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Biomedical subjects

D G Kline

Publications and source records attributed to D G Kline.

At least 37 records · Page 2Linked to original sources
PubMed1998

Resection and graft repair for localized hypertrophic neuropathy.

OBJECTIVES: Formulation of surgical management recommendations for localized hypertrophic mononeuropathy has been difficult because of the infrequency of the lesion, lack of precise pathological diagnosis, and uncertainties regarding its cause. The purpose of this retrospective review of the Louisiana State University (LSU) experience with this unusual neuropathy was to evaluate the efficacy of lesion resection and interposition grafting in its management. METHODS: The charts of 15 patients operated on at LSU during a 15-year period with a pathological diagnosis of localized hypertrophic neuropathy were reviewed. RESULTS: Hypertrophic lesions were located on major named peripheral nerves of the extremities, distributed equally to the upper and lower extremities. Family history was negative for all patients, and entrapment or trauma, other than previous surgery, were unlikely by symptom location or history. Weakness was the most common presentation. The mean length of symptoms was 76 months. Atrophy, sensory loss, Tinel's sign, focal tenderness, and a mass were found in the majority of patients. Preoperative electrophysiological studies showed chronic denervational changes in all patients. At surgery, if no action potential or one of low amplitude was recorded across the lesion, the lesion was resected and an autologous nerve graft measuring from 3.5 to 8.5 cm in length was interposed. During follow-up periods of 1 or more years, seven of nine patients with localized hypertrophic mononeuropathy treated with graft repairs were either unchanged or improved. CONCLUSION: Localized hypertrophic mononeuropathy is a progressive process associated with pathological nerve changes that correlate with eventual severe functional loss. If intraoperative histological examination shows onion bulb neuropathy and intraoperative nerve action potentials confirm a nonfunctioning or poorly functioning segment, lesion resection with interposition graft repair provides the possibility of some degree of recovery.

Action Potentials↗
PubMed1998

Management and results of sciatic nerve injuries: a 24-year experience.

OBJECT: The purpose of this retrospective clinical study was to present results and provide management guidelines for various types of sciatic injuries. METHODS: Over a 24-year period, 380 patients with sciatic nerve injuries were managed. In 230 patients (60%), the injury was at the buttock level, with injection injuries comprising more than half of these cases. Thigh-level sciatic injury was evaluated in 150 cases (40%) and was usually secondary to one of four main causes: 1) gunshot wound; 2) femur fracture; 3) laceration; or 4) contusion. Patients with partial deficits uncomplicated by severe pain or with significant spontaneous recovery or late referral were managed medically. Surgical exploration was not indicated in 23% of injuries at the thigh level and almost 50% of those at the buttock level. Most of these patients achieved partial but good spontaneous recovery, especially in the tibial division distribution. Surgical intervention was required for more complete and persistent deficits in either the tibial or peroneal distribution. Divisions of the sciatic nerve were split apart and evaluated independently. Management was guided by nerve action potential (NAP) recordings, which indicated whether neurolysis or resection of the lesion was required. Repair was then made by using sutures or more frequently by graft placement. In most cases in which neurolysis was performed because a positive NAP was recorded distal to the lesion, useful function was found in the peroneal distribution. Unfortunately, significant recovery occurred in only 36% of patients who received suture or graft repairs of the peroneal division. Good-to-excellent outcome was common for the tibial division, even in cases in which repair was proximal and required lengthy grafts. The relatively favorable recovery of tibial as opposed to peroneal divisions of the sciatic nerve occurred regardless of the level or mechanism of injury. CONCLUSIONS: Surgical exploration and, when necessary, repair of sciatic nerve injuries is worthwhile in selected cases.

Action Potentials↗
PubMed1998

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Central Nervous System↗
PubMed1997

Quality of life and functional outcome following brachial plexus injury.

Thirty-two patients (3 women, 29 men) participated in a mailed questionnaire survey to evaluate long-term subjective, employment, and functional outcome following surgical treatment for brachial plexus injury. The mean age was 37 years and mean postinjury time was 7 years. The main outcome measures were overall life satisfaction, employment status, and the impact of the brachial plexus injury on life domains. Quality-of-life questions were adapted from the interviewer form of the U.S. General Social Survey. Considering overall life satisfaction, 25 patients (78%) reported at least moderate satisfaction and no patients reported extreme dissatisfaction. Ten patients reported that their injury did affect to a great deal their overall quality of life and slightly more than half the patients were employed at the time of the study. These outcomes were not affected by such patient factors as coverage by workers' compensation, litigation, pain, marital status, number of children, educational status, and the degree of functional recovery. These patient factors also did not alter the impact of the injury on overall life satisfaction. In spite of the devastating nature of these injuries, this patient population for the most part reported good quality of life with employment status predicted within the first year following injury.

Adult↗
PubMed1997

Neurotization of motor nerves innervating the lower extremity by utilizing the lower intercostal nerves.

An animal model in the rat was developed to study the reinnervation of ventral roots contributing to lower-extremity nerves by use of intercostal nerves. Intercostal nerves and distal cauda equina roots were anastomosed, using a collagen tube and microsurgical technique. Most experimental animals could lift their previously paralyzed legs and could walk with a severe limp by 9 months postoperatively. Recordings of nerve action potentials (NAPs) and muscle action potentials (MAPs) indicated that the intercostal and sciatic nerves had some functional connections. Histologic analysis 12 months after repair demonstrated axonal regeneration extending from the intercostal nerves to and down lumbar ventral roots. Most of the regenerated fibers were moderately well-myelinated. Connections between the neurons of the anterior horn cells in the lower thoracic spinal cord and the reinnervated sciatic nerve were confirmed by retrograde tracer, using fast blue.

Action Potentials↗
PubMed1997

Ganglion cyst involvement of peripheral nerves.

Despite their benign histological appearance and the current literature composed primarily of case reports with favorable outcomes, ganglion cysts involving peripheral nerves (GCPNs) can cause permanent neurological deficits. The authors present a 27-year Louisiana State University Medical Center (LSUMC) experience with the surgical management of GCPNs. From 1968 to 1995, 27 patients were surgically treated for 27 cysts that involved nerves at nine locations. Cysts of the peroneal nerve were the most common, comprising 52% of the cases. Motor deficit, pain, and sensory changes were present in 83%, 78%, and 48% of cases, respectively. A history of acute trauma was noted in 22%. The mean follow-up duration in these cases was 61 months. Motor recovery was good in only 58% of cases and was related to the severity of the preoperative motor deficit. Pain resolved or was significantly improved in 89% of cases. Five patients underwent nine procedures before referral to LSUMC for treatment of recurrence of their ganglion cysts. None of these patients suffered recurrence after undergoing surgery at LSUMC. However, four additional patients (17%) experienced a total of six recurrences after undergoing their initial procedure. The mean time to recurrence for the patient group as a whole was 16 months. On the basis of their experience, the authors conclude that GCPNs can behave in an aggressive fashion. Patients should be counseled preoperatively about the potential for limited motor recovery and a significant chance for recurrence.

Adolescent↗
PubMed1996

Nerve action potential recording method and equipment.

OBJECTIVE: Nerve action potential (NAP) recording is a proven and useful tool in the surgical management of nerve injury. Understanding its materials and methods as well as its pitfalls and limitations is necessary for successful and routine use of this tool. METHODS: The basic electrophysiology of nerve and its implications in the setting of nerve trauma and regeneration are reviewed. Electrode design and electrode placement are discussed. The use of simple electromyographic/nerve conduction machines for intraoperative recording of NAPs is developed, along with some of the technical problems that result from electrophysiological recording in an electrically hostile environment. RESULTS: NAP recording is a good indicator of useful recovery in nerve trauma. The presence and demonstration of an NAP is associated with a 90% chance of recovery to a useful motor state. CONCLUSION: NAP recording provides useful information regarding the regenerative potential of a damaged nerve long before that potential is clinically evident. This information is critical in the optimal management of nerve injuries. The techniques of NAP recording are straightforward, but attention to detail is important, and full understanding of the method is required.

Action Potentials↗
PubMed1996

Management and results of peroneal nerve lesions.

OBJECTIVE: A retrospective analysis of clinical results in a relatively large series of peroneal nerve lesion is presented. Historically, such lesions have been difficult to manage successfully. METHODS: Between 1967 and 1991, 302 patients with either injury or tumor of the peroneal nerve at the knee were evaluated at Louisiana State University Medical Center. Mechanisms of injury included stretch injury with or without fracture, "sharp" or "blunt" laceration, gunshot wound, compression, entrapment, and iatrogenic injury. Surgery was performed on 183 of 276 patients (66%). If spontaneous recovery had not occurred 4 to 6 months after injury, patients were operated on and lesions in continuity were usually evaluated using nerve action potential recordings. RESULTS: Eighty-six patients required interfascicular grafts. Graft lengths varied from 4 to 20 cm (average, 10 cm). Grafts measured < 5.5 cm in some patients with blunt laceration, gunshot wound, or iatrogenic injury. Eighteen of 24 of those patients (75%) recovered peroneal function to Grade 3 or better, and a kickup foot brace was no longer needed to walk with a reasonable gait. Fourteen of 40 patients (35%) with graft lengths of 6 to 12 cm and only 3 of 22 patients (14%) with graft lengths of 13 to 20 cm recovered function to Grade 3 or better. Seventeen patients received end-to-end suture repair, and 14 (82%) recovered to Grade 3 or better by 24 months. After neurolysis, 71 of 80 patients (89%) with transmittable nerve action potentials across lesions in continuity recovered useful function despite severe preoperative functional loss in most cases. In addition, 24 tumors intrinsic to the peroneal nerve and two lesions caused by hypertrophic neuropathy were resected. CONCLUSION: Neural repair is the first priority in selected patients with peroneal nerve palsy. As with other nerve lesions, a timely operation and thorough intraoperative evaluation are necessary for optimal results.

Action Potentials↗
PubMed1996

Sodium channel accumulation in humans with painful neuromas.

Painful neuromas from 16 patients were examined using site-specific antisodium channel antibodies employed in immunocytochemical and radioimmunoassay methods. Normal sural nerves from six of these patients served as controls. Immunocytochemistry showed abnormal segmental accumulation of sodium channels within many axons in the neuromas. Dens immunolocalization was especially apparent within the axonal tips. Radioimmunoassay confirmed a significantly greater density of sodium channels in the neuromas as compared with the sural nerves. Thus, sodium channel accumulate abnormally within the axons of neuromas in humans. This alteration of the sodium channels may underlie the generation of axonal hyperexcitability and the resulting abnormal sensory phenomena (pain and paresthesias), which frequently occur after peripheral nerve injury.

Amino Acid Sequence↗
PubMed1995

Surgical outcome for intra- and extrapelvic femoral nerve lesions.

Seventy-eight traumatic neuropathies were seen in 94 patients with femoral nerve lesions; 54 of these were operated on because of persistent complete functional loss and/or pain. The most common mechanism of injury to the femoral nerve was iatrogenic due to inguinal herniorrhaphy, total hip replacement, intraabdominal vascular or gynecological operation, and, less commonly, appendectomy, lumbar sympathectomy, and laparoscopic procedures. Femoral nerve injuries also resulted from penetrating gunshot and stab wounds, laceration by glass, and stretch/contusive injuries associated with pelvic fractures. There were no signs of clinical or electrical recovery in 45 of 78 patients with traumatic nerve injuries. These and other partial injuries associated with pain were explored and evaluated by intraoperative nerve stimulation and recording of nerve action potentials (NAPs). Despite complete loss of nerve function preoperatively, 13 patients had recordable NAPs and underwent neurolysis; each recovered function to at least a Grade 3 level. Twenty-seven patients had sural graft repairs performed with graft lengths varying from 2.5 to 14 cm. Most patients had some nerve regeneration and regained function to Grade 3 to 4 levels by 2 years postoperatively. Four of five patients with suture repairs recovered to Grade 3 or better within 2 years postoperatively. Despite a proximal pelvic level for most of these injuries and, as a result, lengthy graft repairs, recovery of some useful function was the rule rather than the exception. Tumors involved the femoral nerve in 16 patients and included eight neurofibromas, four schwannomas, one neurogenic sarcoma, two ganglion cysts, and one leiomyosarcoma. All tumors were treated surgically and most were removed successfully.

Action Potentials↗
PubMed1994

Labeled Schwann cell transplants versus sural nerve grafts in nerve repair.

This study evaluated the ability of Schwann cell transplants to enhance the recovery of function in injured nerves and compared the results to those produced by sural nerve grafts. Schwann cells were isolated from sciatic nerves, prelabeled with gold fluorescent dye admixed with collagen gel, and placed in resorbable collagen tubes. Twenty-four adult rats underwent severing of the bilateral sciatic nerves, with a 10-mm gap between the nerve stumps. The rats were then divided into two groups. A collagen tube with implanted Schwann cells was implanted in one leg of the Group I rats, and the contralateral leg served as a control and was repaired with a collagen tube filled with collagen gel only. The Group II animals received conduits packed with labeled Schwann cells in one leg to bridge the 10-mm gap; the contralateral leg was repaired with an autogenous sural nerve graft. Recovery of function was assessed physiologically and morphologically. Nerve conduction velocity and nerve action potential amplitude measurements showed that the Schwann cell implants induced return of function comparable to that of the sural nerve grafts. Morphological assessments of myelination suggested a tendency toward greater numbers of myelinated axons in Schwann cell implants than in sural nerve grafts. Anatomical analyses of gold fluorescent dye showed both high viability of prelabeled Schwann cells at 120 days after transplantation and migration as far as 30 mm away from the implant site.

Animals↗
PubMed1994

Neural sheath tumors of major nerves.

Over a 22-year period, operations were performed on 263 patients for 288 primary benign tumors of major peripheral nerves. The tumors included 85 schwannomas, 197 neurofibromas, and six plexiform neurofibromas. Total removal was achieved in 83 of the 85 schwannomas, and 76 of these patients were available for follow-up evaluation. Motor function either improved or was unchanged in 87% of these patients and 85% of those with pain in the distribution of the involved nerve had either total or partial resolution of their symptoms. Of the neurofibromas, 123 occurred in 121 patients without von Recklinghausen's disease. All tumors within this group were completely excised using a fascicular approach to the tumor. Of the 99 patients available for follow-up evaluation, 90% had either improved or unchanged motor function and 88% had partial or complete resolution of pain syndromes. Fifty-nine patients with von Recklinghausen's disease had 80 tumors removed: 74 fusiform tumors (58 of which were completely removed) and six plexiform tumors. Forty-eight of the 58 patients with gross total removal of fusiform tumors were available for follow-up evaluation, of whom 83% had improved or unchanged motor function and 74% had partial or complete resolution of pain syndromes. All six patients with plexiform tumors had progression of symptoms postoperatively. One brachial plexus schwannoma recurred and was re-excised without subsequent recurrence at the 5-year follow-up evaluation. Several incompletely excised plexiform neurofibromas have recurred with a symptomatic presentation.

Adult↗
PubMed1994

Windmill pitcher's radial neuropathy.

The authors present two cases of severe radial nerve injury with different sites of pathology but a similar mechanism: the "windmill" pitching motion of competitive softball. Both patients required surgical intervention with neurolysis, and both improved postoperatively. The literature on related radial nerve injuries is briefly reviewed and pathophysiological mechanisms are discussed.

Adolescent↗
PubMed1993

Is laser repair effective for secondary repair of a focal lesion in continuity?

It is possible to seal nerve ends together with the laser, and this can be effective for sharp injuries that are repaired relatively acutely or primarily. The possibility of utilizing the laser for secondary nerve repair after resection of a lesion in continuity was investigated in a rat sciatic nerve model. After baseline recording of nerve and muscle action potentials (MAP), a 3-mm-long crush injury of the sciatic nerve was performed bilaterally in 12 rats. Two weeks later, the crushed segment was resected, and the nerve on one side was repaired by end-to-end anastomosis using epineurial sutures and on the other side by sealing the nerve ends together with the CO2 laser. At reexploration 50 days postoperatively, all 12 suture repairs were anatomically in continuity and conducted a nerve action potential (NAP), while 10 of the 12 laser-repaired nerves had distracted. Laser repairs not distracted showed electrical and histologic evidence of regeneration. It is concluded that laser repair is not effective for delayed repair of lesions in continuity unless tension at the repair site can be lessened.

Action Potentials↗
PubMed1993

Somatosensory evoked potentials induced by stimulating a variable number of nerve fibers in rat.

Somatosensory evoked potentials (SEPs) were recorded from rat spinal cord (sSEPs) and cerebral cortex (cSEPs). Stimulus sites included either one or both sural nerve branches having different fiber populations (group A), or distal to a lesion of controlled size of the sural nerve made 1 week earlier (group B). In the two groups of animals, amplitudes of SEPs correlated with the quantity of large myelinated nerve fibers. Peak latencies of sSEPs in group A related to the ratio of sizes of transmitting fibers. sSEPs and cSEPs in both groups A and B could be recorded in a reproducible fashion by stimulating sural nerve branches or lesioned nerve trunks containing only 100 or less nerve fibers greater than 4 microns in size. Thus, presence of sSEPs or cSEPs after stimulation distal to a lesion site does not insure that many nerve fibers have continuity with the central nervous system (CNS).

Animals↗