Bilateral triad of persistent median artery, a bifid median nerve and high origin of its palmar cutaneous branch. A case report and clinical implications

We report the association of a persistent median artery, a bifid median nerve with a rare very high origin palmar cutaneous branch, presenting bilaterally in the upper limb of a 75-year-old female cadaver. The persistent median nerve with a bifid median nerve has been reported in patients presenting with carpal tunnel syndrome. Reports of this neurovascular anomaly occurring in association with a high origin palmar cutaneous branch however, are few. This subset of patients is at risk of inadvertent nerve transection during forearm and wrist surgery. Pre-operative magnetic resonance imaging (MRI) and high resolution sonography (HRS) can be used to screen this triad. MRI can reveal if the patient’s disability is associated with a persistent median nerve, a bifid median nerve. HRS can help identify a palmar cutaneous branch of the median nerve that arises in an unexpected high forearm location. Such knowledge will help surgeons in selecting the most appropriate surgical procedure, and help avoid inadvertent injury to cutaneous nerves arising in unexpected locations. In patients presenting with a bilateral carpal tunnel syndrome, hand surgeons should consider very high on the list of differential diagnosis a persistent median artery with a concomitant bifid median nerve, with a high suspicion of a possible bilateral occurrence of a bilaterally high arising palmar cutaneous branch of the median nerve. © 2016, Universidad de la Frontera. All rights reserved

Shoulder posture and median nerve sliding

Background: Patients with upper limb pain often have a slumped sitting position and poorshoulder posture. Pain could be due to poor posture causing mechanical changes (stretch; localpressure) that in turn affect the function of major limb nerves (e.g. median nerve). This studyexamines (1) whether the individual components of slumped sitting (forward head position, trunkflexion and shoulder protraction) cause median nerve stretch and (2) whether shoulderprotraction restricts normal nerve movements.Methods: Longitudinal nerve movement was measured using frame-by-frame cross-correlationanalysis from high frequency ultrasound images during individual components of slumped sitting.The effects of protraction on nerve movement through the shoulder region were investigated byexamining nerve movement in the arm in response to contralateral neck side flexion.Results: Neither moving the head forward or trunk flexion caused significant movement of themedian nerve. In contrast, 4.3 mm of movement, adding 0.7% strain, occurred in the forearm duringshoulder protraction. A delay in movement at the start of protraction and straightening of thenerve trunk provided evidence of unloading with the shoulder flexed and elbow extended and thescapulothoracic joint in neutral. There was a 60% reduction in nerve movement in the arm duringcontralateral neck side flexion when the shoulder was protracted compared to scapulothoracicneutral.Conclusion: Slumped sitting is unlikely to increase nerve strain sufficient to cause changes tonerve function. However, shoulder protraction may place the median nerve at risk of injury, sincenerve movement is reduced through the shoulder region when the shoulder is protracted andother joints are moved. Both altered nerve dynamics in response to moving other joints and localchanges to blood supply may adversely affect nerve function and increase the risk of developingupper quadrant pain

Anatomical variations of median nerve formation, distribution and possible communication with other nerves in preserved human cadavers

Formation, distribution and possible communication of the median nerve are essential to know in treatment and surgeries of various conditions of injuries e.g. repair or reconstruction of the median nerve post traumatic accident. In the present study, 44 upper limbs were dissected. Root forming the median nerve, the median nerve in relation with the axillary artery and communication of the median nerve with other nerves were noted

Anatomical variation in the formation and course of median nerve: a cadaveric study

Background: Median nerve is one of the terminal branches of brachial plexus. Its formed by the union of medial root and lateral root coming respectively from medial and lateral cords of brachial plexus. Knowledge of anatomical variations of median nerve at origin and course is important in repair of traumatic injuries and surgical correction of brachial plexus injuries. These conditions need dissection of median nerve and knowledge of its variations.Methods: Present study included 53 cadavers and 106 upper limbs from our department of Anatomy. In this study, anatomically embalmed cadavers which were kept for routine dissection for under graduates were included. The present study we studied the anatomical variations in origin and course of median nerve in arm. We also studied the relation of median nerve with axillary and brachial arteries.Results: In this study we found origin of median nerve from 3 roots in 26.41%, 4 roots from 1.88%. Regarding the relation of median nerve with axillary artery we observed in 8.49% cadavers median nerve lies medial to axillary artery and in 0.94% Median nerve is passing along the lateral side of brachial artery without crossing the artery.Conclusions: This study shows high percentage of deviations from normal anatomy in origin of median nerve. Anatomical variation in brachial plexus and adjacent arteries knowledge is important for anatomist, plastic surgeon and vascular surgeons.

The Palmar Cutaneous Branch of Median Nerve - Its Clinical importance in Carpal Tunnel Release: A Cadaver study

INTRODUCTION: Carpal tunnel syndrome (CTS) is the most common compressive neuropathy of the median nerve at the wrist. In patients with carpal tunnel syndrome, the median nerve under the flexor retinaculum is tightly packed with the long flexor tendons of the fingers with their surrounding synovial sheaths. The decompression of median nerve by sectioning the transverse carpal ligament (flexor retinaculum) is well accepted as the treatment of choice for patients with carpal tunnel syndrome. It is assumed that most of the postoperative complications are due to injuries to the distal branches of the median nerve. The palmar cutaneous branch of the median nerve was one of the main branches of median nerve that can easily get injured during open carpal tunnel release. The precise zone of sensation in the palm is difficult to define, due to the extensive overlap of sensory supply from the main median nerve. The evolution of the technique of carpal tunnel release reflects growing awareness of the cutaneous innervations of the palm and its implication on postoperative scar tenderness. AIMS OF THE STUDY: 1. To study and trace the anatomic course of palmar cutaneous branch of the median nerve. 2. To analyze the variations of palmar cutaneous branch of the median nerve. 3. To assess the other sensory nerve contributions to the palm. 4. To analyze the post operative sequelae following accidental division of palmar cutaneous branch of median nerve in carpal tunnel release. MATERIALS AND METHODS: 24 hands of 12 cadavers were dissected. The incision was made from mid-forearm, extending vertically up to distal wrist crease. The incision turned towards the ulnar half of ring finger up to distal palmar crease. Then the incision turned towards the ulnar aspect of thumb. The incision was deepened. The palmar cutaneous branch of median nerve was traced from midforearm and traced along its course. The median nerve was identified between the tendon of flexor Carpi radialis and Palmaris longus (PL) and then was picked up. Each PCN was identified using blunt dissection, and was traced proximally to its intraneural origin from the median nerve. Each PCBMN was then carefully dissected distally, dividing the skin overlying its course and tracing individual branches radially, and towards the ulnar side until its termination in the undersurface of the skin. The variations and other sensory nerve contributions were noted. The findings were recorded, photographed and tabulated. CONCLUSIONS: Palmar Cutaneous branch of Median nerve is not a myth. • But it is not present as it is described in text books. • It is not a constant branch of Median nerve. • It could be absent unilaterally or bilaterally. • Our dissections show that PCBMN supplies mainly thenar eminence. • So, accidental division of Palmar Cutaneous Branch of Median Nerve may not cause sensory loss in the palm as there are additional contributions from branches from median nerve and common digital nerves

Mechanical tension in the median nerve: The effects of joint positions

Stretch tests are attractive in the diagnosis of nerve root or peripheral nerve lesion. Interpretation of the test results is often difficult since the distribution of tensile forces along the nerve caused by the test manoeuvre is not known. In this study the effect on median nerve tension of 22 positions of the arm was measured with ‘buckle’ force transducers. With the elbow in full extension and the hand in neutral position, altering the position of the shoulder significantly influenced tension in the proximal part of the median nerve; tension in the distal part was not influenced. With the shoulder in 90 ° abduction, dorsiflexion of the hand combined with an extended elbow resulted in an increased tension in both distal and proximal parts of the median nerve. Dorsiflexion of the hand combined with flexion of the elbow caused an increase in tension only in the distal part. At all sites of the median nerve the median nerve upper limb tension test caused a significantly higher tension than the radial and ulnar nerve upper limb tension tests. This study provides insight in the normal distribution of tensile forces along the median nerve and can have clinical consequences. For differentiating nerve root from peripheral nerve lesions a specific provocative tension test for the median nerve is advocated. The results of this study provide a theoretical basis for differentiating between lesions in the proximal and distal parts of the median nerve

Proximal Median Nerve Compression in the Differential Diagnosis of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is the most common median nerve compression neuropathy. Its symptoms and clinical presentation are well known. However, symptoms at median nerve distribution can also be caused by a proximal problem. Pronator syndrome (PS) and anterior interosseous nerve syndrome (AINS) with their typical characteristics have been thought to explain proximal median nerve problems. Still, the literature on proximal median nerve compressions (PMNCs) is conflicting, making this classic split too simple. This review clarifies that PMNCs should be understood as a spectrum of mild to severe nerve lesions along a branching median nerve, thus causing variable symptoms. Clear objective findings are not always present, and therefore, diagnosis should be based on a more thorough understanding of anatomy and clinical testing. Treatment should be planned according to each patient’s individual situation. To emphasize the complexity of causes and symptoms, PMNC should be named proximal median nerve syndrome

Proximal Median Nerve Compression in the Differential Diagnosis of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is the most common median nerve compression neuropathy. Its symptoms and clinical presentation are well known. However, symptoms at median nerve distribution can also be caused by a proximal problem. Pronator syndrome (PS) and anterior interosseous nerve syndrome (AINS) with their typical characteristics have been thought to explain proximal median nerve problems. Still, the literature on proximal median nerve compressions (PMNCs) is conflicting, making this classic split too simple. This review clarifies that PMNCs should be understood as a spectrum of mild to severe nerve lesions along a branching median nerve, thus causing variable symptoms. Clear objective findings are not always present, and therefore, diagnosis should be based on a more thorough understanding of anatomy and clinical testing. Treatment should be planned according to each patient's individual situation. To emphasize the complexity of causes and symptoms, PMNC should be named proximal median nerve syndrome.Peer reviewe

An unusual bilateral variation of musculocutaneous nerve.

Musculocutaneous nerve arises from the lateral cord (C5,6,7) of brachial plexus. Communications between the branches of brachial plexus are not so common. During routine dissection, we observed bilateral variation in 60-year-old female cadaver. In the present case, median nerve represented as a musculocutaneous nerve which supplied biceps brachii and brachialis, further continued into forearm as lateral cutaneous nerve of forearm on the right arm. This branch did not pass through coracobrachialis muscle but the coracobrachialis was innervated by a branch from lateral cord of brachial plexus. We also observed an abnormal communicating branch between the musculocutaneous and median nerve on left side of the arm. These kinds of variations are important for surgeons while performing surgeries of axilla and upperlimb