PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “LUMBOSACRAL PLEXUS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources
PubMed1974

Cell death in the embryonic chick spinal cord.

The events which occur in the death of visceromotor neurons of the cervical region of the chick embryo's spinal cord have been analyzed by electron microscopy. These normal degenerative events are compared with those in the lumbosacral cord where nerve cell death was induced by removal of peripheral organs. The initial set of degenerative changes include a decrease in nuclear size, the clumping of chromatin beneath the nuclear envelope, an increase in electron opacity of the cells, the disappearance of Golgi bodies, and the disaggregation of polysomes. These events are followed by the loss of the nuclear envelope and most of the endoplasmic reticulum, the appearance of bundles of filaments, and the formation of many ribosome crystals. Ribosome crystals are seen only in the dying cells. Their abundance may indicate a drastic reduction in RNA synthesis as one of the initial events which lead to the death of these neurons. The neurons are finally subdivided and engulfed by cells of the normal glial population, and further breakdown of the cell fragments occurs in large phagocytic vesicles of the gliocytes.

Animals↗
PubMed1969

Motor nerve terminals as the site of initial functional changes after denervation.

For the cat soleus nerve-muscle system, motor nerve section 48 hr prior to in situ experiment causes certain characteristic transmission losses. Responses to repetitive stimulation are sharply altered: The capacity to transmit iterative stimulation is severely reduced; post-tetanic potentiation and the post-tetanic repetition of soleus nerve terminals responsible for it are also greatly impaired; a phenomenon of post-tetanic depression was frequently observed. However, function of the extramuscular axons appears normal and single impulse transmission is usually not seriously affected. The loss of reactivity to repetitive stimulation has been traced to soleus motor nerve terminals. In view of these data and the known absence of denervation hypersensitivity at this time, the earliest functional failure may be said to occur in the unmyelinated terminals. This subacutely denervated preparation therefore offers a simple means of evaluating motor nerve terminal responsiveness.

Action Potentials↗
PubMed2004

Extracellular voltage profile for reversing the recruitment order of peripheral nerve stimulation: a simulation study.

Electrical stimulation of peripheral nerve activates large-diameter fibers before small ones. A physiological recruitment order, from small to large-diameter axons, is desirable in many applications. Previous studies using computer simulations showed that selective activation of small fibers could be achieved by reshaping the extracellular voltage profile along the nerve using an array of nine electrodes. In this study, several electrode-array configurations were tested in order to minimize the number of contacts. Electrode arrays of 5, 7, 9, and 11 contacts with 0.75 mm contact separation were performed in computer simulations of dog sacral root (S2). Electrode arrays of 5 and 7 contacts recruited 40% of small axons (<10 microm) when recruiting only 10% of larger axons. Effectiveness of 9- and 11-contact arrays decreased with the presence of epineurium and perineurium. The effectiveness of electrode arrays was independent of stimulation pulsewidth. The biphasic-pulse stimulation with the amplitude of the second phase set as low as possible should be used to prevent the excitation of large axons during the second phase and to minimize the electrode corrosion. Arrays of 5 and 7 contacts also decreased the recruitment curve slope to 26% and 51% of the tripolar electrode, respectively. This modeling study predicts that reversing the recruitment order of peripheral nerve stimulation could be achieved by reshaping the extracellular voltage using electrode arrays of 5 or 7 contacts.

Action Potentials↗
PubMed2000

Retroperitoneoscopic lumbar sympathectomy with balloon dissection: clinical experience.

PURPOSE: To describe our technique and clinical experience of retroperitoneoscopic lumbar sympathectomy with balloon dissection. PATIENTS AND METHODS: From 1995 to 1999, 23 procedures were performed. RESULTS: No complications were noted. The median hospital stay was 4 days. Of the 23 attempts, 2 had to be converted to open technique. Histologic examination demonstrated interruption of the sympathetic chain in 22 of the 23 cases and absence of nervous tissue in 1. CONCLUSIONS: Once the technique is mastered, it can be performed fast, and it offers patients the benefits of a minimally invasive approach without the inconsistent therapeutic results of chemical sympathectomy.

Aged↗
PubMed2005

Collapse in a 79-year-old: a rare case of amyloid tumour of the pelvis.

A 79-year-old man presented to accident and emergency with collapse, unable to bear weight on his left leg. Computed tomography revealed a large isolated lesion (28 x 12 x 8 cm) extending from the pelvis into the abdomen, affecting the left lumbrosacral nerves. Further investigations showed that the mass contained amyloid protein. With no evidence of systemic amyloidosis or malignancy a diagnosis of amyloidoma/amyloid tumour was made. This is the largest amyloid tumour reported in the literature to date. There is limited but conflicting evidence regarding the pathophysiology, management and prognosis of amyloidoma. Clearly amyloidomas are rare, but patients can present acutely and may have a poor prognosis, especially when the tumour is of considerable size.

Aged↗
PubMed1981

A primate model for age and host response to genital herpetic infection: determinants of latency.

Thirty five female Cebus albifrons monkeys (16 adolescents and 19 adults) were infected vaginally with herpes simplex virus (HSV) type 2. Fifteen developed spontaneous recurrent genital HSV infections. All 35 were killed for study eight to 12 months after primary infection, and tissue from the vagina, cervix, uterus, ovary, paracervical autonomic plexus, and lumbosacral dorsal root ganglia of eight animals. Host age was the most important variable influencing viral latency; 69% of adolescents and 42% of adults had latent HSV type 2 infections. Animals that developed latent infections were significantly easier to infect, shed virus during the primary infection significantly longer, and had more severe primary disease than those who did not become latently infected.

Aging↗
PubMed2000

Microvasculitis in non-diabetic lumbosacral radiculoplexus neuropathy (LSRPN): similarity to the diabetic variety (DLSRPN).

Diabetic lumbosacral radiculoplexus neuropathy (DLSRPN) has been shown to be due to ischemic injury from microvasculitis. The present study tests whether ischemic injury and microvasculitis are the pathologic cause of non-diabetic lumbosacral radiculoplexus neuropathy (LSRPN), and whether the pathologic alterations are different between LSRPN and DLSRPN. We studied distal cutaneous nerve biopsies of 47 patients with LSRPN and compared findings with those of 14 age-matched healthy controls and 33 DLSRPN patients. In both disease conditions, we found evidence of ischemic injury (multifocal fiber degeneration and loss, perineurial degeneration and scarring, characteristic fiber alterations, neovascularization, and injury neuroma) that we attribute to microvasculitis (mural and perivascular mononuclear inflammation of microvessels, inflammatory separation, fragmentation and destruction of mural smooth muscle, and previous microscopic bleeding [hemosiderin]). Teased nerve fibers in LSRPN showed significantly increased frequencies of axonal degeneration, segmental demyelination, and empty nerve strands. The segmental demyelination appeared to be clustered on fibers with axonal dystrophy. The nerves with abnormal frequencies of demyelination were significantly associated with nerves showing multifocal fiber loss. We reached the following conclusions: 1) LSRPN is a serious condition with much morbidity that mirrors DLSRPN. 2) Ischemic injury from microvasculitis appears to be the cause of LSRPN. 3) Axonal degeneration and segmental demyelination appear to be linked and due to ischemia. 4) The pathologic alterations in LSRPN and DLSRPN are indistinguishable, raising the question whether these 2 conditions have a common underlying mechanism, and whether diabetes mellitus contributes to the pathology or is a risk factor in DLSRPN. 5) Both LSRPN and DLSRPN are potentially treatable conditions.

Aged↗
PubMed2003

Anterior endoscopic treatment of a huge anterior sacral meningocele: technical case report.

OBJECTIVE AND IMPORTANCE: Anterior endoscopic treatment of a huge anterior sacral meningocele, a rare example of spinal dysraphism, is described. CLINICAL PRESENTATION: A 43-year-old woman presented with severe headache and fever, increasing abdominal pain, and a several-year history of right lower-extremity radicular pain. She exhibited meningeal irritation signs and Currarino's triad. Lumbosacral myelograms and magnetic resonance imaging scans revealed a huge anterior sacral cyst connected with the spinal subarachnoid space. INTERVENTION: A straight rigid endoscope was introduced into the meningocele through a small abdominal incision. The fistula between the meningocele and the spinal subarachnoid space was obliterated with multiple fat grafts harvested from the abdomen. CONCLUSION: An anterior endoscopic procedure is an alternative for the treatment of a huge anterior sacral meningocele.

Adult↗
PubMed2002

Ultrasound guidance for the psoas compartment block: an imaging study.

UNLABELLED: We conducted this study to develop an ultrasound-guided approach to the psoas compartment and to assess its feasibility and accuracy by means of computed tomography (CT). Two examiners performed ultrasound-guided approaches at three levels (L2-3, L3-4, and L4-5) on 10 embalmed cadavers, which were seated prone. After each needle had been advanced into the psoas compartment under ultrasound guidance, the positions of their tips were computed by using two coordinates (A and B). Subsequently, axial transverse CT scans were made to verify the ultrasound measurements by using the same coordinates. In total, 48 approaches were performed (Examiner 1, n = 20; Examiner 2, n = 28). CT revealed that 47 of 48 ultrasound-guided approaches were performed exactly. In 1 of 48 approaches (L3-4), the tip of the needle was located posterior to the psoas muscle. The median differences between ultrasound and CT coordinates were 0.3 plus minus 0.3 cm for A and 0.2 plus minus 0.3 for B. Kendall's coefficient of concordance was 0.9 (P < 0.001) between ultrasound and CT measurements for both coordinates. These results indicate that ultrasound enables exact needle placement, as proved by CT. We conclude that ultrasound guidance might be a useful adjunct to increase the safety and efficacy of the psoas compartment block at these levels. IMPLICATIONS: We developed an ultrasound-guided approach to the psoas compartment at the levels L2-3, L3-4, and L4-5. Feasibility and accuracy were tested on embalmed cadavers and verified by means of computed tomography. Ultrasound guidance proved to be feasible and accurate for the performance of psoas compartment blocks.

Aged↗
PubMed1976

Pedal vasomotor tone following aortofemoral reconstructions: a randomized study of concomitant lumbar sympathectomy.

A prospective randomized trial was undertaken to evaluate effects of lumbar sympathectomy as an adjunct to reconstructive surgery of the lower limb. The objective of this study was to assess the early postoperative effect of these procedures on pedal vasomotor tone. A pedal arterial resistance index (PARI) at rest was derived from the ratio of the ankle-digit systolic pressure gradient and pedal blood flow measured plethysmographically. Studies were performed on 32 normal individuals and pre- and postoperatively in 29 patients undergoing aortic reconstruction, 12 of whom were randomly chosen to have lumbar sympathectomy. The mean postoperative PARI in 17 patients who had reconstructions alone was 42+/-7 (S.E.M.) units which approximated the preoperative PARI (43+/-9 units) and normal control values (45+/-6 units). In contrast, 12 patients who had a concomitant lumbar sympathectomy had a significant reduction in the postoperative PARI (8+/-1 units, Pless than 0.005). These initial results indicate that the addition of lumbar sympathectomy to an aortic reconstruction may enhance blood flow to the foot by significantly reducing outflow resistance.

Adult↗
PubMed1976

Lumbar sympathectomy in end stage arterial occlusive disease.

Sixty-one patients had lumbar sympathectomies performed for end stage occlusive vascular disease manifested by gangrene of less than one-half of the foot, ulcerating ischemic lesions, rest pain or rapidly progressive markedly limiting intermittent claudication. The operative procedure was standardized to permit removal of the lowermost preganglionic fiber at the level of the crus of the diaphragm and the ganglionated chain to the crossing of the iliac vessels. The immediate postoperative mortality was 6.5% from cardiac causes. Over all improvement rate was 60% while early amputation rate was 40% for the entire group. Those patients with rest pain had the poorest prognosis with an amputation rate of 53%. The results are compared to other groups and factors of patient selection, anatomy of the sympathetic chain in relation to operative technique, physiology of decentralization versus devervation are discussed. The procedure is worthwhile in patients who are not candidates for arterial reconstruction who are faced with the prospect of early amputation.

Amputation, Surgical↗