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Results for “Musculocutaneous Nerve”

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At least 19 recordsLinked to original sources
PubMed1987

Satisfactory elbow flexion in complete (preganglionic) brachial plexus injuries: produced by suture of third and fourth intercostal nerves to musculocutaneous nerve.

The third and fourth intercostal nerves were sutured to the musculocutaneous nerve to restore flexion of the elbow joint in complete (preganglionic) brachial plexus injuries. Seventeen patients were followed on the average for 5 years and 7 months after surgery. The results were evaluated by means of manual muscle tests and electrical diagnostic tests. Good (grade IV), or better, flexion of the elbow joint occurred in 12 patients over 3 years after the operation.

Adolescent↗
PubMed2003

Transfer of pectoral nerves to the musculocutaneous nerve in obstetric upper brachial plexus palsy.

OBJECTIVE: To investigate the results of transfer of pectoral nerves to the musculocutaneous nerve for treatment of obstetric brachial palsy. METHODS: In 25 cases of obstetric brachial palsy (20 after breech deliveries), branches of the pectoral nerve plexus were transferred directly to the musculocutaneous nerve. For all patients, the nerve transfer was part of an extended brachial plexus reconstruction. Results were tested both clinically and with the Mallet scale, at a mean follow-up time of 70 months (standard deviation, 34.3 mo). RESULTS: There were two complete failures, which were attributable to disconnection of the transferred nerve endings. The results after transfer were excellent in 17 cases and fair in 5 cases. Steindler flexorplasty improved elbow flexion for three patients. CONCLUSION: Transfer of pectoral nerves to the musculocutaneous nerve for treatment of obstetric upper brachial palsy may be effective, if the specific anatomic features of the pectoral nerve plexus are sufficiently appreciated.

Adolescent↗
PubMed2001

Surgical relationship of the medial pectoral nerve to the musculocutaneous nerve: a cadaveric study.

OBJECTIVE: For purposes of neurotization of the musculocutaneous nerve (MCN) with the medial pectoral nerve (MPN) after upper trunk brachial plexus injuries, the anatomic relationship between these two nerves was defined in a cadaveric model. METHODS: Thirty-five brachial plexuses in 18 adult cadavers were dissected. The distance between the origin of the MPN from the medial cord to the origin of the MCN from the lateral cord was measured. The length, diameter, branching, and location of the MPN were recorded. The diameter of the proximal MCN was recorded. RESULTS: Thirty-seven percent of the MPNs, when detached from the pectoralis muscles, were too short to reach the proximal MCN by a mean distance of 15 mm. The MPN pierced the pectoralis minor muscle in 80% of the dissections. The cross sectional area of the MCN was always larger than the cross sectional area of the MPN by an average factor of 2.5. CONCLUSION: When planning to use the MPN for neurotization of the MCN, one should be prepared to harvest an interposition graft, because over one-third of MPNs may not have enough length to reach the MCN in a tension-free manner. Diameter mismatch occurs predictably between the distal MPN and the proximal MCN.

Adult↗
PubMed2006

Phrenic nerve neurotization of the musculocutaneous nerve with end-to-side neurorrhaphy: a short report in a rabbit model.

This experimental study was performed to evaluate the efficacy of end-to-side coaptation between the musculocutaneous nerve and the phrenic nerve for brachial plexus injuries with nerve-root avulsions. In an experimental rabbit model, neurotization of the musculocutaneous nerve with the phrenic nerve was compared using end-to-end and end-to-side neurorrhaphy. Preliminary results from electrophysiologic and histologic examinations indicate that end-to-side neurotization of the musculocutaneous nerve with the phrenic nerve is an effective means for musculocutaneous nerve repair. The effectiveness of the phrenic nerve is attributed to its large number of motor axons.

Animals↗
PubMed1990

Spinal nerve root origin of the median, ulnar and musculocutaneous nerves and their muscle nerve branches to the canine forelimb.

The contribution individual ventral spinal nerve roots made to the canine median nerve, ulnar nerve, musculocutaneous nerve, and their muscle nerve branches was determined electrophysiologically. Each spinal nerve root was sequentially stimulated. Utilizing quantitative signal averaging techniques, the evoked potential was measured at each tested peripheral nerve. Evoked potential to the median nerve originated from the seventh cervical spinal root (C7) through the second thoracic spinal root (T2) with most input from C8 and T1. The ulnar nerve received evoked potential from C7-T2. Although T1 provided the major input to both the median and ulnar nerves, the relative contribution of T1 was greater in the ulnar nerve. The musculocutaneous nerve received input from ventral spinal roots C6-T1 with C6 and C7 providing most of the evoked potential. The ventral spinal roots which supplied the bulk of the evoked potential to a particular muscle nerve were consistent between individual dogs. Variation of evoked potential input was greatest from spinal roots which supplied less than 10% of the total potential.

Animals↗
PubMed1992

Intercostal nerve transfer of the musculocutaneous nerve in avulsed brachial plexus injuries: evaluation of 66 patients.

Intercostal nerve transfer is a well-established and effective technique for irreparable avulsed brachial plexus injuries. Between 1987 and 1989, 66 patients with brachial plexus injuries were treated by means of intercostal nerve transfer to the musculocutaneous nerve, with or without nerve grafts to obtain elbow flexion. The results were evaluated. Five clinical signs--(1) induction of chest pain by squeezing of biceps, (2) proximal biceps contraction, (3) distal biceps contraction, (4) active elbow flexion against gravity, and (5) active elbow flexion against weight--were identified and used as a guide for functional recovery. The overall success rate with motor function of grade 4 or more was 67%. The motor results were better in 1989 (81%) because of greater familiarity with the anatomy and improved surgical technique. The important factors in obtaining a good result are (1) early exploration (less than 5 months after trauma), (2) use of three intercostal nerves, (3) mixed nerve-to-mixed nerve coaptation, (4) nerve repair without grafts and under no tension, and (5) shoulder stability.

Adolescent↗
PubMed2005

Restoration of elbow flexion by performing contralateral lateral thoracic and thoracodorsal nerve transfers after experimental musculocutaneous nerve transection.

OBJECT: The immediate transfer of the right lateral thoracic nerve (LTN) and the thoracodorsal nerve (TDN) to the transected left musculocutaneous nerve (MCN), leading to nerve cross-neurotization, was performed in cats to evaluate reinnervation of the biceps brachii muscle (BBM). METHODS: Surgery to produce cross-neurotization of the MCN was performed in 12 cats (treatment group). Transection of the MCN was performed without attempts at neurotization in three cats (control group). Reinnervation of the BBM was assessed by performing electromyography (EMG) 6 months (14 cats) and 26 months (one cat) postsurgery. True Blue retrograde axonal tracing studies, tensile force measurements (muscle extensometry), and histopathological analyses were performed. All cats in the treatment group recovered voluntary contraction of the BBM and regained elbow flexion. Electromyography revealed no abnormal spontaneous activity in the BBM. Muscle evoked potentials were recorded in that muscle after right C-8 ventral branch stimulation. The muscle contraction strength in the left BBM varied from 108 to 557 g. The BBMs regained their normal appearances. The region of the MCN distal to the anastomosis displayed a normal histological appearance. Fluorescence was detected in the ventral horn of the spinal cord in the right C-8 and T-1 segments. In contrast, in all cats in the control group there was atrophy of the BBM, no EMG signal, and no clinical sign of recovery. There was no contraction of the BBM, no labeled neuron in the spinal cord, and the MCN displayed major degenerative changes. CONCLUSIONS: These findings demonstrate that the LTN and TDN can be used to neurotize injured contralateral brachial plexus nerves and obtain successful reinnervation in cats.

Animals↗
PubMed2001

Use of intercostal nerves for neurotization of the musculocutaneous nerve in infants with birth-related brachial plexus palsy.

OBJECT: The use of intercostal nerves (ICNs) for the neurotization of the musculocutaneous nerve (MCN) in adult patients with traumatic brachial plexus palsy has been well described. However, its use for brachial plexus palsy in infants has rarely been reported. The authors surgically created 31 ICN-MCN communications for birth-related brachial plexus palsy and present the surgical results. METHODS: Thirty-one neurotizations of the MCN, performed using ICNs, were conducted in 30 patients with birth-related brachial plexus palsy. In most cases other procedures were combined to reconstruct all upper-extremity function. The mean patient age at surgery was 5.8 months and the mean follow-up period was 5.2 years. Intercostal nerves were transected 1 cm distal to the mammary line and their stumps were transferred to the axilla, where they were coapted directly to the MCN. Two ICNs were used in 26 cases and three ICNs in five cases. The power of the biceps muscle of the arm was rated Grade M4 in 26 (84%) of 31 patients. In the 12 patients who underwent surgery when they were younger than 5 months of age, all exhibited a grade of M4 (100%) in their biceps muscle power. These results are better than those previously reported in adults. CONCLUSIONS: Neurotization of the MCN by surgically connecting ICNs is a safe, reliable, and effective procedure for reconstruction of the brachial plexus in patients suffering from birth-related palsy.

Axilla↗
PubMed2003

Functional magnetic resonance imaging and control over the biceps muscle after intercostal-musculocutaneous nerve transfer.

OBJECT: Recent progress in the understanding of cerebral plastic changes that occur after an intercostal nerve (ICN)-musculocutaneous nerve (MCN) transfer motivated a study with functional magnetic resonance (fMR) imaging to map reorganization in the primary motor cortex. METHODS: Eleven patients with traumatic root avulsions of the brachial plexus were studied. Nine patients underwent ICN-MCN transfer to restore biceps function and two patients were studied prior to surgery. The biceps muscle recovered well in seven patients who had undergone surgery and remained paralytic in the other two patients. Maps of neural activity within the motor cortex were generated for both arms in each patient by using fMR imaging, and the active pixels were counted. The motor task consisted of biceps muscle contraction. Patients with a paralytic biceps were asked to contract this muscle virtually. The location and intensity of motor activation of the seven surgically treated arms that required good biceps muscle function were compared with those of the four arms with a paralytic biceps and with activity obtained in the contralateral hemisphere regulating the control arms. Activity could be induced in the seven surgically treated patients whose biceps muscles had regained function and was localized within the primary motor area. In contrast, activity could not be induced in the four patients whose biceps muscles were paralytic. Neither the number of active pixels nor the mean value of their activations differed between the seven arms with good biceps function and control arms. The weighted center of gravity of the distribution of activity also did not appear to differ. CONCLUSIONS: Reactivation of the neural input activity for volitional biceps control after ICN-MCN transfer, as reflected on fMR images, is induced by successful biceps muscle reinnervation. In addition, the restored input activity does not differ from the normal activity regulating biceps contraction and, therefore, has MCN acceptor qualities. After ICN-MCN transfer, cerebral activity cannot reach the biceps muscle following the normal nervous system pathway. The presence of a common input response between corticospinal neurons of the ICN donor and the MCN acceptor seems crucial to obtain a functional result after transfer. It may even be the case that a common input response between donor and acceptor needs to be present in all types of nerve transfer to become functionally effective.

Adolescent↗
PubMedDate not supplied

The musculocutaneous nerve: ultrasound appearance for peripheral nerve block.

BACKGROUND AND OBJECTIVES: To gain complete anesthesia of the forearm, block of the musculocutaneous nerve is necessary. Variations in its course and position make localization of the musculocutaneous nerve problematic. The aim of the study is to describe the ultrasound appearance of the musculocutaneous nerve in the axilla and to suggest potential areas to target neural block. METHODS: We scanned the axillary regions of 19 volunteers and assessed the size and shape of 34 musculocutaneous nerves at entry into, exit from, and in the center of the coracobrachialis muscle. Furthermore, we measured the depth of the musculocutaneous nerve under the skin surface and its distance from the axillary artery at those 3 measurement points. RESULTS: As it travels through the coracobrachialis muscle, the musculocutaneous nerve changes in shape from oval to flat-oval to triangular. During this course, the musculocutaneous nerve also separates from the axillary artery and becomes more lateral while changing its depth from the surface. The musculocutaneous nerve increases its transverse area along this nerve path. In 2 subjects, the musculocutaneous nerve could not be visualized unilaterally within the course of the coracobrachialis muscle. CONCLUSIONS: Knowledge of its ultrasound appearance facilitates localization and successful block of the musculocutaneous nerve. Because the distance between the musculocutaneous nerve and brachial plexus varies, different locations of musculocutaneous nerve puncture during ultrasound-guided regional anesthesia can be chosen.

Axillary Artery↗
PubMed1984

Isolated proximal musculocutaneous nerve palsy: case report.

Isolated musculocutaneous nerve injury is extremely rare. The few reported cases were associated with heavy exercises and violent extension of the forearm. The lesions in those cases were below the coracobrachialis muscle, involving the biceps, brachialis, and cutaneous nerves of the forearm. This patient's lesion was unique, located proximal to the coracobrachialis. There was no antecedent trauma. At follow-up six weeks and four months after onset of symptoms, significant improvement was noted both clinically and electrophysiologically. Musculocutaneous nerve palsy is important to distinguish in certain differential diagnoses, particularly with C5 or C6 radiculopathy and brachial plexus injury.

Adult↗
PubMed1997

Anatomic variations of the musculocutaneous nerve in the arm.

To determine the course and anatomic relationships of the musculocutaneous nerve in the arm, we dissected 54 cadaver arms and measured the length of any interconnection between the musculocutaneous nerve and the median nerve (36% of dissections; mean, 1.77 cm) and the distance from the coracoid process to (1) the musculocutaneous nerve (mean, 0.46 cm distal); (2) the median nerve (mean, 1.91 cm distal); (3) the musculocutaneous nerve's entrance to and exit from the coracobrachialis muscle (mean, 4.99 cm and 7.55 cm, respectively); and (4) the musculocutaneous nerve's entrance into the biceps muscle (mean, 11.66 cm). The high percentage of anomalies found emphasizes the complexities and irregularities of this anatomic region with regard to surgical approaches.

Arm↗
PubMed2002

Patient outcome following a thoracodorsal to musculocutaneous nerve transfer for reconstruction of elbow flexion.

This study reports patient outcome following a thoracodorsal to musculocutaneous nerve transfer. We retrospectively reviewed the charts of six patients who had undergone transfer of the thoracodorsal nerve to the musculocutaneous nerve for reconstruction of elbow flexion. The mean age was 47 years (standard deviation: 24 years; range: 17-72 years). The mean time from injury to surgery was 3 months (standard deviation: 2 months; range: 1-5 months). In all cases, the biceps muscle was successfully reinnervated; in one case the Medical Research Council (MRC) muscle grade was grade 5, in four cases it was grade 4, and in one case it was grade 2. No patients complained of functional weakness with shoulder adduction and/or internal rotation. In the majority of cases, transfer of the thoracodorsal nerve to the musculocutaneous nerve provides excellent recovery of elbow flexion.

Adolescent↗
PubMed2006

Absence of the musculocutaneous nerve together with unusual innervation of the median nerve.

During routine anatomical dissections, absence of the musculocutaneous nerve was determined in a 58-year-old male cadaver. Moreover, the biceps brachii and brachialis muscles were innervated by two separate branches which divided from the median nerve instead of the musculocutaneous nerve. From a branch that divides from the main trunk of the median nerve at nearly the middle of the arm a motor branch again divided that innervated the brachialis muscle and a sensory branch that conveyed the sense of the lateral part of the forearm. Furthermore, it was found that the brachial artery divided into its terminal branches, the radial and ulnar arteries. We believe that this rare variation of the median nerve will shed light upon surgical procedures involving the median nerve.

Arm↗
PubMed1995

The musculocutaneous nerve and its branches to the biceps and brachialis muscles.

The musculocutaneous nerve and its motor branches to the biceps and brachialis were dissected and studied under the operating microscope in 24 fresh-frozen cadaveric specimens. The motor branch to the biceps exits from the musculocutaneous nerve at 119 mm distal to the coracoid process. Anatomic variations were seen in the innervation of the two heads of the biceps. A common primary motor branch that bifurcates to supply the two heads was seen in 20 specimens (type I). Two specimens were observed to have two separate primary branches originating from the main musculocutaneous nerve trunk to individually supply each head of the biceps (type II). The third variation, two specimens (type III), was observed in two specimens to be similar to type I, but with an additional distal motor branch innervating the common belly of the biceps muscle. The motor branch to the brachialis muscle exists from the musculocutaneous nerve 170 mm distal to the coracoid process. A single primary motor branch (type I) was seen in 23 specimens, and 1 specimen (type II) showed two separate primary motor branches innervating the muscle. The motor branches to the biceps and brachialis muscles may be dissected proximally from their points of exit from the main trunk of the musculocutaneous nerve for a mean distance of 44 mm and 53 mm, respectively. This information can be used by surgeons who elect to suture intercostal nerves to the motor branches of the biceps and brachialis muscles for elbow flexion in brachial plexus injuries.

Arm↗
PubMed2005

Three-headed biceps brachii muscle associated with duplicated musculocutaneous nerve.

A unilateral three-headed biceps brachii muscle coinciding with an unusual variant of the musculocutaneous nerve was found during routine dissection of a 79-year-old male cadaver. The supernumerary bicipital head originated from the antero-medial surface of the humerus just beyond the insertion of the coracobrachialis, and inserted into the conjoined tendon of biceps brachii. Associated with this muscular variant was a duplicated musculocutaneous nerve. The proximal musculocutaneous nerve conformed to the normal pattern only in its proximal part, and terminated after innervating the coracobrachialis and biceps brachii muscles. The distal musculocutaneous nerve arose from the median nerve in the lower arm, then passed laterally between the supernumerary bicipital head and the brachialis muscles, supplying both and terminating as the lateral cutaneous nerve of the forearm. The supernumerary bicipital head and the accompanying anomaly of the musculocutaneous nerve seem to be unique in literature.

Aged↗