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Journal of Ultrasound Sep 2020Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy of peripheral nerves, with an incidence of 1-3 patients in 1000. CTS typically occurs between 45... (Review)
Review
Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy of peripheral nerves, with an incidence of 1-3 patients in 1000. CTS typically occurs between 45 and 60 years of age, and it is more frequent in women than in men. The main cause of CTS is chronic compression of the median nerve and ischemic suffering secondary to increased pressure in the carpal tunnel. There are many possible causes of CTS, which can be differentiated into idiopathic causes, which include most cases, and secondary causes. Classical CTS diagnosis is based on the patient's clinical examination and electrophysiological tests, such as electromyography and nerve conduction studies. The latter are helpful for determining the site of nerve compression, assessing its severity, monitoring the course of the disease after therapy, and excluding other causes of median nerve pain, such as cervical radiculopathies, brachial plexopathies, polyneuropathy, or other forms of mononeuropathies. However, clinical examination and electrophysiological tests are not able to differentiate idiopathic forms from secondary forms of CTS, and discrepancies are possible between clinical examination and electrophysiological tests (false negatives). Ultrasound examination is able to recognize most of the secondary forms of CTS. It can evaluate the morphological alterations of the nerve and correlate them with the severity of nerve suffering in all cases, even idiopathic ones, with a sensitivity and specificity equal to those of electrophysiological tests. It can also highlight some anatomical predisposing variants or conditions that may represent contraindications to minimally invasive treatments. Ultrasound examination also plays a fundamental role in evaluating patients with an unfavorable outcome after surgical treatment.
Topics: Carpal Tunnel Syndrome; Humans; Median Nerve; Ultrasonography
PubMed: 32323256
DOI: 10.1007/s40477-020-00460-z -
BMC Neuroscience Aug 2020When planning nerve conduction studies using animal models, the sciatic nerve is often used and the upper extremity nerves are not preferred due to the size of...
BACKGROUND
When planning nerve conduction studies using animal models, the sciatic nerve is often used and the upper extremity nerves are not preferred due to the size of laboratory animals. This study aimed to present the method and mean values of median nerve conduction studies in laboratory rabbits. Fifty-five six-month-old male New Zealand white rabbits weighing 2 to 2.5 kg were included in nerve conduction studies performed under anesthesia. The compound muscle action potential amplitude and distal latency values were recorded for the median motor nerve with the electrodes placed on the flexor digitorum superficialis muscle and tendon.
RESULTS
A total of 110 median nerves were evaluated. The mean amplitude of the median nerve was 30.6 ± 6.8, mV the median nerve distal latency was 1.3 ± 0.2 ms, and the mean intensity of stimulation inducing a response was 2.5 ± 1 mA.
CONCLUSIONS
The mean values obtained by the median motor nerve conduction method in this study can act as a guide for future nerve interventions undertaken in the upper extremities.
Topics: Action Potentials; Animals; Female; Male; Median Nerve; Muscle, Skeletal; Neural Conduction; Rabbits; Reaction Time
PubMed: 32807101
DOI: 10.1186/s12868-020-00584-2 -
African Health Sciences Mar 2022The brachial plexus is highly variable, which is a well-known anatomical fact. Repeated observations on anatomical variations, however, constitute current trends in... (Review)
Review
INTRODUCTION
The brachial plexus is highly variable, which is a well-known anatomical fact. Repeated observations on anatomical variations, however, constitute current trends in anatomical research.
CASE SERIES
In an anatomical dissection course, three uncommon variations in the brachial plexus were identified in three young adults' cadavers. In one case, the musculocutaneous nerve gave a branch to the median nerve, while the median nerve gave or received musculocutaneous branches in the two remaining corpses.
CONCLUSION
Anatomical variations of the brachial plexus do occur in our setting. The cases we presented are about anatomical variations of branching patterns of the median and musculocutaneous nerves. Knowledge of those variations is essential for surgery and regional anesthesia of the upper limbs.
Topics: Cadaver; Humans; Median Nerve; Musculocutaneous Nerve; Research
PubMed: 36032460
DOI: 10.4314/ahs.v22i1.33 -
Median nerve and carpal arch morphology changes in women with type 2 diabetes: a case-control study.Journal of Ultrasound Sep 2022The aim of this study is to investigate the changes in median nerve and transverse carpal ligament (TCL)-formed carpal arch morphology as possible risk factors for...
BACKGROUND
The aim of this study is to investigate the changes in median nerve and transverse carpal ligament (TCL)-formed carpal arch morphology as possible risk factors for median nerve entrapment in women with type 2 diabetes.
METHODS
The distal carpal tunnel was imaged using ultrasound in 30 female subjects (15 with type 2 diabetes, 15 controls). The morphological parameters of the median nerve and carpal arch were derived from the ultrasound images. One-way analysis of variance (ANOVA) was used for statistical analysis.
RESULTS
Diabetic women had an enlarged median nerve area (p < 0.05), salong with a maller carpal arch size, as indicated by a reduced palmar bowing index of the TCL (p < 0.05), and arch area (p < 0.05) than controls. The distance from the median nerve centroid to the volar boundary of the TCL was reduced in diabetic women (p < 0.05) compared to the controls.
CONCLUSIONS
Women with type 2 diabetes have reduced available space for the median nerve within the carpal arch due to the enlarged nerve and reduced arch size, making the median nerve more susceptible to entrapment within the tunnel. The current study shows that presence of diabetes increases the risk of median nerve entrapment in women and requires early detection of symptoms to avoid carpal tunnel syndrome.
Topics: Carpal Bones; Carpal Tunnel Syndrome; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Humans; Median Nerve
PubMed: 34472043
DOI: 10.1007/s40477-021-00606-7 -
Hand (New York, N.Y.) Jan 2023Our purpose was to describe structural and morphological features of the median nerve and carpal tunnel on magnetic resonance imaging (MRI) studies obtained before,...
BACKGROUND
Our purpose was to describe structural and morphological features of the median nerve and carpal tunnel on magnetic resonance imaging (MRI) studies obtained before, immediately after, 6 weeks after, and 6 years after endoscopic carpal tunnel release (ECTR).
METHODS
In this prospective cohort study, 9 patients with a diagnosis of carpal tunnel syndrome (CTS) underwent ECTR. Standardized MRI studies were obtained before ECTR, immediately after ECTR, and 6 weeks and 6 years after surgery. Structural and morphological features of the median nerve and carpal tunnel were measured and assessed for each study with comparisons made between each time point.
RESULTS
All 9 patients had complete symptom resolution postoperatively. On the immediate postoperative MRI, there was a discrete gap in the transverse carpal ligament in all patients. There was retinacular regrowth noted at 6 weeks in all cases. The median nerve cross-sectional area and the anterior-posterior dimension of the carpal tunnel at the level of the hamate increased immediately after surgery and these changes were maintained at 6 years.
CONCLUSIONS
We defined structural and morphological changes on MRI for the median nerve and carpal tunnel in patients with continued symptom resolution 6 years after ECTR. Changes in median nerve and carpal tunnel morphology that occur immediately after surgery remain unchanged at mid-term follow-up in asymptomatic patients. Established imaging criteria for CTS may not apply to postoperative patients. Magnetic resonance imaging appears to be of limited clinical utility in the workup of persistent or recurrent CTS.
Topics: Humans; Median Nerve; Carpal Tunnel Syndrome; Follow-Up Studies; Prospective Studies; Ligaments
PubMed: 34933606
DOI: 10.1177/15589447211058819 -
Journal of Biomechanical Engineering Mar 2023The spacing between the median nerve and transverse carpal ligament (TCL) within the carpal tunnel can potentially affect the nerve morphology. This study aimed to...
The spacing between the median nerve and transverse carpal ligament (TCL) within the carpal tunnel can potentially affect the nerve morphology. This study aimed to quantify the spatial relationship between the median nerve and transverse carpal ligament in asymptomatic hands. Twelve subjects were recruited to image the carpal tunnel using robot-assisted ultrasound. The median nerve and TCL were segmented from each image and three-dimensionally reconstructed using kinematic information from the robot. The TCL-median nerve distance, nerve cross-sectional area, circularity, and position were measured along the entirety of the nerve length within the carpal tunnel. Results were averaged at every 5% of nerve length. At the nerve length percentages of 0% (distal), 25%, 50%, 75%, and 100% (proximal), the TCL-median nerve distance (±SD) was 0.7 ± 0.4, 0.7 ± 0.2, 0.5 ± 0.2, 0.5 ± 0.2, and 0.6 ± 0.3 mm, respectively. The corresponding nerve cross-sectional area was 9.4 ± 1.9, 10.6 ± 2.6, 11.2 ± 2.1, 11.2 ± 1.7, and 9.7 ± 1.9 mm2. A one-way analysis of variance showed no significant differences between the respective percentages of nerve length for TCL-median nerve distance (p = 0.219) and cross-sectional area (p = 0.869). Significant (p < 0.0001) but weak correlations were observed between the TCL-median nerve distance with cross-sectional area (r = -0.247) and circularity (r = -0.244). This study shows that the healthy median nerve morphology is consistent along the continuous nerve length within the carpal tunnel, supporting the use of 2D imaging in the evaluation of the healthy nerve.
Topics: Humans; Median Nerve; Carpal Tunnel Syndrome; Ligaments, Articular; Wrist Joint; Hand
PubMed: 36416297
DOI: 10.1115/1.4056290 -
Folia Medica Cracoviensia 2013Carpal tunnel syndrome belongs to the most common causative factors of surgical interventions in the wrist region. Anatomy of carpal tunnel and median nerve is a subject... (Review)
Review
Carpal tunnel syndrome belongs to the most common causative factors of surgical interventions in the wrist region. Anatomy of carpal tunnel and median nerve is a subject of current revision. Authors paid attention to etiology of the syndrome based on review of literature and their own anatomical studies. They remind basic knowledge on the median nerve and indicate that only based on number of dissections a good orthopedic surgeon may acquire experience necessary to perform procedures in a most appropriate way.
Topics: Carpal Bones; Carpal Joints; Carpal Tunnel Syndrome; Humans; Median Nerve
PubMed: 25556510
DOI: No ID Found -
Journal of Hand Therapy : Official... 2017Systematic review. (Review)
Review
STUDY DESIGN
Systematic review.
INTRODUCTION
It is accepted that the etiology of carpal tunnel syndrome (CTS) is multifactorial. One of the most commonly accepted etiologic factors for CTS is compromise of the kinematic behavior and excursion of the median nerve.
PURPOSE OF THE STUDY
The objective of this systematic review was to establish if there is a relationship between impaired median nerve excursion and CTS.
METHODS
A systematic review, following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, was conducted. Studies were sought where in vivo median nerve excursion was compared between people with CTS to an appropriate control group. Quality appraisal for each study was conducted using the Newcastle-Ottawa Scale by 2 independent evaluators.
RESULTS
Ten case-control studies using ultrasound imaging to quantify median nerve excursion were included. All studies were rated as of "moderate" methodologic quality having scored 6 or 7 (of 9 stars) for the Newcastle-Ottawa Scale. Seven of the 10 studies concluded that median nerve excursion was reduced in a CTS population when compared with controls.
CONCLUSION
The literature suggests that median nerve excursion is reduced in people with CTS when compared with healthy controls.
LEVEL OF EVIDENCE
3a.
Topics: Carpal Tunnel Syndrome; Humans; Median Nerve; Motion
PubMed: 27692791
DOI: 10.1016/j.jht.2016.09.002 -
PloS One 2019Essential tremor (ET) is a common movement disorder characterized by postural or kinetic tremor. We aimed to evaluate median nerve enlargement in patients with ET using...
Essential tremor (ET) is a common movement disorder characterized by postural or kinetic tremor. We aimed to evaluate median nerve enlargement in patients with ET using ultrasonography (USG). Thirty-eight hands from 19 patients with ET and 24 hands from 13 controls underwent nerve conduction studies (NCS) and USG at the wrist. Tremor severity was measured using the Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS). The median nerve cross sectional area (mCSA) in USG and NCS parameters were compared using ANCOVA. We evaluated the correlation between mCSA and NCS parameters or FTM-TRS scores using linear regression analysis. mCSA was significantly larger (p<0.001) and NCS parameters were different in two groups. Also, mCSA was negatively correlated with part B and C scores of FTM-TRS (p<0.001 and p = 0.039, respectively). In conclusion, median nerve enlargement with the changes of NCS parameters was observed and correlated with the severity of tremor in patients with ET.
Topics: Action Potentials; Adult; Aged; Essential Tremor; Female; Hand; Humans; Male; Median Nerve; Middle Aged; Muscle, Skeletal; Organ Size; Prospective Studies; Severity of Illness Index; Ultrasonography
PubMed: 31013299
DOI: 10.1371/journal.pone.0215750 -
Hand (New York, N.Y.) Sep 2021Median nerve entrapment in the forearm (MNEF) without motor paralysis is a challenging diagnosis. This retrospective study evaluated the clinical presentation,...
Median nerve entrapment in the forearm (MNEF) without motor paralysis is a challenging diagnosis. This retrospective study evaluated the clinical presentation, diagnostic studies, and outcomes following surgical decompression of MNEF. The study reviewed 147 patient medical charts following MNEF surgical decompression. With exclusion of patients with combined nerve entrapments (radial and ulnar), polyneuropathy, neurotmetic nerve injury, or median nerve motor palsy, the study sample included 27 patients. Data collected include: clinical presentation and pain, strength, provocative testing, functional outcomes, and Disabilities of the Arm, Shoulder and Hand (DASH) scores. The study included 27 patients (mean follow-up = 7 months), and 13 patients had previous carpal tunnel release (CTR). Clinical presentation included pain (n = 27) (forearm, n = 22; median nerve innervated digits, n = 21; and palm, n = 21) and positive clinical tests (forearm scratch collapse test, n = 27; pain with compression over the flexor digitorum superficialis arch/pronator, n = 24; Tinel sign, n = 11). Positive electrodiagnostic studies were found for MNEF (n = 2) and carpal tunnel syndrome (n = 11). Primary CTR was performed in 10 patients and revision CTR in 7 patients. Postoperatively, there were significant ( < .05) improvements in strength, pain, quality of life, and DASH scores. The MNEF without motor paralysis is a clinical diagnosis supported by pain drawings, pain quality, and provocative tests. Patients with persistent forearm pain and median nerve symptoms (especially after CTR) should be evaluated for MNEF. Surgical decompression provides satisfactory outcomes.
Topics: Carpal Tunnel Syndrome; Forearm; Humans; Median Nerve; Quality of Life; Retrospective Studies
PubMed: 31540555
DOI: 10.1177/1558944719874137