finger movements was greater and had a steeper fitted curve in the normal subjects than in the patients with mild or severe CTS. The temporal changes in transverse sliding of the median nerve within the carpal tunnel were found to be correlated with the presence of CTS and its severity. The representative transverse sliding patterns of the median nerve during finger movements were demonstrated to be useful for quantitatively estimating median nerve dysfunction in CTS patients.

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

PURPOSE: The purpose of this study was to investigate the displacement of the median nerve in the carpal tunnel during finger motion at varied wrist positions using transverse ultrasound in healthy volunteers, in order to clarify the appropriate position of a wrist splint in treating carpal tunnel syndrome. METHODS: Fifty wrists of 25 asymptomatic volunteers were evaluated by transverse ultrasound. The location of the median nerve in the carpal tunnel was examined at 5 wrist positions (neutral, 60° dorsiflexion, 60° palmar flexion, 40° ulnar flexion, 10° radial flexion) with all 5 fingers in full extension, all 5 fingers in full flexion, and isolated thumb in full flexion, respectively. RESULTS: The median nerve was located significantly (p<0.05) more dorsally at the wrist dorsal flexion position, more ulnopalmarly at the wrist palmar flexion position, more radially at the wrist radial flexion position, and more radially at the wrist ulnar flexion position than at the wrist neutral position in all 5 fingers at full extension. The median nerve moved the most significantly dorsally among all wrist positions during finger motion at the wrist dorsal flexion position (p<0.05). Conversely, the median nerve moved the most significantly ulnopalmarly at the wrist palmar flexion position with all 5 fingers in full flexion among all wrist positions during finger motion (p<0.05). This latter wrist and finger position induced significant displacement of the median nerve toward the transverse carpal ligament, and compressed it between the flexor tendons and the transverse carpal ligament. CONCLUSIONS: This study showed that there is a significant relationship between the median nerve displacement in the carpal tunnel and the motion of the wrist and fingers. This finding suggests that the compression or the shearing stress of the median nerve caused by the movement of the flexor tendons is reduced in the wrist dorsal flexion position compared with other wrist positions. This wrist dorsal flexion position could be the appropriate position for a wrist splint in the treatment for carpal tunnel syndrome. This ultrasound information provides further knowledge and understanding of the biomechanics and pathophysiology of the carpal tunnel. It could also help in the accurate analysis and assessment of diagnostic images and treatment for carpal tunnel syndrome.

Carpal tunnel syndrome assessment with ultrasonography: value of inlet-to-outlet median nerve area ratio in patients versus healthy volunteers.

OBJECTIVE: To evaluate the diagnostic value of the Inlet-to-outlet median nerve area ratio (IOR) in patients with clinically and electrophysiologically confirmed carpal tunnel syndrome (CTS). METHODS: Forty-six wrists in 46 consecutive patients with clinical and electrodiagnostic evidence of CTS and forty-four wrists in 44 healthy volunteers were examined with ultrasonography. The cross-sectional area (CSA) of the median nerve was measured at the carpal tunnel inlet (the level of scaphoid-pisiform) and outlet (the level of the hook of the hamate), and the IOR was calculated for each wrist. Ultrasonography and electrodiagnostic tests were performed under blinded conditions. Electrodiagnostic testing combined with clinical symptoms were considered to be the gold standard test. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic value between the inlet CSA and IOR. RESULTS: The study population included 16 men and 30 women (mean age, 45.3 years; range, 18-83 years). The control population included 18 men and 26 women (mean age, 50.4 years; range, 18-79 years). The mean inlet CSA was 8.7 mm2 in healthy controls and 14.6mm2 in CTS group (P<0.001). The mean IOR in healthy volunteers (1.0) was smaller than that in patients (1.6, P<0.001). Receiver operating characteristic analysis revealed a diagnostic advantage to using the IOR rather than the inlet CSA (P<0.01). An IOR cutoff value of ≥ 1.3 would yield 93% specificity and 91% sensitivity in the diagnosis of CTS. CONCLUSION: The IOR of median nerve area promises to be an effective means in the diagnosis of CTS. A large-scale, randomized controlled trial is required to determine how and when this parameter will be used.

Electrophysiological assessment of carpal tunnel syndrome in elderly patients: one-year follow-up study.

PURPOSE: To objectively assess elderly patients with carpal tunnel syndrome to characterize their preoperative severity and prognosis after carpal tunnel release using a electrophysiological severity scale. METHODS: Electrophysiologic assessment was performed preoperatively and 1 year postoperatively following carpal tunnel release in 112 hands in patients over 70 years of age prospectively by the use of the following electrophysiological severity scale: stage 1, normal distal motor latency (DML) and normal sensory conduction velocity (SCV); stage 2, DML ≥ 4.5 milliseconds and normal SCV; stage 3, DML ≥ 4.5 milliseconds and SCV < 40.0 m/s; stage 4, DML ≥ 4.5 milliseconds and non-measurable SCV; stage 5; non-measurable DML and non-measurable SCV. Additionally, the outcomes of clinical symptoms of pain, nocturnal symptoms, numbness, loss of 2-point discrimination in the median nerve territory, and thenar atrophy were assessed. RESULTS: The mean age of patients was 77 years at the time of the operation. Preoperatively, the most common severity was stage 5 (70 of 112 hands, 63%), and clustering stage 4 and 5 together as severe resulted in 103 hands (92%). One year postoperatively, 97 hands (87%) demonstrated at least one stage improvement, and the numbers of mild (stage 1 or 2) increased from 3 (3%) to 45 hands (40%). Parallel with the electrophysiological improvement, pain and nocturnal symptoms resolved in 17 of 17 hands and 11 of 11 hands, respectively, in whom they were present preoperatively. Numbness, loss of 2-point discrimination, and thenar atrophy demonstrated the improvement in 96 of 112 (86%) hands, in 58 of 112 (52%) hands, and in 80 of 96 (83%) hands. CONCLUSIONS: We observed electrophysiologic improvement in 86% of elderly patients following carpal tunnel release. Electrophysiologic outcomes correlated with improvement in clinical variables. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Comparison of ultrasound and electrodiagnostic testing for diagnosis of carpal tunnel syndrome: study using a validated clinical tool as the reference standard.

BACKGROUND: Ultrasound examination is both accurate and cost-effective for the confirmation of a clinical diagnosis of carpal tunnel syndrome. Previous studies have shown electrodiagnostic testing and ultrasound to be similar with regard to sensitivity and specificity. The purpose of this study was to compare the sensitivity and specificity of ultrasound and electrodiagnostic testing by using a validated clinical diagnostic tool as the reference standard. METHODS: All consecutive patients referred to an upper-extremity practice for electrodiagnostic testing for any reason over a three-month period were recruited to participate in this study. All patients were evaluated with the use of the Carpal Tunnel Syndrome 6 (CTS-6) clinical diagnostic tool, and a score of ≥12 was considered positive for carpal tunnel syndrome. A positive finding on ultrasound was considered to be a cross-sectional area of the median nerve, measured just proximal to the level of the pisiform, of ≥10 mm(2). A positive finding on electrodiagnostic testing was a distal motor latency of ≥4.2 ms and/or a distal sensory latency of ≥3.2 ms. Sensitivity, specificity, and accuracy were calculated for ultrasound and electrodiagnostic testing with use of the CTS-6 as the reference standard. RESULTS: With use of the CTS-6 as the reference standard, ultrasound had a sensitivity of 89% and a specificity of 90% in our series of eighty-five patients. Electrodiagnostic testing had a sensitivity of 89% and a specificity of 80%. The positive predictive value of ultrasound was 94% compared with 89% for electrodiagnostic testing. The negative predictive value of ultrasound was 82% compared with 80% for electrodiagnostic testing. Ultrasound was accurate in seventy-six (89%) of the eighty-five cases whereas electrodiagnostic testing was accurate in seventy-three (86%) of the eighty-five cases (p = 0.5). CONCLUSIONS: While ultrasound will not replace electrodiagnostic testing in complicated or unclear cases, in a select group of patients with a positive CTS-6, ultrasound can be used to confirm the diagnosis of carpal tunnel syndrome with better specificity and equal sensitivity as compared with those of electrodiagnostic testing. LEVEL OF EVIDENCE: Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Effects of varying case definition on carpal tunnel syndrome prevalence estimates in a pooled cohort.

OBJECTIVE: To analyze differences in carpal tunnel syndrome (CTS) prevalence using a combination of electrodiagnostic studies (EDSs) and symptoms using EDS criteria varied across a range of cutpoints and compared with symptoms in both ≥1 and ≥2 median nerve-served digits. DESIGN: Pooled data from 5 prospective cohorts. SETTING: Hand-intensive industrial settings, including manufacturing, assembly, production, service, construction, and health care. PARTICIPANTS: Employed, working-age participants who are able to provide consent and undergo EDS testing (N=3130). INTERVENTIONS: None. MAIN OUTCOME MEASURES: CTS prevalence was estimated while varying the thresholds for median sensory latency, median motor latency, and transcarpal delta latency difference. EDS criteria examined included the following: median sensory latency of 3.3 to 4.1 milliseconds, median motor latency of 4.1 to 4.9 milliseconds, and median-ulnar sensory difference of 0.4 to 1.2 milliseconds. EDS criteria were combined with symptoms in ≥1 or ≥2 median nerve-served digits. EDS criteria from other published studies were applied to allow for comparison. RESULTS: CTS prevalence ranged from 6.3% to 11.7%. CTS prevalence estimates changed most per millisecond of sensory latency compared with motor latency or transcarpal delta. CTS prevalence decreased by 0.9% to 2.0% if the criteria required symptoms in 2 digits instead of 1. CONCLUSIONS: There are meaningful differences in CTS prevalence when different EDS criteria are applied. The digital sensory latency criteria result in the largest variance in prevalence.

Assessment of the effectiveness of interferential current therapy and TENS in the management of carpal tunnel syndrome: a randomized controlled study.

We assessed the effectiveness of interferential current (IFC) and transcutaneous electrical nerve stimulation (TENS) therapies in the management of carpal tunnel syndrome (CTS) compared with splint therapy, a standard treatment modality for CTS. This was a prospective, single-blinded, single-center, randomized, three-group parallel intervention study of 3 weeks duration. Efficacy was examined in the third week after the end of treatments. Subjects were assigned randomly to one of three groups: group I patients received splint therapy, group II patients received TENS applied on the palmar surface of the hand and the carpal tunnel, and group III patients underwent IFC therapy applied on the palmar surface of the hand and the volar surface of the forearm. TENS and ICF treatments were applied five times weekly for a total of 15 sessions. Group 1 patients were stabilized with volar wrist splints for 3 weeks. The efficacy of the therapies was assessed before initiation of therapy and at 3 weeks after completion of therapy using a visual analog scale (VAS), a symptom severity scale, the functional capacity scale of the BCTQ, and measurement of median nerve motor distal latency (mMDL) and median sensory nerve conduction velocity (mSNCV). Groups were compared pairwise using the Mann-Whitney U test to identify the source of differences between groups. The Wilcoxon test was used to analyze changes in variables over time within a group. In the VAS, BCTQ, MDL, and mSNCV, no significant difference was observed between the groups (p > 0.05). In the VAS, BCTQ, and mSNCV, statistically significant improvements were detected in all groups (p < 0.05). There was no statistically significant difference between TENS and splint therapy with respect to improvement in clinical scores, whereas IFC therapy provided a significantly greater improvement in VAS, mMDL, and mSNCV values than splint therapy (VAS: 4.80 ± 1.18 and 6.37 ± 1.18; p = 0.001, mMDL: 3.89 ± 0.88 and 4.06 ± 0.61; p = 0.001, mSNCV: 41.80 ± 1.76 and 40.75 ± 1.48; p = 0.010). IFC therapy provided a significantly greater improvement in VAS, symptom severity, functional capacity, and mMDL and mSNCV values than TENS therapy (VAS: 4.80 ± 1.18 and 6.68 ± 1.42; p < 0.001, symptom severity: 2.70 ± 1.03 and 3.37 ± 1.21; p = 0.015, functional capacity: 1.90 ± 1.21 and 2.50 ± 0.78; p = 0.039, mMDL: 3.89 ± 0.88 and 4.06 ± 0.88; p = 0.003, and mSNCV: 41.80 ± 1.76 and 41.38 ± 1.78; p = 0.021). IFC may be considered a new and safe therapeutic option for the treatment of CTS.

Ultrasonic assessment of females with carpal tunnel syndrome proved by nerve conduction study.

INTRODUCTION: Carpal tunnel syndrome (CTS) is the most commonly diagnosed entrapment neuropathy of the upper extremity. The objective of this study was to diagnose CTS and to assess its severity using high resolution ultrasound (HRUS) depending on the results of nerve conduction study (NCS). METHODS: A prospective cross-sectional study, in which HRUS was performed at 63 wrists of 35 female patients with different severity of CTS (as proved by NCS). Furthermore, 40 healthy volunteers (80 wrists) underwent the same tests as the patients and have been chosen to match the patients in gender, age, and body mass index (BMI). The cross section area (CSA) of the median nerve (MN) was obtained using HRUS at the carpal tunnel inlet by direct tracing method. RESULTS: There was a significant difference in the CSA of the MN at the tunnel inlet in CTS patients when compared with the control group. In fact, the CSA of the control group showed a significant difference from each of patients subgroups. Furthermore, a significant difference in the CSA was seen in between these subgroups. In conclusion, the US examination of the MN seems to be a promising method in diagnosing and grading of carpal tunnel syndrome.