Surgical strategies for managing foraminal nerve sheath tumors: the emerging role of CyberKnife ablation.

Sixteen Stanford University Medical Center (SUMC) patients with foraminal nerve sheath tumors had charts reviewed. CyberKnife radiosurgery was innovative in management. Parameters were evaluated for 16 foraminal nerve sheath tumors undergoing surgery, some with CyberKnife. Three neurofibromas had associated neurofibromatosis type 1 (NF1). Eleven patients had one resection; others had CyberKnife after one (two) and two (three) operations. The malignant peripheral nerve sheath tumor (MPNST) had prior field-radiation and adds another case. Approaches included laminotomy and laminectomies with partial (three) or total (two) facetectomies/fusions. Two cases each had supraclavicular, lateral extracavitary, retroperitoneal and Wiltze and costotransversectomy/thoracotomy procedures. Two underwent a laminectomy/partial facetectomy, then CyberKnife. Pre-CyberKnife, one of two others had a laminectomy/partial facetectomy, then total facetectomy/fusion and the other, two supraclavicular approaches. The MPNST had a hemi-laminotomy then laminectomy/total facetectomy/fusion, followed by CyberKnife. Roots were preserved, except in two. Of 11 single-operation-peripheral nerve sheath tumors, the asymptomatic case remained stable, nine (92%) improved and one (9%) worsened. Examinations remained intact in three (27%) and improved in seven (64%). Two having a single operation then CyberKnife had improvement after both. Of two undergoing two operations, one had symptom resolution post-operatively, worsened 4 years post-CyberKnife then has remained unchanged after re-operation. The other such patient improved post-operatively, had no change after re-operation and improved post-CyberKnife. The MPNST had presentation improvement after the first operation, worsened and after the second surgery \and CyberKnife, the patient expired from tumor spread. In conclusion, surgery is beneficial for pain relief and function preservation in foraminal nerve sheath tumors. Open surgery with CyberKnife is an innovation in these tumors' management.

Surgical treatment and outcomes in 45 cases of posterior interosseous nerve entrapments and injuries.

OBJECT: The authors report data in 45 surgically treated posterior interosseous nerve (PIN) entrapments or injuries. METHODS: Forty-five PIN entrapments or injuries were managed surgically between 1967 and 2004 at Louisiana State University Health Sciences Center (LSUHSC) or Stanford University Medical Center. Patient charts were reviewed retrospectively. The LSUHSC grading system was used to assess PIN-innervated muscle function. Injuries were caused by nontraumatic (21 PIN entrapments and four tumors) and traumatic (nine lacerations, eight fractures, and three contusions) mechanisms. Presentations included weakness in the extensor carpi ulnaris muscle, causing compromised wrist extension and radial drift; extensor digitorum, indicis, and digiti minimi muscles with paretic finger extension; extensor pollicis brevis and longus muscles with weak thumb extension; and abductor pollicis longus muscle with rare decreased thumb abduction due to substitutions of the median nerve-innervated abductor pollicis brevis muscle and, at 90 degrees, the extensor pollicis brevis and longus muscles. Preoperative evaluations consisted of electromyography and nerve conduction studies, elbow and forearm plain x-ray films, and magnetic resonance imaging for tumor detection. At surgery, in continuity lesions were found in 21 entrapments and three fracture-related and three contusion injuries; all transmitted nerve action potentials (NAPs) and were treated with neurolysis. Five fracture-related PIN injuries, one of which was a lacerating injury, were in continuity and transmitted no NAPs; graft repairs were performed in all of these cases. Among nine lacerations, three PINs appeared in continuity, although intraoperative NAPs were absent. Two of these nerves were treated with secondary end-to-end suture anastomosis repair and one with secondary graft repair. There were six transected lacerations: three were treated with primary suture anastomosis repair, two with secondary suture anastomosis, and one with graft repair. Four tumors involving the PIN were resected. Most muscles innervated by 45 PINs had LSUHSC Grade 3 or better functional outcomes. CONCLUSIONS: Forty-five PIN entrapments or injuries responded well to PIN release and/or repair.

Surgical treatment and outcomes in 15 patients with anterior interosseous nerve entrapments and injuries.

OBJECT: The authors present data obtained in 15 surgically treated patients with anterior interosseous nerve (AIN) entrapments and injuries. METHODS: Fifteen patients with AIN entrapments and injuries underwent surgery between 1967 and 1997 at Louisiana State University Health Sciences Center (LSUHSC) or Stanford University Medical Center. Patient charts were reviewed retrospectively. The LSUHSC grading system was used to evaluate the function of muscles supplied by the AIN. Nontraumatic injuries included seven AIN compressions by bone or soft tissue. Traumatic injury mechanisms consisted of stretch or contusion (six patients), injection (one patient), and burn scar (one patient). Presentations included weakness in the flexor digitorum profundus (FDP) muscle to the index finger, FDP muscle to the middle finger, pronator quadratus muscle, and flexion of the distal phalanx of the thumb. Preoperative evaluations included electromyography and nerve conduction studies as well as elbow and forearm plain radiographs. On surgery, lesions in continuity involved seven compressions, four stretch or contusion injuries, and one injection injury, all of which demonstrated nerve action potentials (NAPs) and were treated with neurolysis. Among the seven compression and four stretch or contusion injury cases, six and three patients, respectively, had LSUHSC Grade 3 or better functional recoveries postoperatively. Two stretch or contusion injuries involved lesions in continuity but demonstrated negative NAPs at surgery. Thus, each was treated using a graft repair after resection of a neuroma. There was one burn scar injury, which was treated via an end-to-end suture anastomosis, leading to a functional recovery better than Grade 3. CONCLUSIONS: Fifteen AIN entrapments or injuries responded favorably to nerve release and/or repair.

Neurofibromatosis-associated nerve sheath tumors. Case report and review of the literature.

In this paper the authors describe a patient with neurofibromatosis Type 1 (NF1) who presented with sequelae of this disease. They also review the current literature on NF1 and NF2 published between 2001 and 2005. The method used to obtain information for the case report consisted of a family member interview and a review of the patient's chart. For the literature review the authors used the search engine Ovid Medline to identify papers published on the topic between 2001 and 2005. Neurofibromatosis Type 1 appears in approximately one in 2500 to 4000 births, is caused by a defect on 17q11.2, and results in neurofibromin inactivation. The authors reviewed the current literature with regard to the following aspects of this disease: 1) diagnostic criteria for NF1; 2) criteria for other NF1-associated manifestations; 3) malignant peripheral nerve sheath tumors (PNSTs); 4) the examination protocol for a patient with an NF1-related NST; 5) imaging findings in patients with NF1; 6) other diagnostic studies; 7) surgical and adjuvant treatment for NSTs and malignant PNSTs; and 8) hormone receptors in NF1-related tumors. Pertinent illustrations are included. Neurofibromatosis Type 2 occurs much less frequently than NF1, that is, in one in 33,000 births. Mutations in NF2 occur on 22q12 and result in inactivation of the tumor suppressor merlin. The following data on this disease are presented: 1) diagnostic criteria for NF2; 2) criteria for other NF2 manifestations; 3) malignant PNSTs in patients with NF2; 4) examination protocol for the patient with NF2 who has an NST; and 5) imaging findings in patients with NF2. Relevant illustrations are included. It is important that neurosurgeons be aware of the sequelae of NF1 and NF2, because they may be called on to treat these conditions.

A series of 397 peripheral neural sheath tumors: 30-year experience at Louisiana State University Health Sciences Center.

OBJECT: This is a retrospective review of 397 benign and malignant peripheral neural sheath tumors (PNSTs) that were surgically treated between 1969 and 1999 at the Louisiana State University Health Sciences Center (LSUHSC). The surgical techniques and adjunctive treatments are presented, the tumors are classified with respect to type and prevalence at each neuroanatomical location, and the management of malignant PNSTs is reviewed. METHODS: There were 361 benign PNSTs (91%). One hundred forty-one benign lesions were brachial plexus tumors: 54 schwannomas (38%) and 87 neurofibromas (62%), of which 55 (63%) were solitary neurofibromas and 32 (37%) were neurofibromatosis Type 1 (NF1)-associated neurofibromas. Among the brachial plexus lesions supraclavicular tumors predominated with 37 (69%) of 54 schwannomas; 34 (62%) of 55 solitary neurofibromas; and 19 (59%) of 32 NF1-associated neurofibromas. One hundred ten upper-extremity benign PNSTs consisted of 32 schwannomas (29%) and 78 neurofibromas (71%), of which 45 (58%) were sporadic neurofibromas and 33 (42%) were NF1-associated neurofibromas. Twenty-five benign PNSTs were removed from the pelvic plexus. Lower-extremity PNSTs included 32 schwannomas (38%) and 53 neurofibromas (62%), of which 31 were solitary neurofibromas and 22 were NF1-associated neurofibromas. There were 36 malignant PNSTs: 28 neurogenic sarcomas and eight other sarcomas (fibro-, spindle cell, synovial, and perineurial sarcomas). CONCLUSIONS: The majority of tumors were benign PNSTs from the brachial plexus region. Most of the benign PNSTs in all locations were neurofibromas, with sporadic neurofibromas predominating. Similar numbers of schwannomas were found in the upper and lower extremities, whereas neurofibromas were more prevalent in the upper extremities. Despite aggressive limb-ablation or limb-sparing surgery plus adjunctive therapy, malignant PNSTs continue to be associated with high morbidity and mortality rates.

A series of 146 peripheral non-neural sheath nerve tumors: 30-year experience at Louisiana State University Health Sciences Center.

OBJECT: This is a retrospective review of 146 surgically treated benign and malignant peripheral non-neural sheath tumors (PNNSTs). Tumor classifications with patient numbers, locations of benign PNNSTs, and surgical techniques and adjunctive treatments are presented. The results of a literature review regarding tumor frequencies are presented. METHODS: One hundred forty-six patients with 111 benign and 35 malignant PNNSTs were treated between 1969 and 1999 at the Louisiana State University Health Sciences Center (LSUHSC). The benign tumors included 33 ganglion cysts, 16 cases of localized hypertrophic neuropathy, 12 lipomas, 12 tumors of vascular origin, and 11 desmoid tumors. There were four each of lipofibrohamartomas, myositis ossificans, osteochondromas, and ganglioneuromas; two each of meningiomas, cystic hygromas, myoblastoma or granular cell tumors, triton tumors, and lymphangiomas; and one epidermoid cyst. The locations of benign PNNSTs were the following: 33 in the brachial plexus region, 39 in an upper extremity, one in the pelvic plexus, and 38 in a lower extremity. The malignant PNNSTs included 35 surgically treated carcinomas, 15 of which originated in the breast and nine in the lung. There were two melanomas metastatic to nerve and one tumor each that had metastasized from the bladder, rectum, skin, head and neck, and thyroid, and from a primary Ewing sarcoma. There was a single lymphoma that had metastasized to the radial nerve and one chordoma and one osteosarcoma, each of which had metastasized to the brachial plexus. CONCLUSIONS: There were more benign PNNSTs than malignant ones. Benign tumors were relatively equally distributed in the brachial plexus region and upper and lower extremities, with the exception of the pelvic plexus, which had only one tumor.

Biomechanical Comparisons of Pull Out Strengths After Pedicle Screw Augmentation with Hydroxyapatite, Calcium Phosphate, or Polymethylmethacrylate in the Cadaveric Spine.

OBJECTIVE: In vertebrae with low bone mineral densities pull out strength is often poor, thus various substances have been used to fill screw holes before screw placement for corrective spine surgery. We performed biomechanical cadaveric studies to compare nonaugmented pedicle screws versus hydroxyapatite, calcium phosphate, or polymethylmethacrylate augmented pedicle screws for screw tightening torques and pull out strengths in spine procedures requiring bone screw insertion. METHODS: Seven human cadaveric T10-L1 spines with 28 vertebral bodies were examined by x-ray to exclude bony abnormalities. Dual-energy x-ray absorptiometry scans evaluated bone mineral densities. Twenty of 28 vertebrae underwent ipsilateral fluoroscopic placement of 6-mm holes augmented with hydroxyapatite, calcium phosphate, or polymethylmethacrylate, followed by transpedicular screw placements. Controls were pedicle screw placements in the contralateral hemivertebrae without augmentation. All groups were evaluated for axial pull out strength using a biomechanical loading frame. RESULTS: Mean pedicle screw axial pull out strength compared with controls increased by 12.5% in hydroxyapatite augmented hemivertebrae (P = 0.600) and by 14.9% in calcium phosphate augmented hemivertebrae (P = 0.234), but the increase was not significant for either method. Pull out strength of polymethylmethacrylate versus hydroxyapatite augmented pedicle screws was 60.8% higher (P = 0.028). CONCLUSIONS: Hydroxyapatite and calcium phosphate augmentation in osteoporotic vertebrae showed a trend toward increased pedicle screw pull out strength versus controls. Pedicle screw pull out force of polymethylmethacrylate in the insertion stage was higher than that of hydroxyapatite. However, hydroxyapatite is likely a better clinical alternative to polymethylmethacrylate, as hydroxyapatite augmentation, unlike polymethylmethacrylate augmentation, stimulates bone growth and can be revised.

Biomechanical comparison of cervical fixation via transarticular facet screws without rods versus lateral mass screws with rods.

OBJECTIVE: Transarticular facet screws restore biomechanical stability to the cervical spine when posterior cervical anatomy has been compromised. This study compares the more recent, less invasive, and briefer transarticular facet screw system without rods with the lateral mass screw system with rods. METHODS: For this study, 6 human cervical spines were obtained from cadavers. Transarticular facet screws without rods were inserted bilaterally into the inferior articular facets at the C5-C6 and C5-C6-C7 levels. Lateral mass screws with rods were inserted bilaterally at the same levels using Magerl's technique. All specimens underwent range of motion (ROM) testing by a material testing machine for flexion, extension, lateral bending, and axial rotation. RESULTS: Both fixation methods, transarticular facet screws without rods and lateral mass screws with rods, reduced all ROM measurements and increased spinal stiffness. No statistically significant differences between the 2 stabilization methods were found in ROM measurements for 1-level insertions. However, in 2-level insertions, ROM for the nonrod transarticular facet screw group was significantly increased for flexion-extension and lateral bending. CONCLUSIONS: Transarticular facet screws without rods and lateral mass screws with rods had similar biomechanical stability in single-level insertions. For 2-level insertions, transarticular facet screws without rods are a valid option in cervical spine repair.

Management and outcomes in 318 operative common peroneal nerve lesions at the Louisiana State University Health Sciences Center.

OBJECTIVE: This study analyzes 318 operative knee-level common peroneal nerve lesions managed at the Louisiana State University Health Sciences Center between 1967 and 1999. METHODS: Each patient was retrospectively evaluated for injury mechanism, preoperative neurological status, electrophysiological studies, lesion type, and operative technique, i.e., neurolysis, suture, or graft repair. All lesions in continuity had intraoperative nerve action potential recordings. RESULTS: There were 141 stretch/contusions without fracture/dislocations (44%), 39 lacerations (12%), 40 tumors (13%), 30 entrapments (9%), 22 stretch/contusions with fracture/dislocations (7%), 21 compressions (7%), 13 iatrogenic injuries (4%), and 12 gunshot wounds (4%). After neurolysis, 107 (88%) of 121 knee-level common peroneal nerve lesions with recordable intraoperative nerve action potentials recovered useful function. Nineteen patients underwent end-to-end suture repair, and 16 (84%) of these achieved good recovery by 24 months. Graft repair was performed in 138 peroneal injuries. Thirty-six patients (26%) had grafts less than 6 cm long, of which 27 (75%) achieved Grade 3 or greater peroneal function. Twenty-four (38%) of 64 patients with 6- to 12-cm grafts, and only 6 (16%) of 38 patients with 13- to 24-cm grafts, attained good peroneal function. Longer grafts correlated with more severe injuries and thus poorer outcomes. Thirty-two (80%) of 40 tumors were resected with preservation of preoperative clinical function. CONCLUSION: Surgical exploration and repair of peroneal nerve lesions achieved good results with timely operations and thorough intraoperative evaluations. Useful function was achieved in 27 (75%) of 36 patients with grafts less than 6 cm in length and in only 88 (44%) of 202 patients with grafts greater than 6 cm in length.

Management and outcomes in 353 surgically treated sciatic nerve lesions.

OBJECT: This is a retrospective analysis of 353 surgically treated sciatic nerve lesions in which injury mechanisms, location, time to surgical repair, surgical techniques, and functional outcomes are reported. Results are presented to provide guidelines for management of these injuries. METHODS: One hundred seventy-five patients with buttock-level and 178 with thigh-level sciatic nerve injury were surgically treated at the Louisiana State University Health Sciences Center between 1968 and 1999. Buttock-level injury mechanisms included injection in 64 patients, hip fracture/dislocation in 26, contusion in 22, compression in 19, gunshot wound (GSW) in 17, hip arthroplasty in 15, and laceration in 12; at the thigh level, GSW was the cause in 62 patients, femoral fracture in 34, laceration in 32, contusion in 28, compression in 12, and iatrogenic injury in 10. Patients with sciatic nerve divisions in which positive intraoperative nerve action potentials (NAPs) were found underwent neurolysis and attained at least Grade 3 functional outcomes in 108 (87%) of 124 and in 91 (96%) of 95 buttock- and thigh-level tibial divisions, respectively, compared with 84 (71%) of 119 and 75 (79%) of 95, respectively, in the peroneal divisions. For suture repair, recovery to at least Grade 3 occurred in eight (73%) of 11 buttock-level and in 27 (93%) of 29 thigh-level tibial division injuries, and in three (30%) of 10 buttock-level and 20 (69%) of 29 thigh-level peroneal division lesions. For graft repair, good recovery occurred in 21 (62%) of 34 and in 43 (80%) of 54 buttock- and thigh-level tibial divisions, respectively, even in proximal repairs requiring long grafts, and in only nine (24%) of 37 and 22 (45%) of 49 buttock- and thigh-level peroneal division lesions, respectively. CONCLUSIONS: Surgical exploration and neurolysis after positive NAP readings, or repair with sutures or grafts after negative NAP results are worthwhile in selected cases.

Intrapelvic and thigh-level femoral nerve lesions: management and outcomes in 119 surgically treated cases.

OBJECT: The authors present a retrospective analysis of 119 surgically treated femoral nerve lesions at intrapelvic and thigh levels seen at the Louisiana State University Health Sciences Center. METHODS: Femoral nerve lesions treated between 1967 and 2000, (89 traumatic injuries and 30 tumors and cystic lesions) were evaluated for injury mechanisms, resulting lesions, surgical management, and postoperative functional outcomes by using retrospective chart reviews. The most common injury mechanism was iatrogenic (52 cases), which occurred after hernia and hip operations (10 each), followed by arterial bypass and gynecological procedures (eight each), angiography (seven), abdominal surgery (five), appendectomy (two), a laparoscopy, and a lumbar sympathectomy. Other injury mechanisms included hip or pelvic fractures (19), gunshot wounds (10), and lacerations (eight). The 30 femoral nerve tumors and cystic lesions consisted of neurofibromas (16), schwannomas (nine), ganglionic cysts (two), neurogenic sarcomas (two), and a leiomyosarcoma. Forty-four patients underwent neurolysis. Some had recordable nerve action potentials (NAPs) across their lesions in continuity, despite severe distal loss. Others with recordable NAPs had mild loss, but also experienced a pain problem, which was helped in some by neurolysis. In 36 patients, in whom repairs were performed using long sural grafts for mostly proximal pelvic-level injuries, recovery of useful function occurred. Eight of nine thigh-level suture repairs led to improvement to good functional levels. Most of the tumors and cystic lesions were resected, with preservation of preoperative function. CONCLUSIONS: The majority of femoral nerve injuries resulted in lesions in continuity, and intraoperative NAP recordings were essential in evaluating axonal regeneration across these lesions. Despite severe and frequently proximal injury levels requiring repairs with long grafts, femoral nerve lesion repairs resulted in good functional recovery.

Surgical outcomes of 654 ulnar nerve lesions.

OBJECT: In this article the authors present a retrospective analysis of 654 surgical outcomes in patients with ulnar nerve entrapments, injuries, and tumors during a 30-year period. METHODS: Data were gathered between 1968 and 1998 at Louisiana State University Health Sciences Center. Mechanisms of injuries or lesions included 460 entrapments at the elbow level (70%), 76 lacerations (12%), 52 stretches/contusions (8%), 34 fractures/dislocations (5%), 12 gunshot wounds (2%), two injection-induced injuries (0.3%), and 13 nerve sheath tumors (2%). In cases of entrapment, direct operative recordings uniformly demonstrated a slowing of conduction at the elbow, even in cases in which preoperative noninvasive studies had been nondiagnostic. Intraoperative electrical "inching" studies also demonstrated significant conduction abnormalities that lie just proximal to and through the olecranon notch rather than distal, beneath the flexor carpi ulnaris muscle. There were only eight exceptions to this. Lesions not in continuity due to the injury required primary or secondary end-to-end sutures or graft repair. Aided by intraoperative nerve action potential recording, lesions in continuity received either external or internal neurolysis and split repair or resection followed by end-to-end suture or graft repair. Functional recoveries of Grade 3 or better were seen in 81 (92%) of 88 patients who underwent neurolysis, 42 (72%) of 58 patients who received suture repair, and 24 (67%) of 36 patients who received graft repair. Nevertheless, fewer Grade 4 or 5 recoveries were reached than those seen in patients with radial or median nerve injuries. Nerve sheath tumors were resected with preservation of preoperative function in five of seven patients. CONCLUSIONS: Although difficult to obtain, useful functional recovery can be achieved with proper surgical management of ulnar nerve entrapments and injuries.

Operative outcomes of 546 Louisiana State University Health Sciences Center peripheral nerve tumors.

The surgical management of benign PNSTs and some other benign tumors can result in successful outcomes. Schwannomas and nonplexiform neurofibromas can be resected with minimal deficit by sparing all but the fascicles entering and exiting the tumor. These fascicles, if not functional by NAP testing, can be resected, and the tumor can be removed. Surgery to remove other benign lesions, such as intraneural ganglion cysts, hemangiomas,and ganglioneuromas, has become more timely. The desmoid tumor, although microscopically benign, is locally and regionally invasive, and chemotherapy and radiation therapy may need to be used as adjunctive therapy. Neurogenic sarcomas and other malignancies have high morbidity and mortality despite aggressive limb ablation or limb-sparing surgery with adjunctive therapy. Thus, surgery involving decompression as well as the most complete resection possible remains the essential initial step in the management of most malignancies.

Surgical techniques for total sacrectomy and spinopelvic reconstruction.

The surgical management of sacral tumors requires partial or total sacrectomy and spinopelvic reconstruction. These lesions present a great surgical challenge, because most spine surgeons are unfamiliar with the techniques required for these procedures. The authors describe a step-by-step operative technique and provide several illustrations. Total sacrectomy is performed by sequential anterior and posterior approaches that involve a rectus abdominis pullthrough pedicle flap reconstruction. The anterior procedure is an intraperitoneal approach used to expose the anterior aspect of the tumor, to ligate the main tumor vessels, and to conduct an anterior partial sacrectomy. After this, the rectus abdominis myocutaneous flap, based on the inferior epigastric vessel, is prepared, and a posterior sacrectomy is performed, dividing all sacral nerve roots in the thecal sac. After complete en bloc extirpation of the sacrum with tumor, spinopelvic reconstruction and closure with a myocutaneous flap are performed. Spinopelvic reconstruction is undertaken using a modified Galveston technique or double iliac screw fixation combined with posterior lumbar segmental fixation. These provide a long lever arm within the ilium to counteract the forces exerted by the lumbar spine. Understanding the nature of the disease as well as the biomechanics of the lumbosacral pelvic area and spinopelvic fixation will help surgeons select the appropriate treatment for sacral tumors.

Mechanisms of injury in operative brachial plexus lesions.

OBJECT: The authors focus on injury mechanisms involved in 1019 operative brachial plexus injuries (BPIs) managed between 1968 and 1998 at Louisiana State University Health Sciences Center (LSUHSC). METHODS: Data regarding these mechanisms of injury were obtained via retrospective chart reviews of patients who had undergone operations at LSUHSC. Five main mechanisms of injury to the brachial plexus occurred in the series. These included 509 stretch/contusion injuries (49%) with four patterns of presentation in 366 patients: 208 C5-T1 nerve injuries; 75 C5-7, 55 C5-6 injuries; and 28 involving the C8-T1 or C7-T1 nerves. Stretch/contusion injury was followed in frequency by gunshot wound (GSW), resulting in 118 injuries (12%). Most of the 293 involved plexus elements had some gross continuity when surgically exposed. Seventy-one lacerations involved the brachial plexus (7%), including 83 sharp lacerations caused by knives or glass; 61 blunt transections due to automobile metal, fan, and motor blades, chain saws, or animal bites. Nontraumatic BPIs included 160 cases of thoracic outlet syndrome or 16% of the total of 1019 BPIs. There were 161 tumors (16%) of neural sheath origin including 55 solitary neurofibromas (34%), 32 neurofibromas associated with von Recklinghausen disease (20%), 54 schwannomas (34%), and 20 malignant nerve sheath tumors (20%) removed. Obstetrical BPI was not included in the original series; however, the current literature is reviewed in this paper. CONCLUSIONS: The conclusion of this study is that the brachial plexus can be injured by multiple mechanisms of which stretch/contusion injury is the most frequently encountered, followed by GSWs.

Penetrating injuries due to gunshot wounds involving the brachial plexus.

The authors review 118 operative brachial plexus gunshot wounds (GSWs), causing 293 element injuries that were managed over a 30-year period at Louisiana State University Health Sciences Center (LSUHSC). Retrospective chart reviews were performed. Using the LSUHSC grading system for motor sensory function, each element's grades were combined and averaged. Most of the 293 injured elements were found to have gross continuity at operation and of 202 elements with complete neurological loss, only 16 (8%) exhibited total disruption. Of 293 injuries, 128 elements with complete or incomplete loss were not only in continuity when explored but also had positive intraoperative nerve action potentials (NAPs). After neurolysis, 120 of 128 elements in continuity (94%) improved to greater than or equal to Grade 3 function. Elements not regenerating early usually required repair. One hundred fifty-six of 202 completely or incompletely injured elements (77%) required resection and suture or graft repair based on intraoperative NAPs. Neurolysis achieved greater than or equal to Grade 3 results in 42 (91%) of 46 elements with complete loss. Suture repair resulted in good outcomes in 14 (67%) of 21 and in 73 (54%) of 135 undergoing graft repairs (1 to 3.5 cm length) and presenting with complete loss. Of 91 incomplete elements, intraoperative NAPs were positive in 82 (90%) and 78 of 82 had good results. Nine had negative NAPs and six elements required suture repair. Three required grafts with results of greater than or equal to Grade 3 in five (83%) of six and two (67%) of three, respectively. Based on 118 patient results with 293 injured elements, guidelines for the management of GSWs were established as described in this paper.

Infraclavicular brachial plexus stretch injury.

OBJECT: The authors report the surgery-related results obtained in 143 patients with stretch-induced infraclavicular brachial plexus injuries (BPIs). The entire series comprised 1019 operative BPIs managed at the Louisiana State University Health Sciences Center between 1968 and 1998. METHODS: Infraclavicular lesions represented 143 (28%) of the total of 509 stretch injuries involving both the infra- and supraclavicular brachial plexus, of which 366 (72%) were supraclavicular lesions. The operative approach is thoroughly outlined, and common patterns and combinations of involvement of nerves peculiar to the infraclavicular area are presented. Overall, the results of suture and graft repair were favorable for the lateral and posterior cord and their outflows. Repair of medial cord-median nerve also yielded acceptable results. The results of medial cord and medial cord-ulnar nerve, however, were poor. The incidence of associated injuries in the infraclavicular as opposed to the supraclavicular area, including shoulder dislocation and fracture and humeral fractures as well as vascular injuries including axillary artery injury was higher. Results of a literature search supported the finding that vascular injuries were increased due to the juxtaposition of vessels among the brachial plexus elements. CONCLUSIONS: Thus, although less common than their supraclavicular counterpart, infraclavicular stretch injury lesions when they occur are technically more difficult to treat and are associated with a higher incidence of vascular and dislocation/fraction injuries. Favorable results were obtained for lateral and posterior cord lesions and their outflows, with acceptable outcome after medial cord-median nerve stretch injury repair. The results of medial cord and medial cord to ulnar nerve, however, were poor.

Pituitary stalk Langerhans cell histiocytosis treated with CyberKnife radiosurgery.

OBJECTIVE: Langerhans cell histiocytosis (LCH) is a rare idiopathic disease that is characterized by clonal proliferation of Langerhans histiocytes in various parts of the body. These atypical cells have been found to infiltrate single or multiple organs, including bone, lungs, liver, spleen, lymph nodes, and skin. Central nervous system invasion in LCH patients has rarely been reported, especially in the adult population. METHODS AND RESULTS: We describe three histopathologically confirmed cases of adult LCH that involves both the pituitary stalk and hypothalamus, and report our limited experience of such cases in this location that has been treated with CyberKnife radio surgery. CONCLUSION: The treatment goal of controlling lesion growth is achieved by CyberKnife radiosurgery in this case series. All patients tolerated the treatment well without obvious complications.

A giant cell tumor of the cranial base treated by stereotactic radiosurgery.

Giant cell tumors (GCTs) developing from the cranial bones are rare. Occurrence of these tumors in the vicinity of eloquent areas precludes complete excision. Fractionated external beam radiotherapy (FEBRT) has been used for those cases, but with inconsistent outcomes. The authors report a case of a patient with a GCT involving the left occiput which was successfully treated by CyberKnife stereotactic radiosurgery (CK RS). There was improvement in the neurological deficit and occipital pain without adjunctive treatment. This is the first report of stereotactic radiosurgery (SRS) adopted as a primary treatment modality for a cranial GCT.