-
Experimental and Toxicologic Pathology... Sep 2014The representative areas for examination of the mouse peripheral nervous system are the spinal cord, containing central components of the peripheral nervous system that... (Review)
Review
The representative areas for examination of the mouse peripheral nervous system are the spinal cord, containing central components of the peripheral nervous system that needs to be examined at least at cervical and lumbar level, the sciatic and the tibial nerve. Skeletal muscle samples should include the soleus muscle and the quadriceps femoris or long digital extensor, as well as the medial gastrocnemius. Examination can be extended to the thoracic spinal cord, lumbar dorsal root ganglia and spinal nerve roots, as well as the plantar nerve, and other areas of interest. Perfusion fixation is considered optimal for the nervous system; however, immersion fixation allows producing microscopic sections of excellent quality as well. Paraffin-embedded, hematoxylin and eosin-stained sections can be made from all areas, save for small nerves such as the tibial or plantar nerve, which are examined with advantage in hard plastic sections. It is possible to produce hard plastic sections also of the vertebral column, including the spinal cord, dorsal root ganglia and nerve roots. For special investigations, mice can be fixed in toto, decalcified, embedded and sectioned to reveal the areas of interest. In the mouse peripheral nerves, myelination progresses until the adult age. In aging peripheral nerves there is axonal atrophy, degeneration, nerve fiber loss, increase of collagen and sporadic demyelination, especially radiculoneuropathy. The dorsal root ganglia of untreated control animals show frequent cytoplasmic vacuolation. Axonal degeneration is distally, primary demyelination proximally accentuated. Mouse is not very sensitive to peripheral neurotoxicity: to induce toxic peripheral neuropathy mostly parenteral administration and/or newborn animals are used. Naturally occurring infection affecting the spinal cord and peripheral nerves is Theiler's encephalomyelitis virus inducing acute poliomyelitis or chronic demyelination. Any experimental results are to be assessed taking into account spontaneous, age-related, background changes.
Topics: Aging; Animals; Disease Models, Animal; Mice; Peripheral Nervous System; Spinal Cord; Tissue Culture Techniques
PubMed: 24867273
DOI: 10.1016/j.etp.2014.04.005 -
Plantar compartment block for hallux valgus surgery: a proof-of-concept anatomic and clinical study.Regional Anesthesia and Pain Medicine Feb 2024Hallux valgus surgery is associated with moderate to severe postoperative pain. We hypothesized that a plantar compartment block may be a good technique for...
BACKGROUND
Hallux valgus surgery is associated with moderate to severe postoperative pain. We hypothesized that a plantar compartment block may be a good technique for postoperative analgesia. We describe an anatomic approach to ultrasound-guided plantar compartment block and assess the clinical efficacy of the block for outpatient surgery.
METHODS
The anatomic study was aimed to describe the plantar compartment, using both dissection methods and imaging, and to define a volume of local anesthetic. Patients scheduled for hallux valgus surgery with a popliteal sciatic nerve block, and combined plantar compartment and peroneal blocks were included in the clinical study. Data on attaining the criteria for rapid exit from the outpatient center, duration of sensory and analgesic block, visual analog scale (VAS) values for postoperative pain at rest and during movement, and the consumption of morphine as rescue analgesia were recorded.
RESULTS
Plane-by-plane dissections and cross-sections were done in five cadaveric lower limbs. The medial calcaneal nerve divides into medial plantar and lateral plantar nerves in the upper part of the plantar compartment. These nerves were surrounded by 5 mL of colored gelatin, and 10 mL of injectates dye spread to the medial calcaneal branches. Thirty patients (26 women) were included in the clinical study. There were no failures of surgical block. Ninety per cent of patients successfully passed functional testing for ambulatory exit from the center within 5 hours (25th-75th centiles, 3.8-5.5 hours). The median duration of plantar compartment sensory block was 17.3 hours (10.5-21.5 hours), and the first request for rescue analgesic was 11.75 hours (10.5-23 hours) after surgery. The median VAS score for maximum pain reported within the 48-hour period was 2 (1-6). Twelve patients received 2.5 mg (0-5 mg) of morphine on day 1. Patients were highly satisfied and no adverse events were noted.
CONCLUSIONS
This anatomic description of the ultrasound-guided plantar compartment block reported the injection area to target the medial and lateral plantar nerves with 5 mL of local anesthetic. Normal walking without assistance is attained rapidly with this regional anesthesia technique, and the time to request postoperative analgesia after hallux valgus surgery is long.
TRIAL REGISTRATION NUMBER
NCT03815422.
PubMed: 38373818
DOI: 10.1136/rapm-2023-105246 -
Anatomical Science International Mar 2010The tibial nerve (TN) has three main terminal branches: the medial and lateral plantar nerves and the calcaneal branch (CB), which innervates the foot sole. The design...
The tibial nerve (TN) has three main terminal branches: the medial and lateral plantar nerves and the calcaneal branch (CB), which innervates the foot sole. The design and implantation of nerve cuff electrodes with separate channels for each of these three terminal branches would provide significant sensory information, which can be used in functional electrical stimulation systems to assist standing or to correct foot drop. Detailed quantitative anatomical data about fascicular size and separability of the terminal branches of TN are needed for the design and implantation of such cuff electrodes. Therefore, the branching pattern, the fascicular separability and the fascicular size of the TN posterior to the medial malleolar-calcaneal axis were examined in this study, using ten human TN specimens. The TN branching patterns were highly dispersed. For the CBs, multiple branches were identified in five (50%) of the specimens. For the TN, the bifurcation point was located within the tarsal tunnel in eight (80%) of the cases. The distance proximal to the medial malleolar-calcaneal axis for which the TN could be split ranged form 0 to 41 mm. Quantitative and qualitative data were obtained for the fascicular size and separability of the TN. Only the CB of the TN proved separable for a sufficient length for nerve cuff electrode implantation. The results suggest the use of a two-channel cuff with one common channel for the lateral and medial plantar nerves, having multiple electrodes for selective recording, and one channel for the CB.
Topics: Calcaneus; Foot; Humans; Tibial Nerve
PubMed: 19449089
DOI: 10.1007/s12565-009-0045-y -
Restorative Neurology and Neuroscience Jan 1994Hand injuries with nerve lesions often leave the patient with a persistent sensory deficit, particularly with respect to glabrous skin. The present study examines axonal...
Hand injuries with nerve lesions often leave the patient with a persistent sensory deficit, particularly with respect to glabrous skin. The present study examines axonal regeneration in the foot branch of the superficial peroneal nerve (fSPN) and the lateral plantar nerve (LPN), supplying hairy skin and glabrous skin together with some intrinsic muscles, respectively, after sciatic nerve lesions in the rat. Following crush lesions, the number of myelinated axons is normal in the fSPN, and the occurrence of C-fibers appears slightly reduced. In the LPN, the numbers of myelinated axons and C-fibers are both significantly increased. Post-crush regenerated myelinated fSPN and LPN axons show normal size ranges, but the proportion of small myelinated axons is increased. After neurotomy and suture, the numbers of myelinated axons and C-fibers in the fSPN are not significantly different from normal. The LPN exhibits a significantly increased number of myelinated axons, but the number of C-fibers is not significantly abnormal. In both nerves, the myelinated axons present an abnormally narrow size range. These findings show that the quantitative outcome of regeneration in a nerve innervating glabrous skin (and some intrinsic muscles) differs significantly from that of branches to hairy skin of the foot, with respect to myelinated as well as unmyelinated axons. To what extent these differences mirror functional differences awaits elucidation.
PubMed: 21551768
DOI: 10.3233/RNN-1994-7104 -
Der Anaesthesist Nov 2007Despite the increasing use of ultrasound, electrical nerve stimulation is commonly used as the standard for both plexus and peripheral nerve blocks. Several recent... (Review)
Review
Despite the increasing use of ultrasound, electrical nerve stimulation is commonly used as the standard for both plexus and peripheral nerve blocks. Several recent randomized trials have contributed to a better understanding of physiological and clinical correlations. Traditionally used currents and impulse widths are better defined in relation to the distance between needle tip and nerves. Commercially available devices enable transcutaneous nerve stimulation and provide new opportunities for the detection of puncture sites and for training. The electrically ideal position of the needle usually is defined by motor responses which can not be interpreted without profound anatomical knowledge. For instance, interscalene blocks can be successful even after motor responses of deltoid or pectoral muscles. Infraclavicular blocks should be aimed at stimulation of the posterior fascicle (extension). In contrast to multiple single nerve blocks, axillary single-shot blocks more commonly result in incomplete anaesthesia. Blockade of the femoral nerve can be performed without any nerve stimulation if the fascia iliaca block is used. Independently of the various approaches to the sciatic nerve, inversion and plantar flexion are the best options for single-shot blocks. Further clinical trials are needed to define the advantages of stimulating catheters in continuous nerve blocks.
Topics: Catheterization; Electric Stimulation; Humans; Nerve Block; Peripheral Nerves
PubMed: 17896093
DOI: 10.1007/s00101-007-1238-1 -
Cureus Jan 2022Introduction Advanced glycation end-products (AGEs) have the potential to serve as biomarkers of aging and metabolic diseases; however, how their expression relates to...
Introduction Advanced glycation end-products (AGEs) have the potential to serve as biomarkers of aging and metabolic diseases; however, how their expression relates to clinical symptoms is not well defined. In this study, we sought to determine whether the accumulation of pentosidine, one type of AGE, at the peripheral nerve is associated with cutaneous pain or hypersensitivity caused by ovariectomy (OVX). Methods We assigned 12-week-old female Sprague Dawley rats into either the OVX group (n = 6) or the sham group (n = 6). Cutaneous hindpaw sensitivity to mechanical stimuli was measured with von Frey filaments, using Chaplan's adapted method, and the 50% withdrawal threshold was calculated. Then, the accumulation of pentosidine, which represents AGEs, was measured in sciatic nerve fibers after staining with an anti-pentosidine antibody. Results OVX rats showed significantly increased plantar hypersensitivity to mechanical stimuli compared to sham rats 8 weeks after OVX ( = 0.017). Pentosidine-positive sciatic nerves were detected at a higher rate in OVX rats than in sham rats ( = 0.035). The pentosidine positivity rate in sciatic nerve fibers showed a negative correlation with withdrawal threshold ( < 0.001). Conclusions This study showed that higher levels of pentosidine in sciatic nerve fibers are associated with higher plantar hypersensitivity. Accumulation of pentosidine at the sciatic nerve, caused by OVX, may result in cutaneous hindpaw hypersensitivity.
PubMed: 35165537
DOI: 10.7759/cureus.21059 -
Physical Therapy Oct 2022This study aims to evaluate the effectiveness of neural mobilization (NM) in the management of sensory dysfunction and nerve degeneration related to experimental painful...
OBJECTIVE
This study aims to evaluate the effectiveness of neural mobilization (NM) in the management of sensory dysfunction and nerve degeneration related to experimental painful diabetic neuropathy (PDN).
METHODS
This is a pre-clinical animal study performed in the streptozocin-induced diabetic rat model. Three groups were included: a treatment group of rats with PDN receiving NM under anesthesia (PDN-NM, n = 10), a sham treatment group of rats with PDN that received only anesthesia (PDN-Sham, n = 9), and a vehicle control group with nondiabetic animals (Vehicle, n = 10). Rats in the PDN-NM and PDN-Sham groups received 1 treatment session on days 10, 12, and 14 after streptozocin injection, with a 48-hour rest period between sessions. Behavioral tests were performed using von Frey and Plantar tests. Evaluation for peripheral nerve degeneration was performed through measuring protein gene product 9.5-positive intra-epidermal nerve fiber density in hind-paw skin biopsies. All measurements were performed by a blinded investigator.
RESULTS
The behavioral tests showed that a single NM session could reduce hyperalgesia, which was maintained for 48 hours. The second treatment session further improved this treatment effect, and the third session maintained it. These results suggest that it requires multiple treatment sessions to produce and maintain hypoalgesic effects. Skin biopsy analysis showed that the protein gene product 9.5-positive intra-epidermal nerve fiber density was higher on the experimental side of the PDN-NM group compared with the PDN-Sham group, suggesting NM may mitigate the degeneration of peripheral nerves.
CONCLUSION
This study demonstrated that NM may be an effective method to manage experimentally induced PDN, potentially through mitigation of nerve degeneration. Further studies are needed to develop standardized protocols for clinical use.
IMPACT
These findings provide neurophysiological evidence for the use of NM in PDN and can form the basis for the development of physical therapy-based programs in clinics.
Topics: Animals; Rats; Diabetes Mellitus; Diabetic Neuropathies; Nerve Degeneration; Peripheral Nerves; Streptozocin
PubMed: 35913760
DOI: 10.1093/ptj/pzac104 -
Journal of Ultrasound in Medicine :... Jun 2018High-resolution ultrasonography (US) can play an important role in studying nerves, as it has several advantages. Entrapments of distal tibial nerve branches can be...
OBJECTIVES
High-resolution ultrasonography (US) can play an important role in studying nerves, as it has several advantages. Entrapments of distal tibial nerve branches can be mapped out or diagnosed with selective anesthetic blocks, and US can guide therapeutic procedures, such as radiofrequency ablation and selective infiltrations of specific nerve branches. The aim of this study was to verify that US is an effective method for accurately locating the posterior tibial nerve and its terminal branches, such as the medial calcaneal branch, the first calcaneal branch, and the medial and lateral plantar nerves.
METHODS
In this study, we analyzed the correlation between US mapping and real anatomy after cadaveric dissection, assessing the distribution and variability of the tibial nerve and its terminal branches. We used 12 fresh anatomic specimens of the foot and ankle, including the calf. A high-resolution US study of the tibial nerve and its branches was performed.
RESULTS
The results of the US studies of the anatomic specimens were drawn as paper diagrams and in data collection tables. Both were completed twice per anatomic specimen, first using the results of the US study and second using the results from dissection of the anatomic specimens; this approach enabled us to compare the results and verify whether the US study and the dissection correlated on the topography of the tibial nerve and its terminal branches. We found almost total agreement between the US and dissection results, with no significant differences between the evaluations.
CONCLUSIONS
On the basis of this work, we can conclude that high-resolution US is almost 100% effective as a tool for identifying the tibial nerve and its branches, enabling the specialist to make diagnoses or perform selective treatments on each nerve branch and even to design surgical interventions by observing the patient's anatomy before performing the dissection.
Topics: Cadaver; Foot; Humans; Prospective Studies; Reproducibility of Results; Tibial Nerve; Ultrasonography
PubMed: 29205431
DOI: 10.1002/jum.14499 -
American Family Physician Jun 2014When choosing an infiltrative anesthetic agent, the type of procedure, the length of time required for anesthesia, and the pharmacodynamics of each medication are...
When choosing an infiltrative anesthetic agent, the type of procedure, the length of time required for anesthesia, and the pharmacodynamics of each medication are important considerations. Distraction techniques and buffering with sodium bicarbonate can be used to decrease the pain associated with injection. Local cutaneous infiltration is the most commonly used anesthetic technique and involves direct injection into the area requiring anesthesia. Field blocks provide anesthesia by circumferentially blocking innervation to the area. Nerve blocks target the innervation to a specific area and are useful on the face and digits. Using easily identifiable landmarks, blockade of the supraorbital, supratrochlear, infraorbital, and mental nerves can provide site-specific anesthesia. Dorsal and palmar or plantar digital nerve blocks can be performed at a variety of locations on the hands and feet.
Topics: Ambulatory Surgical Procedures; Anesthesia, Local; Anesthetics, Local; Humans; Nerve Block; Pain
PubMed: 25162162
DOI: No ID Found -
Foot & Ankle International Oct 2017The purpose of this study was to assess the risk of iatrogenic injury to plantar neurovascular structures of the foot during insertion of a curved retrograde...
BACKGROUND
The purpose of this study was to assess the risk of iatrogenic injury to plantar neurovascular structures of the foot during insertion of a curved retrograde tibiotalocalcaneal (TTC) fusion nail.
MATERIAL AND METHODS
Ten below-knee thawed fresh-frozen cadaveric specimens underwent curved retrograde nailing of the ankle. The shortest distance between the nail and the main plantar neurovascular branches and injured structures were recorded during dissection. We also evaluated the relative position of these structures along 2 lines (AB, connecting the calcaneus to the first metatarsal, and BC, connecting the first and fifth metatarsal).
RESULTS
The lateral plantar artery was found to be in direct contact with the nail 70% of the time, with a macroscopic laceration 30% of the time. The Baxter nerve was injured 20% of the time, as was the lateral plantar nerve. The medial plantar artery and nerve were never injured. The most proximal structure to cross line AB was the Baxter nerve followed by the lateral plantar artery, the nail, the lateral plantar nerve, and the medial plantar nerve.
CONCLUSION
Our cadaveric anatomic study found that the most common structures at risk for iatrogenic injury by lateral curved retrograde TTC fusion nails were the lateral plantar artery and nerve, and the Baxter nerve.
CLINICAL RELEVANCE
Determination of a true neurovascular safe zone is challenging and therefore warrants careful operative dissection to minimize neurovascular injuries.
Topics: Aged; Ankle Joint; Arthrodesis; Bone Nails; Cadaver; Calcaneus; Dissection; Foot; Humans; Iatrogenic Disease; Male; Middle Aged; Sensitivity and Specificity; Tibia; Tibial Arteries; Tibial Nerve
PubMed: 28731802
DOI: 10.1177/1071100717715909