Little finger abduction and adduction testing in ulnar nerve lesions.

We aimed to evaluate the abduction and adduction of the little finger based on a new clinical test in the context of ulnar nerve lesions. We tested little finger abduction and adduction in 34 patients with an isolated ulnar nerve injury and 20 patients with cubital tunnel syndrome. With their forearms supinated, patients were asked to fully abduct their little finger. Then, the examiner held the patients' index, middle, and ring fingers in extension and maximal radial deviation, and then asked the patients to touch their little finger to their radially deviated ring finger. In patients with ulnar nerve injuries, either above or below the elbow, little finger abduction and adduction were impossible. In the patients with cubital tunnel syndrome, 19 had partial paralysis of little finger adduction and one patient had complete paralysis. Abduction and adduction of the little finger is not possible when the ulnar nerve is transected. In cubital tunnel syndrome, this little finger adduction test was able to identify decreased range of motion, possibly indicating muscle weakness.

Transfer of the musculocutaneous nerve branch to the brachialis muscle to the triceps for elbow extension: anatomical study and report of five cases.

We report the study of the anatomical feasibility of transferring the nerve to the brachialis muscle to the upper medial head motor branch that innervate the triceps, and outcomes of such transfers in restoring elbow extension in five patients with posterior cord lesion of the brachial plexus. The length of the branches to the brachialis muscle measured 7.6 cm and the triceps upper medial head motor branch was 5 cm in 10 adult cadavers. Five male patients were treated with this transfer 5 months after the injury (range 4 to 6 months) after posterior cord injury of the brachial plexus with a mean follow-up of 31 months (range 28 to 36 months). Elbow extension scored M4 in all cases. No complications occurred. These preliminary results suggest that transferring the nerve to the brachialis muscle is an effective technique for the reconstruction of elbow extension after posterior cord brachial plexus injuries. LEVEL OF EVIDENCE: IV.

Brachialis muscle transfer to the forearm muscles in obstetric brachial plexus palsy.

Tendon transfers are frequently needed to improve hand function in obstetric brachial plexus injuries. The reconstruction cannot always be achieved using local donor transfers in the forearm as these are not always available. In such cases, we propose the use of the brachialis muscle as a useful donor for transfer. Five adolescents with obstetric brachial plexus palsy were operated on to reconstruct wrist extension and/or pronation using the brachialis muscle transfer to the pronator teres (n=1), extensor carpi radialis brevis (n=1) and extensor carpi radialis longus (n=3). Twelve months after surgery, average active motion recovery was 20 degrees for wrist extension and 14 degrees for pronation. Active and passive range of motion was similar.

Variation in nerve autograft length increases fibre misdirection and decreases pruning effectiveness: an experimental study in the rat median nerve.

OBJECTIVES: In the clinical set, autologus nerve grafts are the current option for reconstruction of nerve tissue losses. The length of the nerve graft has been suggested to affect outcomes. Experiments were performed in the rat in order to test this assumption and to detect a possible mechanism to explain differences in recovery. METHODS: The rat median nerve was repaired by ulnar nerve grafts of different lengths. Rats were evaluated for 12 months by behavioural assessment and histological studies, including ATPase myofibrillary histochemistry and retrograde neuronal labelling. RESULTS: It was demonstrated that graft length interferes in behavioural functional recovery that here correlates to muscle weight recovery. Short nerve grafts recovered faster and better. Reinnervation was not specific either at the trunk level or in the muscle itself. The normal mosaic pattern of Type I muscle fibres was never restored and their number remained largely augmented. An increment in the number of motor fibres was observed after the nerve grafting in a predominantly sensory branch in all groups. This increment was more pronounced in the long graft group. In the postoperative period, about a 20% reduction in the number of misdirected motor fibres occurred in the short nerve graft group only. CONCLUSION: Variation in the length of nerve grafts interferes in behavioural recovery and increases motor fibres misdirection. Early recovery onset was related to a better outcome, which occurs in the short graft group.

Tendon palpation during agonist contraction and antagonist co-contraction to assess wrist flexor and extensor muscle function.

The aim of this study was to validate direct tendon palpation during agonist contraction and antagonist co-contraction as a method to assess wrist flexor and extensor muscle function in cases of upper limb paralysis. On one occasion, five doctors examined 17 patients with partial paralysis of the upper limb resulting from brachial plexus or cervical spinal cord injury. We asked examiners to determine if the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor carpi ulnaris (ECU), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU) and palmaris longus (PL) were paralyzed, weak or strong in each patient. Examiners tested flexion - extension and radial - ulnar deviation against resistance and palpated wrist motor tendons. While palpating tendons, co-contractions were encouraged by soliciting finger extension to evaluate the FCU, thumb extension to evaluate the ECU, and finger flexion to evaluate the ECRB. Kappa values were 0.8 for the ECRL, 0.7 for the ECRB, 0.5 for the ECU, 0.8 for the FCR, 0.6 for the PL, and 0.8 for the FCU, indicating moderate to almost perfect agreement between examiners. Tendon palpation during muscle examination was adequate to identify complete paralysis, as well as weak and strong muscle contractions. This assessment helps to identify muscles that could be used during nerve or tendon transfer for reconstruction of extensive upper limb paralysis.

Muscle fiber type reorganization and behavioral functional recovery of rat median nerve repair with vascularized or conventional nerve grafts.

In 1921, Ney introduced the concept of nerve grafts with preservation of the vascular blood supply. Today, over 70 years later, the use of vascularized nerve grafts in clinical practice is still controversial. Although the results of experiments with vascularized and conventional nerve grafts have been compared on the basis of electrophysiological and histological observations, the literature includes no vaJid comparison of the clinical and behavioral significance of these results. Therefore, in the experiments reported here, the rat median nerve was repaired using either a vascularized or a conventional ulnar nerve graft. The rates behavior between 0 and 360 days after surgery was assessed by the grasping test. Nienty-five, 120, 150, 210 and 360 days after surgery rats were submitted to retrograde labeling studies and muscle samples were removed and studied using routine hematoxilin-eosin and ATPase histochemistry. The present study provides evidence that autografting is a reliable procedure for nerve repair. Motor axons were able to reinnervate and largely respecify muscle properties. Reinnervation was not selective either at the nerve trunk level or at the muscle fiber. A mechanism of collateral pruning might have been present in the early phases of reinnervation. This mechanism was, however, self limiting and unable to correct all wrong projections. A mechanism of terminal sprouting was in part responsible for time-related improvement in muscle force recovery. While the present study does provide evidence that recovery was 20% faster in rats with vascularized grafts than in those with conventional grafts (P < 0.0001), it does not, however, provide evidence for better functional recovery in long-term assessment.

Behavioral evaluating methods in the objective clinical assessment of motor function after experimental brachial plexus reconstruction in the rat.

Unfortunately, the results of brachial plexus surgery have not fulfilled expectations. Although the components of the rat brachial plexus are similar to those of the human plexus, experimental work in this field is limited. No functional test to assess experimental brachial plexus reconstruction has so far been published. We worked out a method of evaluating brachial plexus impairment in rats in the laboratory. It consists of a simple test in which a bowl of water is projected over the animal's head, eliciting grooming movements of the forepaws towards the head. This test is therefore called the 'grooming test'. A system of scoring the animals' performance is suggested. Rats were also submitted to walking tracks analysis, but this was of limited value in assessing brachial plexus impairment.

The grasping test: a simple behavioral method for objective quantitative assessment of peripheral nerve regeneration in the rat.

Behavioral recovery is the major goal of neuroscience research on the peripheral nervous system. However, behavioral methods of assessing peripheral nerve regeneration are still lacking. In the present work we used the median nerve and finger flexors as the experimental model. After resection or crush injury of the median nerve, rats were submitted daily to the grasping test. For this, they were gently lifted by the tail and allowed to grasp a grid connected to an ordinary electronic balance. While grasping the animal continued to be lifted by the tail with increasing firmness until it lost its grip. At this precise moment the value shown by the balance was recorded. In the crushed median nerve, recovery of function was clearly demonstrated by the grasping test. The test also indicated the exact day on which recovery began and its improvement with time. This very simple objective behavioral method provides a sensitive quantitative technique for assessing recovery. The experimental model using the median nerve seems to be better than the sciatic nerve model, as no articular contractures or autotomies were noted in the present experimental animals.

Median nerve neurotization by peripheral nerve grafts directly implanted into the spinal cord: anatomical, behavioural and electrophysiological evidences of sensorimotor recovery.

Over the years, peripheral nerve grafts, a favorable environment to support axonal elongation, have given rise to increasing interest as a possible solution for promoting spinal cord repair. In the experiments described here, following an avulsion injury of the rat brachial plexus, the median nerve was repaired by a peripheral nerve graft (PN) inserted directly into the dorsal side of the spinal cord. Eight months later the animals were submitted to behavioral tests, electrophysiological and histological studies. Regrowth of axons from both motoneurons and ganglionic neurons was demonstrated following a single superficial dorsal implantation of a PN. Sensorimotor peripheral reinnervation allowed most of the studied animals to recover enough flexor activity for grasping. Reinnervation was achieved even without prior root avulsion suggesting that the presence of a PN is sufficient to induce sprouting in the spinal cord from axotomized and non-axotomized neurons.

Selective restoration of sensation by peripheral nerve grafts directly implanted into the contralateral C7 dorsal root ganglion: an experimental study in rat brachial plexus.

OBJECTIVE: In brachial plexus injuries, when the dorsal root ganglion (DRG) is avulsed from the spinal cord there is no possibility of direct repair. Therefore, in the present report the median nerve was connected directly to the contralateral C7 DRG, to restore forepaw sensation. METHODS: The ulnar nerve was sectioned, and a 15-mm segment of nerve was removed. The median nerve was sectioned, transposed dorsally, and repaired using a sural nerve graft directly implanted into the C7 contralateral DRG. Rats were then assessed 6 and 12 months later by behavioral, histological, and plasma extravasion techniques. RESULTS: All animals recovered sensation in the forepaw. Retrogradely labeled sensory neurons were demonstrated in the C7 DRG, and the whole forepaw was labeled after plasma extravasion induction by median nerve antidromic stimulation. Several myelinated and positively neurofilament-stained fibers were demonstrated in the grafted median nerve. CONCLUSION: The surgical strategy proposed might be a useful alternative to selective sensory repair in the emerging field of brachial plexus reconstruction by direct spinal cord surgery.

Selective motor hyperreinnervation by using contralateral C-7 motor rootlets in the reconstruction of an avulsion injury of the brachial plexus. Case report.

Brachial plexus avulsion injuries are a clinical challenge. In recent experimental studies the authors have demonstrated the high degree of muscle reinnervation attained when a C-4 motor rootlet was directly connected to the musculocutaneous nerve. This degree of reinnervation was attributed to the good chance that a muscle fiber can be reinnervated by a motor fiber when the number of regenerating motor neurons is increased and when competitive sensory fibers are excluded from the process. The authors present the first clinical case in which this phenomenon has been observed. This 26-year-old man, who was involved in an automobile accident, presented with an upper brachial plexus avulsion, for which he underwent operation 4 months later. The axillary and suprascapular nerves were directly surgically connected to the motor rootlets of the C-7 contralateral root by using two cables of sural nerve graft. Two years postsurgery, the patient was able to perform shoulder abduction of 120 degrees and hold an 800-g weight at 90 degrees. These results are encouraging, and in selected patients motor rootlet transfer might prove to be a useful surgical strategy.

Brachial plexus repair by peripheral nerve grafts directly into the spinal cord in rats. Behavioral and anatomical evidence of functional recovery.

Over the years, peripheral nerve grafts, a favorable environment for the support of axonal elongation, have attracted interest as a possible means of promoting spinal cord repair. In the experiments described here, rats underwent an avulsion injury of the brachial plexus, and the musculocutaneous nerve was repaired by direct insertion of peripheral nerve grafts into the spinal cord. After varying postoperative periods, the rats were submitted to a series of behavioral tests to evaluate forelimb and hindlimb function. They also underwent retrograde double-labeling studies. Nerve grafts were harvested and processed for electronic microscopy. The biceps muscle was removed and weighed and its histology studied. After surgery, central axons effectively regenerated about 65 mm along the peripheral nerve grafts, restoring normal active elbow flexion. Forelimb movements were well coordinated in both voluntary and automatic activities. Clinical investigations showed that there were no side effects in the ipsilateral forepaw, contralateral forelimb, or either hindlimb. Regenerating axons stemmed from original motoneurons, foreign motoneurons, and even antagonist motoneurons, but this did not impair function. Ganglionic neurons from adjacent roots also sent processes to the peripheral nerve grafts.

Brachial plexus dorsal rhizotomy in the treatment of upper-limb spasticity.

OBJECT: This study was conducted to evaluate the effects of dorsal rhizotomy on upper-limb spasticity, functional improvement, coordination, and hand sensibility. METHODS: Fifteen spastic upper limbs in 13 patients were selected and prospectively studied. Brachial plexus dorsal rhizotomy was performed in which two, three, or four dorsal roots were completely sectioned. Patients were followed up for at least 12 months after surgery; the mean follow-up period was 15.6 months and the maximum period was 30 months. A remarkable relief of spasticity was observed in all cases. Recurrence was observed in only one patient and was caused by insufficient dorsal root section. Functional improvement was observed in all cases, and functional improvement in the hand was found to be related to the presence of active finger extension in the preoperative period. Even when extended dorsal root section was performed, no hand anesthesia, either total or partial, was observed. No patient lost movement ability in the postoperative period, and no ataxic limbs were observed. CONCLUSIONS: Brachial plexus dorsal rhizotomy is very effective as a treatment for upper-limb spasticity and results in functional improvement without loss of sensation in the hand.

Selective motor hyperreinnervation using motor rootlet transfer: an experimental study in rat brachial plexus.

Misdirection of sensory fibers into motor pathways is, in part, responsible for the poor results obtained after peripheral nerve repair. After avulsion of the C-5 root in rats, the authors connected a C-4 ventral rootlet to the musculocutaneous nerve by means of a sural nerve graft. In this way, they were able to increase the number of regenerating motor fibers and avoid growth of sensory fibers into the nerve grafts. Functional recovery was evaluated electrophysiologically and histologically. The origin of the axons that reinnervated the nerve graft was analyzed by means of morphological studies including retrograde labeling procedures. Motor neurons survived and regenerated after the rootlet transfer and there was no functional impairment. Many neurons were retrograde labeled in the ventral horn and widespread biceps muscle reinnervation was demonstrated with recovery of nearly normal electrophysiological properties. Motor hyperreinnervation of the musculocutaneous nerve was observed. This high degree of reinnervation in a long (40-mm) graft was attributed to the good chance that a muscle fiber can be reinnervated by a motor fiber when the number of regenerating motor neurons is increased and when competitive sensory fibers are excluded from reinnervation.

Retrograde-flow neurocutaneous island flaps in the forearm: anatomic basis and clinical results.

The neurocutaneous island flap is an axial flap whose arterial vascularization is provided by the vascular plexus around and inside the cutaneous nerve. In previous studies we successfully harvested neurocutaneous island flaps in the hand and in the forearm. Here we report on reverse-flow neurocutaneous island flaps for reconstructions in the distal third of the forearm. The vascularization of the cutaneous nerve of the forearm was studied in 15 fresh human upper limbs injected with polyester resin. The vascularization of the cutaneous nerve was found to be very closely connected with the vascularization of the skin. A vascular arcade followed the cutaneous nerve of the forearm. These paraneural vessels linked the neurocutaneous perforators and together with the cutaneous nerve overlay a major vascular axis. A close relationship between the cutaneous nerve and the neurocutaneous perforators was clearly identified. The cutaneous nerve crossed in every instance the point at which the neurocutaneous perforators reached the skin. Anastomosis between the paraneural vessels and the intraneural circulation was consistently found. On the basis of these anatomic findings, reverse-flow neurocutaneous island flaps were raised on the forearm of three patients and are reported on.

The plantar marginal septum cutaneous island flap: a new flap in forefoot reconstruction.

Soft-tissue reconstruction of the foot very often requires flap coverage to preserve exposed structures such as bone, joint, tendons, and weight-bearing areas. However, forefoot coverage remains a challenge, since the alternatives for flap coverage are very limited. The vascularization of the medial side of the foot was studied in 25 injected limbs. Based on this anatomic knowledge, the plantar marginal septum cutaneous island flap is described. The plantar marginal septum cutaneous island flap is a reversed-flow flap based on the superficial branch of the medial division of the medial plantar artery and its distal anastomosis with the lateral plantar artery, first dorsal metatarsal artery, and lateral branch of the medial plantar artery. The venous drainage is ensured by the accompanying veins. The flap arc of rotation includes the forefoot plantar and dorsal region and the first and second toes. Eight cases have been operated on and are reported.

The neurocutaneous flap based on the dorsal branches of the ulnar artery and nerve: a new flap for extensive reconstruction of the hand.

Soft-tissue repair in the hand often requires skin flaps due to exposure of bone, tendons, nerves, and arteries. However, alternatives for flap surgery are very limited, especially in dealing with palmar hand reconstruction. In the present report, the dorsal branch of the ulnar nerve and its accompanying artery were studied anatomically, and a neurocutaneous flap distally based on these structures was developed. The flap was raised on the medial aspect of the hand and distal half of the forearm, and its rotation point was located dorsally near the metacarpalphalangeal joints. The clinical use of this flap for the repair of skin defects in the hand is reported. All the clinical flaps survived completely, including a 3.5 x 13-cm large flap. Donor site morbidity was minimal. This flap represents a new alternative in hand reconstruction.

Vascular freezing--a new method for immediate and permanent vasospasm relief: an experimental study in the rat.

Although much work has been done on the etiology and prevention of vasospasm, a spasmolytic agent capable of firmly protecting against or reversing vasospasm has not yet been found. In this paper, we describe a new physical method of treating vasospasm. It consists of directly freezing the arterial walls. Experiments were performed on the epigastric artery of 40 female Sprague-Dawley rats. A vasospasm was created by mechanical vessel manipulation. The vasospasm was treated by freezing the vessel walls with a dermatologic hand-held liquid nitrogen spray. Vascular spasm and patency controls were made immediately after thawing and 30 minutes and 3, 10, and 120 days after freezing. Epigastric island flaps were harvested based on the frozen artery at 3, 10, and 120 days after the freezing procedure. Histologic studies also were effectuated 3, 10, and 120 days after the freezing procedure. Relief from vasospasm was instantaneous and permanent. After freezing, almost all the cells in the media and endothelium died and the adrenergic fibers degenerated. This was followed by a phagocytic debridement, complete regeneration of the endothelium, and a limited regeneration of the muscle fibers in the media. The adrenergic innervation was recovered, and no alterations in the adrenergic fibers distal to the lesion were noted at any time. None of the arteries examined underwent thrombosis, and all the flaps harvested survived very well, indicating that the vascular bed distal to the site of the freezing was normal. This vascular freezing technique may well have clinical applications for microsurgical transfers and for the prophylactic treatment of vasospasm disease. However, its indications still require clarification.

Sensitive areolar reconstruction in using a neurocutaneous island flap based on the medial antebrachial cutaneous nerve.

Sensory reconstruction has recently been stressed in breast reconstruction. However, there are no reports concerning the reconstruction of a sensitive areola. The bilateral reconstruction of a sensitive areola using a neurocutaneous flap based on the medial antebrachial cutaneous nerve is reported. The flap was harvested from the distal third of the forearm as an island flap and tunneled to reach the apex of the new breast, which was previously reconstructed using a 135-cc, gel-filled, silicone prosthesis covered by a latissimus dorsi myocutaneous flap. Six months later, fine sensibility in the reconstructed areola was demonstrated. The patient could perceive light touch, pain, and 14 mm two-point discrimination. At 2 months after surgery, 50 percent of cutaneous faulty stimulus location was observed. However, at 4 and 6 months after surgery, faulty location disappeared. Six months after harvesting the medial antebrachial cutaneous nerve, the sensory deficit was minimal; it included a hypoesthesic zone of 4 to 7 cm and an anesthesic zone of 2.5 to 5 cm on the middle third of the forearm. Fifteen months after the procedure, no hypoesthesic zone was observed; only a 2 to 3 cm anesthesic zone on the proximal medial side of the forearm existed. This sensory deficit passed unnoticed by the patient. The technique developed here is a refinement in breast reconstruction, and we think it should be used in selected patients.

The towel test: a useful technique for the clinical and electromyographic evaluation of obstetric brachial plexus palsy.

The towel test consists of covering an infant's face with a towel and seeing if he/she can remove it with either arm. In this study it has been used to aid the clinical and electromyographic assessment of 21 infants with obstetric brachial plexus palsy. At 2 to 3 months, none of the 21 infants succeeded in removing the towel, either with their normal or affected arm. At 6 months, all the infants succeeded in removing the towel with their normal arm, but 11 could not with their affected arm, and the same was observed at a further assessment at 9 months. The towel test is a reliable technique for evaluating children with obstetric brachial plexus injuries.