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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 -
Journal of Ultrasonography Nov 2021The median nerve is a mixed sensory and motor nerve that innervates part of the flexor muscles in the anterior compartment of the forearm and muscles in the lateral part...
The median nerve is a mixed sensory and motor nerve that innervates part of the flexor muscles in the anterior compartment of the forearm and muscles in the lateral part of the hand; palmar cutaneous and digital cutaneous nerves branch from the median nerve, which provides sensory innervation to the skin on the radial side of the palm. Also, the median nerve is an object of interest because neuropathy of the median nerve at the level of the carpal tunnel is the most common entrapment neuropathy which increases dramatically in patients with diabetes. Neuromuscular ultrasound provides extensive diagnostic information and has proved itself as a useful complementary test to electrodiagnostic examinations in cases involving median nerve neuropathy. It often happens that the cause of nerve entrapment and neuropathy are variants of several anatomical structures along the course of the median nerve. It is important to be aware and report such anatomical variations of the median nerve in order to avoid damaging the nerve during surgical treatment. Despite the frequently documented abnormalities in the pathway of the brachial plexus and the median nerve, the anatomical variations are unusual to see and are rarely reported. Moreover, there are variations that do not fit under any of the classifications described in the literature.
PubMed: 34970443
DOI: 10.15557/JoU.2021.0053 -
Journal of Ayub Medical College,... 2022Carpal tunnel syndrome (CTS) is the most common nerve entrapment neuropathy caused by compression of median nerve at wrist as it passes through Osseo fibrous canal known...
BACKGROUND
Carpal tunnel syndrome (CTS) is the most common nerve entrapment neuropathy caused by compression of median nerve at wrist as it passes through Osseo fibrous canal known as carpal tunnel. Epidemiological statistics shows one in every ten people develops the disease at any stage of life. CTS mostly affect females than males with mean age of 50. Clinical features are considered to be enough for establishing the diagnosis of carpal tunnel syndrome. However, nerve conduction studies give quantitative information regarding median nerve function therefore good at predicting outcome of intervention. Ultrasound being easily available, cost effective and real time is a promising modality for diagnosis and grading carpal tunnel syndrome.
METHODS
This correlational study was conducted in collaboration of Neurology and Radiology Department of Pakistan Institute of Medical Sciences, Islamabad from January 2018 to January 2019. Total 50 patients with 85 wrists involved were included in the study. All patients with positive nerve conduction study were included. Patient with history of wrist trauma were not included. Detailed history and clinical features were recorded. All patients with positive result on nerve conduction studies underwent ultrasound examinations. Fifty control wrists were also included to establish the normal median nerve cross sectional area value in our study population. Results were recorded. Data was analyzed and appropriate statistical tests were applied by using SPSS v20.
RESULTS
Mean cross sectional area of median nerve for controls was 6.34±1.23. Mean cross sectional area of median nerve for mild CTS was 8.05±1.72, moderate CTS was 11.15±2.32, severe was 17.49±4.93. Strong correlation was found between (r=0.76, p-value <0.0001) between increased cross-sectional area on Ultrasonography and severity of CTS on NCS. Other finding on Ultrasonography included flattening in 4 and fluid in 10 affected wrists.
CONCLUSIONS
Increased cross-sectional area on Ultrasonography and severity of carpal tunnel syndrome on nerve conduction studies are very strongly correlated.
Topics: Carpal Tunnel Syndrome; Female; Humans; Male; Median Nerve; Middle Aged; Neural Conduction; Ultrasonography; Wrist
PubMed: 35576289
DOI: 10.55519/JAMC-02-9892 -
Arquivos de Neuro-psiquiatria Sep 2023The distinction between sensory neuronopathies (SN), which is by definition purely sensory, and sensory polyneuropathies (SP) and sensory multineuropathies (SM) is...
BACKGROUND
The distinction between sensory neuronopathies (SN), which is by definition purely sensory, and sensory polyneuropathies (SP) and sensory multineuropathies (SM) is important for etiologic investigation and prognosis estimation. However, this task is often challenging in clinical practice. We hypothesize that F-wave assessment might be helpful, since it is able to detect subtle signs of motor involvement, which are found in SP and SM, but not in SN.
OBJECTIVE
The aim of the present study was to determine whether F-waves are useful to distinguish SN from SP and SM.
METHODS
We selected 21 patients with SP (12 diabetes mellitus, 4 transthyretin familial amyloid polyneuropathy, 4 others), 22 with SM (22 leprosy), and 26 with SN (13 immune-mediated, 10 idiopathic, 3 others) according to clinical-electrophysiological-etiological criteria. For every subject, we collected data on height and performed 20 supramaximal distal stimuli in median, ulnar, peroneal, and tibial nerves, bilaterally, to record F-waves. Latencies (minimum and mean) and persistences were compared across groups using the Kruskal-Wallis and Bonferroni tests. -values < 0.05 were considered significant.
RESULTS
All groups were age, gender, and height-matched. Overall, there were no significant between-group differences regarding F-wave latencies. In contrast, F-wave persistence was able to stratify the groups. Peroneal F-wave persistence was higher, bilaterally, in the SN group compared to SM and SP ( < 0.05). In addition, F-waves persistence of the ulnar and tibial nerves was also helpful to separate SN from SP ( < 0.05).
CONCLUSION
F-wave persistence of the peroneal nerves might be an additional and useful diagnostic tool to differentiate peripheral sensory syndromes.
Topics: Humans; Neural Conduction; Median Nerve; Ulnar Nerve; Tibial Nerve; Peroneal Nerve; Polyneuropathies; Syndrome; Peripheral Nerves
PubMed: 37793400
DOI: 10.1055/s-0043-1772599 -
Folia Morphologica 2022The aim of this study is to investigate the location of nerves that innervate the flexor digitorum profundus (FDP), the flexor pollicis longus (FPL) and the pronator...
BACKGROUND
The aim of this study is to investigate the location of nerves that innervate the flexor digitorum profundus (FDP), the flexor pollicis longus (FPL) and the pronator quadratus muscles. It also investigates the change in nerve location with hand movement.
MATERIALS AND METHODS
We studied 30 adult cadavers (17 males and 13 females) with a mean age of 69.5 years (range: 60-95 years). The reference line was from the humeral epicondylar line to the styloid process line of both the radius and ulnar bones. This study measured the anterior interosseous nerve (AIN) branch outpoint and the innervated muscle nerve entry point to the muscle belly. It also examines nerve position changes as related to making a fist.
RESULTS
The reference line mean distance was 24.1 ± 1.2 cm. The median nerve branched into the AIN at 18.0 ± 4.0%. We found the most densely distributed section of the nerves' entry point to the muscle belly to be at a distance of 30% to 40% for the FDP and from 30% to 40% for the FPL. Except for the FPL, the nerve branch outpoints and the FDP moved by 3.0%, depending upon hand movements.
CONCLUSIONS
The results of this study show that it will be necessary to consider the anatomy of the nerve location as it enters the muscle belly as well as how it changes with movement.
Topics: Aged; Aged, 80 and over; Cadaver; Female; Forearm; Hand; Humans; Male; Median Nerve; Middle Aged; Muscle, Skeletal
PubMed: 34355783
DOI: 10.5603/FM.a2021.0078 -
Diabetes, Metabolic Syndrome and... 2022Diabetes is a documented risk factor for peripheral neuropathy. It was reported that associated hypertension could increase this risk. The present study aimed to assess...
PURPOSE
Diabetes is a documented risk factor for peripheral neuropathy. It was reported that associated hypertension could increase this risk. The present study aimed to assess the effect of hypertension and diabetes on median nerve using high-resolution ultrasound.
METHODS
The study includes 50 hypertensive patients (HTN group), 50 diabetic patients (DM group), 50 patients with coexisting diabetes and hypertension (HTN + DM group) and 50 healthy controls. Median nerve affection in the studied groups was studied by vibration perception thresholds (VPT). The median nerve cross-sectional area was determined at the nerve cross-sectional area of the median nerve at the carpal tunnel by high-resolution ultrasound. Clinical symptoms were assessed using Toronto Clinical Severity Score (TCSS).
RESULTS
There was significantly higher median nerve CSA in all patient groups in comparison to controls. HTN + DM group had significantly higher median nerve CSA when compared with DM group. Patients with peripheral neuropathy in HTN + DM and DM groups had significantly higher median nerve CSA than patients without. Using ROC curve analysis, it was shown that median CSA could successfully distinguish patients with peripheral neuropathy from patients without in HTN + DM group [AUC (95% CI): 0.71 (0.54-0.89)] and in DM group [AUC (95% CI): 0.86 (0.72-0.99)].
CONCLUSION
Hypertensive patients with and without diabetes have significantly higher median nerve CSA when compared with controls.
PubMed: 35068936
DOI: 10.2147/DMSO.S340111 -
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 -
Frontiers in Cellular Neuroscience 2019The successful introduction of innovative treatment strategies into clinical practise strongly depends on the availability of effective experimental models and their... (Review)
Review
The successful introduction of innovative treatment strategies into clinical practise strongly depends on the availability of effective experimental models and their reliable pre-clinical assessment. Considering pre-clinical research for peripheral nerve repair and reconstruction, the far most used nerve regeneration model in the last decades is the sciatic nerve injury and repair model. More recently, the use of the median nerve injury and repair model has gained increasing attention due to some significant advantages it provides compared to sciatic nerve injury. Outstanding advantages are the availability of reliable behavioural tests for assessing posttraumatic voluntary motor recovery and a much lower impact on the animal wellbeing. In this article, the potential application of the median nerve injury and repair model in pre-clinical research is reviewed. In addition, we provide a synthetic overview of a variety of methods that can be applied in this model for nerve regeneration assessment. This article is aimed at helping researchers in adequately adopting this model for pre-clinical evaluation of peripheral nerve reconstruction as well as for interpreting the results in a translational perspective.
PubMed: 31316355
DOI: 10.3389/fncel.2019.00288 -
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 -
Human Movement Science Feb 2023The carpal tunnel is an elaborate biomechanical structure whose pathomechanics plays an essential role in the development of carpal tunnel syndrome. The purpose of this... (Review)
Review
The carpal tunnel is an elaborate biomechanical structure whose pathomechanics plays an essential role in the development of carpal tunnel syndrome. The purpose of this article is to review the movement related biomechanics of the carpal tunnel together with its anatomical and morphological features, and to describe the pathomechanics and pathophysiology associated with carpal tunnel syndrome. Topics of discussion include biomechanics of the median nerve, flexor tendons, subsynovial tissue, transverse carpal ligament, carpal tunnel pressure, and morphological properties, as well as mechanisms for biomechanical improvement and physiological restoration. It is our hope that the biomechanical knowledge of the carpal tunnel will improve the understanding and management of carpal tunnel syndrome.
Topics: Humans; Carpal Tunnel Syndrome; Ligaments; Median Nerve; Tendons; Wrist
PubMed: 36442295
DOI: 10.1016/j.humov.2022.103044