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European Journal of Vascular and... May 2010Damage to the sural nerve (SuN) may arise from surgical stripping or thermal ablation of the small saphenous vein (SSV).
BACKGROUND
Damage to the sural nerve (SuN) may arise from surgical stripping or thermal ablation of the small saphenous vein (SSV).
OBJECTIVE
This study aims to demonstrate that visualisation of the SuN and its point of contact with the SSV ('risk point') using ultrasound imaging can be achieved in routine clinical practice.
TYPE OF STUDY
This is a cohort study.
PATIENTS
Fifteen normal subjects and five patients with chronic venous insufficiency (CVI) (two with a dilated, incompetent SSV).
METHOD
The SuN was identified using high-resolution ultrasound imaging using 14- and 18-MHz probes. Two manoeuvres were found to improve visualisation: (1) the contrast of the nerve was increased compared with the other tissues by varying the angle of insonation; and (2) the transducer was moved up and down the limb for a short distance during transverse imaging of the calf. The muscles and other soft tissues appeared 'out of focus', whereas the SuN retained both shape and echogenicity. Once the nerve has been identified, proceeding proximally, the point of separation of the two components is often detectable. It is then possible to follow the two different nerves observing the medial sural cutaneous nerve (MSCN) inside the 'triangle' of connective tissue below the SSV joining the tibial nerve and the lateral sural cutaneous nerve (LCSN) joining the common peroneal nerve, which runs inside a tiny fascial duplication. The extent of nerves, which were identified, was recorded in each limb as well as their anatomical distribution.
RESULTS
The SuN and the point at which it might be at risk were identified on ultrasound images in 39 of 40 limbs (97%) studied. In transverse section, it was readily identified within the saphenous compartment. It lies in close proximity to the SSV only in the distal third of the limb, where the two components of the nerve: MSCN, a branch of the tibial nerve; and LSCN, a branch of the common peroneal nerve join together. The relationship between the SuN and the SSV is very variable, with the nerve running separately or in close contact with the vein for variable distances, in many different combinations.
CONCLUSIONS
The SuN and 'risk point' can be identified by ultrasonography (US). We propose that this technique could be used to prevent damage to the SuN during surgical or thermal ablation of the SSV and during Achilles tendon surgery.
Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Chronic Disease; Cohort Studies; Female; Humans; Male; Middle Aged; Saphenous Vein; Sural Nerve; Trauma, Nervous System; Ultrasonography, Doppler, Duplex; Varicose Veins; Vascular Surgical Procedures; Venous Insufficiency
PubMed: 20018530
DOI: 10.1016/j.ejvs.2009.11.024 -
Brain and Behavior Aug 2017The progression and pathophysiology of neuropathy in impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) is poorly understood, especially in relation to...
OBJECTIVES
The progression and pathophysiology of neuropathy in impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) is poorly understood, especially in relation to autophagy. This study was designed to assess whether the presence of autophagy-related structures was associated with sural nerve fiber pathology, and to investigate if endoneurial capillary pathology could predict the development of T2DM and neuropathy.
PATIENTS AND METHODS
Sural nerve physiology and ultrastructural morphology were studied at baseline and 11 years later in subjects with normal glucose tolerance (NGT), IGT, and T2DM.
RESULTS
Subjects with T2DM had significantly lower sural nerve amplitude compared to subjects with NGT and IGT at baseline. Myelinated and unmyelinated fiber, endoneurial capillary morphology, and the presence and distribution of autophagy structures were comparable between groups at baseline, except for a smaller myelinated axon diameter in subjects with T2DM and IGT compared to NGT. The baseline values of the subjects with NGT and IGT who converted to T2DM 11 years later demonstrated healthy smaller endoneurial capillary and higher -ratio versus subjects who remained NGT. At follow-up, T2DM showed a reduction in nerve conduction, amplitude, myelinated fiber density, unmyelinated axon diameter, and autophagy structures in myelinated axons. Endothelial cell area and total diffusion barrier was increased versus baseline.
CONCLUSIONS
We conclude that small healthy endoneurial capillary may presage the development of T2DM and neuropathy. Autophagy occurs in human sural nerves and can be affected by T2DM. Further studies are warranted to understand the role of autophagy in diabetic neuropathy.
Topics: Adult; Aged; Autophagy; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Neuropathies; Female; Glucose Intolerance; Glucose Tolerance Test; Humans; Longitudinal Studies; Male; Middle Aged; Neural Conduction; Sural Nerve
PubMed: 28828222
DOI: 10.1002/brb3.763 -
Muscle & Nerve Nov 2016The aim of this study was to compare results of orthodromic sural nerve conduction studies (NCS) using ultrasound-guided needle positioning (USNP) to those of surface...
INTRODUCTION
The aim of this study was to compare results of orthodromic sural nerve conduction studies (NCS) using ultrasound-guided needle positioning (USNP) to those of surface electrode recordings.
METHODS
Fifty-one healthy subjects, aged 24-80 years, divided into 5 age groups, were examined. Electrical stimuli were applied behind the lateral malleolus. Sensory nerve action potentials (SNAPs) were recorded 8 and 15 cm proximally with surface and needle electrodes.
RESULTS
Mean SNAP amplitudes (surface / needle electrodes) averaged 12.7 (SD 7.6) μV / 40.6 (SD 20.8) μV (P < 0.001) for subjects aged 20-29 years, and 5.0 (SD 2.4) μV / 19.8 (SD 9.8) μV (P < 0.01) for subjects >60 years of age. SNAP amplitudes were smaller at the proximal recording location.
CONCLUSIONS
NCS using USNP yield higher amplitude responses than surface electrodes in all age groups at all recording sites. SNAP amplitudes are smaller at proximal recording locations due to sural nerve branching. Muscle Nerve 54: 879-882, 2016.
Topics: Action Potentials; Adult; Age Factors; Aged; Aged, 80 and over; Aging; Female; Humans; Male; Middle Aged; Needles; Neural Conduction; Neurologic Examination; Reference Values; Sural Nerve; Ultrasonography; Young Adult
PubMed: 27061276
DOI: 10.1002/mus.25133 -
Neurology India 2022Sensory nerve conduction parameters in Guillain Barre Syndrome (GBS) are underemphasized.
BACKGROUND
Sensory nerve conduction parameters in Guillain Barre Syndrome (GBS) are underemphasized.
OBJECTIVE
To describe abnormalities on sensory conduction studies in a large cohort of prospectively evaluated patients of GBS and to correlate with clinico-electrophysiological features.
METHODS AND MATERIALS
Sensory conduction parameters of three nerves (median, ulnar, and sural) were analyzed using standard protocols in 238 patients (M: F 163:75, mean age: 35.76 ± 15.9 years). Electrophysiological subtyping was based on criteria of Hadden et al., and Rajabally et al.
RESULTS
Among patients with "typical" GBS who underwent electrophysiological testing within 30 days of symptom-onset (n = 219), 183 (83.5%) had abnormal sensory potentials (one nerve = 52, two nerves = 77, all three nerves = 54). Frequency of abnormalities in sensory potentials increased with duration of illness. Commonest abnormality was reduced amplitude or in-excitable nerves. Mean amplitude and velocity of median and ulnar nerve sensory potentials were significantly lower among those with demyelinating electrophysiology (P < 0.05). Proportion of subjects with reduced amplitude and velocity of median and ulnar nerve sensory potentials was higher among those who required mechanical ventilation (P < 0.05). Frequency of "sural sparing" ranged from 10.5% to 84.5% depending on the criteria used and almost always was significantly associated with demyelinating neuropathy.
CONCLUSION
This prospective study provides comprehensive data on sensory conduction parameters in GBS. Abnormalities are frequent and vary with duration of illness. While median nerve is most frequently and more severely affected, involvement of sural nerve may have prognostic value.
Topics: Humans; Young Adult; Adult; Middle Aged; Guillain-Barre Syndrome; Prospective Studies; Sural Nerve; Neural Conduction; Respiration, Artificial
PubMed: 36537422
DOI: 10.4103/0028-3886.364073 -
Turkish Journal of Medical Sciences Apr 2021The aim of the present study was to determine the course and possible variations of the sural nerve with all anatomical details in human fetal cadavers.
BACKGROUND/AIM
The aim of the present study was to determine the course and possible variations of the sural nerve with all anatomical details in human fetal cadavers.
MATERIALS AND METHODS
This study was performed on 60 fetal cadavers. Formation type and level of the sural nerve was detected.
RESULTS
According to trimesters, it was determined that the mean transverse and vertical distance between the lowest point of the LM and the SN varied between 1.1 and 2.9 mm and 1.54 and 3.58 mm, respectively. Type 2 was the most common seen type of sural nerve (35.83%). It was determined that the sural nerve was mostly formed at the middle third of the leg (42.5%).
CONCLUSION
Sural nerve graft with the knowledge of the anatomical details may be used for peripheral nerve reconstruction is required in congenital lesions, such as facial paralysis, obstetric brachial paralysis, and posttraumatic lesions in infants and children.
Topics: Cadaver; Child; Dissection; Female; Fetus; Gestational Age; Humans; Infant; Leg; Male; Peripheral Nerve Injuries; Pregnancy; Pregnancy Trimesters; Plastic Surgery Procedures; Sural Nerve
PubMed: 32718120
DOI: 10.3906/sag-2005-225 -
Neurology Jul 2021The primary objective of this study was to evaluate the correlation of large mitochondrial DNA (mtDNA) deletions in skin samples of people with HIV (PWH) with measures... (Clinical Trial)
Clinical Trial
OBJECTIVE
The primary objective of this study was to evaluate the correlation of large mitochondrial DNA (mtDNA) deletions in skin samples of people with HIV (PWH) with measures of neuropathy and prior exposure to therapy. We hypothesized that deletions would be associated with neuropathy. As secondary objectives, we determined the correlation of deletion burden with demographic data and neuropathy measures.
METHODS
In this retrospective cohort study, we measured the accumulation of large mtDNA deletions in skin biopsies from PWH recruited as part of the AIDS Clinical Trials Group (ACTG). Our cohort includes individuals with and without sensory neuropathy, as well as individuals with normal or abnormal skin biopsies. Skin biopsies, sural and peroneal nerve conduction studies, total neuropathy score, and deletion burden scores were measured, along with baseline demographic data such as age, CD4+ cell count, viral counts, and prior nucleoside reverse transcriptase inhibitor exposures.
RESULTS
Sixty-seven PWH were enrolled in the study. The mean age of the cohort (n = 67) was 44 years (SD 6.8, range 32-65 years), and 9 participants were female. The mean CD4+ T-cell count was 168 cells/mm (SD 97 cells/mm, range 1-416 cells/mm) and mean viral load was 51,129 copies/mL (SD 114,586 copies/mL, range 147-657,775 copies/mL). We determined that there was a correlation between the total mtDNA deletion and intraepidermal nerve fiber density (IENFD) ( = -0.344, = 0.04) and sural nerve amplitude ( = -0.359, = 0.004).
CONCLUSIONS
Both IENFD and sural nerve amplitude statistically correlate with mitochondrial mutation burden in PWH, specifically in those with HIV-associated sensory neuropathy as assessed by skin biopsy.
Topics: Adult; DNA, Mitochondrial; Female; HIV Infections; Humans; Male; Middle Aged; Mutation; Peripheral Nervous System Diseases; Peroneal Neuropathies; Retrospective Studies; Skin; Sural Nerve
PubMed: 33947785
DOI: 10.1212/WNL.0000000000012142 -
Knee Surgery, Sports Traumatology,... Jun 2023Several authors have described methods to predict the sural nerve pathway with non-proportional numerical distances, but none have proposed a person-proportional,...
PURPOSE
Several authors have described methods to predict the sural nerve pathway with non-proportional numerical distances, but none have proposed a person-proportional, reproducible method with anatomical references. The aim of this research is to describe ultrasonographically the distance and crossing zone between a surface reference line and the position of the sural nerve.
METHODS
Descriptive cross-sectional study, performed between January and April 2022 in patients requiring foot surgery who met inclusion criteria. The sural nerve course in the posterior leg was located and marked using ultrasound. Landmarks were drawn with a straight line from the medial femoral condyle to the tip of the fibula. Four equal zones were established in the leg by subdividing the distal half of the line. This way, areas based on simple anatomical proportions for each patient were studied. The distance between the marking and the ultrasound nerve position was measured in these 4 zones, creating intersection points and safety areas. Location and distances from the sural nerve to the proposed landmarks were assessed.
RESULTS
One-hundred and four lower limbs, 52 left and 52 right, assessed in 52 patients were included. The shortest median distance of the nerve passage was 2.9 mm from Point 2. The sural nerve intersection was 60/104 (57.7%) in Zone B, 21/104 (20.1%) in Zone C and 19/104 (18.3%) in Zone A. Safety zones were established. Average 80.5% of coincidence in sural nerve localization was found in the distal half of the leg, in relation to the surface reference line when comparing both legs of each patient.
CONCLUSIONS
This study proposes a simple, reproducible, non-invasive and, for the first time, person-proportional method, that describes the distance and location of the main areas of intersection of the sural nerve with points and zones (risk and safe zones) determined by a line guided by superficial anatomical landmarks. Its application when surgeons plan and perform posterior leg approaches will help to avoid iatrogenic nerve injuries.
LEVEL OF EVIDENCE
IV.
Topics: Humans; Leg; Sural Nerve; Cross-Sectional Studies; Fibula; Ultrasonography; Cadaver
PubMed: 36571617
DOI: 10.1007/s00167-022-07294-8 -
Scientific Reports Dec 2017The blood-nerve barrier (BNB), formed by tight junction-forming microvessels within peripheral nerve endoneurium, exists to regulate its internal microenvironment...
The blood-nerve barrier (BNB), formed by tight junction-forming microvessels within peripheral nerve endoneurium, exists to regulate its internal microenvironment essential for effective axonal signal transduction. Relatively little is known about the unique human BNB molecular composition. Such knowledge is crucial to comprehend the relationships between the systemic circulation and peripheral nerves in health, adaptations to intrinsic or extrinsic perturbations and alterations that may result in disease. We performed RNA-sequencing on cultured early- and late-passage adult primary human endoneurial endothelial cells and laser-capture microdissected endoneurial microvessels from four cryopreserved normal adult human sural nerves referenced to the Genome Reference Consortium Human Reference 37 genome browser, using predefined criteria guided by known transcript or protein expression in vitro and in situ. We identified 12881 common transcripts associated by 125 independent biological networks, defined as the normal adult BNB transcriptome, including a comprehensive array of transporters and specialized intercellular junctional complex components. These identified transcripts and their interacting networks provide insights into peripheral nerve microvascular morphogenesis, restrictive barrier formation, influx and efflux transporters with relevance to understanding peripheral nerve homeostasis and pharmacology, including targeted drug delivery and the mediators of leukocyte trafficking in peripheral nerves during normal immunosurveillance.
Topics: Adult; Blood-Nerve Barrier; Cells, Cultured; Endothelial Cells; Female; Gene Expression Profiling; Humans; Laser Capture Microdissection; Male; Middle Aged; Primary Cell Culture; Sciatic Nerve; Sequence Analysis, RNA; Sural Nerve; Transcriptome
PubMed: 29234067
DOI: 10.1038/s41598-017-17475-y -
Journal of Neurology, Neurosurgery, and... Jul 1978The excitabilities of separate fibre populations were examined in the ulnar nerve in 74 healthy subjects, and in the posterior tibial, peroneal, and sural nerves in 23...
The excitabilities of separate fibre populations were examined in the ulnar nerve in 74 healthy subjects, and in the posterior tibial, peroneal, and sural nerves in 23 of these subjects. Square wave electric stimuli of varying duration were applied to the nerve in different locations, while recording the evoked muscle or nerve action potential. "Threshold" strengthduration curves were derived for motor, sensory, and mixed nerve fibre populations. These curves did not vary significantly one from another, in upper versus extremity, or over time. No correlations between excitability and other measures of peripheral nerve function were observed. Excitability appears to reflect some element of nerve structure or function other than myelin.
Topics: Action Potentials; Adolescent; Adult; Electric Stimulation; Electrophysiology; Evoked Potentials; Female; Humans; Male; Motor Neurons; Muscles; Nerve Fibers; Neural Conduction; Peroneal Nerve; Sural Nerve; Tibial Nerve; Ulnar Nerve
PubMed: 690642
DOI: 10.1136/jnnp.41.7.642 -
Yonsei Medical Journal Dec 2006Neuropathic pain can be divided into sympathetically maintained pain (SMP) and sympathetically independent pain (SIP). Rats with tibial and sural nerve transection (TST)...
Neuropathic pain can be divided into sympathetically maintained pain (SMP) and sympathetically independent pain (SIP). Rats with tibial and sural nerve transection (TST) produce neuropathic pain behaviors, including spontaneous pain, tactile allodynia, and cold allodynia. The present study was undertaken to examine whether rats with TST would represent SMP- or SIP-dominant neuropathic pain by lumbar surgical sympathectomy. The TST model was generated by transecting the tibial and sural nerves, leaving the common peroneal nerve intact. Animals were divided into the sympathectomy group and the sham group. For the sympathectomy group, the sympathetic chain was removed bilaterally from L2 to L6 one week after nerve transection. The success of the sympathectomy was verified by measuring skin temperature on the hind paw and by infra red thermography. Tactile allodynia was assessed using von Frey filaments, and cold allodynia was assessed using acetone drops. A majority of the rats exhibited withdrawal behaviors in response to tactile and cold stimulations after nerve stimulation. Neither tactile allodynia nor cold allodynia improved after successful sympathectomy, and there were no differences in the threshold of tactile and cold allodynia between the sympathectomy and sham groups. Tactile allodynia and cold allodynia in the neuropathic pain model of TST are not dependent on the sympathetic nervous system, and this model can be used to investigate SIP syndromes.
Topics: Animals; Male; Models, Animal; Neuralgia; Rats; Rats, Sprague-Dawley; Sural Nerve; Sympathectomy; Tibial Nerve; Tibial Neuropathy
PubMed: 17191315
DOI: 10.3349/ymj.2006.47.6.847