Nerve Crossover Research Articles

Facial palsy reconstruction.

The facial nerve stimulates the muscles of facial expression and the parasympathetic nerves of the face. Consequently, facial nerve paralysis can lead to facial asymmetry, deformation, and functional impairment. Facial nerve palsy is most commonly idiopathic, as with Bell palsy, but it can also result from a tumor or trauma. In this article, we discuss traumatic facial nerve injury. To identify the cause of the injury, it is important to first determine its location. The location and extent of the damage inform the treatment method, with options including primary repair, nerve graft, cross-face nerve graft, nerve crossover, and muscle transfer. Intracranial proximal facial nerve injuries present a challenge to surgical approaches due to the complexity of the temporal bone. Surgical intervention in these cases requires a collaborative approach between neurosurgery and otolaryngology, and nerve repair or grafting is difficult. This article describes the treatment of peripheral facial nerve injury. Primary repair generally offers the best prognosis. If primary repair is not feasible within 6 months of injury, nerve grafting should be attempted, and if more than 12 months have elapsed, functional muscle transfer should be performed. If the affected nerve cannot be utilized at that time, the contralateral facial nerve, ipsilateral masseter nerve, or hypoglossal nerve can serve as the donor nerve. Other accompanying symptoms, such as lagophthalmos or midface ptosis, must also be considered for the successful treatment of facial nerve injury.

ID 21 – Riche–Cannieu anastomosis: A case report

Riche–Cannieu anastomosis (RCA) is a rare type of anomalous innervation. It is characterized as innervation of medial and lateral part of palm involving the deep branch of the ulnar nerve crossover to the recurrent branch of the median nerve in the hand. A 44 years old woman who has numbness and pain her hands evaluated by nerve conduction studies and needle electromyography. In neurological examination, there was no wasting or weakness of the hand muscles, nor sensory impairment. Nerve conduction studies showed dual innervation (mainly ulnar nerve) of abductor pollicis brevis muscle bilaterally. Median nerve motor conduction studies recorded from APB muscles obtained by stimulating the nerve at the wrist and elbow showed responses with very low amplitude bilaterally. Needle electromyography of bilateral abductor pollicis brevis and abductor digiti minimi muscles are found as normal. Ulnar to median anastomosis in the palm should be kept in mind in patient with unexpected electrophysiological results. If the hand muscles are clinically intact but electrophysiological examination shows a severe median nerve lesion, RCA should be suspected.

Tomasz Drobnik (1858–1901)—An Assistant Who Equalled His Masters

Tomasz Drobnik (1858–1901) was a Polish-born practicing surgeon who developed new surgical techniques despite working under adverse political conditions. Having completed his medical studies in Wurzburg, he worked in a few German hospitals, among others in Strasbourg, where he developed new principles of thyroid surgery, particularly a new method of accessing the gland. Beginning in 1887 Drobnik worked in Koningsberg, in Professor Mikulicz-Radecki’s hospital, where he developed a new method of surgical repair of cleft palate, as well as a technique of facial nerve crossover anastomosis, probably the first in the world. He continued his research and practice in Poznan, where he moved in 1890. This is where he laid the foundations of a new branch of medicine, today known as neuro-orthopedics. He was the first to perform a successful tendon transfer, subperiosteal implantation of a tendon, and vascularized muscle transfer. His perception of musculoskeletal system disorders as being dynamic led him to develop a cutting-edge method of club foot treatment. Drobnik achieved all this on his own while working as an assistant in a Poznan Town Hospital devoid of the research facilities of academic medical centers. Alongside his research, he was also engaged in community service. He was equally devoted to his Polish and German patients, even at the time of escalation of national animosities.

P3-3 Confirming median-to-ulnar nerve crossover at the forearm (Martin-Gruber) by simultaneous stimulation of both median and ulnar nerves at the upper arm

P3-3 Confirming median-to-ulnar nerve crossover at the forearm (Martin-Gruber) by simultaneous stimulation of both median and ulnar nerves at the upper arm

Reanimation of reversible facial paralysis by the double innervation technique using an intraneural-dissected sural nerve graft

In treating reversible facial paralysis, cross-facial nerve grafting offers voluntary and emotional reanimation. In contrast, rapid re-innervation and strong neural stimulation can be obtained with hypoglossal-facial nerve crossover. In this article, we describe the method of a combination of these techniques as a one-stage procedure. A 39-year-old man presented with facial paralysis due to nerve avulsion within the stylomastoid foramen. The sural nerve was harvested and two branches were created at its distal end by intraneural dissection. One branch was anastomosed to the contralateral facial nerve, and the other branch was used for hypoglossal-facial nerve crossover, followed by connecting the proximal stump of the graft to the trunk of the paralysed facial nerve in an end-to-end fashion. At 9 months postoperatively, almost complete facial symmetry and co-ordinated movements of the mimetic muscles were obtained with no obvious tongue atrophy. Since our method can efficiently gather neural inputs from the contralateral facial nerve and the ipsilateral hypoglossal nerve, it may become a good alternative for reanimation of reversible facial paralysis when the ipsilateral facial nerve is not available.

The Polish Surgeon Tomasz Drobnik (1858 to 1901): Pioneer in Facial Nerve Crossover Anastomosis and Tendon Transfer

The Polish Surgeon Tomasz Drobnik (1858 to 1901): Pioneer in Facial Nerve Crossover Anastomosis and Tendon Transfer

Ultrastructural Observations on the Progress of Nerve Degeneration and Regeneration at the Suture Site following Vagal-Hypoglossal Nerve Coaptation in Cats

Nerve degeneration and regeneration have been investigated at the suture site following proximal-to-distal vagal-hypoglossal nerve coaptation (VHC) in cats at different time points (from 3 to 315 days postoperatively; dpo). Massive axonal degeneration and myelin breakdown and removal of degraded neural debris were observed during the first 2 weeks postoperatively. This was followed by active Schwann cell multiplication and inflammatory cell invasion at 14 dpo. Schwann cells appeared mobile, and were guided to the newly developed growth cones, dividing them into axonal sprout clusters. At 18 dpo, the migrating Schwann cells were confined to the preexisting basal lamina scaffolds, forming bands of Büngner. It is suggested that the latter may play a key role in navigating the regenerating axons to their newly acquired target organ at 22 dpo. Remyelination of axons was not observed till 46 dpo. Compared with the rapid axonal reaction in other models of nerve injury, the degeneration process in VHC was protracted and, furthermore, regeneration and remyelination were delayed. The subtle remodeling of the nerve in cross-coaptation may be far greater than previously recognized, and this may have clinical importance since patients undergoing nerve crossover microsurgery exhibit delayed motor rehabilitation, apparently as a direct result of a change in target innervation. Defining the mechanisms underlying the neuroplastic program could thus potentially improve the prognosis of crossover of two different peripheral nerves.

Sir Charles Alfred Ballance (1856–1936) and the introduction of facial nerve crossover anastomosis in 1895

Sir Charles Ballance (1856-1936) was the first surgeon in history to perform a facial nerve crossover anastomosis in 1895. Although, recently, several papers on the history of facial nerve surgery have been published, little is known about this historically important operation, the theoretical reasoning behind the operation or the surgical perspective in which Ballance developed this method. An original document on the operation, dated in 1895, is not known. The earliest report of the operation is a paper by Ballance, published in 1903. Study of this 1903 paper reveals that Ballance stopped performing the operation after his first attempt in 1895 until he resumed in December 1901. What was the reason for this interruption? Why did Ballance start doing it again in 1901? Between 1895 and Ballance's 1903 paper, several other surgeons had published the results of their facial nerve crossovers. Were they inspired by Ballance's operation from 1895 to do the same or did they invent the method independently? To enhance our knowledge about the early history of facial nerve surgery, the original manuscripts by Ballance and his contemporaries have been studied. Ballance's first facial nerve crossover from 1895 is described in the surgical perspective of the end of the 19th century. The theoretical reasoning for the operation is discussed. It was discovered that Ballance's operation was first recorded in St. Thomas's Hospital Report of 1895, which was published in 1897. However, this report was probably hardly known by Ballance's contemporaries and consequently could not have stimulated them to perform the operation themselves. Jean Louis Faure (1863-1944), from France, appears to have been the first to have performed the operation until Ballance's 1903 paper was published. In 1903, after Ballance's paper had been published, many other accounts of this method were reported in the literature. At that moment facial nerve crossover seems to have been widely regarded as a potential successful technique, a technique which, a century later, is still part of our repertoire.

Reflections on the development of facial nerve crossover anastomosis

Reflections on the development of facial nerve crossover anastomosis

Reconstruction of reflex pathways to the atonic bladder after conus medullaris injury: Preliminary clinical results

Neurogenic bladder dysfunction following spinal cord injury is a major medical and social problem for which there is no ideal treatment strategy. In this study, spinal root anastomoses were performed in 10 paraplegic patients with traumatic lesions of the conus medullaris, in an attempt to reinnervate the paralyzed bladder. For the operation, the functional T11 ventral root (VR) above the lesion was transected and anastomosed to the S2 ventral roots unilaterally through a nerve graft. The T11 dorsal root was left intact as the trigger for micturition after axonal regeneration. All patients underwent urodynamic evaluation before surgery and at follow-up. The mean follow-up duration was 2 years. Of the 10 patients, 7 (70%) regained satisfactory bladder control within 18-24 months after VR microanastomosis. In these seven patients, the average bladder capacity decreased from 508 +/- 83 (mean +/- SD) to 370 +/- 59 ml, residual urine decreased from 477 +/- 98 to 35 +/- 11 ml, and urinary infections were not observed. Patients with impaired renal function experienced a full recovery. Three patients failed to show any improvement after the operation. These results suggest that a restitutive process occurs in the bladder following reinnervation from new T11 VR connections to the bladder nerves. Spinal cord lesions that may benefit from such a nerve crossover surgery are those located at the conus, whereby a functional suprasacral nerve can be connected to the sacral roots to bypass the injury in an attempt to restore central connections to the bladder.

Surgical results of the Hypoglossal-Facial nerve Jump Graft technique

The Hypoglossal-Facial nerve crossover has appeared as a surgical option for those scenarios where the facial nerve is injured in its intracranial course, but the conventional technique unequivocally leads to twelfth cranial nerve deficit. In recent years a number of different surgical approaches have been introduced with a view to avoiding the complete section of the hypoglossal nerve, such as the Jump Graft technique. This paper aims to present the results of the Hypoglossal-Facial nerve Jump Graft technique in relation to facial musculature reanimation capability and hemitongue function preservation. A retrospective analysis of the records of eight patients submitted to Hypoglossal-Facial nerve Jump Graft technique was performed. The surgical approach was characterised by the interposition of a short graft sutured to the distal stump of the transected facial nerve and sutured end-to-side to the hypoglossi, with cutting of only a third of the diameter of the latter. The facial nerve injuries were secondary to temporal bone trauma in five cases and to cerebellopontine angle tumour surgery in three. Grafts were harvested from the greater auricular nerve in six patients and from the sural nerve in two. The results of facial reanimation demonstrated facial symmetry and improvement in the facial tone in all cases, and classified as House-Brackmann grade IV in three (37.5%) and grade III in five (62.5%) patients. There was no incidence of definitive hemitongue atrophy and no patient complaint of swallowing or speech difficulty. The modification of the conventional technique of Hypoglossal-Facial nerve anastomosis by means of sectioning one third of the hypoglossal nerve area does not lead to dysfunction of this nerve and the surgical results in terms of facial reanimation are satisfactory.

Laterality in avian vigilance: do sparrows have a favourite eye?

Visual scanning for predators is one of a bird's most basic means of avoiding predation while feeding, and the detection of an approaching predator may present a difficult visual task. If birds have a dominant hemisphere for processing visual information, then given the nearly complete optic nerve crossover in the avian brain, the eye contralateral to that dominant hemisphere should be favoured in antipredatory vigilance. In short, vigilant birds should have a favourite eye. We conducted an experiment that examined laterality in eye use during the antipredatory scanning of wintering emberizid sparrows: dark-eyed juncos, Junco hyemalis, and American tree sparrows, Spizella arborea. Free-living birds were allowed to feed parallel to a visual obstruction, thereby forcing them to choose which eye to orient away from the visual obstruction and towards possible approaching predators. Juncos oriented themselves such that their right eye was oriented outward more than would be expected by chance. Tree sparrows had a marginally nonsignificant tendency to favour the left eye. The mechanics of the scanning process itself in these birds favoured one eye over the other. Both species turned their heads towards the visual obstruction when their preferred eye was facing away from the obstruction more often than would be expected by chance (right eye in juncos, left eye in tree sparrows); such behaviour allowed for a preferred-eye view of the area directly opposite protective cover. These results suggest that laterality exists in avian vigilance, and that laterality may differ even in closely related species.

Preservation of denervated muscle by sensory protection in rats.

The goal of this study was to determine whether sensory motor nerve crossover could alter post-denervation atrophy of skeletal muscle. Sixty adult Lewis rats were divided into three groups: 1) unilateral transection of the tibial nerve alone; 2) unilateral transection of the tibial nerve with immediate repair; and 3) unilateral tibial and sural nerve transections with repair of the proximal sural nerve (sensory) to the distal tibial nerve (motor). The unoperated hind legs acted as positive controls. At 1 and 2 months postoperatively, posterior compartment musculature was harvested, weighed, then fixed and stained for histologic analysis. One month postoperatively, mean muscle weight in Group 1 animals (transection alone) was 23.0 +/- 2.6 percent of the control side; for Group 2 animals (motor-motor repair) was 40.9 +/- 42 percent; and for the sensory-protected Group 3 animals (sensory-motor repair) was 26.7 +/- 2.8 percent of controls (n = 15 per group). Two months postoperatively, the mean weights were 14.5 +/- 0.9 percent, 58.8 +/- 7.3 percent, and 21.1 +/- 3.1 percent of controls for Groups 1, 2, and 3, respectively (n = 5 per group). Differences between groups were statistically significant. Histologic analysis of Group 1 specimens revealed generalized atrophy of all muscle fibers. In Group 2, specimens showed evidence of reinnervation and less atrophy. Group 3 specimens demonstrated an atrophic pattern with islands of non-atrophic fibers scattered throughout. Sensory protection was thus shown to have significant effect on post-denervation atrophy in rat skeletal muscle.

Hypoglossal‐facial nerve interpositional‐jump graft for facial reanimation without tongue atrophy

The hemitongue paralysis that occurs as a result of a classic hypoglossal-facial nerve crossover procedure can result in profound functional deficits in speech, mastication, and swallowing. The procedure is not an option in patients with bilateral facial paralysis or those at risk for combined cranial nerve deficits. To address some of the drawbacks and limitations of this classic procedure, we developed the hypoglossal-facial nerve interpositional jump graft (12-7 jump graft) procedure. This procedure involves interposing a nerve graft between a partially severed but functionally intact twelfth cranial nerve and the degenerated seventh cranial nerve, and is often combined with other reanimation procedures. To date, we have performed 33 12-7 jump graft procedures in 30 patients (three were treated for bilateral facial paralysis); this report describes the procedure and its indications, and details the results of 23 procedures performed in 20 patients for whom 24-month follow-up data are available. Twelfth nerve deficits occurred in only three patients in this report. Recovery of facial function began between 3 and 24 months postoperatively. Facial tone and symmetry were achieved in every patient, no patient had significant mass movement, and 13 patients (two of whom were treated for bilateral facial paralysis) had excellent and three had superb restoration of facial movement. These results show the 12-7 jump graft to be a valuable adjunct for facial reanimation in selected patients.

Root reconstruction for bladder reinnervation: An experimental study in rats

Nerve transfer (or nerve crossover) is a well established technique for achieving reinnervation of a valuable sensory or motor territory by reconnection using a functional nerve of lesser value. Patients with lower spinal cord lesions causing neurogenic bladder dysfunction could theoretically benefit from such an approach for return of useful micturition. Based on the known anatomical details of the spinal nerve, a new reconstructive method was created to provide intradural ventral root transfer for pure motor-to-motor reinnervation and extradural postganglionic spinal nerve transfer for pure sensory-to-sensory reinnervation. Experimental studies in rats were performed, demonstrating the feasibility of this approach. A modified method is further suggested that would use nerve grafts for extradural approaches to pure motor and sensory transfers, without the need for extensive laminectomy and dura opening. This proposed approach is anticipated to minimize the associated morbidity and mortality with such spinal nerve reconstruction.

Early facial reanimation following radical parotid and temporal bone tumor resections

A retrospective study of 35 patients who underwent early facial reanimation following extirpative parotid and temporal bone surgery requiring facial nerve sacrifice was performed. Regional facial reanimation performed immediately or within several days included 16 patients who underwent temporalis muscle transposition and 27 who underwent gold weight or eyespring lid reanimation with lower lid tightening. Simultaneous nerve grafts or nerve crossover procedures were performed in 22 patients. The authors' favored approaches to facial reanimation are discussed, with an emphasis on the value of early reanimation using properly selected techniques.

Nerve Crossover Techniques for Urinary Bladder Reinnvervation: Animal and Human Cadaver Studies

Interruption of spinal pathways integrating central and peripheral bladder control mechanisms will result in neurogenic bladder dysfunction. If central pathways could be restored to the decentralized bladder through a microneural reconstructive technique a return of useful function might be achieved. This anatomical study describes the nerve crossover techniques used in human cadaver dissections for connecting intercostal nerves to sacral roots intraspinally. The techniques were modified from and compared to similar procedures used in an animal model where adjacent extradural roots were connected through a nerve graft. We have shown previously that the unilaterally decentralized bladder of the cat can be recentralized after a nerve crossover procedure. If additional laboratory studies can document return of useful bladder function we anticipate that selected patients may benefit from similar nerve crossover techniques to bypass a spinal cord lesion to recentralize the bladder.

Cheiloplasty in the treatment of facial paralysis.

There have been dramatic improvements in the treatment of facial paralysis. These include the successful use of free autogenous nerve grafting, nerve crossover techniques, regional masticatory muscle transposition, and free muscle grafts. The techniques are applied to total, partial, and regional paresis. The bulk of information on rehabilitation of the face has come from clinical empiricism, but basic research in nerve and muscle physiology and attempts at multiple classifications regarding indications and criteria have added to the splendor of this drama. One facet that has not been emphasized is the use of cheiloplasty in long-standing facial paralysis. Long-standing facial paralysis has both a neural and muscular deficit that cannot be rectified by a single concept or operation. It is essential to regionalize the rehabilitation, implant a kinetic muscular potential, supply some static support and elevation, and address the nonfunctional muscles about the paralyzed lips. This latter concept includes lip shortening and lip-flap transposition. A coordinated combination of these techniques has the best opportunity of maximizing the improvement in long-standing facial paralysis associated with severe muscle atrophy.

Hypoglossal-Facial Nerve Anastomosis for Reinnervation of the Paralyzed Face

The hypoglossal-facial nerve crossover is a valuable surgical procedure for the treatment of certain types of facial paralysis. It is most effective when used as an integral part of a primary ablative operation for the treatment of cancer in this region. In the treatment of long-standing facial paralysis, its application requires an intact peripheral facial nerve system and some functioning mimetic muscles with an obliterated proximal facial nerve segment. It is recognized that other procedures are available for repair in patients who meet essentially these same criteria. The disadvantages are minimal intraoral crippling, mass movements of the face and, in some instances, hypertonia of the face. The advantages are improved facial tone, protection of the eye, intentional facial movements controlled by the tongue, and movements associated with physiological functions of the tongue.

Reconstruction following temporal bone resection.

The aggressive initial treatment of external auditory canal and middle ear malignancies using ablative surgery in the form of temporal bone resection combined with postoperative curative doses (6,000 rads) of irradiation has resulted in meaningful palliation and a seeming increase in cure rates for these lesions. This combined therapy regimen has placed new demands on the wound of the temporal bone resection and subsequently necessitated development of a more substantial reconstructive effort. Hypoglossal nerve crossover has proved to be an efficient means of facial reanimation following temporal bone resection, with minimal morbidity associated with the loss of motor function to one half of the tongue. The composite posterior cervical flap, including a portion of trapezius musculature, has satisfied both the functional and cosmetic needs of this combined therapy program.