-
Hand Surgery & Rehabilitation Feb 2020The median nerve is a mixed sensory and motor nerve. It is classically described as the nerve of pronation, of thumb, index finger, middle finger and wrist flexion, of... (Review)
Review
The median nerve is a mixed sensory and motor nerve. It is classically described as the nerve of pronation, of thumb, index finger, middle finger and wrist flexion, of thumb antepulsion and opposition, as well as the nerve of sensation for the palmar aspect of the first three fingers. It takes its name from its middle position at the end of the brachial plexus and the forearm. During its course from its origin at the brachial plexus to its terminal branches, it runs through various narrow passages where it could be compressed, such as the carpal tunnel or the pronator teres. The objective of this review is to summarize the current knowledge on the median nerve's anatomy: anatomical variations (branches, median-ulnar communicating branches), fascicular microanatomy, vascularization, anatomy of compression sites, embryology, ultrasonographic anatomy. The links between its anatomy and clinical, surgical or diagnostic applications are emphasized throughout this review.
Topics: Central Nervous System; Efferent Pathways; Fascia; Hand; Humans; Humeral Fractures; Median Nerve; Median Neuropathy; Nerve Compression Syndromes; Nerve Endings; Neurologic Examination; Neurons; Peripheral Nerve Injuries; Spinal Nerves; Upper Extremity
PubMed: 31816428
DOI: 10.1016/j.hansur.2019.10.197 -
Handbook of Clinical Neurology 2024Median mononeuropathy is common, with carpal tunnel syndrome the most frequently encountered acquired mononeuropathy in clinical practice. However, other disorders of... (Review)
Review
Median mononeuropathy is common, with carpal tunnel syndrome the most frequently encountered acquired mononeuropathy in clinical practice. However, other disorders of the median nerve and many known anatomical variants can lead to misdiagnosis and unexpected surgical complications if their presence is not correctly identified. A number of inherited and acquired disorders can affect the median nerve proximal to the wrist, alone or accompanied by other affected peripheral nerves. Recognizing other disorders that can masquerade as median mononeuropathies can avoid misdiagnosis and misguided management. This chapter explores median nerve anatomical variants, disorders, and lesions, emphasizing the need for careful examination and electrodiagnostic study in the localization of median neuropathy.
Topics: Humans; Median Neuropathy; Median Nerve; Electrodiagnosis; Carpal Tunnel Syndrome
PubMed: 38697748
DOI: 10.1016/B978-0-323-90108-6.00011-9 -
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 -
Praxis 2018Diagnosis of Carpal Tunnel Syndrome: Value of Ultrasound Compared to Nerve Conduction Studies Abstract. Carpal tunnel syndrome is the most common compression syndrome of...
Diagnosis of Carpal Tunnel Syndrome: Value of Ultrasound Compared to Nerve Conduction Studies Abstract. Carpal tunnel syndrome is the most common compression syndrome of the peripheral nerves. The patient's history with nocturnal brachialgia, daytime brachialgia, nocturnal paraesthesia and daytime paraesthesia (part of the 6-item CTS symptom scale) and a specific clinical exam take part while making a diagnosis. Additional diagnostics include electrophysiological testings. A high-resolution ultrasound examination for the evaluation of the morphology of the median nerve has gained importance in diagnosis of a carpal tunnel syndrome, whilst an electrophysiological exam allows a functional evaluation. Cardinal finding in ultrasound is an absolute or relative enlargement of the cross-section of the nerve at the edge proximal to the flexor retinaculum. Despite multiple studies that demonstrated ultrasound as a fist-line diagnostic tool, there is no consensus on optimal sonographic criteria for the definition of a compressed median nerve. Our aim was to demonstrate the use of ultrasound and electrophysiological exams for diagnostics of carpal tunnel syndrome in our own patient population and compared to the literature.
Topics: Carpal Tunnel Syndrome; Humans; Median Nerve; Neurologic Examination; Ultrasonography
PubMed: 30426839
DOI: 10.1024/1661-8157/a003169 -
Hand Clinics Aug 2016The median nerve serves a crucial role in extrinsic and intrinsic motor and sensory function to the radial half of the hand. High median nerve injuries, defined as... (Review)
Review
The median nerve serves a crucial role in extrinsic and intrinsic motor and sensory function to the radial half of the hand. High median nerve injuries, defined as injuries proximal to the anterior interosseous nerve origin, therefore typically result in significant functional loss prompting aggressive surgical management. Even with appropriate recognition and contemporary nerve reconstruction, however, motor and sensory recovery may be inadequate. With isolated persistent high median nerve palsies, a variety of available tendon transfers can improve key motor functions and salvage acceptable use of the hand.
Topics: Forearm; Hand; Humans; Median Nerve; Median Neuropathy; Medical Illustration; Photography; Recovery of Function; Sensation; Tendon Transfer
PubMed: 27387077
DOI: 10.1016/j.hcl.2016.03.004 -
Hand Clinics Feb 2022Diagnostic ultrasound in the diagnosis of carpal tunnel syndrome is firmly established. Preoperative evaluation is based on quantitative parameters such as measurement... (Review)
Review
Diagnostic ultrasound in the diagnosis of carpal tunnel syndrome is firmly established. Preoperative evaluation is based on quantitative parameters such as measurement of the pathologically enlarged cross-sectional area of the nerve. The value of postoperative ultrasound lies in the visualization of the anatomy and the conclusions that can be drawn from it. It focuses on the semiquantitative sonographic parameters of nerve compression. Nerve lesions and persistent strictures can be visualized and clearly localized. In recurrent disease, the primary focus is to dynamically exclude postoperative scarring, which results in a reduction of nerve gliding.
Topics: Carpal Tunnel Syndrome; Humans; Median Nerve; Sensitivity and Specificity; Ultrasonography
PubMed: 34802607
DOI: 10.1016/j.hcl.2021.08.003 -
Current Rheumatology Reviews 2022Fibrolipoma of the median nerve is a rare benign lesion responsible for carpal tunnel syndrome. Fibrolipoma is often misdiagnosed. This article aimed to review and... (Review)
Review
INTRODUCTION
Fibrolipoma of the median nerve is a rare benign lesion responsible for carpal tunnel syndrome. Fibrolipoma is often misdiagnosed. This article aimed to review and summarize current knowledge regarding fibrolipoma of the median nerve. We emphasize the clinical and imaging features of this disease.
METHODS
To examine the characteristics of fibrolipoma of the median nerve, we performed a litera-ture review using MEDLINE. The search included only English studies published from database in-ception to June 2021.
RESULTS
Forty-six cases of fibrolipoma of the median nerve were included. Fibolipoma is characterized by diffuse infiltration of peripheral nerves by normal-appearing fibrous and adipose tissues. The fibrolipoma of the median nerve can be responsible for macrodactyly, numbness, paresthesia, and weakness within the median nerve distribution. Ultrasonography shows a fusiform hyperechoic mass along the nerve containing hypoechoic bands corresponding to nerve fascicles. Magnetic resonance imaging is the gold standard for the diagnosis of fibrolipoma. It typically shows a contrast between the low signal nerve fibers and the high signal fatty tissues, revealing a characteristic « cable-like » appearance on axial sections and a «spaghetti-like» appearance on coronal sections.
CONCLUSION
Fibrolipoma should be considered in young patients with carpal tunnel syndrome. This review emphasizes the clinical and radiological features of fibrolipoma. We highlight the images of ultrasonography in the diagnosis of rare structural causes of carpal tunnel syndrome.
Topics: Humans; Median Nerve; Carpal Tunnel Syndrome; Lipoma; Fingers; Ultrasonography
PubMed: 35379153
DOI: 10.2174/1573397118666220404080616 -
Hand Clinics May 2016This article describes the clinically significant motor and sensory deficits that follow high median nerve injuries and addresses the indications, limitations, and... (Review)
Review
This article describes the clinically significant motor and sensory deficits that follow high median nerve injuries and addresses the indications, limitations, and outcomes of nerve transfers, when striving to overcome the deficits these patients' experiences. Preferred surgical reconstructive strategy using motor and sensory nerve transfers, and surgical techniques used to perform these transfers, are described.
Topics: Humans; Median Nerve; Motor Disorders; Nerve Transfer; Peripheral Nerve Injuries; Peripheral Nerves; Range of Motion, Articular; Plastic Surgery Procedures; Somatosensory Disorders
PubMed: 27094892
DOI: 10.1016/j.hcl.2015.12.008 -
Occupational Medicine (Oxford, England) Jul 2017Ultrasound is an established method of viewing the median nerve in the carpal tunnel syndrome (CTS). There is some evidence to suggest that immediate changes may occur... (Review)
Review
BACKGROUND
Ultrasound is an established method of viewing the median nerve in the carpal tunnel syndrome (CTS). There is some evidence to suggest that immediate changes may occur in the median nerve before and after hand activity. The evidence for the validity and reliability of ultrasound for testing acute changes in the median nerve has not been systematically reviewed to date.
AIMS
To evaluate the evidence for visible change in ultrasound appearance of the median nerve after hand activity.
METHODS
A literature search was designed, and three reviewers independently selected published research for inclusion. Two reviewers independently appraised papers using the Evidence Based Library and Information Practice (EBLIP) appraisal checklist, while the third reviewer resolved discrepancies between appraisals.
RESULTS
Ten studies were appraised and the results showed an increase in median nerve cross-sectional area following activity, with a return to normal size within 1 h following activity. Both healthy individuals and those diagnosed with CTS participated, all were small convenience samples. Ultrasonographic measurements of the median nerve were reliable in the four studies reporting this, and the studies demonstrated high quality.
CONCLUSIONS
Good-quality evidence as identified by the EBLIP appraisal checklist suggests that following hand activity, the median nerve changes in size in the carpal tunnel. The results may not be generalizable to all people and activities due to the use of small convenience sampling and narrow range of activities studied, in all of the studies appraised.
Topics: Carpal Tunnel Syndrome; Female; Hand; Humans; Male; Median Nerve; Movement; Ultrasonography
PubMed: 28582584
DOI: 10.1093/occmed/kqx059 -
Muscle & Nerve Jun 2016The most frequently described anomalous neural connections between the median and ulnar nerves in the upper limb are: Martin-Gruber anastomosis (MGA), Marinacci... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
The most frequently described anomalous neural connections between the median and ulnar nerves in the upper limb are: Martin-Gruber anastomosis (MGA), Marinacci anastomosis (MA), Riche-Cannieu anastomosis (RCA), and Berrettini anastomosis (BA). The reported prevalence rates and characteristics of these anastomoses vary significantly between studies.
METHODS
A search of electronic databases was performed to identify all eligible articles. Anatomical data regarding the anastomoses were pooled into a meta-analysis using MetaXL 2.0.
RESULTS
A total of 58 (n = 10,562 upper limbs) articles were included in the meta-analysis. The pooled prevalences were: MGA, 19.5% (95% confidence interval [CI], 16.2%-23.1%); MA, 0.7% (95% CI, 0.1%-1.7%); RCA, 55.5% (95% CI, 30.6%-79.1%); and BA, 60.9% (95% CI, 36.9%-82.6%). The results also showed that MGA was more commonly found unilaterally (66.8%), on the right side (15.7%), following an oblique course (84.8%), and originating from the anterior interosseous nerve with a prevalence of 57.6%.
CONCLUSIONS
As anastomoses between the median and ulnar nerves occur commonly, detailed anatomical knowledge is essential for accurate interpretation of electrophysiological findings and reducing the risk of iatrogenic injuries during surgical procedures. Muscle Nerve 54: 36-47, 2016.
Topics: Databases, Factual; Humans; Median Nerve; Nervous System Malformations; Neural Conduction; Ulnar Nerve; Upper Extremity
PubMed: 26599506
DOI: 10.1002/mus.24993