Ultrasound in Dual Nerve Impairment after Proximal Radial Nerve Lesion

IntroductionSonography in classical nerve entrapment syndromes is an established and validated method. In contrast, few publications highlight lesions of the radial nerve, particularly of the posterior interosseus nerve (PIN).MethodFive patients with a radial nerve lesion were investigated by electromyography, nerve conduction velocity and ultrasound. Further normative values of 26 healthy subjects were evaluated.ResultsFour patients presented a clinical and electrophysiological proximal axonal radial nerve lesion and one patient showed a typical posterior interosseous nerve syndrome (PINS). The patient with PINS presented an enlargement of the PIN anterior to the supinator muscle. However four patients with proximal lesions showed an unexpected significant enlargement of the PIN within the supinator muscle.ConclusionHigh-resolution sonography is a feasible method to demonstrate the radial nerve including its distal branches. At least in axonal radial nerve lesions, sonography might reveal abnormalities far distant from a primary proximal lesion site clearly distinct from the appearance in classical PINS.     

Current approach to radial nerve paralysis

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Identify all potential points of radial nerve compression and other likely causes of radial nerve injury. 2. Accurately diagnose both surgical and nonsurgical causes of radial nerve paralysis. 3. Define a safe and effective approach to the surgical release and reconstruction of the radial nerve. Radial nerve paralysis, which can result from a complex humerus fracture, direct nerve trauma, compressive neuropathies, neuritis, or (rarely) from malignant tumor formation, has been reported throughout the literature, with some controversy regarding its diagnosis and management. The appropriate management of any radial nerve palsy depends primarily on an accurate determination of its cause, severity, duration, and level of involvement. The radial nerve can be injured as proximally as the brachial plexus or as distally as the posterior interosseous or radial sensory nerve. This article reviews the etiology, prognosis, and various treatments available for radial nerve paralysis. It also provides a new classification system and treatment algorithm to assist in the management of patients with radial nerve palsies, and it offers a simple, five-step approach to radial nerve release in the forearm.     

The source of the nerve fibres forming the deep muscular and circular muscle plexuses in the small intestine of the guinea-pig

Summary A quantitative ultrastructural study was made of the neuntes forming the deep muscular and circular muscle plexuses of the guinea-pig small intestine following microsurgical lesions designed to interrupt intrinsic and extrinsic nerve pathways within the intestinal wall. Removal of a collar of longitudinal muscle with attached myenteric plexus from the circumference of a segment of small intestine resulted in the subsequent disappearance of 99.3% of neurites in the underlying circular muscle. The few surviving neurites in the deep muscular plexus and circular muscle disappeared completely from lesioned segments that were, in addition, extrinsically denervated surgically. These results indicate that the majority of nerve fibres in the deep muscular and circular muscle plexuses of the guinea-pig small intestine is intrinsic to the intestine and originates from nerve cell bodies located in the overlying myenteric plexus. At the light-microscopic level, nerve bundles were traced from the myenteric plexus to the circular muscle.     

Mononeuropathies of the radial nerve: clinical and neurographic findings in 91 consecutive cases.

Retrospective features of 91 consecutive cases (68 men, 23 women; mean age 44.4 years) of radial mononeuropathy diagnosed over the last 8 years in two electromyography (EMG) services are reported to define the clinical and electrophysiological findings of radial neuropathies in relation to traumatic and non-traumatic causes and site of injury. The occurrence of radial neuropathy was 0.65 x 100 first electromyographic examinations. The most frequent site of damage was the main trunk at the spiral groove of the humerus (36%); the most frequent cause was nerve trauma (70%) due to fracture (36%). In neuropathies of the main trunk and posterior interosseous (PI) nerve, "complete nerve injury" was observed in 36% of cases, conduction motor block in 33% and motor conduction velocity slowing in 46%. At least one of these findings was present in 51%, whereas motor neurography was normal in 13% of cases. Sensory action potential (SAP) anomalies were observed in 51% of cases. In neuropathy of the superficial radial nerve, no SAP was detected in 30% of cases; in all others except one, SAP was reduced in amplitude. Non-traumatic neuropathies showed severer conduction block and less severe anomalies of SAP than traumatic neuropathies. No differences were found between men and women. EMG is essential for confirming the site of injury and neurographic study may be helpful for diagnosis, providing information about lesion type and severity.     

The arteria radialis superficialis. An unusual variation of the arteria radialis of man and its phylogenetic significance

During the clinical investigation of 570 soldiers of the German army, we were not able to feel the pulse in 5 cases at the typical place of the radial pulse in the distal part of the forearm. In these 5 cases we were able to find a subcutaneous artery which coursed superficial to the anatomical snuffbox and crossed superficial to the tendon of the extensor pollicis longus muscle. This superficial radial artery enters the deep aspect of the palm between the first and the second metacarpale bones. In three cases we found a bilateral occurrence of this artery, the other variations were observed unilaterally, two on the right side and one on the left side of the forearm. In the family of two patients other members were found who had the same variation of the radial artery. In one of the cases an arteriography of the vessels was made to find the exact anatomical course of the observed variation. We compared our results with the literature on this variation of the radial artery and found agreement on the following course for this vessel. The radial artery divides in the distal fourth of the forearm (5-7 cm proximal to the wrist joint) into two branches. The dorsal branch courses subcutaneously over the tendon of the brachioradialis muscle and runs over the tendon of the extensor pollicis longus muscle to enter the deep aspect of the palm in the first metacarpal space. This dorsal branch courses parallel to the superficial branch of the radial nerve. The palmar branch can be regarded as the 'normal' radial artery, which continues along the medial border of the brachioradialis muscle and courses deep under the tendons of the dorsal muscles of the thumb. The rare appearance (frequency approximately 1%) of a superficial radial artery in man has probably some phylogenetic importance. This is proven by studies on the comparative anatomy of mammals. This variation of the radial artery seems to be homologous to the superficial radial artery which is described in many lower mammals. In human embryos a superficial radial artery is found as well which courses parallel to the superficial branch of the radial nerve and ends on the dorsal side of the hand. Taking all the anatomical and embryological facts into consideration we propose to name this variation of the radial artery the 'arteria radialis superficialis'.     

The relationship of the superficial and deep facial fascias: relevance to rhytidectomy and aging.

Controversy persists regarding the relationship of the superficial facial fascia (SMAS) to the mimetic muscles, deep facial fascia, and underlying facial nerve branches. Using fresh cadaver dissection, and supplemented by several hundred intraoperative dissections, we studied facial soft-tissue anatomy. The facial soft-tissue architecture can be described as being arranged in a series of concentric layers: skin, subcutaneous fat, superficial fascia, mimetic muscle, deep facial fascia (parotidomasseteric fascia), and the plane containing the facial nerve, parotid duct, and buccal fat pad. The anatomic relationships existing within the facial soft-tissue layers are (1) the superficial facial fascia invests the superficially situated mimetic muscles (platysma, orbicularis oculi, and zygomaticus major and minor); (2) the deep facial fascia represents a continuation of the deep cervical fascia cephalad into the face, the importance of which lies in the fact that the facial nerve branches within the cheek lie deep to this deep fascial layer; and (3) two types of relationships exist between the superficial and deep facial fascias: In some regions of the face, these fascial planes are separated by an areolar plane, and in other regions of the face, the superficial and deep fascia are intimately adherent to one another through a series of dense fibrous attachments. The layers of the facial soft tissue are supported in normal anatomic position by a series of retaining ligaments that run from deep, fixed facial structures to the overlying dermis. Two types of retaining ligaments are noted as defined by their origin, either from bone or from other fixed structures within the face.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intact radial and median nerve after open third degree distal fracture of the humerus

A 54 year old man sustained a third degree open fracture at the distal part of the right humerus with massive soft tissue defect involving most of the upper arm. The radial and median nerves were completely bared and exposed by 6 cm for radial and 3 cm for median nerve. The nerves were in continuity, but there was complete rupture of surrounding muscles: biceps, triceps and brachialis. The fracture was stabilized by external fixation method--reinforced by wires. Preoperative and postoperative sensorimotor status of the right hand was good. One year later sensory and motoric status of right hand showed no deficiencies, but flexion and extension in elbow were limited to 100 and 180 degrees respectively. Pronosupination was restricted. This case report is consistent with results of biomechanical studies in vitro confirming high tolerance of radial and median nerve to stretching injury.     

NADPH-diaphorase localization in the radial nerve cords of the starfish Patiria pectinifera

The presence and localization of NADPH-diaphorase (NADPH-d) in the radial nerve cords of Patiria pectonifera was shown by electron histochemistry. NADPH-d-positive structures were found in ectoneural and hyponeural regions of the radial nerve cord. Ultrastructural localization of NADPH-d was detected in neurons, sensory cells, supporting cells, and in the nerve plexus. The highest enzymatic activity in ectoneural region of the radial nerve cord is due, presumably, to the involvement of NADPH in sensory signal processing.     

Functional topography and ultrastructure of periarticular mechanoreceptors in the lateral elbow region of the rat

The distribution and ultrastructure of sensory nerve endings were investigated in the deep lateral elbow region of the rat. Three zones of distribution of mechanoreceptors were distinguished, each in relation to the functional architecture of the connective and muscular tissue in that area: (1) a zone with muscle spindles, Golgi tendon organs, free nerve endings and single small lamellated corpuscles ('muscle-tendon spectrum'), situated in the middle third of the supinator muscle and its superficial aponeurosis; (2) a zone with small lamellated corpuscles and free nerve endings, situated pericapsularly to the humeroradial joint capsule ('shearing spectrum'): this moderately dense, irregular connective tissue is covered by the proximal continuation of the supinator's aponeurosis, and muscle fibers insert from beneath this aponeurosis, which displays, as a part of the joint capsule, a strong collagenous tissue plate; (3) a zone with only free nerve endings within the tendon-like, most proximal part of the supinator's aponeurosis, inserting into the periosteal layer of the lateral humeral epicondyle ('endotenonial spectrum'): it is part of the joint capsule. The ultrastructure of these sensory endings is described and the distribution pattern of the mechanoreceptors observed is discussed in relation to the classification into 'muscle receptors' and 'joint receptors'.     

Ultrastructure of the circumoral nerve ring and the radial nerve cords in holothurians (Echinodermata)

The circumoral nerve ring and the radial nerve cords (RNCs) of Eupentacta fraudatrix and Pseudocnus lubricus (Holothuroidea) were examined as an example of holothurian nervous tissue. The RNC is composed of outer ectoneural and inner hyponeural layers, which are interconnected with one another via short neural bridges. The circumoral nerve ring is purely ectoneural. Both ectoneural and hyponeural components are epithelial tubes with a thick neuroepithelium at one side. A thin ciliated non-neuronal epithelium complements the neuroepithelium to form a tube, thereby enclosing the epineural and hyponeural canals. The whole of the ectoneural and hyponeural subsystems is separated from the surrounding tissue by a continuous basal lamina. The nerve ring and the ectoneural and hyponeural parts of the radial nerves are all neuroepithelia composed of supporting cells and neurons. Supporting cells are interpreted as being glial cells. Based on ultrastructural characters, three types of neurons can be distinguished: (1) putative primary sensory neurons, whose cilium protrudes into the epineural or hyponeural canal; (2) non-ciliated neurons with swollen rough endoplasmic reticulum cisternae; (3) monociliated neurons that are embedded in the trunk of nerve fibers. Different types of synapses occur in the neuropile area. They meet all morphological criteria of classical chemical synapses. Vacuolated cells occur in the neuroepithelium of E. fraudatrix, but are absent in P. lubricus; their function is unknown. The cells of the non-neuronal epithelia that overlie the ectoneural and hyponeural canals are hypothesized to belong to the same cell type as the supporting cells of the neuroepithelium.     

Transverse abdominal flaps and the deep epigastric arcade.

Further experience with the transverse abdominal flap, based on the deep epigastric arcade, is described. This flap is a logical extension of the concept of the deltopectoral flap (based on the internal mammary). The transverse abdominal flap derives its blood supply from the perforating branches of the deep epigastric arcade, and it can be used without a delay procedure when so constructed.     

Electromyography of pronators and supinators in great apes.

We obtained electromyographic recordings from the supinator, biceps brachii, pronator quadratus, and pronator teres muscles of a chimpanzee and a gorilla and from the supinator, pronator quadratus, and biceps brachii muscles of an orangutan as they stood and walked quadrupedally on horizontal and inclined surfaces, engaged in suspensory behavior, reached overhead, and manipulated a variety of foods and artifacts. In Pan troglodytes and Pan gorilla, as in Homo sapiens, the supinator muscle is the prime supinator, with the biceps brachii muscle serving to augment speed or force of supination. Primary of the pronator quadratus muscle over the pronator teres muscle during pronation is less clear in the African apes than in humans. Possibly, pongid radial curvature or forelimb elongation or both factors are related to the somewhat different patterns of activity that we observed in the pronator muscles of Pan versus those reported for Homo sapiens. In Pongo pygmaeus, as in P. troglodytes and P. gorilla, the pronator quadratus muscle acts as a pronator and the supinator muscle acts to supinate the hand at the radioulnar joints. The biceps brachii muscle is active at low levels as the orangutan supinates its hand with the elbow flexed.     

Comparison of median and radial nerve sensory latencies in the electrophysiological diagnosis of carpal tunnel syndrome

An electrophysiological diagnosis of carpal tunnel syndrome (CTS) was made on the basis of the median sensory nerve action potential (SNAP) alone in 79 of 161 (49.1%) symptomatic hands without electrophysiological evidence of a generalised peripheral neuropathy. Comparison of distal sensory latencies (DSLs) for the median and radial nerves yielded abnormal results in 17 of the remaining hands with normal median nerve DSLs, increasing the electrodiagnostic yield to 59.6%. Carpal tunnel decompression has been performed in seven of these hands, with abnormal intraoperative findings reported in two, while all improved clinically following surgery, substantiating the diagnosis of CTS. Although the technique described here would not appear to increase the electrodiagnostic yield more than comparison of DSLs for the median and ulnar nerves, which has been reported previously, it remains an affective, quick and simple procedure for increasing the sensitivity of the nerve conduction studies.     

Ramification pattern of intermetacarpal branches of the deep branch (ramus profundus) of the ulnar nerve in the human hand.

The branching pattern of the deep branch (ramus profundus) of the ulnar nerve and its relation with the target were analyzed in the human hand by an improved dissection method. After sending off branches to the hypothenar muscles, the r. profundus branched off an ulnar stem and a radial stem to the fourth, to the third and to the second intermetacarpal spaces, respectively, in this order, and an ulnar stem to the first to become terminal branches. The ulnar stems included an ulnar interosseous branch and a superficial articular branch in addition to a lumbrical branch in the third and fourth intermetacarpal spaces. The radial stems included only a radial interosseous branch. The branching pattern of the ulnar stems as well as its topographical relationship with the radial stems indicated a fundamental spatial arrangement of the branches in the intermetacarpal spaces: the lumbrical, superficial articular, ulnar interosseous and radial interosseous branches were arranged fundamentally in this order from ulnar to radial in each space; the first three branches may form a common trunk. The present observations demonstrate that individual nerves in the extremities may have a regular branching pattern, contrary to most of the previous observations.     

Sympathetic nerve activity in arm and leg muscles during lower body negative pressure in humans

Nonhypotensive lower body negative pressure (LBNP) is reported to decrease forearm but not calf blood flow as measured by strain-gauge plethysmography. This suggests that unloading of cardiopulmonary receptors increases sympathetic outflow to arm but not to leg. To test this hypothesis we measured muscle sympathetic nerve activity (MSA) in the arm (radial nerve) and leg (peroneal nerve) simultaneously during LBNP. In eight healthy subjects, we measured heart rate, blood pressure, and radial and peroneal MSA during LBNP at 10 and 20 mmHg. There was no difference between radial and peroneal MSA at rest, and there were successive parallel increases of MSA in both nerves during LBNP at 10 and 20 mmHg. These data indicate that there are nearly identical increases of sympathetic outflow to the arm and leg during mild to moderate degrees of orthostatic stress.     

An anomalous muscle (accessory subscapularis-teres-latissimus muscle) in the axilla penetrating the brachial plexus in man.

An anomalous muscle passing through the brachial plexus was found in 10 cases out of 380 sides of 190 human cadavers in the dissection course. The muscle was designated as 'accessory subscapularis-teres-latissimus muscle'. This muscle arose near the lateral margin of the scapula, either from the surface of the subscapularis muscle or from the border of the quadrangular terminal tendon of the latissimus dorsi or from both of those sources when the muscle was divided into two heads. It ran obliquely upward to fuse with the insertion of the subscapularis. The largest anomaly was 2.5 cm in width and 7 cm in length. This muscle could be classified into three types on the basis of its nerve supply and its relation to the brachial plexus. The type I muscle crossed over the axillary and lower subscapular nerves, behind the radial nerve and was innervated by the lower subscapular nerves. The type II musclepenetrated the brachial plexus separating the radial nerve into two roots; the upper from the posterior division of the upper trunk and the lower from the posterior divisions of the middle and lower trunks. The type II muscle was supplied by a branch of the radial nerve, which originated always at the same level as the origin of the thoracodorsal nerve. The type III muscle passed through the further more ventrocaudal level of the plexus; in one case it divided the radial nerve into an upper root from the posterior divisions of the upper and middle trunks and a lower root from the lower trunk, and, in another case, into an upper main root from all the three trunks and a lower slender root from the lower trunk. The type III muscle was supplied by branches from the radial and in addition from the thoracodorsal nerve in one case. In four out of ten cases, the subscapular or thoracodorsal artery also passed posterior to the anomalous muscle. A discussion was made on the nature of the anomalous muscle.     

Anatomical variations of the abducent nerve in humans

Anatomical variation of the nervus abducens in human encephali were found and described. They consisted of (1) an unusual trifurcation of the abducent nerve, limited to the extradural portion of the neural trunk (1.4% of the cases) and (2) the duplicity (11.1%) of the neural trunk, starting before reaching the orbit and ending before reaching the m. rectus lateralis. The possibility of correlating these variations with clinical aspects and forensic interpretations is mentioned.     

The effects of stimulus rates upon median,ulnar and radial nerve somatosensory evoked potentials

We examined the effect of stimulus rates on the somatosensory evoked potential (SEP) amplitude following stimulation of the median nerve (MN) and the ulnar nerve (UN) at the elbow or wrist, and the radial nerve (RN) at the wrist in 12 normal subjects. We measured the amplitude of frontal (P14-N18-P22-N30) and parietal peaks (P14-N20-P26-N34) at a stimulus rate of 1.1, 3.5 and 5.7 Hz. The amplitude attenuation was found at frontal P22 and N30 and to a lesser degree at parietal N20 and P26 peaks with an increasing stimulus rate from 1.1 to 5.7 Hz. The amplitude attenuation was greatest at the elbow when compared to the wrist stimulation for both MN and UN. The attenuation was least for wrist stimulation for the RN. The UN block by local anesthesia just distal to the stimulus electrode at the elbow abolished the amplitude attenuation caused by the fast stimulus rate. The observed amplitude attenuation with the faster stimulus rate is probably due, in part, to interference from the “secondary” afferent inputs. The secondary afferent inputs arise from peripheral receptor stimulation (muscle, joint and/or cutaneous) as a subsequent effect of efferent volleys initiated from the point of stimulation. The greater number of peripheral receptors being activated as more proximal sites of stimulation in a mixed nerve would result in greater attenuation of the SEP recorded from scalp electrodes. We postulate that the attenuation of frontal peaks by the fast stimulus rate is due to the frontal projection of interfering “secondary” afferent inputs.     

Aberrant cutaneous nerve of the thigh arising from the sciatic nerve in the human

An aberrant cutaneous nerve of the thigh arising from the peroneal portion of the human sciatic nerve or common peroneal nerve was observed in 9 cases (4.6% of sides). After giving a branch to the short head of the biceps femoris muscle and a branch to the knee joint, this cutaneous nerve reaches the subcutaneous tissue by passing between the short head of the biceps femoris and the vastus lateralis or by piercing through the biceps femoris. The authors presume that the cutaneous nerve shows the presence of the potential cutaneous nerve routes from the common peroneal nerve to the skin of the lateral aspect of the thigh.     

Innervation pattern of the deep extensor abdominal muscle in the crayfish species Astacus astacus

The deep extensor abdominal muscle consisting of one medial and two lateral muscle bundles together with the nerve innervating the muscles of crayfish species Astacus astacus, was prepared. Light microscopic investigations of methylene blue stained preparations showed that the nerve innervating the deep extensor abdominal muscle consists of five distinct axons. The five axons were stained separately with lucifer yellow and the innervation pattern of the axons was determined. To confirm the histological results the axons were also stimulated with a suction electrode to elicit excitatory postsynaptic currents on the muscle membrane which were detected using a macro patch electrode. The muscle is innervated by a common excitatory and a common inhibitory axon branching over all three muscle bundles and sending additionally a branch to the L1-bundle of the next posterior segment, and by two axons specific for the two lateral muscle bundles. The axon specific for the innervation of the L1-bundle sends also a branch to the L1-bundle of the next posterior segment. In addition there is one excitatory axon which directly innervates the medial muscle bundle of the next posterior segment branching in most of the cases also to the medial bundle of the segment where it originates.Abbreviations DEAM deep extensor abdominal muscle - EPSC excitatory postsynaptic current - IPSC inhibitory postsynaptic current - L lateral - M medial - GABA -aminobutyric acid