Aetiologies of iatrogenic occipital nerve injury and outcomes following treatment with nerve decompression surgery

INTRODUCTION

This study analyzed the etiologies and treatment of iatrogenic occipital nerve injuries.

METHODS

Patients with occipital neuralgia (ON) who were screened for occipital nerve decompression surgery were prospectively enrolled. Patients with iatrogenic occipital nerve injuries who underwent nerve decompression surgery were identified. Data included surgical history, pain characteristics, and surgical technique. Outcomes included pain frequency (days/month), duration (h/day), intensity (0-10), migraine headache index (MHI), and patient-reported percent-resolution of pain.

RESULTS

Among the 416 patients with ON, who were screened for occipital nerve decompression surgery, 12 (2.9%) cases of iatrogenic occipital nerve injury were identified and underwent surgical treatment. Preoperative headache frequency was 30 (±0.0) days/month, duration was 19.4 (±6.9) h, and intensity was 9.2 (±0.9). Neuroma excision was performed in 5 cases followed by targeted muscle reinnervation in 3, nerve cap in 1, and muscle burial in 1. In patients without neuromas, greater occipital nerve decompression and/or lesser occipital nerve neurectomy were performed. At the median follow-up of 12 months (IQR 12-12 months), mean pain frequency was 4.0 (±6.6) pain days/month (p < 0.0001), duration was 6.3 (±8.9) h (p < 0.01), and intensity was 4.4 (±2.8) (p < 0.001). Median patient-reported resolution of pain was 85% (56.3%-97.5%) and success rate was (≥50% MHI improvement) 91.7%.

CONCLUSIONS

Iatrogenic occipital nerve injuries can be caused by various surgical interventions, including craniotomies, cervical spine interventions, and scalp tumor resections. The associated pain can be severe and chronic. Iatrogenic ON should be considered in the differential diagnosis of post-operative headaches and can be treated with nerve decompression surgery or neuroma excision with reconstruction of the free nerve end.

Berberine enhances survival and axonal regeneration of motoneurons following spinal root avulsion and re-implantation in rats

Brachial plexus avulsion (BPA) occurs when the spinal nerve roots are pulled away from the surface of the spinal cord and disconnects neuronal cell body from its distal downstream axon, which induces massive motoneuron death, motor axon degeneration and de-innervation of targeted muscles, thereby resulting in permanent paralysis of motor functions in the upper limb. Avulsion injury triggers oxidative stress and intense local neuroinflammation at the lesioned site, leading to the death of most motoneurons. Berberine (BBR), a natural isoquinoline alkaloid derived from medicinal herbs of Berberis and Coptis species, has been reported to possess neuro-protective, anti-inflammatory and anti-oxidative effects in various animal models of central nervous system (CNS)-related disorders. In this study, we aimed to investigate the effect of BBR on motoneuron survival and axonal regeneration following spinal root avulsion plus re-implantation in rats. Our results indicated BBR significantly accelerated motor function recovery in the forelimb as revealed by the increased Terzis grooming test score, facilitated motor axon regeneration as evidenced by the elevated number of Fluoro-Gold-labeled and P75-positive regenerative motoneurons. The survival of motoneurons was notably promoted by BBR administration presented with boosted ChAT-immunopositive and neutral red-stained neurons. BBR treatment efficiently alleviated muscle atrophy, attenuated functional motor endplates loss in biceps and prevented the reduction of motor axons in the musculocutaneous nerve. Additionally, BBR treatment markedly mitigated the avulsion-induced neuroinflammation via inhibiting microglial and astroglial reactivity, up-regulated the expression of antioxidative indicator Cu/Zn SOD, and down-regulated the levels of nNOS, 3-NT, lipid peroxidation and NF-κB, as well as promoted SIRT1, PI3K and Akt activation. Collectively, BBR might be a promising therapy to assist re-implantation surgery for the treatment of BPA.

Thoracodorsal nerve graft for reconstruction of facial nerve branching

OBJECT

Surgical treatment of parotid malignancies may frequently involve facial nerve amputation to achieve oncological radical resection. The entire facial nerve branching from its exit from the stylomastoid foramen to the periphery of the gland is often sacrificed. The first reconstructive strategy is the immediate reconstruction of the facial nerve by directly anastomosing the trunk of the facial nerve to its distal branches by interpositional nerve grafting. The present study was performed to determine the adequacy of thoracodorsal nerve grafting for immediate repair of the facial nerve. The anatomical features of the thoracodorsal nerve make it particularly appropriate to match its trunk to the stump of the facial nerve at its exit from the stylomastoid foramen. Up to seven branches of the thoracodorsal nerve may be distally anastomosed to the severed distal branches of the facial nerve. More complex reconstruction may be addressed simultaneously by contemporary harvesting a de-epithelialized free flap from the same site based on thoracodorsal vessel perforators and preparing a rib graft from the same donor site.

METHODS

Between October 2003 and August 2010, seven patients affected by parotid tumors (6 with parotid malignancies and 1 with multiple recurrences of pleomorphic adenoma) underwent radical parotidectomy with intentional sacrifice of the facial nerve to obtain oncological radical resection. In all patients, the facial nerve was reconstructed with an interpositional thoracodorsal nerve graft. In four patients, a de-epithelialized free flap based on the latissimus dorsi was transposed to cover soft tissue defects. Moreover, two of these patients also required a rib graft to reconstruct both the condyle and ramus of the mandible. With the exception of one patient affected by recurrent pleomorphic adenoma, all patients underwent radiotherapy after surgical treatment.

RESULTS

All patients in our study recovered mimetic facial function. Facial muscles showed clinical signs of recovery within 5-14 (mean: 7.8) months, with varying degrees of mimetic restoration, and almost complete facial symmetry at rest in all patients. The House-Brackmann final score was I in two patients, II in two patients, and III in three patients.

CONCLUSIONS

A thoracodorsal nerve graft to replace extratemporal facial nerve branching is a valid alternative technique to multiple classical nerve grafts, with good matching at both the proximal and distal anastomoses.

Motor recovery and the breathing arm after brachial plexus surgical repairs, including re-implantation of avulsed spinal roots into the spinal cord

Forty-four patients with severe traction brachial plexus avulsion injuries were studied following surgical repairs. In eight patients, re-implanting avulsed spinal roots directly to the spinal cord was performed with other repairs and motor recovery in the proximal limb was similar to that achieved by conventional nerve grafts and transfers when assessed using the MRC clinical grades, Narakas scores, EMG and Transcranial Magnetic Stimulation (TMS). Thirty-four of the 37 patients had co-contractions of agonist and antagonist muscle groups. Spontaneous contractions of limb muscles in synchrony with respiration, the "breathing arm", were noted in 26 of 37 patients: in three patients, the source of the breathing arm was from spinal cord re-connection, providing evidence of regeneration from the CNS to the periphery. Our study shows that re-connection of avulsed spinal roots can produce good motor recovery and provides a clinical model for developing new treatments which may enhance nerve regeneration.

Direct repair (nerve grafting), neurotization, and end-to-side neurorrhaphy in the treatment of brachial plexus injury

Object

The authors present the long-term results of nerve grafting and neurotization procedures in their group of patients with brachial plexus injuries and compare the results of “classic” methods of nerve repair with those of end-to-side neurorrhaphy.

Methods

Between 1994 and 2006, direct repair (nerve grafting), neurotization, and end-to-side neurorrhaphy were performed in 168 patients, 95 of whom were followed up for at least 2 years after surgery. Successful results were achieved in 79% of cases after direct repair and in 56% of cases after end-to-end neurotization. The results of neurotization depended on the type of the donor nerve used. In patients who underwent neurotization of the axillary and the musculocutaneous nerves, the use of intraplexal nerves (motor branches of the brachial plexus) as donors of motor fibers was associated with a significantly higher success rate than the use of extraplexal nerves (81% compared with 49%, respectively, p = 0.003). Because of poor functional results of axillary nerve neurotization using extraplexal nerves (success rate 47.4%), the authors used end-to-side neurorrhaphy in 14 cases of incomplete avulsion. The success rate for end-to-side neurorrhaphy using the axillary nerve as a recipient was 64.3%, similar to that for neurotization using intraplexal nerves (68.4%) and better than that achieved using extraplexal nerves (47.4%, p = 0.19).

Conclusions

End-to-side neurorrhaphy offers an advantage over classic neurotization in not requiring sacrifice of any of the surrounding nerves or the fascicles of the ulnar nerve. Typical synkinesis of muscle contraction innervated by the recipient nerve with contraction of muscles innervated by the donor was observed in patients after end-to-side neurorrhaphy.

Laryngeal Reinnervation by Ansa Cervicalis Nerve Implantation for Unilateral Vocal Cord Paralysis in Humans

BACKGROUND

Ansa cervicalis (AC)-recurrent laryngeal nerve anastomosis (RLN) is usually not desirable for correction of paralytic dysphonia when it is difficult to find a viable distal stump of the recurrent laryngeal nerve. Nerve implantation of the thyroarytenoid muscle with the ansa cervicalis is a simple alternative method.

STUDY DESIGN

Ten patients with unilateral vocal cord paralysis were prospectively designed to receive nerve implantation. A minimum period of 12 months after onset of paralysis was allowed to elapse to permit possible spontaneous reinnervation or compensation. Patients were followed long enough (at least 2 years) to determine if the procedure was successful. All patients were subjected to preoperative and postoperative voice recording, acoustic analysis, and videolaryngoscopy. Some of them underwent laryngeal electromyography.

RESULTS

Ten patients underwent nerve implantation of the thyroarytenoid muscles by using the ansa cervicalis, and 8 of 10 (80%) had improved phonatory quality. Laryngeal electromyography showed that the procedure produced satisfactory reinnervation of the thyroarytenoid muscle.

CONCLUSIONS

Nerve implantation of the thyroarytenoid muscle by the anso cervicalis is a simple and efficient alternative to nerve transfer if dense scarring at the cricothyroid articulation and lack of a viable distal stump of the recurrent laryngeal nerve preclude the procedure of nerve transfer. But careful selection of the appropriate candidate seems to be the earliest prerequisite for a successful procedure.

Surgical interventions for traumatic lesions of the brachial plexus: a retrospective study of 134 cases

Object. Surgical therapy for traumatic brachial plexus lesions is still a great challenge in the field of peripheral nerve surgery. The aim of this study was to present the results of different surgical interventions in patients with this lesion type.

Methods. One hundred thirty-four patients with traumatic brachial plexus lesions underwent surgery between January 1991 and September 1999. In more than 50% of the patients, injury was caused by a motorbike accident. Patients underwent surgery a mean of 6.3 months posttrauma. The following surgical techniques were applied: neurolysis for nerve lesions in continuity (27 cases), grafting for lesions in discontinuity (149 cases), and neurotization for root avulsions (67 cases). Sixty-five patients were evaluated for at least 30 months (mean follow up 42.1 months) after surgery.

Function was graded using the Louisiana State University Health Sciences Center classification system. Only 2% of the patients had Grade 3 or better function preoperatively, increasing to 52% postoperatively. The effect of surgical measures on the functional results for different muscles were compared (supra- or infraspinatus, deltoid, biceps, and triceps muscles); the best results were obtained for biceps muscle function (57% of patients with Medical Research Council Grades M3–M5 function). Graft reconstruction yielded a better outcome than neurotization. Surgery within 5 months posttrauma clearly resulted in improved recovery of motor function compared with later interventions. Sural nerve grafts (monofascicular nerves) showed better results.

Conclusions. The results of neurosurgical interventions for brachial plexus lesions are satisfactory, especially when the operation is performed between 3 and 6 months after trauma.

Reinnervation of the rat musculocutaneous nerve stump after its direct reconnection with the C5 spinal cord segment by the nerve graft following avulsion of the ventral spinal roots: a comparison of intrathecal administration of brain-derived neurotrophic factor and Cerebrolysin

Experimental model based on the C5 ventral root avulsion was used to evaluate the efficacy of brain-derived neurotrophic factor (BDNF) and Cerebrolysin treatment on motor neuron maintenance and survival resulted in the functional reinnervation of the nerve stump. In contrast to vehicle, BDNF treatment reduced the loss and atrophy of motor neurons and enhanced the regrowth axon sprouts into the distal stump of musculocutaneous nerve. However, the axon diameter of the myelinated fibers was smaller than those of control rats. The morphometric results were related to a low score in behavioral test similar to vehicle-treated rats. Cerebrolysin treatment greatly protected the motor neurons against cell death. Moreover, morphometric features of myelinated axons were better than those of rats treated with vehicle or BDNF. The mean score of grooming test suggested better results of the functional motor reinnervation than after BDNF administration. The majority of rescued motor neurons regenerating their axons through nerve graft in both BDNF- and Cerebrolysin-treated rats expressed choline acetyltransferase immunostaining. The results demonstrate that BDNF has more modest effects in preventing the death of motor neurons and functional recovery of injured motor nerve after root avulsion than Cerebrolysin.

Restoration of stepping-forward and ambulatory function in patients with paraplegia: rerouting of vascularized intercostal nerves to lumbar nerve roots using selected interfascicular anastomosis

The objective of this study is to restore stepping-forward and ambulatory function in paraplegic patients with chronic injuries. Two to four normal vascularized intercostal nerves above the spinal cord injury site were obtained by cutting in the distal end at the midclavicular line. The proximal ends were disconnected from the levatores costarum. Nerves were then transferred to the vertebral canal through a submuscle tunnel and sutured with the selected fascicula of lumbar nerve roots (L 1/2 or L 3/4) by epiperineurial neurorrhaphy in the subdura or extradura. If the selected intercostal nerve was not of sufficient length to reach the specific lumbar region, a sural nerve segment was isolated, sheared into two segments, and attached to the intercostal nerve for grafting. Twenty-three patients, whose injury sites were between the thoracic T9 and T12 levels, were followed postoperatively for a period ranging from 2 to 11 (average: 3.5) years. Of these patients, 18 (78%) regained the stepping-forward function and were able to walk with crutches or other ambulatory assistive devices. In addition, 21 (91%) patients had improved thigh sensation. This intercostals nerve rerouting procedure restores significant stepping-forward and, in turn, ambulatory function and thigh muscle sensation in paraplegic patients.

Dorsal root implant on lesioned spinal cord morphologic findings of regeneration of synapses in the mammalian spinal cord--repair and recovery

Earlier work concerning regeneration of synaptic connection had been studied primarily in amphibia. Sperry and Miner and Stevens showed that functional regeneration of synapses followed sectioning and anastomosis of the central process of the dorsal root of one side to the proximal stump of the dorsal root of the opposite. A number of studies have shown that the dorsal roots and dorsal columns of mammals have adequate regenerative capacities. There is no functional or morphologic evidence for reestablishment of synaptic connections reported in the mammalian studies. A number of authors have reported that regenerating dorsal root fibers are confronted with a barrier at the neutilemmal-glial junctions. Previous studies have shown that peripheral nerve fibers inserted into the spinal cord grow profusely. Theorizing that regenerating dorsal root fibers would grow and reestablish synaptic connection more readily, it was decided to insert the neurilemmal portion- including Schwann cells- of the dorsal roots into the spinal cord to the depths of the gray columns.

Reconstruction of the inferior alveolar nerve by autologous graft: a retrospective study of 20 cases examining donor nerve length

The purpose of this study was to confirm the length and kind of donor nerves used in nerve grafts for reconstruction of inferior alveolar nerve defects. The authors conducted a retrospective study of surgeries that were performed between 1977 and 1996. A total of 20 patients underwent nerve grafting procedures during this period. The greater auricular nerve was selected as the donor nerve in 16 cases, while the sural nerve was selected in 4. Mean lengths of donor nerves were 7.28 +/- 1.6 cm and 11.5 +/- 3.4 cm for the greater auricular and sural nerves, respectively. As indicated, the sural nerves were significantly longer (p < 0.01). Mean lengths of donor nerves grafted for partial resection and hemi-mandibulectomy were 7.23 +/- 1.6 cm and 10.8 +/- 3.4 cm, respectively. Statistical analysis indicated that grafts used in the hemi-mandibulectomy group were significantly longer (p < 0.05). In terms of types of donor nerve used in mandibulectomies, the greater auricular nerve was used in the majority of partial resections, and the sural nerve was employed for hemi-mandibulectomy.

Clinicostatistical study of ameloblastoma treatment

The purpose of this study was to investigate the treatment of 190 cases of ameloblastoma in our department from 1966 to 1994. The statistical results with regard to age, sex and region agreed with those of other investigators. Thirty-five of 43 (81.4%) cases underwent enucleation in 1960s, but the sixteen of 27 (59.3%) cases underwent partial resection of mandible in 1990s. The defect of mandible was reconstructed with iliac bone grafting since 1968, grafts with a mixture of iliac blocked bone and PCBM (particulate cancellous bone and marrow) have been used since 1975. Grafting of the inferior alveolar nerve with the great auricular nerve to the defect has been performed in our department since 1977. Recently, technique involving pull-through of the inferior alveolar nerve bundle has been used in our department. When the reconstruction method for the mandible and nerve has been established, it becomes possible to operate radically and positively. Recurrence occurred in 17 cases after the primary enucleation. It is thought that the primary treatment of ameloblastoma must be as radical as possible. It appears to be necessary to observe progress and perform follow-up in cases of ameloblastoma for more than ten years, because there was one recurrence at 9 years and 4 months after the first operation. In fact, three quarters of our cases were lost to follow-up. Such losses can problems in confirming recurrence and responding rapidly.

Correlation between histopathological findings in C-5 and C-6 nerve stumps and motor recovery following nerve grafting for repair of brachial plexus injury

OBJECT

Proximal spinal nerve stumps were used as donor sites for grafts to repair brachial plexus traction lesions. The quality of the stumps was assessed histologically, and its correlation with the strength attained in the target muscle was studied.

METHODS

Four histopathological parameters in frozen tissue sections of 31 C-5 or C-6 nerve stumps were examined by a neuropathologist. The total quantity of myelin was compared with normal values. Also, thick myelinated fibers, fibrosis, and misdirected axons were assessed. Stumps embedded in plastic were used in a morphometric study of myelinated fiber profiles. The fiber density, mean size, and size distribution in five donor stumps were determined; three normal C-5 spinal nerves obtained at autopsy served as controls. Finally, the relative area occupied by fiber profiles and interspace was computed. Linear regression was used as a multivariate analysis, adjusting the outcome of surgical repair for effects of age, interval between trauma and surgery, and graft length. Histopathological examination showed that the total quantity of myelin in donor stumps used for biceps muscle reinnervation was considerably reduced. On morphometric examination the fiber density did not differ significantly between stumps obtained in patients and control stumps obtained at autopsy. However, a significant reduction of the area occupied by myelinated fibers was measured: from 46% in controls to 13% in patients (p < 0.0001). Likewise, a significant reduction was found in the mean fiber size: from 7.4 microm in controls to 3.7 microm in patients (p < 0.0001). The relationship between the myelin quantity in the proximal stump and the grade of biceps muscle recovery was statistically significant (p = 0.02). From the 95% confidence interval it was concluded that the estimated effect of a mean increase of myelinated fibers by 25% almost equals an increase in recovery of one point on the Medical Research Council scale (grade range 0-5).

CONCLUSIONS

Both histopathological and morphometric examination showed a reduction of the quantity of myelin in C-5 or C-6 stumps used as donor sites for grafts. The amount of myelin is significantly correlated with biceps muscle function after nerve grafting. Because it is possible to assess the quantity of myelin by intraoperative examination of frozen sections, this correlation is potentially useful in the decision-making process of whether to use stumps for grafting or to use nerve transfer procedures to restore biceps muscle function.

Treatment of brachial plexus injury

A brachial plexus injury is the most severe nerve injury of the extremities. To achieve good results from treatment, correct diagnosis and early nerve repair are mandatory. The brachial plexus should be explored as early as possible if there is an incised wound, if clinical findings or diagnostic imaging indicate that at least one root is avulsed, if there is damage to the subclavian artery, and if there is total-type injury. With an upper-type injury with no clinical signs of a preganglionic lesion, the patient should be treated conservatively for 3 months and if there are no signs of recovery, then the brachial plexus should be explored. During this exploration, recording of the spinal cord evoked potential (ESCP) or the somatosensory evoked potential (SEP) is mandatory to determine the site of injury. Nerve grafting is indicated for a rupture in the root demonstrating a positive ESCP or SEP potential, in the trunk or in the cord. Exploration of the brachial plexus should be extended distally as far as possible to achieve good results after nerve grafting; when this was done more than M3 (MRC grading) power of the infraspinatus, deltoid, and biceps was achieved in more than 70% of our 32, 30, 33 patients, respectively. Results of nerve grafting for the forearm muscles have been very poor. Intercostal nerve transfer is recommended to restore elbow flexion in root avulsion type of injury, with elbow flexion to more than M3 being regained in 70% of our 221 patients. The best results of intercostal nerve transfer were achieved in patients younger than 30 years who received the operation within 6 months after injury. Motor recovery of hand function after intercostal nerve transfer was poor but protective sensation was restored in fingers innervated by the median nerve. The recommended treatment for each type of injury is described according to the results achieved.

Clinical evaluation of C7 spinal nerve transection: 21 patients with at least 2 years' follow-up

We have performed C7 spinal nerve transfer to treat root injury of the brachial plexus since 1989. Out of a total of 43 patients, 21 have been followed up for at least 2 years. Evaluation of the effect of C7 transection included clinical examination, intraoperative C7 stimulation, LIDO Workset machine and electrophysiological studies to test C7 innervated muscles, and histochemical analysis of the anterior and posterior division of the upper trunk using acetylcholinesterase stain. Nearly half of the study group (48%) reported no significant sensory changes and most patients (81%) did not notice any weakness of the limb following C7 transection. Some patients did experience sensory and motor abnormalities which were most frequent during the first postoperative month, improved during the 2nd month and in most cases resolved in the 3rd postoperative month. The only longer persistent abnormality was the triceps reflex, which becomes weak or absent. We also found that intraoperative C7 stimulation was a useful predictor of possible post-transection morbidity. Subclinical deficits, detected by the LIDO workset machine and by electro-physiological studies, were quite common. Histochemical analysis revealed that the posterior division of C7 had more motor fibres than the anterior division.

[Regrowth of central respiratory pathways in neural graft. From research tool on the axonal regeneration to a strategy of post-traumatic reparation]

This review focuses on the regrowth of respiratory pathways after nerve grafting within the central nervous system of the adult rat. After a general presentation of the background and of the grafting procedure, we summarize our nerve grafting results of while it is now well established that severed axons of adult central neurons can regenerate within segments of peripheral nerve partially implanted within the brain or spinal cord, the functional properties of the regenerating neurons remain generally unknown. With a view to assessing the extent to which the functional capacities of central neurons can be maintained after axonal regeneration, we have carried out experiments on central respiratory neurons which are a good example of a highly organized neuronal network with characteristic patterns of spontaneous discharge. We have shown that axonal regrowth of central respiratory neurons was successfully induced in blind-ended medullary and spinal autografts implanted respectively within the respiratory centers of the medulla oblongata and within the cervical spinal cord at the level of descending respiratory pathways. The grafts consisted of true "supplementary nerve" in which normal afferent and efferent respiratory pathways were confirmed by recording respiratory unitary discharges from teased fibers within the grafts. The efferent discharges reflected the activity of central respiratory neurons that had regenerated axons within the grafts: these neurons manifested spontaneous activity and normal responsiveness to respiratory stimuli that resemble those of normal respiratory cells. In order to evaluate the possibility of experimental nerve banking, the feasibility of using short-term and long-term stored nerves as potential spinal nerve grafts was established using in vitro pre-degenerated nerve and cryopreserved nerve grafts after assessment of Schwann cell viability. The extent of respiratory reinnervation of the different grafts (medullary, spinal and stored nerve grafts) was compared. The discussion focuses on the main data and the strategy for future nerve grafting is evoked: functional characteristics of regenerating respiratory axons, extent of graft reinnervation, functional schwann cell survey within stored/grafted nerve and post-traumatic grafting.

[Paralysis of the brachial plexus caused by supraclavicular injuries in the adult. Long-term comparative results of nerve grafts and transfers]

PURPOSE OF THE STUDY

Recovery of active elbow flexion constitutes the first priority in microsurgical repair after closed injuries of the supraclavicular brachial plexus in adults. However, there are many controversial issues between the proponents of nerve grafting from available roots, and the proponents of nerve transfer.

MATERIAL AND METHODS

The results concerning elbow flexor muscle recovery following microsurgical nerve repair of supraclavicular brachial plexus lesions were analysed in 62 patients. The average age at operation was 23 years old and the average delay between trauma and nerve repair was 7 months. Nerve grafting from C5 or C6 was performed in 43 patients. Nerve transfer using 3 intercostal nerves was done in 10 patients and using the spinal accessory nerve in 7 patients. A combination of both techniques was performed in 2 patients. Conventional sural nerve grafts were used every time. Functional evaluation was based on the assessment of active range of motion including flexion and supination, and on the assessment of maximum isotonic strength of the elbow flexors.

RESULTS

With an average follow up of 8.5 years (range from 3 to 16 years) the average functional score of the elbow flexors was 4.4 out of a possible 11. Sixty six percent of patients had a strength recovery of M3 or more. Nerve repair using nerve graft from a non avulsed root seems to give better functional scores than nerve transfer from intercostal nerves or spinal accessory nerve using interpositional nerve graft, even if the differences were not statistically significant.

DISCUSSION

In order to restore elbow flexion in case of supraclavicular brachial plexus lesion, nerve graft from an available root should be preferred to nerve transfer with interpositional nerve graft, when no avulsion exists among C5 and C6. Nerve transfer with interpositional nerve graft to the musculocutaneous nerve is indicated in case of avulsion of one or more roots among C5 and C6.

[Lesions to the axillary nerve]

PURPOSE OF THE STUDY

The authors have reviewed 67 axillary nerve lesions from 1987 to 1993. 35 times the lesion was isolated; 20 times it was associated to other nerve lesions (9 times supra scapular nerve, 3 times musculocutaneous nerve, 8 times posterior cord) and 12 times lesions were associated to rotator cuff injury.

MATERIAL AND METHODS

RESULTS

DISCUSSION

Injury corresponded 9 times to stretching mechanism in upper limb traction and came 58 times with osteoarticular lesions (30 anterior dislocations and 28 shoulder fractures). In 11 cases, shoulder active abduction was normal, inspite of deltoïd's complete palsy and this accounted for diagnosis delay. Concerning axillary nerve isolated lesions (35 cases), 7 recovered spontaneously and 28 have been operated. Surgical operation was undertaken 9 months after injury using a combined anterior and posterior approach. Rupture was located in the quadrilateral space and 23 nerve grafts, 4 neurolysis and 1 direct suture were performed. Results were good (muscle measured to M4) and excellent (muscle measured to M5) in 57 per cent of cases. Concerning axillary nerve lesions associated to suprascapular nerve lesions (9 cases) and musculocutaneous nerve (3 cases), all axillary nerve lesions were grafted with 50 per cent of good and very good results. The scapular nerve was neurolysed 6 times with 4 good and excellent results and evaluated irreparable in 3 cases. Musculocutaneous nerve was grafted in all cases with 2 good results out of 3. Posterior cord lesions (8 cases) required an osteotomy of the clavicle. Five grafts and 3 neurolysis were performed with aleatory results. At last, when associated lesions of the rotator cuff muscle were found (12 cases), 6 cases recovered spontaneously and 3 times cuff rupture was small enough to be reinserted with 2 good results. The 6 other cases corresponded to an axillary nerve rupture which were all grafted with 2 good results. On the cuff, result was in relation with lesion's type. Twice a supraspinatus tendon rupture was reinserted with 1 good result and 1 fair result. In 3 older patients, there was a small size rupture which has been reinserted with 1 good result, 1 fair result and 1 failure. At last, one surgical repair of a large rupture couldn't be justified.

CONCLUSION

These encouraging results suggest to propose repair of axillary nerve when deltoid muscle palsy does not recover until 3 to 6 months. Rupture diagnosis is then suspected and the best surgical technique is a nerve graft.

Obstetrical palsy: early treatment and secondary procedures

Obstetrical palsy has been described since a long time. Unfortunately, until the last 20 years, few options were available to correct its sequelae. During the last two decades, there has been a regain of interest because of the possibility to microsurgically repair these lesions. Tassin in 1984 demonstrated that babies who have no recovery of the biceps function by three months of age should be operated without delay. At brachial plexus exploration, in the presence of neuroma, nerve grafting is usually necessary. In cases of root avulsion, internal or external neurotization should be performed depending on the severity of the lesions. Physiotherapy and long-term follow-up of these patients are primordial to prevent joint ankylosis and to identify the patients who will benefit from secondary surgery. Our results are presented either after early treatment or after secondary procedures. These results justify aggressive management of obstetrical brachial plexus palsy because of children's great capacity for regeneration and accommodation.

Cross-chest C7 nerve grafting followed by free muscle transplantations for the treatment of total avulsed brachial plexus injuries: a preliminary report

The number of donor nerves available for nerve transfer in the reconstruction of total root avulsion injuries of the brachial plexus is always insufficient. Use of the contralateral normal C7 cervical nerve as a donor nerve is a new approach to obtain more nerve fibers but also is a controversial procedure. Fifteen patients with total root avulsion of the brachial plexus received cross-chest C7 nerve grafting as the first stage of reconstruction. Eight of these patients, after an interval of 11 to 20 months, had free muscle transplantations (one to three muscles transferred per individual) to the affected limb. A long period of rehabilitation (at least 2 years) is required. The donor limbs of the 15 patients showed negligible deficits of motor and sensory function. Although independent movement of the transferred muscles from the contralateral limb has not been achieved, useful function of the reconstructed limb is possible. The preliminary results are encouraging.

Recovery of brachial plexus injuries

Despite technical advances, the ability to restore function following severe brachial plexus traction lesions is limited. Major problems hampering good results are the inability to recognize corresponding fascicles in case of a large nerve gap and the lack of a proximal nerve stump in root avulsions. This article discusses the diagnosis and treatment of such injuries in combination with research in this field.

NGF-like trophic support from peripheral nerve for grafted rhesus adrenal chromaffin cells

Autopsy results on patients and corresponding studies in nonhuman primates have revealed that autografts of adrenal medulla into the striatum, used as a treatment for Parkinson's disease, do not survive well. Because adrenal chromaffin cell viability may be limited by the low levels of available nerve growth factor (NGF) in the striatum, the present study was conducted to determine if transected peripheral nerve segments could provide sufficient levels of NGF to enhance chromaffin cell survival in vitro and in vivo. Aged female rhesus monkeys, rendered hemiparkinsonian by the drug MPTP (n-methyl-4-phenyl-1,2,3,6 tetrahydropyridine), received autografts into the striatum using a stereotactic approach, of either sural nerve or adrenal medulla, or cografts of adrenal medulla and sural nerve (three animals in each group). Cell cultures were established from tissue not used in the grafts. Adrenal chromaffin cells either cocultured with sural nerve segments or exposed to exogenous NGF differentiated into a neuronal phenotype. Chromaffin cell survival, when cografted with sural nerve into the striatum, was enhanced four- to eightfold from between 8000 and 18,000 surviving cells in grafts of adrenal tissue only up to 67,000 surviving chromaffin cells in cografts. In grafts of adrenal tissue only, the implant site consisted of an inflammatory focus. Surviving chromaffin cells, which could be identified by both chromogranin A and tyrosine hydroxylase staining, retained their endocrine phenotype. Cografted chromaffin cells exhibited multipolar neuritic processes and numerous chromaffin granules, and were also immunoreactive for tyrosine hydroxylase and chromogranin A. Blood vessels within the graft were fenestrated, indicating that the blood-brain barrier was not intact. Additionally, cografted chromaffin cells were observed in a postsynaptic relationship with axon terminals from an undetermined but presumably a host origin.

Nerve regeneration through the cryoinjured allogeneic nerve graft in the rabbit

To examine whether the 3-4-cm-long allogeneic basal lamina tubes of Schwann cells serve as conduits for regenerating axons in rabbits, allogeneic saphenous nerve, which had been predenervated and pretreated by freezing, were transplanted from Japanese White rabbits (JW) to New Zealand White rabbits (NW). Animals were killed 1, 2, 6, 8, and 14 weeks after transplantation, and the cytology at the mid-portion of the grafts was examined by electron microscopy. The distal portion of the host saphenous nerves was also examined 14 weeks after grafting. Myelin sheath debris was phagocytosed by macrophages, while the basal lamina of Schwann cells were left intact in the form of tubes. Regenerating axons were first found in such basal lamina tubes 2 weeks after grafting, and gradually increased in number. Host Schwann cells accompanied the regenerating axons behind their growing tips, separating them into individual fibers and forming thin myelin sheaths on thick axons by 6 weeks after grafting. Regenerating nerves were divided into small compartments by new perineurial cells. Newly formed blood vessels were situated outside the compartment 8 weeks after grafting. The percentage of myelinated fibers in the regenerating nerves was roughly 10% at 8 weeks and 30% at 14 weeks after grafting. The diameter of the regenerating axons, both myelinated and unmyelinated, was less than that of normal axons at all the stages examined. Numerous regenerating axons, some of which were fully myelinated, were found at the site 10 mm distal to the distal end of the graft 14 weeks after grafting.(ABSTRACT TRUNCATED AT 250 WORDS)

Current trends in the treatment of established unilateral facial palsy

A unilateral facial palsy can be considered established and therefore unlikely to recover, if a year has passed since the injury which initiated it. Fascial slings and muscle transfers have still a place in maintaining static position and preventing the mouth swinging to the animated side on smiling. They do not, however, produce a smile responsive to emotion. Crossed facial nerve grafting is rather unreliable and rarely produces a symmetrical smile. Since the mid 1970s vascularised muscle grafts have been employed to compensate for the degeneration of the paralysed facial musculature. The pectoralis minor is a particularly suitable muscle for transplantation to the face because of size and shape. Experience with these techniques and the results of the first 30 cases using this muscle are presented.