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

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

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OBLIGATORY ALTERATIONS IN THE MORPHOLOGY OF MEDIAN NERVE: A SONOGRAPHIC STUDY IN ASYMPTOMATIC INDIVIDUALS

Journal of Anatomical Sciences - Volume 27(2), December 2019 ◽

10.46351/jas.v26i2pp01-09 ◽

2018 ◽

Vol 26 (2) ◽

Author(s):

Vandana Lakra ◽

Garima Sehgal ◽

Jyoti Chopra ◽

Anita Rani ◽

Kaweri Dande

Keyword(s):

Carpal Tunnel Syndrome ◽

Median Nerve ◽

Carpal Tunnel ◽

Cross Sectional Area ◽

Sectional Area ◽

Cross Sectional ◽

Linear Probe ◽

Tunnel Syndrome ◽

Asymptomatic Individuals ◽

Flattening Ratio

Introduction: Median nerve is formed in axilla by contributions from medial and lateral cords of brachial plexus. It descends in the arm, forearm and then through carpal tunnel in close conjunction with flexor tendons of forearm. Carpal tunnel syndrome (CTS) is a common entrapment neuropathy. Median nerve cross sectional area (CSA) and ratio of nerve major axis to minor axis (flattening ratio) serve as potential diagnostic criteria for carpal tunnel syndrome. Median nerve cross sectional area and flattening ratio (FR) can be assessed by ultrasonography (US). Aim of the study was to assess median nerve by US and tabulate mean values for CSA and FR in asymptomatic population. This would serve to limit the cut-off values that differentiate asymptomatic nerves from neuropathic nerves. Material & Methods: Study was conducted in the Department of Anatomy, KGMU, Lucknow. Fifty randomly selected asymptomatic volunteers (undergraduate students: 30 males, 20 females) participated in the study. Sonography was performed to evaluate certain morphological dimensions of median nerve. Height, weight and wrist circumference of participants were also noted. Ultrasonography was performed using high frequency linear probe and observations were made at two pre-determined sites. Observations were recorded, tabulated and analyzed. Results: Median nerve was easily observable at both sites. It was round in shape in forearm (Fo), and flattened as it reached the carpal tunnel (Ct). Among all 50 study subjects, at both sites, flattening was more on right side (FRFoRt-1.71; FRCtRt-3.08) than on left side (FRFoLt-1.66; FRCtLt-2.78). In right forearm, nerve was flatter in females (FRFoRt-1.77) as compared to males (FRFoRt-1.68). In left forearm, median nerve was slightly rounder in females (FRFoLt-1.65) as compared to males (FRFoLt-1.67). At the distal wrist crease on right side, increased flattening was observed in females (FRCtRt-3.30) as compared to males (FRCtRt-2.94), whereas on left side, at same site flattening was more in females (males FRCtLt-2.74; females FRCtLt-2.83). Conclusion: Altered FR has both diagnostic as well as prognostic values in carpal tunnel syndrome. The database generated from the study will help in facilitating comparisons between normal, asymptomatic and pathological, asymptomatic individuals.

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Efficacy of Diagnosing Carpal Tunnel Syndrome Using the Median Nerve Stenosis Rate Measured on Ultrasonographic Sagittal Imagery: Clinical Case-Control Study

Hand ◽

10.1177/15589447211017225 ◽

2021 ◽

pp. 155894472110172

Author(s):

Toshiyuki Okura ◽

Tomohisa Sekimoto ◽

Tomomi Matsuoka ◽

Hajime Fukuda ◽

Hiroaki Hamada ◽

...

Keyword(s):

Carpal Tunnel Syndrome ◽

Median Nerve ◽

Carpal Tunnel ◽

Cross Sectional Area ◽

Control Group ◽

Sectional Area ◽

Cross Sectional ◽

Ultrasonographic Examination ◽

Stenosis Rate ◽

Tunnel Syndrome

Background The purpose of the present study was to evaluate the usefulness of the median nerve stenosis rate (MNSR) measured on sagittal sonographic images of the median nerve in the diagnosis of carpal tunnel syndrome (CTS). Methods The study population consisted of 45 hands from 37 patients with idiopathic CTS (CTS group), and 60 hands from 35 asymptomatic healthy subjects (control group). Carpal tunnel syndrome was diagnosed by clinical findings and positive electrophysiological study results. All patients and control subjects underwent ultrasonographic examination. At the carpal tunnel level, the transducer was placed longitudinally to the median nerve, and an image of the longitudinal median nerve was obtained. The minimum median nerve diameter (MND) was measured at the middle part of the capitate level, while the maximum MND was measured at the distal radioulnar joint level. The MNSR was calculated as (1 – minimum MND/maximum MND) × 100 (%). The cross-sectional area of the median nerve was also measured at the level of the pisiform. Results On longitudinal sonographic images, the MNSR was significantly larger in the CTS group than the control group. When the cut-off value of the MNSR was 26.73%, the sensitivity and specificity were 91.1% and 80%, respectively. The area under the receiver operating characteristic curve was larger for the MNSR than for the cross-sectional area. Conclusion The results suggest that the MNSR proposed in the present study may be useful as an auxiliary method for CTS diagnosis on ultrasonographic examination.

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Reduction in median nerve cross-sectional area at the forearm correlates with axon loss in carpal tunnel syndrome

Clinical Neurophysiology Practice ◽

10.1016/j.cnp.2021.06.001 ◽

2021 ◽

Author(s):

Lauri Martikkala ◽

Katri Mäkelä ◽

Sari-Leena Himanen

Keyword(s):

Carpal Tunnel Syndrome ◽

Median Nerve ◽

Carpal Tunnel ◽

Cross Sectional Area ◽

Sectional Area ◽

Cross Sectional ◽

Axon Loss ◽

Tunnel Syndrome

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Cross-Sectional Area of the Median Nerve Characterized by Ultrasound in Patients With Carpal Tunnel Syndrome Before and After the Release of the Transverse Carpal Ligament

Journal of Diagnostic Medical Sonography ◽

10.1177/8756479313477731 ◽

2013 ◽

Vol 29 (3) ◽

pp. 116-121 ◽

Cited By ~ 2

Author(s):

Benedito F. Pimentel ◽

Claudia A. Abicalaf ◽

Larissa Braga ◽

Walter M. Albertoni ◽

Carlos H. Fernandes ◽

...

Keyword(s):

Carpal Tunnel Syndrome ◽

Median Nerve ◽

Carpal Tunnel ◽

Cross Sectional Area ◽

Sectional Area ◽

Transverse Carpal Ligament ◽

Cross Sectional ◽

Before And After ◽

Tunnel Syndrome

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Ultrasound Assessment of the Median Nerve Does Not Adequately Discriminate the Carpal Tunnel Syndrome among Patients Diagnosed with Diabetes

Diabetology ◽

10.3390/diabetology2040020 ◽

2021 ◽

Vol 2 (4) ◽

pp. 226-231

Author(s):

Carlos Antonio Guillen-Astete ◽

Monica Luque-Alarcon ◽

Nuria Garcia-Montes

Keyword(s):

Carpal Tunnel Syndrome ◽

Median Nerve ◽

Carpal Tunnel ◽

Cross Sectional Area ◽

Diabetic Patients ◽

Sectional Area ◽

Cross Sectional ◽

Patients With Diabetes ◽

Ultrasound Assessment ◽

Tunnel Syndrome

Background: Carpal tunnel syndrome is the most prevalent peripheral nerve entrapment condition of the upper limb. Among metabolic risk factors, diabetes is considered the most relevant. Although wrist ultrasound assessment of the median nerve has demonstrated a good correlation with the gold standard for the diagnosis of this syndrome, neurophysiological study, its usefulness in patients with diabetes is questionable because the compressive phenomenon is not the predominant one. Method: We conducted a retrospective study to compare the clinical and median nerve ultrasound features of patients with carpal tunnel syndrome previously diagnosed or not diagnosed with diabetes. Additionally, a linear multivariate regression analysis was performed to determine to what extent the cross-sectional area of the median nerve was dependent on the condition of diabetes by fixing other variables such as sex, age, or time of evolution. Results: We included 303 records of patients (mean age 44.3 ± 11.7 years old, 57.89% female, mean of time of evolution 13.6 ± 8.3 months) from 2012 to 2020. The cross-sectional area of the median nerve was 10.46 ± 1.44 mm2 in non-diabetic patients and 8.92 ± 0.9 mm2 in diabetic patients (p < 0.001). Additionally, diabetic patients had a shorter time of evolution (7.91 ± 8.28 months vs. 14.36 ± 0.526 months, p < 0.001). In the multivariate analysis, the resultant model (fixed R-square = 0.659, p = 0.003) included a constant of the following four variables: the evolution time (Beta coeff. = 0.108, p < 0.001 95% CI 0.091 to 0.126, standardized coeff. = 0.611), the condition of diabetes (Beta coeff. = −0.623, p < 0.001 95% CI −0.907 to −0.339, standardized coeff. = −0.152), the severity (Beta coeff. = 0.359, p = 0.001 95% CI 0.147 to 0.571, standardized coeff. = 0.169), and the masculine sex (Beta coeff. = 0.309, p = 0.003, 95% CI 0.109 to 0.509, standardized coeff. = 0.103). Conclusions: Ultrasound assessment of the median nerve in patients with diabetes is not a useful tool to confirm whether carpal tunnel syndrome should be diagnosed or not diagnosed.

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