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Journal of Visualized Experiments : JoVE Jan 2023The tibial neuroma transposition (TNT) is a rat model in which allodynia at the neuroma site (tibial nerve) can be independently evaluated from allodynia at the plantar...
The tibial neuroma transposition (TNT) is a rat model in which allodynia at the neuroma site (tibial nerve) can be independently evaluated from allodynia at the plantar surface of the hind paw innervated by the intact sural nerve. This TNT model is suitable to test therapies for neuroma pain, such as the potential superiority of certain surgical therapies that are already used in the clinic, or to evaluate new drugs and their effect on both pain modalities in the same animal. In this model, a distal lesion (neurotmesis) is made in the tibial nerve, and the proximal nerve end is transposed and fixed subcutaneously and pretibially to enable assessments of the neuroma site with a 15 g Von Frey monofilament. To assess allodynia over the sural nerve, Von Frey monofilaments can be used via the up-down method on the plantar lateral region of the hind paw. After cutting the tibial nerve, mechanical hypersensitivity develops at the neuroma site within 1 week after surgery and persists at least until 12 weeks after surgery. Allodynia at the sural innervated plantar surface develops within 3 weeks after surgery compared to the contralateral limb. At 12 weeks, a neuroma forms on the proximal end of the severed tibial nerve, indicated by dispersion and swirling of axons. For the TNT model surgery, multiple critical (micro)surgical steps need to be followed, and some surgery practice under terminal anesthesia is advised. Compared to other neuropathic pain models, such as the spared nerve injury model, allodynia over the neuroma site can be independently tested from sural nerve hypersensitivity in the TNT model. However, the neuroma site can be tested only in rats, not in mice. The tips and directions provided in this protocol can help research groups working on pain successfully implement the TNT model in their facility.
Topics: Rats; Mice; Animals; Hyperalgesia; Disease Models, Animal; Tibial Nerve; Neuralgia; Neuroma
PubMed: 36688541
DOI: 10.3791/64659 -
Journal of Nephrology Jul 2023Impaired mobility is a debilitating consequence of hemodialysis. We examined the efficacy of intradialytic-plantar-electrical-nerve-stimulation (iPENS) to promote... (Randomized Controlled Trial)
Randomized Controlled Trial
Intradialytic plantar electrical nerve stimulation to improve mobility and plantar sensation among adults with diabetes undergoing hemodialysis: a randomized double-blind trial.
BACKGROUND
Impaired mobility is a debilitating consequence of hemodialysis. We examined the efficacy of intradialytic-plantar-electrical-nerve-stimulation (iPENS) to promote mobility among diabetes patients undergoing hemodialysis..
METHODS
Adults with diabetes undergoing hemodialysis received either 1-h active iPENS, (Intervention-Group) or non-functional iPENS (Control-Group) during routine hemodialysis for 12 weeks (3 sessions/week). Participants and care-providers were blinded. Mobility (assessed using a validated pendant-sensor) and neuropathy (quantified by vibration-perception-threshold test) outcomes were assessed at baseline and 12 weeks.
RESULTS
Among 77 enrolled subjects (56.2 ± 2.6 years old), 39 were randomly assigned to the intervention group, while 38 were assigned to the control group. No study-related adverse events and dropouts were reported in the intervention group. Compared to the control group, significant improvements with medium to large effect sizes were observed in the intervention group at 12 weeks for mobility-performance metrics, including active-behavior, sedentary-behavior, daily step counts, and sit-to-stand duration variability (p < 0.05), Cohen's d effect size (d = 0.63-0.84). The magnitude of improvement in active-behavior was correlated with improvement in the vibration-perception-threshold test in the intervention group (r = - 0.33, p = 0.048). A subgroup with severe-neuropathy (vibration-perception-threshold > 25 V) showed a significant reduction in plantar numbness at 12 weeks compared to baseline (p = 0.03, d = 1.1).
CONCLUSIONS
This study supports feasibility, acceptability, and effectiveness of iPENS to improve mobility and potentially reduce plantar numbness in people with diabetes undergoing hemodialysis. Considering that exercise programs are not widely used in hemodialysis clinical practice, iPENS may serve as a practical, alternative solution to reduce hemodialysis-acquired weakness and promote mobility.
Topics: Humans; Adult; Middle Aged; Hypesthesia; Renal Dialysis; Diabetes Mellitus; Exercise; Sensation
PubMed: 37326952
DOI: 10.1007/s40620-023-01625-9 -
American Journal of Veterinary Research Jun 2024The objective of this study was to optimize an MRI-based diffusion tensor imaging (DTI) protocol for imaging the plantar nerves at the level of the tarsus in normal...
OBJECTIVE
The objective of this study was to optimize an MRI-based diffusion tensor imaging (DTI) protocol for imaging the plantar nerves at the level of the tarsus in normal equine limbs.
SAMPLE
12 pelvic cadaver limbs from horses without evidence of proximal suspensory pathology were imaged with a 3T MRI system.
METHODS
For diffusion-weighted imaging, b values of 600, 800, and 1,000 s/mm2 were tested. Data were processed with DSI Studio. Cross-sectional areas of the medial and lateral plantar nerve along the plantar tarsus were recorded. The length and number of fiber tracts, signal-to-noise ratio, and DTI variables were recorded.
RESULTS
At the level of interest, the mean cross-sectional areas of the plantar nerves ranged from 5.03 to 7.42 mm2. The DTI maps consistently generated tracts in the region of the lateral and medial plantar nerves with DTI values in the range of values reported for peripheral nerves in humans. Our findings demonstrate that DTI of the medial and lateral plantar nerves can be performed successfully and used to generate quantitative parameters including fractional anisotropy and mean, axial, and radial diffusivity.
CLINICAL RELEVANCE
Quantitative data generated with this imaging technique can be used to noninvasively characterize the microstructural integrity of neural tissue with possible applications in the evaluation of pathologic changes to the plantar tarsal and metatarsal nerves of horses with proximal suspensory desmopathy.
PubMed: 38889743
DOI: 10.2460/ajvr.24.03.0092 -
Dermatologic Surgery : Official... Dec 2021Palmar and plantar hyperhidrosis (HH) is a common condition characterized by excessive sweating of the palms and soles. Botulinum neurotoxin (BTX) is a very effective... (Review)
Review
BACKGROUND
Palmar and plantar hyperhidrosis (HH) is a common condition characterized by excessive sweating of the palms and soles. Botulinum neurotoxin (BTX) is a very effective and safe treatment. However, the associated intense injection pain is a major limiting factor deterring patients from selecting this treatment.
OBJECTIVE
The aim of this study was to review the numerous techniques used to minimize pain accompanying injections for palmoplantar HH. Additionally, the advantages and limitations of each modality will be discussed.
MATERIALS AND METHODS
The authors performed a comprehensive literature search in PubMed/MEDLINE, Embase, Cochrane Central, and Google Scholar on randomized controlled trials, cohort studies, and case series on techniques to relieve pain of BTX injections for treatment of palmar and plantar HH.
RESULTS
Current available techniques in reducing botulinum injection with merits and drawbacks are nerve blocks, Bier blocks, cryoanalgesia, needle-free anesthesia, topical anesthetics, and vibration anesthesia.
CONCLUSION
Topical anesthesia, ice, and vibration are the safest and most convenient noninvasive available methods to relieve pain associated with botulinum injection. Nerve blocks, Bier block, and needle-free anesthesia provide better anesthesia but are limited by the need for training and equipment.
Topics: Anesthesia; Botulinum Toxins; Humans; Hyperhidrosis; Injections; Pain, Procedural
PubMed: 34743126
DOI: 10.1097/DSS.0000000000003182 -
Pediatric Neurology Mar 2023Childhood cancer survivors (CCS) are at risk of polyneuropathy due to chemotherapy, but studies in young survivors are scarce and diagnosis is challenging. We aimed to...
BACKGROUND
Childhood cancer survivors (CCS) are at risk of polyneuropathy due to chemotherapy, but studies in young survivors are scarce and diagnosis is challenging. We aimed to study the presence of polyneuropathy and the possible effect of cumulative doses of chemotherapeutic agents in a representative group of adolescent survivors.
METHODS
CCS aged nine to 18 years and age- and sex-matched controls were recruited from the cross-sectional Physical Activity and Fitness among Childhood Cancer Survivors (PACCS) study. CCS with various cancer diagnoses who had ended cancer treatment one year or more before study were included. Polyneuropathy was evaluated clinically and with nerve conduction studies (NCSs) in three motor and five sensory nerves. We used mixed-effects linear regression models to compare CCS and controls, and investigate possible associations between cumulative chemotherapy doses and NCS amplitudes.
RESULTS
A total of 127 CCS and 87 controls were included, with 14% CCS having probable or confirmed polyneuropathy. NCS amplitudes were lower in survivors compared with controls in all nerves. The largest mean difference was 3.47 μV (95% confidence interval [CI], 2.18 to 4.75) in the tibial plantar medial sensory and 1.91 mV (95% CI, 0.78 to 3.04) in the tibial motor nerve. The cumulative dose of platinum derivatives was associated with lower tibial motor nerve amplitude (-0.20; 95% CI, -0.35 to -0.04 mV for 100 mg/m dose increase) but not in other nerves. We found no significant associations between vinca alkaloids cumulative dose and amplitudes.
CONCLUSIONS
CCS without clinical signs or symptoms of polyneuropathy may have subtle nerve affection. The clinical long-term impact of this novel observation should be evaluated in larger, longitudinal studies.
Topics: Humans; Child; Adolescent; Cancer Survivors; Cross-Sectional Studies; Neoplasms; Polyneuropathies; Exercise
PubMed: 36586183
DOI: 10.1016/j.pediatrneurol.2022.11.012 -
European Journal of Applied Physiology Jun 2021Distal lower limb motor impairment impacts gait mechanics in individuals with cerebral palsy (CP), however, the contribution of impairments of muscle activation to...
PURPOSE
Distal lower limb motor impairment impacts gait mechanics in individuals with cerebral palsy (CP), however, the contribution of impairments of muscle activation to reduced gross motor function (GMF) is not clear. This study aimed to investigate deficits in plantar flexion voluntary activation capacity in CP compared to typically developed (TD) peers, and evaluate relationships between voluntary activation capacity, strength and GMF.
METHODS
Fifteen ambulant individuals with spastic CP (23 ± 6 years, GMFCS I-III) and 14 TD (22 ± 2 years) people participated. Plantar- and dorsiflexion strength were assessed with a dynamometer. Voluntary activation capacity was assessed using the interpolated twitch technique via single twitch supramaximal tibial nerve stimulation. GMF was assessed using the timed upstairs test, 10 m walk test, muscle power sprint test and six-minute walk test.
RESULTS
Plantar- and dorsiflexion strength were 55.6% and 60.7% lower in CP than TD (p < 0.001). Although voluntary activation capacity was 17.9% lower on average for CP than TD (p = 0.039), 46.7% of individuals with CP achieved a sufficiently high activation to fall within one standard deviation of the TD mean. Plantar flexion voluntary activation capacity did not correlate with strength (R = 0.092, p = 0.314) or GMF measures in the high functioning CP group (GMFCS I-II).
CONCLUSION
In contrast to previous research, plantar flexion activation capacity did not strongly predict weakness or reduced GMF. We propose that muscle size contributes more to weakness than voluntary activation capacity in high functioning individuals with CP and that relationships between muscle activation and functional capacity are complicated by effects at multiple joints.
Topics: Adolescent; Adult; Cerebral Palsy; Electromyography; Female; Foot; Gait Disorders, Neurologic; Humans; Isometric Contraction; Lower Extremity; Male; Muscle Strength
PubMed: 33687530
DOI: 10.1007/s00421-021-04638-z -
Journal of Ultrasonography Sep 2023To present the anatomy of the tarsal tunnel and demonstrate the utility of high-resolution ultrasound for tarsal tunnel examination.
AIM OF THE STUDY
To present the anatomy of the tarsal tunnel and demonstrate the utility of high-resolution ultrasound for tarsal tunnel examination.
MATERIALS AND METHODS
Anatomical dissection was performed on a defrosted cadaveric model to demonstrate relevant anatomical structures of the tarsal tunnel, namely tendons, vessels and nerves. The tibial nerve division was demonstrated; the bifurcation of the tibial nerve into the medial and lateral plantar nerve, two medial calcaneal nerve branches were identified originating from the tibial nerve and the Baxter's nerve was identified as the first branch of the lateral plantar nerve. An ultrasound examination of the tarsal tunnel region was performed on a healthy volunteer. A linear probe was used and sonographic images were obtained at different levels of the tarsal tunnel: the proximal tarsal tunnel, the tibial nerve division into the medial and lateral plantar nerves, the distal tarsal tunnel, the Baxter's nerve branching point and the Baxter's nerve crossing between the abductor hallucis and quadratus plantae muscle.
RESULTS
Sonographic images were correlated with anatomical structures exposed during cadaveric dissection.
CONCLUSIONS
We presented the anatomic-sonographic correlation of the tarsal tunnel and showed that high-resolution ultrasound is a useful imaging modality for tarsal tunnel assessment.
PubMed: 37701055
DOI: 10.15557/jou.2023.0023 -
Journal of Applied Physiology... Nov 2020Tissue-directed stretching interventions can preferentially load muscular or nonmuscular structures such as peripheral nerves. How these tissues adapt mechanically to... (Randomized Controlled Trial)
Randomized Controlled Trial
Tissue-directed stretching interventions can preferentially load muscular or nonmuscular structures such as peripheral nerves. How these tissues adapt mechanically to long-term stretching is poorly understood. This randomized, single-blind, controlled study used ultrasonography and dynamometry to compare the effects of 12-wk nerve-directed and muscle-directed stretching programs versus control on maximal ankle dorsiflexion range of motion (ROM) and passive torque, shear wave velocity (SWV; an index of stiffness), and architecture of triceps surae and sciatic nerve. Sixty healthy adults were randomized to receive nerve-directed stretching, muscle-directed stretching, or no intervention (control). The muscle-directed protocol was designed to primarily stretch the plantar flexor muscle group, whereas the nerve-directed intervention targeted the sciatic nerve tract. Compared with the control group [mean; 95% confidence interval (CI)], muscle-directed intervention showed increased ROM (+7.3°; 95% CI: 4.1-10.5), decreased SWV of triceps surae (varied from -0.8 to -2.3 m/s across muscles), decreased passive torque (-6.8 N·m; 95% CI: -11.9 to -1.7), and greater gastrocnemius medialis fascicle length (+0.4 cm; 95% CI: 0.1-0.8). Muscle-directed intervention did not affect the SWV and size of sciatic nerve. Participants in the nerve-directed group showed a significant increase in ROM (+9.9°; 95% CI: 6.2-13.6) and a significant decrease in sciatic nerve SWV (> -1.8 m/s across nerve regions) compared with the control group. Nerve-directed intervention had no effect on the main outcomes at muscle and joint levels. These findings provide new insights into the long-term mechanical effects of stretching interventions and have relevance to clinical conditions where change in mechanical properties has occurred. This study demonstrates that the mechanical properties of plantar flexor muscles and sciatic nerve can adapt mechanically to long-term stretching programs. Although interventions targeting muscular or nonmuscular structures are both effective at increasing maximal range of motion, the changes in tissue mechanical properties (stiffness) are specific to the structure being preferentially stretched by each program. We provide the first in vivo evidence that stiffness of peripheral nerves adapts to long-term loading stimuli using appropriate nerve-directed stretching.
Topics: Adaptation, Physiological; Adult; Ankle Joint; Biomechanical Phenomena; Humans; Muscle Stretching Exercises; Muscle, Skeletal; Range of Motion, Articular; Single-Blind Method; Torque
PubMed: 32853116
DOI: 10.1152/japplphysiol.00239.2019 -
Arthroscopy Techniques Dec 2022Closed-wedge high tibial osteotomy (CWHTO) may be carried out to realign the knee in patients with knee osteoarthritis who do not meet the criteria for open-wedge high...
Closed-wedge high tibial osteotomy (CWHTO) may be carried out to realign the knee in patients with knee osteoarthritis who do not meet the criteria for open-wedge high tibial osteotomy or total knee arthroplasty. The procedure involves both fibular and tibial osteotomy, and care is needed to prevent peroneal nerve and vessel injury during fibular osteotomy. Notably, use of a tourniquet may mask the development of hematomas or aneurysms until after surgery. We developed a 3-step ankle-angle-adjusting (triple-A) technique to relax the muscles, allowing easy retraction of the peroneal vessels. Crucially, the procedure does not require a tourniquet, thus allowing bleeding to be detected and stopped during surgery. The process involves adjusting the ankle angle by plantar-flexion and applying varus stress to highlight the tension difference between the lateral and posterior compartments; plantar-flexion of the great toe to loosen the flexor hallucis longus muscle, thus exposing the fibular posterior aspect; and valgus stress to loosen the peroneus longus muscle. The muscles can then be retracted sufficiently to allow distal and proximal osteotomies to be performed, and any bleeding can be detected and resolved before wound closure. This technique may improve the ease and safety of fibular osteotomy in patients undergoing CWHTO.
PubMed: 36632397
DOI: 10.1016/j.eats.2022.08.018 -
The Korean Journal of Pain Jan 2022Thrombospondin-4 (TSP4) upregulates in the spinal cord following peripheral nerve injury and contributes to the development of neuropathic pain (NP). We investigated the...
BACKGROUND
Thrombospondin-4 (TSP4) upregulates in the spinal cord following peripheral nerve injury and contributes to the development of neuropathic pain (NP). We investigated the effects of cyanocobalamin alone or in combination with morphine on pain and the relationship between these effects and spinal TSP4 expression in neuropathic rats.
METHODS
NP was induced by chronic constriction injury (CCI) of the sciatic nerve. Cyanocobalamin (5 and 10 mg/kg/day) was administered 15 days before CCI and then for 4 and 14 postoperative days. Morphine (2.5 and 5 mg/kg/day) was administered only post-CCI. Combination treatment included cyanocobalamin and morphine, 10 and 5 mg/kg/day, respectively. All drugs were administered intraperitoneally. Nociceptive thresholds were detected by esthesiometer, analgesia meter, and plantar test, and TSP4 expression was assessed by western blotting and fluorescence immunohistochemistry.
RESULTS
CCI decreased nociceptive thresholds in all tests and induced TSP4 expression on the 4th postoperative day. The decrease in nociceptive thresholds persisted except for the plantar test, and the increased TSP4 expression reversed on the 14th postoperative day. Cyanocobalamin and low-dose morphine alone did not produce any antinociceptive effects. High-dose morphine improved the decreased nociceptive thresholds in the esthesiometer when administered alone but combined with cyanocobalamin in all tests. Cyanocobalamin and morphine significantly induced TSP4 expression when administered alone in both doses for 4 or 14 days. However, this increase was less when the two drugs are combined.
CONCLUSIONS
The combination of cyanocobalamin and morphine is more effective in antinociception and partially decreased the induced TSP4 expression compared to the use of either drug alone.
PubMed: 34966013
DOI: 10.3344/kjp.2022.35.1.66