Abnormalities Of Median Nerve Research Articles

Role of ultrasound and magnetic resonance neurography in the detection of median nerve abnormalities in carpal tunnel syndrome

BackgroundThe most prevalent cause of peripheral nerve entrapment is carpal tunnel syndrome, which is characterized by compression of the median nerve at the wrist as a result of nearby or localized microvascular interference as well as structural alterations to the median nerve or adjacent tissues. However, no special information regarding the median nerve or its surroundings is provided by clinical examination or electrophysiological testing. The purpose of this study is to evaluate the effectiveness of magnetic resonance neurography (MRN) and ultrasound in identifying changes and abnormalities of the median nerve in carpal tunnel syndrome.MethodsThe twenty-five patients in this study ranged in age from 27 to 63 years old, with a mean age of 47. There were 18 female patients and seven male patients. All patients were sent to the radiology department from the orthopedics, neurology, outpatient clinic, and neurology department, at Ain Shams Hospital, Faculty of Medicine, Ain Shams University. All of the patients had clinically manifested pain along the median nerve distribution, each of the sixteen patients had hand paresthesia, and four had thenar muscle atrophy.ResultsIn the current study, Ultrasound exhibits low negative predictive value of 67% and specificity of 67%, but high positive predictive value of 95%, sensitivity of 95%, and overall accuracy of 92%. On the other hand, (MRN) exhibits a low negative predictive value of 60% and a high specificity of 75% in the diagnosis of nerve entrapment, but it also displays a high positive predictive value of 95%, sensitivity of 90%, and overall accuracy of 88%. Regarding the assessment of the recurrence cause and post-surgical evaluation is more reliable by Magnetic Resonance Neurography examination.ConclusionsMagnetic resonance neurography and high-resolution ultrasonography can be utilized to diagnose patients with median nerve entrapment and patients who cannot be diagnosed electrophysiologically.MRN is a more accurate method for detecting the exact location of nerve entrapment and evaluating nerve recovery after surgical intervention than nerve conduction studies and electromyography. Additionally, MRN can be used to identify causes that were not previously recognized based on physical examination and electrophysiological tests.

Hourglass-Like Constriction Neuropathy of the Upper Limb Nerve: Diffusion-Weighted Magnetic Resonance Neurography Imaging Findings.

The purposes of this study were to determine reliable diffusion-weighted magnetic resonance neurography (DW-MRN) features of hourglass-like constriction of the upper limb nerve and to evaluate the application value of DW-MRN compared with ultrasonography (US). We retrospectively reviewed MRN studies of 13 patients. Qualitative and quantitative image analyses were carried out. The number of constrictions based on DW-MRN and US findings was compared. Of the 13 cases, there were 7 cases with radial nerve abnormalities, 4 with median nerve abnormalities, and 2 with radial and median nerve abnormalities. Diffusion-weighted MRN showed a single-segmental constriction in 7 of 13 cases and multisegmental constrictions in 6 of 13 cases; the hourglass-like constriction appeared in all cases (13 of 13). Thirty-three nerve constrictions were found in DW-MRN, and 29 nerve constrictions were found in US. Diffusion-weighted MRN is a noninvasive and helpful diagnostic for hourglass-like constriction of the upper limb nerve.

Ulnar and Median Nerve Abnormalities in Carpal Tunnel Syndrome.

Nerve compression underlying carpal tunnel syndrome (CTS) results in an increase in the threshold of superficial sensation in the area supplied by the median nerve, which is a mixed nerve dominated by sensory fibres. The distribution of sensory symptoms is strongly dependent on the degree of electrophysiological dysfunction of the median nerve. The association between carpal tunnel syndrome and ulnar nerve entrapment at wrist level is still unclear. Patho-logical processes leading to median neuropathy in CTS may affect ulnar nerve motor and sensory fibers in the Guyon canal. This may explain the extra-median spread of sensory symptoms in CTS patients. The study involved 88 patients (104 hands), with 70 women (83 hands) and 18 men (21 hands) aged between 25 and 77 years. 50 age- and sex-matched subjects without carpal tunnel syndrome were used as a control group. The diagnosis of carpal tunnel syndrome was made according to the criteria of the American Academy of Neurology 1993 guidelines. Based on the results of an ENG trace evaluating the degree of conduction disturbances in the median nerve, the patients were classified to one of three severity subgroups. The threshold of sensory excitability to pulsed current was determined in a test with single 100 ms rectangular pulses. 1. The threshold of sensation in the fingers innervated by the median and ulnar nerve is significantly lon-ger in patients with CTS than in controls. 2. Surgical treatment decreases the threshold of sensation in the fingers innervated by the median nerve. 3. Surgical treatment does not decrease the threshold of sensation in the fingers innervated by the ul-nar nerve. 4. The preoperative and postoperative threshold of sensation in the fingers innervated by the median and ulnar nerve is significantly longer in patients with severe carpal tunnel than in mild and moderate cases.

Electrophysiological analysis of the patients with hourglass-like constriction of radial nerve/posterior interosseous nerve

Objective To analyze the electrophysiological characteristics of the patients with hourglass-like constriction of radial nerve (RN)/posterior interosseous nerve (PIN) and explore the possible causes. Methods From January 2011 to November 2018, 18 patients with hourglass-like constriction of RN/PIN were treated in our hospital. The electrophysiological results of them were analyzed retrospectively. The extent and degree of lesion involvement were evaluated. Results The course of disease was 3 weeks to 13 months before electrophysiological examination in 18 patients. 14 patients (77.8%) suffered from complete injury and 4 patients (22.1%) suffered from incomplete injury. The coincidence rate between electrophysiological results and intraoperative findings was 94.4%. In addition to the abnormalities directly related to hourglass-like constriction, 88.9% of RN hourglass-like constriction patients and 11.1% of PIN hourglass-like constriction patients were associated with other neurological abnormalities. Among them, 8 patients with RN hourglass-like constriction were complicated with the abnormalities of median nerve (50%), ulnar nerve (50%), musculocutaneous nerve (37.5%), axillary nerve (25%), suprascapular nerve (25%), triceps brachii branch (75%), and the nerves of contralateral upper extremity (25%), contralateral phrenic nerve (12.5%) and the nerves of four extremities (12.5%). The main manifestations were abnormal insertion potential, resting spontaneous fibrillation potential, prolongation of light contraction time limit, simple phase of forced contraction and decrease of amplitude of motor evoked potential in sensory and motor nerve conduction. There was no obvious abnormality in nerve conduction velocity. Conclusion The hourglass-like constriction of RN/PIN is often associated with other neural abnormalities. The higher the location of hourglass-like constriction, the wider the range of involvement. It is different from the electrophysiological characteristics of peripheral nerve entrapment, indicating possible presence of neuralgic amyotrophy. Key words: Electrophysiology; Radial nerve; Posterior interosseous nerve; Hourglass-like constriction

Role of High Resolution Ultrasound in Assessment of Abnormalities of Median Nerve in Carpal Tunnel Syndrome

Background: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and consists of the compression of the median nerve as it courses through the carpal tunnel. Carpal tunnel syndrome was diagnosed by history and physical examination, electrodiagnostic studies (EDX) were used to confirm the diagnosis. However, these studies are painful for most of the patients with high incidence of false positive or false negative results. Ultrasound is a low cost, short time and non-invasiveness technique that could be used to assess a number of parameters of the median nerve (MN) in cases of CTS. Objective: To assess the utility of high resolution ultrasound (HRUS) in assessment of median nerve in carpal tunnel syndrome through different ultrasound diagnostic criteria in patients with clinical and electrodiagnostic evidence of CTS. Patients and Methods: This study included a total of 60 participants divided into 2 groups; group A, the patients group included 30 patients with a clinical diagnosis of carpal tunnel syndrome (CTS) and group B, the control group who included 30 sex and age-matched healthy individuals. All the included cases were subjected to full history taking, full general and general examination. Nerve conduction studies were performed using a Caldwell Sierra Wave and the NCS consisted of sensory median nerve conduction tests using standard techniques. High resolution US was performed by using an Aplio 400 Ultrasound System. The following measurement was recorded in each of the included subjects including cross sectional area (CSA) of the median nerve, flattening ratio (FR) of median nerve and palmar bowing (PB) of the flexor retinaculum. Results: There was high statistically significant difference in the mean CSA and mean PB between the cases with CTS and healthy control. No statistically significant difference in the mean FR between the cases with CTS and healthy control. Optimal CSA cut-off value to differentiate between cases with CTS and control was (10.2 mm2) and the optimal PB cut-off value to differentiate between cases with CTS and control was (3.3 mm). Positive correlation was detected between the CSA and PB with increasing the severity of CTS. Conclusion: Electrophysiological studies are the most utilized diagnostic methods for diagnosing nerve entrapment including median nerve in CTS. Hugh resolution ultrasound (HRUS) is non- invasive sensitive diagnostic tool in diagnosing CTS.

Normative Data for Median Nerve Conduction in Healthy Young Adults from Punjab, India.

Background:Nerve conduction studies (NCSs) are essential for diagnosing various kinds of focal and diffuse neuropathies. Due to the paucity of local NCS data, electrodiagnostic laboratories in Punjab rely on values from Western and other Indian studies.Aim:This study was conducted to provide normative data for median nerve conduction parameters (motor and sensory) in Punjabi populace.Materials and Methods:A cross-sectional study was done on 290 participants (150 males and 140 females), aged 17–21 years, as per standardized protocol. The data were analyzed separately for both genders using SPSS version 20. It consisted of distal latencies and conduction velocities of motor and sensory divisions of median nerve. Student's unpaired t-test was used for statistical analysis.Results:There was no effect of gender on any of the median nerve conduction parameters. Height and weight had nonsignificant negative and positive correlation, respectively (P > 0.05), with conduction velocity in both motor and sensory median nerves. For median motor nerve, the values of distal latency and conduction velocity in males were 2.9 ± 0.16 ms and 60.25 ± 2.99 m/s, respectively, whereas, in females, they were 2.6 ± 0.43 ms and 59.83 ± 2.82 m/s. Similarly, for median sensory nerve, the latency and velocity values in males were 2.8 ± 0.56 ms and 54.81 ± 3.70 m/s, whereas, in females, they were 2.4 ± 0.33 ms and 54.56 ± 3.65 m/s, respectively.Conclusion:The data in this study compared favorably with already existing data. It would help the local electrodiagnostic laboratories in assessing the median nerve abnormalities with greater accuracy in this population subset.

Clinical and electrophysiological evaluation of carpal tunnel syndrome: approach and pitfalls.

One of the most common referrals to the electrodiagnostic (EDX) laboratory is to confirm a clinical impression of carpal tunnel syndrome (CTS). The EDX studies are valuable in localizing median nerve abnormalities to the wrist, grading its severity, and excluding other condition that can mimic or coexist with CTS. However, there are many clinical and EDX pitfalls that can lead to misdiagnosis. Careful clinical assessment and attention to technical factors and details of the EDX techniques are fundamental for the quality and accurate interpretation of the study. This review aims to discuss the clinical and the EDX approaches to the diagnosis of CTS with emphasis on the commonly encountered pitfalls.

Has the median nerve involvement in rheumatoid arthritis been overemphasized?

Rheumatoid arthritis (RA) is a well and widely recognized cause of carpal tunnel syndrome (CTS). In the rheumatoid wrist, synovial expansion, joint erosions and ligamentous laxity result in compression of the median nerve due to increased intracarpal pressure. We evaluated the published studies to determine the prevalence of CTS and the characteristics of the median nerve in RA and its association with clinical parameters such as disease activity, disease duration and seropositivity. A total of 13 studies met the eligibility criteria. Pooled data from 8 studies with random selection of RA patients revealed that 86 out of 1561 (5.5%) subjects had CTS. Subclinical CTS, on the other hand, had a pooled prevalence of 14.0% (30/215). The cross sectional area of the median nerve of the RA patients without CTS were similar to the healthy controls. The vast majority of the studies (8/13) disclosed no significant relationship between the median nerve findings and the clinical or laboratory parameters in RA. The link between RA and the median nerve abnormalities has been overemphasized throughout the literature. The prevalence of CTS in RA is similar to the general population without any correlation between the median nerve characteristics and the clinical parameters of RA.

O envolvimento do nervo mediano na artrite reumatoide tem sido excessivamente valorizado?

Rheumatoid arthritis (RA) is a well and widely recognised cause of carpal tunnel syndrome (CTS). In the rheumatoid wrist, synovial expansion, joint erosions and ligamentous laxity result in compression of the median nerve due to increased intracarpal pressure. We evaluated the published studies to determine the prevalence of CTS and the characteristics of the median nerve in RA and its association with clinical parameters such as disease activity, disease duration and seropositivity. A total of 13 studies met the eligibility criteria. Pooled data from 8 studies with random selection of RA patients revealed that 86 out of 1561 (5.5%) subjects had CTS. Subclinical CTS, on the other hand, had a pooled prevalence of 14.0% (30/215). The cross sectional area of the median nerve of the RA patients without CTS were similar to the healthy controls. The vast majority of the studies (8/13) disclosed no significant relationship between the median nerve findings and the clinical or laboratory parameters in RA. The link between RA and the median nerve abnormalities has been overemphasized throughout the literature. The prevalence of CTS in RA is similar to the general population without any correlation between the median nerve characteristics and the clinical parameters of RA.

Correlation between median nerve conduction studies and ultrasonography in cases of carpal tunnel syndrome

Background Nerve conduction studies (NCS) have long been the only objective measure used to confirm the diagnosis of carpal tunnel syndrome (CTS), localize median nerve abnormalities, and exclude alternative diagnosis. Ultrasonography (US) can give information about the contents of carpal tunnel (CT) as well as aid in assessing the size of the median nerve (MN). Aim The aim of this study was to detect the relation between median NCS and cross-sectional area (CSA) of the MN measured using US in different grades of CTS. Patients and methods This study was a case–control, age-group matched, cross-sectional one. It included 60 wrists of 30 patients diagnosed with CTS and 60 wrists from 30 controls. Candidates were subjected to clinical assessment, median NCS, and measurement of CSA using US. Results There was a significant positive correlation between CSA of the MN at CT inlet and both motor and sensory responses latencies (r=0.638, P Conclusion US is highly correlated to NCS results in CTS. CSA of the MN at CT inlet measured using ultrasonography can be used as a screening tool for detection as well as discrimination of severe cases of CTS.

Comparison of Automated Versus Traditional Nerve Conduction Study Methods for Median Nerve Testing in a General Worker Population

ObjectiveTo investigate the validity of automated nerve conduction studies compared to traditional electrodiagnostic studies (EDS) for testing median nerve abnormalities in a working population. DesignAgreement study and sensitivity investigation from 2 devices. SettingField research testing laboratory. ParticipantsActive workers from several industries participating in a longitudinal study of carpal tunnel syndrome. MethodsSixty-two subjects received bilateral median and ulnar nerve conduction testing across the wrist with a traditional device and the NC-stat automated device. We compared the intermethod agreement of analogous measurements. Main outcome measurementNerve conduction study parameters. ResultsMedian motor and sensory latency comparisons showed excellent agreement (intraclass correlation coefficients 0.85 and 0.80, respectively). Areas under the receiver operating characteristic curves were 0.97 and 0.96, respectively, using the optimal thresholds of 4.4-millisecond median motor latency (sensitivity 100%, specificity 86%) and 3.9-millisecond median sensory latency (sensitivity 100%, specificity 87%). Ulnar nerve testing results were less favorable. ConclusionThe automated NC-stat device showed excellent agreement with traditional EDS for detecting median nerve conduction abnormalities in a general population of workers, suggesting that this automated nerve conduction device can be used to ascertain research case definitions of carpal tunnel syndrome in population health studies. Further study is needed to determine optimal thresholds for defining median conduction abnormalities in populations that are not seeking clinical care.

Indirect Decompression of the Carpal Tunnel During Basal Joint Arthroplasty of the Thumb

In patients having basal joint arthroplasty, rates of concomitant carpal tunnel syndrome may exceed 43%. Excision of the trapezium during basal joint arthroplasty partially releases the transverse carpal ligament. The objective of this study was to determine whether indirect release of the remaining fibers of the ligament at its insertion on the scaphoid tubercle through the same incision would adequately decompress the carpal canal. This would avoid the morbidity of a second incision. We retrospectively reviewed 10 consecutive patients treated over a 2-year period who had concurrent ligament reconstruction, tendon interposition basal joint arthroplasty of the thumb with complete trapezial resection, and indirect carpal tunnel release through a single incision. Self-reported postoperative pain relief was documented. Preoperative and postoperative evaluations of light touch sensibility, Tinel's sign, Phalen's test, median nerve compression test, and Weinstein Enhanced Sensory Test monofilament testing were analyzed. All patients had preoperative electrodiagnostic testing. At mean 12 month follow-up (range, 5-35 months), numbness and paresthesias resolved in all cases: 9 patients had good or excellent pain relief and 1 reported fair pain relief despite transient postoperative reflex sympathetic dystrophy. Tinel's, Phalen's, and median nerve compression tests were each positive in 9 patients preoperatively and 0 patients postoperatively. Diminished light touch sensibility was present in 7 preoperatively and 1 postoperatively. WEST monofilament thresholds improved postoperatively in 8 patients. These improvements were statistically significant. One patient had postoperative nerve conduction studies performed to evaluate an ulnar nerve lesion at the elbow; the preoperative median nerve abnormalities had normalized. Carpal tunnel syndrome can be successfully managed with indirect release of the transverse carpal ligament during basal joint arthroplasty, thus avoiding a second incision, reducing operating time, and potentially reducing the possibility of perineural adhesions, recurrent motor branch injury, palmar cutaneous nerve damage, weakness, stiffness, and pillar pain. Therapeutic IV.

Current Perception Threshold Screening for Carpal Tunnel Syndrome

Screening for the onset of carpal tunnel syndrome (CTS), which is associated with excess ergonomic stresses of the wrist and hand, is a major concern in occupational medicine. CTS questionnaires, physical examinations, and quantitative sensory function determination through neuroselective current perception threshold (CPT) measurements were obtained from the median digital nerves of 16 assembly line workers who were symptomatic with hand pain. Median nerve evaluations by CPT detected sensory abnormalities in 75% of the workers, and abnormalities in 50% of the workers were detected by clinical evaluations (p less than .05, df = 22). CPT abnormalities were characterized as "hypoesthetic" in 25% and hyperesthesic in 42% of the workers. The noninvasive, nonaversive CPT technique provided sensitive and easily obtained quantitative measures. Regular use of this procedure in the occupational setting may assist in preventing the development of advanced CTS for it provides early detection of median nerve abnormalities.