A modified, less invasive posterior subscapular approach to the brachial plexus: case report and technical note.

The traditional posterior subscapular approach offers excellent exposure of the lower brachial plexus and has been successfully used in patients with recurrent thoracic outlet syndrome after an anterior operation, brachial plexus tumors involving the proximal roots, and postirradiation brachial plexopathy, among others. However, this approach also carries some morbidity, mostly related to the extensive muscle dissection of the trapezius, rhomboids, and levator scapulae. In this article, the authors present the surgical technique and video illustration of a modified, less invasive posterior subscapular approach, using a small, self-retaining retractor and only a partial trapezius and rhomboid minor muscle dissection. This approach is likely to result in decreased postoperative morbidity and a shorter hospital stay.

Advances in the neurological and neurosurgical management of peripheral nerve trauma.

Peripheral nerve trauma frequently affects younger people and may result in significant and long-lasting functional disability. Currently, diagnosis and monitoring of peripheral nerve injury relies on clinical and electrodiagnostic information, supplemented by intraoperative electrophysiological studies. However, in a significant proportion of nerve injuries, the likelihood of spontaneous regeneration resulting in good functional outcome remains uncertain and unnecessary delays to treatment may be faced while monitoring for recovery. Advances in non-invasive imaging techniques to diagnose and monitor nerve injury and regeneration are being developed, and have the potential to streamline the decision-making process. In addition, advances in operative and non-operative treatment strategies may provide more effective ways to maximise functional outcomes following severe peripheral nerve trauma. This review discusses these advances in light of the current state of the art of management of peripheral nerve trauma.

Silas Weir Mitchell and "The Strange Case of George Dedlow".

It has been said of Silas Weir Mitchell (1829-1914) that as a young man he was first among the physiologists of his day, in middle age first among physicians, and as an older man, one of the most noted novelists of his country. Mitchell's novels were written in his later life as a means to avoid boredom during lengthy summer vacations that were the norm for that time among the affluent members of Philadelphia society. These novels were criticized by some because of poor plots, which in some instances failed to move along, or for text that offered a stereotyped depiction of genteel society and the effects that war or personal disaster had on the characters' behavior The criticism came despite the fact that all critics agreed that Mitchell's portrayals of psychopathology in his fictional characters was unique and accurate. However, in his 30s, Mitchell had written and by chance had published a fictional short story that not only transcended such criticisms but became immensely popular. "The Strange Case of George Dedlow" portrays a union officer who was not a physician but who had some medical background and who sustained a series of war wounds leading to severe nerve pain, the author's first description of causalgia, multiple amputations, and the psychological as well as physical symptoms of phantom limb syndrome. The protagonist tells of his torments in the first person in a very engaging fashion. Thus, long before he began writing his, at that time, acclaimed novels in the 1880s, Mitchell wrote a piece of fiction that combines accurate and very important medical observations with fiction of great historical interest. The following rendering of this now classic short story includes selected quotes and some interpretation and is perhaps appropriate for this year, 2 years after the centenary year of his death in 1914.

G. Carl Huber (1865-1934): A Michigan Pioneer in Peripheral Nerve Injury and Regeneration.

The treatment of peripheral nerve injuries has seen tremendous innovations over the past century. Dr Gotthelf Carl Huber, an American immigrant and early experimental pioneer in the field of peripheral nerve injury, created a foundation of scientific knowledge for these advancements. At the beginning of his career, Huber published novel work in peripheral nerve injury, supporting the concept of Wallerian degeneration and demonstrating the use of nerve grafting for repair. As his scientific career evolved into other research areas at the University of Michigan, Huber's impact extended far beyond just the study of peripheral nerve injury. Because of the external forces of the First World War, Dr Huber's focus returned to translational projects concentrated on the treatment of neuromas and war time peripheral nerve injuries. Huber's scientific impact in the field of peripheral nerve injury and repair came as a result of his incredible work ethic, mentorship, and tremendous leadership qualities; through this, his work still influences clinical practice today, a century later.

Axillary nerve injury associated with sports.

OBJECT: The aim of this retrospective study was to present and investigate axillary nerve injuries associated with sports. METHODS: This study retrospectively reviewed 26 axillary nerve injuries associated with sports between the years 1985 and 2010. Preoperative status of the axillary nerve was evaluated by using the Louisiana State University Health Science Center (LSUHSC) grading system published by the senior authors. Intraoperative nerve action potential recordings were performed to check nerve conduction and assess the possibility of resection. Neurolysis, suture, and nerve grafts were used for the surgical repair of the injured nerves. In 9 patients with partial loss of function and 3 with complete loss, neurolysis based on nerve action potential recordings was the primary treatment. Two patients with complete loss of function were treated with resection and suturing and 12 with resection and nerve grafting. The minimum follow-up period was 16 months (mean 20 months). RESULTS: The injuries were associated with the following sports: skiing (12 cases), football (5), rugby (2), baseball (2), ice hockey (2), soccer (1), weightlifting (1), and wrestling (1). Functional recovery was excellent. Neurolysis was performed in 9 cases, resulting in an average functional recovery of LSUHSC Grade 4.2. Recovery with graft repairs averaged LSUHSC Grade 3 or better in 11 of 12 cases CONCLUSIONS: Surgical repair can restore useful deltoid function in patients with sports-associated axillary nerve injuries, even in cases of severe stretch-contusion injury.

Peroneal nerve injury associated with sports-related knee injury.

OBJECT: This study analyzes 84 cases of peroneal nerve injuries associated with sports-related knee injuries and their surgical outcome and management. METHODS: The authors retrospectively reviewed the cases of peroneal nerve injury associated with sports between the years 1970 and 2010. Each patient was evaluated for injury mechanism, preoperative neurological status, electrophysiological studies, lesion type, and operative technique (neurolysis and graft repair). Preoperative status of injury was evaluated by using a grading system published by the senior authors. All lesions in continuity had intraoperative nerve action potential recordings. RESULTS: Eighty-four (approximately 18%) of 448 cases of peroneal nerve injury were found to be sports related, which included skiing (42 cases), football (23 cases), soccer (8 cases), basketball (6 cases), ice hockey (2 cases), track (2 cases) and volleyball (1 case). Of these 84 cases, 48 were identified as not having fracture/dislocation and 36 cases were identified with fracture/dislocation for surgical interventions. Good functional outcomes from graft repair of graft length < 6 cm (70%) and neurolysis (85%) in low-intensity peroneal nerve injuries associated with sports were obtained. Recovery from graft repair of graft length between 6 and 12 cm (43%) was good and measured between Grades 3 and 4. However, recovery from graft repair of graft length between 13 and 24 cm was obtained in only 25% of patients. CONCLUSIONS: Traumatic knee-level peroneal nerve injury due to sports is usually associated with stretch/contusion, which more often requires graft repair. Graft length is the factor to be considered for the prognosis of nerve repair.

Inflammatory pseudotumor of nerve: clinicopathological characteristics and a potential therapy.

We sought to determine the clinical, electrophysiological, neuroimaging, and pathological features of inflammatory pseudotumor of nerve. Five patients were identified. All cases presented with a gradually progressive mononeuropathy with symptoms of weakness, sensory loss, and prominent neuropathic pain. The median duration of symptoms was 7 months (range 3-36 months). Electrophysiological results were in keeping with chronic axonal mononeuropathies with variable findings of active denervation and reinnervation. MRI demonstrated irregular, large masses involving and surrounding nerve with heterogenous signal characteristics on T1- and T2-weighted and post-contrast sequences. Histopathological features of the nerve slightly varied but shared commonalities including chronic inflammatory infiltrates, increased collagen, and increased numbers of microvessels. Axonal degeneration and decreased density of myelinated fibers were also noted. Three patients were treated with weekly courses of intravenous steroids for 3 months. All reported improvement in pain and weakness. Inflammatory pseudotumor of nerve is not a neoplasm and has reactive features of inflammation, increased vascularity, and marked fibrosis. It presents as a progressive axonal mononeuropathy with weakness, sensory loss, and pain that may be episodic. The primary pathophysiology is unknown but the inflammation and response to treatment suggests that there may be an immune component.

Inside and somewhat outside Charity.

On August 29, 2005, a hurricane named Katrina struck the Gulf Coast. Many feared the consequences of such a storm, but very few believed that it could ever happen. This article is a narrative written shortly after the evacuation of patients and personnel from the flooded Charity Hospital. The days at Charity hospital were hot and humid following Katrina, and as time passed the air was permeated by a stench that was inescapable. Rendering care to patients without electricity, and thus light and air conditioning, with a temperature in the 90's and no running water was a challenge. Trying to cool patients with central fever and providing adequate ventilation for unconscious patients was extremely difficult. Without elevators, climbs up to and down from the 14th floor-where the author and his colleagues had their sleeping rooms-and the 12th (surgical intensive care unit [ICU]), seventh (neuro ICU and step-down units), and sixth (medical ICU) floors were tedious. The descent to check the emergency department and obtain a closer look at flooding in the streets around the hospital, which maintained a 4- to 5-foot water level, became prohibitive because of the contemplation of the necessary return ascent. There were 21 patients, mostly neurosurgical, in the neuro ICU and step-down units and wards. This is their story.

Hypertrophic mononeuropathy.

Hypertrophic localized mononeuropathy is a condition that comes to clinical attention as a painless focal swelling of a peripheral nerve in an arm or leg and is associated with a slow but progressive loss of motor and sensory function. Whether the proliferation of perineurial cells is neoplastic or degenerative--an ongoing controversy among nerve pathologists--for some patients resection of the involved portion of a nerve with autologous interposition grafting results in better functional outcome than allowing disease to follow its natural course. Patients with a painless focal enlargement of a nerve associated with progressive weakness and/or sensory loss may benefit from surgery for resection and grafting.

Tumors of the brachial plexus.

Tumors of the brachial plexus are relatively rare and present a clinical challenge for the neurosurgeon. The management of these tumors therefore requires not only an understanding of the complex anatomy of the brachial plexus but also an appreciation of the appropriate surgical approach to the various tumors that may be encountered. Over a 30-year period (1969-1999), 226 patients with brachial plexus tumors were evaluated and surgically treated by the senior authors (R.L.T., D.G.K.). In the present paper they review the most common benign and malignant brachial plexus tumors and discuss management and surgical principles established through their experience at the Louisiana State University Health Sciences Center.

Surgical approaches to paraspinal nerve sheath tumors.

OBJECT: The goal of this study was to analyze the results of surgical treatment of paraspinal nerve sheath tumors (NSTs) and review the surgical approaches to paraspinal NSTs. METHODS: A retrospective review of the cases of paraspinal NSTs treated surgically by two senior authors during the period between 1970 and 2006 was undertaken. Surgical approaches that allow minimal disruption of normal anatomy and are aimed at complete resection of paraspinal lesions and preservation of spinal stability are reviewed according to the spinal level. RESULTS: Eighty-eight paraspinal NSTs were treated surgically during the period: 56 schwannomas, seven solitary neurofibromas, 21 neurofibromas associated with neurofibromatosis Type 1 (NF1), and four malignant peripheral NSTs. Schwannomas tended to occur in the cervical and thoracic areas. Neurofibromas were usually associated with NF1 and tended to occur in the cervical area. Pain (79 patients, 90%) and paresthesia (81 patients, 92%) were the predominant clinical presenting symptoms; others included weakness (28 patients) and myelopathy (12 patients). Total resection of the tumor was achieved in 50 patients (89.3%) with schwannomas and 22 patients (78.6%) with neurofibromas. There was a large reduction of pain in 70 (88.6%) of 79 patients who had preoperative pain, and weakness improved in 18 (64.3%) of 28. Postoperative transient weakness occurred in 12 (42.9% ) of these patients, but in 85% of this group, the symptom improved over a 12-month period. Myelopathy was reduced in eight (66.7%) of 12 patients. The average follow-up period was 18 months. CONCLUSIONS: Paraspinal NSTs present unique surgical challenges given their anatomical relationships to the spine, spinal cord, nerve roots, and major vasculature. The surgical technique should take into account the location of the lesion and its relationship to paraspinal anatomy, the extent of resection, sparing of normal anatomy, and spinal instability.

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.

Surgical management and outcome of iatrogenic radial nerve injection injuries.

OBJECTIVE: Iatrogenic injury to the radial nerve can occur following intramuscular or intravenous injections of the upper extremity. In this study, we review the injury mechanism, operative techniques, and outcomes of patients evaluated for radial nerve injection injuries. METHODS: Data from 33 patients evaluated by the senior authors (DGK and DHK) from 1970-2011 with radial nerve injection injuries were reviewed retrospectively. All patients had injury of the nerve during injection. All corrective operations involved the use of direct intraoperative nerve action potential (NAP) recordings and either neurolysis, neurectomy, or suture/graft repair. The Louisiana State University Health Science (LSUHS) grading system was used for clinical assessment. RESULTS: Of the 33 patients, 23 underwent surgical intervention for persistent neurological deficit and/or pain. Of the 24 patients evaluated for injuries at the arm level, 17 required surgical exploration and repair for persistent symptoms. Nine patients required external neurolysis because the lesions were in continuity and positive NAP recording was across the lesion. All of these patients achieved a Grade 4 or better in functional recovery. Eight patients with lesions in continuity but in which NAP could not be recorded underwent either end-to-end suture (7) or graft repair (1) following resection of a 3.0 cm non-recordable segment. All patients achieved Grade 3 or 4 functional recovery. Six patients with forearm injuries involving the superficial sensory branch of radial nerve underwent either neurolysis (3) or neurectomy (3). CONCLUSIONS: Surgical exploration may be indicated when pain or disabling motor deficits persist. Early diagnosis and operative intervention can achieve favorable outcomes through exploration and radial nerve repair.

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.

Intraoperative positioning nerve injuries.

Intraoperative positioning nerve injuries are regrettable complications of surgery thought to arise from stretch and/or compression of vulnerable peripheral nerves. Generally thought to be preventable, these injuries still occur in patients despite rigorous preventative measures. Sometimes injuries, initially thought to be due to malpositioning, are caused by other factors, such as retraction injury or brachial plexitis. Because of the diversity of nerves susceptible to positioning injury, the clinician must be aware of a variety of presentations and must be able to distinguish them from other postoperative complaints. Prevention remains the mainstay of the management of positioning injuries. Diagnosed and managed appropriately, these lesions typically improve completely over time.

Direct plexus repair by grafts supplemented by nerve transfers.

This article reviews the Louisiana State University Health Sciences Center experience with direct repair of brachial plexus lacerations, gunshot wounds, and stretch/contusive/avulsive injuries. In the stretch category, limited outcomes with direct repair have led to addition of nerve transfers rather than their exclusive use. It is important to per-form direct plexus repair in conjunction with nerve transfers in the same patient when-ever possible. The intent of such a "pants-over-vest" approach is to maximize axonal input to denervated structures.

Surgical outcomes of 156 spinal accessory nerve injuries caused by lymph node biopsy procedures.

OBJECT: Iatrogenic injuries to the spinal accessory nerve (SAN) are not uncommon during lymph node biopsy of the posterior cervical triangle (PCT). In this study, the authors review the operative techniques and surgical outcomes of 156 surgical repairs of the SAN following iatrogenic injury during lymph node biopsy procedures. METHODS: This retrospective study examines the authors' clinical and surgical experience with 156 patients with SAN injury between 1980 and 2012. All patients suffered iatrogenic SAN injuries during lymph node biopsy, with the vast majority (154/156, 98.7%) occurring in Zone I of the PCT. Surgery was performed on the basis of anatomical and electro-physiological findings at the time of the operation. The mean follow-up period was 24 months (range 8-44 months). RESULTS: Of the 123 patients who underwent graft or suture repair, 107 patients (87%) improved to Grade 3 functionality or higher using the Louisiana State University Health Science Center (LSUHSC) grading system. Neurolysis was performed in 29 patients (19%) when the nerve was found in continuity with recordable nerve action potential (NAP) across the lesion. More than 95% of patients treated by neurolysis with positive NAP recordings recovered to LSUHSC Grade 3 or higher. Forty-one patients (26%) underwent end-to-end repair, while 82 patients (53%) underwent graft repair, and Grade 3 or higher recovery was assessed for 90% and 85% of these patients, respectively. The average graft length used was 3.81 cm. Neurotization was performed in 4 patients, 2 of whom recovered to Grade 2 and 3, respectively. CONCLUSIONS: SAN injuries present challenges for surgical exploration and repair because of the nerve's size and location in the PCT. However, through proper and timely intervention, patients with diminished or absent function achieved favorable functional outcomes. Surgeons performing lymph node biopsy procedures in Zone I of the PCT should be aware of the potential risk of injury to the SAN.