Left Common Peroneal Nerve Research Articles

Left common peroneal nerve palsy caused by cross-legged sitting during epidural labor analgesia: a case report

BackgroundNerve injury in epidural labor analgesia can occur with various potential causes. We report a rare case of left common peroneal nerve palsy after delivery caused by a prolonged period of sitting cross-legged during epidural labor.Case reportEpidural labor analgesia in a 28-year-old primipara started at 39 weeks of gestation. She sat cross-legged to prompt delivery for approximately 4 h with a break of a few minutes every hour. She had numbness in her left lower limb and difficulty in dorsiflexion of the ankle joint that did not improve until 3 h after delivery. We made a diagnosis of left common peroneal nerve palsy. Most of the symptoms had improved at 2 months postpartum.ConclusionEpidural labor analgesia prevented recognition of prolonged peroneal head compression caused by sitting cross-legged. When this position is used to facilitate delivery, it should be released frequently owing to the possibility of a neurologic deficit.

A70 INABILITY TO AMBULATE FOLLOWING COLONOSCOPY: AN UNEXPECTED COMPLICATION

Abstract Background The peroneal nerve innervates the lower extremities. Compression injury has been documented in the adult patients following the lithotomy position perioperatively, but has rarely been described in pediatric patients following colonoscopy. Aims To report a rare complication following colonoscopy and discuss possible aetiologies. Methods A chart review of a post-colonoscopy peroneal nerve injury in a pediatric patient was conducted along with a literature review. Results A 12 year old boy with ulcerative colitis underwent a colonoscopy for flare symptoms. He was in the left lateral decubitus position for 60 minutes. Immediately after the procedure, he experienced loss of sensation from the left knee to the plantar aspect of the foot, and left foot drop. He had no symptoms of weakness or paresthesia in the right lower extremity or the upper extremities. Prior to the procedure, he reported normal strength, function, and sensation of all extremities. He had no history of injury, joint inflammation or previous surgery affecting his left leg. He had no recent history of steroid use or systemic illness. Two months post procedure he had some symptom improvement and could independently ambulate. He had normal range of motion, strength, and sensation in the upper extremities and right lower extremity. His left leg had 4/5 strength on dorsiflexion and decreased pinprick and light touch sensation. He had difficulty with heel-toe walking. Reflexes were normal. Left leg X-ray and spine MRI were normal. Electrodiagnostic evaluation supported a left common peroneal nerve injury, predominantly demyelinating in nature with minimal axonal contribution, likely secondary to compression around the fibular head during the time of the colonoscopy. He showed full recovery and returned to baseline by 7 months. Conclusions Peroneal nerve injury post colonoscopy is very rare. A study focusing on pediatric colonoscopy found that 3 of 746 patients experienced postoperative neuropathies in their lower extremities. Procedure times were between 70-120 minutes. Presentations and recovery periods were variable, lasting several days to 3 months. The mechanisms of this injury are unclear and felt unlikely to be secondary to positioning alone. It is speculated that BMI, procedure length, frog leg position and position changes, as well as systemic inflammation may be contributory. Factors such as hypothermia, dehydration, hypotension, hypoxia, and electrolyte disturbances may further place patients at risk. Awareness of this rare event and potential modifiable risk factors is important. Funding Agencies None

Electrophysiological Evaluation of Common Peroneal Nerve in Chronic Cigarette Smokers.

Background: Researchers have identified multiple negative health effects of smoking on the respiratory and cardiovascular systems. It was recently reported that substances in cigarette smoke also have pathological effects on peripheral nerves, which causes neuronal impairment. The common peroneal nerve conduction study is an essential electrodiagnostic test of the lower limb for the detection of peripheral motor nerve dysfunction.Objectives: To assess the potential influence of smoking on the electrophysiological status of common peroneal nerve in young male chronic cigarette smokers.Materials and Methods: This case-control study was conducted in the Department of Physiology, Sir Salimullah Medical College, Dhaka, from July 2017 to June 2018, including thirty male cigarette smokers aged 25 to 40 years. For comparison, another thirty age and BMI-matched healthy male non-smoker subjects were selected in the control group. The electrophysiological parameters (distal latency, amplitude, and motor nerve conduction velocity) of the left common peroneal nerve were evaluated by standard methods in the Department of Neurology, Dhaka Medical College Hospital. For the statistical analysis, an independent t-test was performed.Result: In this study, the mean distal latency of the common peroneal nerve was slightly prolonged, while the mean amplitude was slightly reduced in smokers. However, these changes were not statistically significant. However, the motor nerve conduction velocity was significantly (p ˂ 0.05) slower in cigarette smokers compared to non-smokers.Conclusion: Chronic cigarette smoking causes significant impairment of common peroneal motor nerve conduction, while it does not affect the amplitude in young individuals. KYAMC Journal Volume: 14, No: 03, October 2023: 111-115.

432 A Rare Case of Ipsilateral Foot Drop Due to Common Peroneal Nerve Palsy at the Level of Fibular Head Following Total Hip Arthroplasty

Abstract Background Common peroneal nerve (CPN) palsy after primary total hip arthroplasty (THA) is a rare complication with poor functional outcome and has a prevalence of 0.3-2.1%. Case Presentation A 77-year-old gentleman was diagnosed with severe osteoarthritis of the left hip and underwent a hybrid left total hip replacement via posterior approach in right-lateral position. There was no usage of spinal anaesthesia, leakage from the wound, intra-operative nerve injury or any localised haematoma. Post-operatively on day 3, he was noted to have foot drop with loss of foot eversion and dorsiflexion with sensory loss along the distribution of the superficial peroneal and tibial nerve. Clinical Outcomes Nerve conduction study of left lower limb showed absent left superficial peroneal sensory response, absent left peroneal to extensor digitorum brevis and tibialis anterior motor responses with denervation across the anterior and lateral left lower leg muscles suggestive of a severe partial lesion of the left common peroneal nerve at the level of fibular head. Patient was placed in a foot drop splint with follow-up neurological evaluation. Discussion Post-operative CPN palsy are mostly neuropraxias caused due to direct compression, either by surgical instruments or anatomical structures, or from tension or ischemia to the nerve during intra-operative limb manipulation or limb lengthening. Additionally, usage of cement less components combined with Enoxaparin or due to any haematoma may compress the nerve. Age, BMI and initial severity of sensory and motor neurological deficits are prognostic factors indicating recovery. Full recovery is between 16-56% of cases at an average of 15 months.

Nerve Conduction and Surface Electromyography of Physically Active Healthy Medical Undergraduates of Nepal

Introduction: Physical activity is defined as any bodily movement produced by skeletal muscles that requires energy expenditure. Nerve conduction studies and surface EMG provides a comprehensive evaluation of nerve, muscle or neuromuscular impairment. However, such studies are mostly done on professional athletes. Methods: Healthy physically active (n=17) and non-active (n=17) medical undergraduate students from B.P. Koirala Institute of Health Sciences (BPKIHS), Nepal were enrolled in the study using convenient sampling technique. Anthropometric and motor nerve conduction parameters of common peroneal nerves and surface EMG of gastrocnemius muscle were recorded using standard technique in Neurophysiology Lab II, BPKIHS. Descriptive analysis was done. Unpaired t-test was applied for comparing the nerve conduction and surface EMG variables between the groups. Pearson’s correlation was applied between anthropometric and nerve conduction & surface EMG variables. Objectives: To compare nerve conduction parameters of common peroneal nerve and surface EMG of Gastrocnemius muscle between active and non-active individuals. Results: The distal and proximal amplitudes of left common peroneal nerve were significantly higher in physically active compared to non-active individuals (LCPDA-p value: 0.026, LCPPA-p value: 0.009). Anthropometric parameters showed significant correlation with nerve conduction parameters. Conclusion: Nerve conduction parameters are affected in the physically active individuals. Anthropometric variables showed significant relation with the nerve conduction parameters. Keywords: Nerve Conduction Velocity, Surface Electromyography, Peroneal Nerve, Gastrocnemius.

ASSESSMENT OF THE AUTONOMIC AND PERIPHERAL NERVE FUNCTION IN PATIENTS WITH THALASSAEMIC SYNDROME IN A TERTIARY CARE HOSPITAL - A CROSS SECTIONAL STUDY

INTRODUCTION: β-thalassaemia is an inherited disorder of haemoglobin characterized by an absence or reduced synthesis of the β-globin chain. The net result is an excess of α-chains, which precipitate and destroy the red cell precursors, leading to anaemia, skeletal changes, splenomegaly and numerous other complications. Treatment is by regular blood transfusion coupled with iron chelation therapy to prevent iron accumulation and organ damage. AIM: To assess the autonomic and peripheral nerve function in patients with thalassaemic syndrome. MATERIALAND METHODS: Patients attending the Thalassaemia Clinic of Medical College Hospital, Kolkata. Indoor patients from Medicine st th ward and Institute of Haematology and Transfusion Medicine wards of Medical College Hospital, Kolkata from 1 May 2008 to 30 April 2009. After inclusion patients were divided into following groups: Group1 (THAL1): Patients requiring regular blood transfusion and are either receiving inadequate iron chelation or no iron chelation at all. Group2 (THAL2): Patients who require regular blood transfusion and are receiving adequate iron chelation. Group3 (THAL3): Patients who do not require regular blood transfusion RESULT: The median value of distal latency of right common peroneal nerve is slightly increased in all 3 groups. The normal value should be < 4.55ms, thus increase in distal latency is seen in all 3 groups. The median values of distal latency of left common peroneal nerve as well as distal latency of common peroneal nerve as a whole is within normal limits. Distal latency of common peroneal nerve (p value=0.012). Proximal latency of left common peroneal nerve(p value=0.013). Proximal latency of common peroneal (p value=0.001) CONCLUSION: There is demyelinating type of neuropathy of right common peroneal nerve of all the groups. This indicates presence of motor peripheral neuropathy in patients of thalassaemia. All other latencies and amplitudes of both motor and sensory nerves are within normal limits. There were statistically increased motor latencies in patients receiving iron chelation therapy with adequate chelation when compared to the other groups, although the overall latency was within acceptable limits of the laboratory standards. This may be due to subclinical affection of the motor nerves in the form of demyelination. Therefore, the role of toxic effects of iron chelator on peripheral nerves needs to be studied further.

Characteristics of ocular findings of patients with neuronal intranuclear inclusion disease.

This study aimed to explore the ocular characteristics of neuronal intranuclear inclusion disease (NIID), caused by GGC repeat expansion in the NOTCH2NLC gene, combined with the systemic clinical manifestations, and propose early diagnostic features of NIID. Six patients (12 eyes) were enrolled in this study. In vivo corneal confocal microscopy (IVCCM), fundus photography, fundus autofluorescence (FAF) imaging, optical coherence tomography (OCT), full-field electroretinography (ERG), and electromyography were performed. The average corneal nerve fiber density (CNFD) was 6.83 ± 4.96 number/mm2, and the corneal nerve fiber length (CNFL) was 6.76 ± 1.96mm/mm2. The nerves were looser and more curved in affected individuals. Dendritic cells were observed in patients with NIID. Chorioretinal atrophy, hyper-AF spots, and outer retinal abnormalities were observed during FAF imaging and OCT examinations. In full-field ERGs, the amplitudes of the a-wave and b-wave reduced or extinguished over time. The compound muscle action potential and motor nerve conduction velocity of the left common peroneal nerve decreased substantially. The findings of IVCCM and retinal changes should be included in the diagnostic criteria for NIID. Corneal confocal characteristics may precede the systemic neurological manifestations and provide a clinical basis for the early treatment and staging of the disease. ClincalTrials.gov. Identifier: ChiCTR21000500227.

Painless foot drop: an unusual acute presentation of new onset type 1 diabetes mellitus.

SummaryA 26-year-old Caucasian female with no past medical history or family history of auto-immune disease presented to the emergency department with new onset painless left foot drop. A panel of blood tests revealed blood glucose of 49.9 mmol/L and raised blood ketone levels. The patient was referred to the diabetes team who made a clinical diagnosis of type 1 diabetes (T1DM) and insulin treatment was initiated. Elevated levels of diabetes auto-antibodies were subsequently detected. Nerve conduction studies demonstrated a left common peroneal nerve lesion with conduction block at the fibular head. After 2 weeks of insulin treatment, a significant improvement of her foot drop was observed and after 8 weeks she was walking normally. The most probable cause of her foot drop was acute diabetic mononeuropathy. To our knowledge, there are no similar cases in adult patients reported in the literature. Our case highlights the importance of physicians being aware of atypical presentation of new onset T1DM.Learning points There is an increasing incidence of T1DM with more than half of patients presenting after the age of 20. Diabetic peripheral neuropathy can present both acutely and as a mononeuropathy. Although rare, clinicians should be aware of mononeuropathy as a presenting symptom of T1DM to avoid delay in the treatment initiation. This case highlights an unusual presentation of T1DM and illustrates the importance of the early diagnosis and management of T1DM.

Activation Of Specific Estrogen Receptor Isotype Mediates Skeletal Muscle Force Potentiation In Ovariectomized Mice

Estrogens affect force generation of skeletal muscle. Post-tetanic potentiation (PTP) of force is low in ovariectomize mice, and estradiol supplementation rescues potentiation both in vivo and in vitro. However, it is not known whether this estrogenic influence is through estrogen receptors, and if so, which isotype. PURPOSE: We hypothesized activation of estrogen receptor beta (ERβ) or G protein-coupled estrogen receptor (GPER), but not estrogen receptor alpha (ERα) would enhance in vivo muscle PTP in ovariectomized mice. METHODS: Adult female C57BL/6J mice (n = 4-12 per treatment) had a nerve cuff surgically implanted on the left common peroneal nerve. Six weeks later mice were ovariectomized (OVX). Four weeks later, PTP of the anterior crural muscles was measured immediately before and 1 h after treatment with either vehicle (OVX+Veh), 17β-estradiol (OVX+E2), ERα agonist PPT (OVX+PPT; 1 μM PPT), ERβ agonist DPN (OVX+DPN; 50 nM DPN) or GPER agonist G1 (OVX+G1, 2.4 nM G1) via tail vein injection. PTP was calculated as the percent increase in twitch torque from baseline to the highest torque of the post-tetanic twitches. One-way ANOVAs with Holm-Sidak post hoc tests were used for data analysis. Results are reported as mean ± SE. RESULTS: Peak torques of unpotentiated, baseline twitches were not different among the five groups: 0.47 ± 0.03, 0.59 ± 0.04, 0.62 ± 0.12, 0.52 ± 0.11 and 0.54 ± 0.03 mN*m, respectively (p=0.25). Potentiated twitches generated 7-108% more torque than unpotentiated twitches. PTP of OVX+E2 and OVX+G1 was significantly greater than that of OVX+Veh mice (59 ± 5% and 61 ± 7% vs 35 ± 5% increase, respectively; p=0.01). PTP of OVX+PPT and OVX+DPN were not significantly different from OVX+Veh mice (41 ± 4% and 49 ± 7% vs 35 ± 5% increase, respectively; p=0.37). CONCLUSION: Acute treatment with ERα or ERβ agonist does not increase in vivo PTP of the anterior crural muscles in OVX mice to the extent that E2 or GPER agonist does. This result partially supports our hypothesis that estrogenic modulation of skeletal muscle force potentiation is not through ERα, and is through GPER. Supported by NIH grants R01-AG031743 and T32-AR050938, and Metropolitan State University Professional Development Grant.

High-resolution ultrasound features of greater auricular nerve in leprosy

A 42-yr-male presented with left foot drop of 2 months duration. General examination showed enlarged greater auricular nerve (GAN) and hypoanesthetic patch over dorsum of left leg (figure 1A,B). Neurological...

Sites of Disruption in Dystrophic Muscle Following Eccentric Contractions

PURPOSE: Dystrophin is responsible for maintaining plasmalemmal integrity and cellular homeostasis. A key feature of skeletal muscle that lacks dystrophin, as in the mdx mouse model for Duchenne muscular dystrophy (DMD), is a heightened sensitivity to eccentric (ECC) contraction-induced strength loss. However, the mechanisms responsible for the exaggerated loss of strength in dystrophic muscle have yet to be fully established. The purpose of this study was to determine possible sites within mdx muscle that are disrupted following ECC contractions. METHODS: Male wildtype and mdx mice (n = 8 per group) were chronically implanted with stimulating electrodes on the left common peroneal nerve and EMG electrodes on the left tibialis anterior (TA) muscle. The left anterior crural muscles (TA and extensor digitorum longus; EDL) of anesthetized mice performed 50 maximal ECC contractions. In vivo peak dorsiflexion torque and M-wave root mean square (RMS) were measured prior to and immediately after the ECC contractions. Following the in vivo assessment, the EDL was removed and ex vivo peak isometric force and caffeine-induced force were analyzed. RESULTS: Peak torque and force in wildtype mice were reduced 36 ± 4 and 28 ± 4% (p ≤ 0.001) following the ECC contractions, while no changes were observed in M-wave RMS (10 ± 2%; p = 0.49) or caffeine-induced force (10 ± 4%; p = 0.20). To the contrary, both M-wave RMS and caffeine-induced force were reduced in mdx muscle (60 ± 4 and 58 ± 5; p ≤ 0.001), and corresponded to reductions of 60 ± 2 and 67 ± 8% (p ≤ 0.001) in peak torque and force. CONCLUSIONS: On the basis of the disproportional reductions in strength measured in vivo and ex vivo (36 and 28%, respectively) compared with that of in vivo M-wave RMS (10%) and ex vivo caffeine-induced force (10%), we confirm that ECC contractions uncouple the plasmalemma from the ryanodine receptors (RyRs) in wildtype muscle. However, in mdx muscle, in vivo peak torque and M-wave RMS in addition to ex vivo force and caffeine-induced force were all reduced to a similar degree (58-67%), indicating that various sites were disrupted immediately following the injury. These data indicate strength loss in wildtype and mdx mice differ, in that plasmalemmal function and sites at or distal to the RyRs may all be impaired in dystrophic muscle following ECC contractions.

Increased Fiber Excitability Does Not Contribute to Post‐Tetanic Potentiation in Mice

PurposePost‐tetanic potentiation (PTP) is the enhancement of twitch force following tetanic stimulation and is an important component when studying skeletal muscle physiology and plasticity. Mechanistically, it is plausible that PTP could be associated with an increase in fiber excitability and/or any event following sarcoplasmic reticulum (SR) calcium release (i.e., at the contractile apparatus). Therefore, the goal of this study was to determine if increased fiber excitability contributes to PTP.MethodsAdult female C57BL/6J mice were chronically implanted with stimulating electrodes on the left common peroneal nerve and electromyographic (EMG) electrodes on the left tibialis anterior (TA) muscle. Following surgical recovery (at least 2 weeks after EMG electrode implantation), in vivo PTP of the anterior crural muscles was performed with simultaneous M‐wave recording from the TA muscle. To measure PTP, baseline twitch torque production was measured using a 0.1‐ms electrical stimulus pulse. Ten seconds later, muscles were stimulated using 0.1‐ms pulses at 100 Hz for 1 s to produce a prolonged, isometric tetanic contraction. Starting 2 s later, two post‐tetanic twitches were elicited with 2 s between the two. Changes in twitch torque (i.e., PTP) and M‐wave amplitude were calculated as percent increases in twitch torque and the corresponding M‐wave from baseline to the highest values following tetanic stimulation. All data were analyzed using paired t‐tests and are reported as means ± SE.ResultsTwitch torque at baseline was 0.45 ± 0.07 mN·m and represented the unpotentiated twitch. Following the tetanic stimulation, twitch torque increased by 34.0 ± 7.3% to 0.60 ± 0.07 mN·m (p=0.01). However, no change was detected in twitch M‐wave amplitude from before to after the tetanic stimulation (0.37 ± 0.03 to 0.39 ± 0.04 mV, p=0.48).ConclusionOn the basis of the disproportionate increase in twitch torque (34%) compared to the corresponding M‐wave amplitude increase (5%) after tetanic stimulation (p=0.02), we suggest that the PTP was not due to an increase in fiber excitability. Instead, it is more likely that PTP was attributable to an enhancement at or distal to SR calcium release such as phosphorylation of myosin regulatory light chain, which is consistent with previously reported mechanisms underlying PTP.Support or Funding InformationSupported by NIH grants R01‐AG031743 and T32‐AR007612, and Metropolitan State University Professional Development Grant.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Protective distal side-to-side neurorrhaphy in proximal nerve injury\u2014an experimental study with rats

BackgroundSide-to-side neurorrhaphy may protect the denervated end organ and preserve the initial connection with proximal stump. We examined the effect of protective side-to-side anastomosis on nerve and end organ regeneration in proximal nerve injury model.MethodsThe left common peroneal nerve of 24 Sprague Dawley rats was proximally transected. In groups B and C, side-to-side neurorrhaphy was performed distally between the peroneal and tibial nerves without (group B) and with (group C) partial donor nerve axotomy inside the epineural window. Group A served as an unprotected control. After 26 weeks, the proximal transection was repaired with end-to-end neurorrhaphy on all animals. Regeneration was followed during 12 weeks with the walk track analysis. Morphometric studies and wet muscle mass calculations were conducted at the end of the follow-up period.ResultsThe results of the walk track analysis were significantly better in groups B and C compared to group A. Groups B and C showed significantly higher wet mass ratios of the tibialis anterior and extensor digitorum longus muscle compared to group A. Group C showed significantly higher morphometric values compared to group A. Group B reached higher values of the fibre count, fibre density, and percentage of the fibre area compared to group A.ConclusionsProtective distal side-to-side neurorrhaphy reduced muscle atrophy and had an improving effect on the morphometric studies and walk track analysis. Distal side-to-side neurorrhaphy does not prevent the regenerating axons to grow from the proximal stump to achieve distal nerve stump.

The effects of audiovisual distraction on the muscle sympathetic responses to experimental muscle pain.

Pain elicited by intramuscular infusion of hypertonic saline solution causes muscle sympathetic nerve activity (MSNA) to increase in some subjects, yet decrease in others. Although the direction of the response is not predictable based on baseline physiological and psychological parameters, we know that it results from sustained functional changes in specific brain regions that are responsible for the behavioral and cardiovascular responses to psychological stressors, as well as those involved in attention. The aim of this study was to investigate whether MSNA responses to experimental muscle pain in humans could be altered with an audiovisual stimulus that served to distract them from the pain. MSNA was recorded from the left common peroneal nerve of 20 young healthy individuals during a 45-min intramuscular infusion of hypertonic saline solution into the ipsilateral tibialis anterior muscle. The distracting stimulus commenced 15min after the start of the infusion and lasted for 15min. Fifteen subjects showed an increase in mean burst amplitude of MSNA (to 176.4 ± 7.9% of baseline), while five showed a decrease (to 73.1 ± 5.2% of baseline); distraction had no effect on these profiles. These results indicate that even though the subjects were attending to the audiovisual stimulus, and were presumably distracted from the pain, it failed to alter the MSNA responses to muscle pain.

The metaboreflex does not contribute to the increase in muscle sympathetic nerve activity to contracting muscle during static exercise in humans.

It is not clear how sympathetic activity to contracting muscle is controlled. We recorded muscle sympathetic nerve activity (MSNA) to the ipsilateral tibialis anterior muscle during 4min of isometric dorsiflexion of the ankle and 6min of post-exercise ischaemia, which was repeated contralaterally. MSNA to the contracting muscle increased within 1min of static exercise and returned to pre-contraction levels at the end. Unlike the increase in MSNA seen in the non-contracting muscle, post-exercise ischaemia had no effect on MSNA to the contracted muscle. We conclude that central command is the primary mechanism responsible for increasing MSNA to contracting muscle and also that the metaboreflex is not expressed in contracting muscle. Both central command and metaboreflex inputs from contracting muscles increase muscle sympathetic nerve activity (MSNA) to non-contracting muscle during sustained isometric exercise. We recently showed that MSNA to contracting muscle also increases in an intensity-dependent manner, although whether this can be sustained by the metaboreflex is unknown. MSNA was recorded from the left common peroneal nerve and individual spikes of MSNA extracted from the nerve signal. Eleven subjects performed a series of 4min dorsiflexions of the left ankle at 10% of maximum voluntary contraction under three conditions: without ischaemia, with 6min of post-exercise ischaemia, and with ischaemia during and after exercise; these were repeated in the right leg. Compared with pre-contraction values, MSNA to the contracting muscles increased and plateaued in the first minute of contraction (50±18 vs. 34±10spikesmin-1 , P=0.01), returned to pre-contraction levels within 1min of the contraction ending and was not influenced by ischaemia during or after contraction. Conversely, MSNA to the non-contracting muscles was not different from pre-contraction levels in the first minute of contraction (34±9 vs. 32±5spikesmin-1 , P=0.48), whereas it increased each minute and was significantly greater by the second minute (44±8spikesmin-1 , P=0.01). Ischaemia augmented the MSNA response to contraction (63±25spikesmin-1 after 4min, P<0.05) and post-exercise ischaemia (63±27spikesmin-1 after 6min, P<0.01) for the non-contracting muscles only. These findings support our conclusion that the metaboreflex is not expressed in the contracting muscle during sustained static exercise.

Multiple peroneal nerve abscesses: The first presentation of borderline tuberculoid leprosy

A 53-year-old male presented with multiple swellings over the left leg associated with sensory loss and weak dorsiflexion of the left foot for 4 months. Neurophysiological studies revealed absent sensory and motor action potentials in the left common peroneal nerve. Multiple hypoechoic areas were seen in the subcutaneous plane on ultrasound and were found to be nerve abscesses along the peroneal neurovascular bundle on magnetic resonance imaging of the left leg. Skin biopsy was suggestive of borderline tuberculoid leprosy. He was started on corticosteroids and paucibacillary multidrug therapy. The swelling subsided over the next 1 month, and the motor paralysis improved gradually with treatment.

Vibration upshot of operating mechanical sewing machine: an insight into common peroneal nerve conduction study

BackgroundMost of the people associated with tailoring occupation in Nepal are still using mechanical sewing machine as an alternative of new technology for tailoring. Common peroneal nerves of both right and left legs are exposed to strenuous and chronic stress exerted by vibration and paddling of mechanical sewing machine.MethodsThe study included 30 healthy male tailors and 30 healthy male individuals. Anthropometric variables as well as cardio respiratory variables were determined for each subject. Standard Nerve Conduction Techniques using constant measured distances were applied to evaluate common peroneal nerve (motor) in both legs of each individual. Data were analyzed and compared between study and control groups using Man Whitney U test setting the significance level p ≤ 0.05.ResultsAnthropometric and cardio respiratory variables were not significantly altered between the study and control groups. The Compound muscle action potential (CMAP) latency of common peroneal nerves of both right [(11.29 ± 1.25 vs. 10.03 ± 1.37), P < 0.001] and left [(11.28 ± 1.38 vs. 10.05 ± 1.37), P < 0.01] legs was found to be significantly prolonged in study group as compared to control group. The Amp-CMAP of common peroneal nerves of both right [(4.57 ± 1.21 vs. 6.22 ± 1.72), P < 0.001] and left [(4.31 ± 1.55 vs. 6.25 ± 1.70), P < 0.001] legs was found significantly reduced in study group as compared to control group. Similarly, the motor nerve conduction velocity (MNCV) of common peroneal nerves of both right [(43.72 ± 3.25 vs. 47.49 ± 4.17), P < 0.001] and left [(42.51 ± 3.82 vs. 46.76 ± 4.51), P < 0.001] legs was also found to be significantly reduced in study group in comparison to control group.ConclusionOperating mechanical sewing machine by paddling chronically and arduously could have attributed to abnormal nerve conduction study parameters due to vibration effect of the machine on right and left common peroneal nerves. The results of present study follow the trend towards presymptomatic or asymptomatic neuropathy similar to subclinical neuropathy.

The Analgesic Effects of (5R,6R)6-(3-Propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1] Octane on a Mouse Model of Neuropathic Pain.

Both pharmacologic and genetic approaches have been used to study the involvement of the muscarinic acetylcholine system in the regulation of chronic pain. Previous studies suggest that the M2 and M4 subtypes of muscarinic acetylcholine receptors (mAChRs) are important targets for the development of chronic pain. (5R,6R)6-(3-Propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1] octane (PTAC) has agonist effects on muscarinic M2 and M4 receptors and antagonist effects on muscarinic M1, M3, and M5 receptors. However, its analgesic effects have been less studied. Male C57B L/6 mice were anesthetized, and left common peroneal nerve (CPN) ligation was performed to induce neuropathic pain. Before and after the application of PTAC systemically or specifically to the anterior cingulate cortex (ACC), the withdrawal thresholds to mechanical stimulation and static weight balance were measured, and the effects of PTAC on the conditioned place preference (CPP) were further evaluated. Western blotting was used to examine the expression of M1 and M2 in the striatum, ACC, and ventral tegmental area. The application of PTAC ([i.p.] intraperitoneal injection) increased the paw withdraw threshold in both the early (0.05 mg/kg, mean difference [95% confidence interval, CI]: 0.19 [0.05-0.32]; 0.10 mg/kg: mean difference [95% CI]: 0.34 [0.22-0.46]) and the late phases (0.05 mg/kg: mean difference [95% CI]: 0.45 [0.39-0.50]; 0.1 mg/kg: mean difference [95% CI]: 0.44 [0.37-0.51]) after nerve injury and rebalanced the weight distribution on the hind paws of mice (L/R ratio: before, 0.56 ± 0.03. 0.05 mg/kg, 1.00 ± 0.04, 0.10 mg/kg, 0.99 ± 0.03); however, it failed to induce place preference in the CPP (0.05 mg/kg, 2-way analysis of variance, P > .05; 0.2 mg/kg, 2-way analysis of variance, P > .05,). At the same doses, the analgesic effects at D3-5 lasted longer than the effects at D14-16. This may be due to the down-regulation of the M2 and M1 in tested brain regions. These observations suggested that PTAC has analgesic effects on the neuropathic pain induced by nerve injury.

Myotonic Dystrophy Type 1 with Syringomyelia in a Young Patient

Myotonic Dystrophy Type 1 with Syringomyelia in a Young Patient

Motion sickness is associated with an increase in vestibular modulation of skin but not muscle sympathetic nerve activity.

We have previously shown that sinusoidal galvanic vestibular stimulation (sGVS), delivered bilaterally at frequencies of 0.08-2.00Hz, causes a pronounced modulation of muscle sympathetic nerve activity (MSNA) and skin sympathetic nerve activity (SSNA), together with robust frequency-dependent illusions of side-to-side motion. At low frequencies of sGVS (≤0.2Hz), some subjects report nausea, so we tested the hypothesis that vestibular modulation of MSNA and SSNA is augmented in individuals reporting nausea. MSNA was recorded via tungsten microelectrodes inserted into the left common peroneal nerve in 22 awake, seated subjects; SSNA was recorded in 14 subjects. Bipolar binaural sGVS (±2mA, 100 cycles) was applied to the mastoid processes at 0.08, 0.13, and 0.18Hz. Nausea was reported by 21 out of 36 subjects (58%), but across frequencies of sGVS there was no difference in the magnitude of the vestibular modulation of MSNA in subjects who reported nausea (27.1±1.8%) and those who did not (30.4±2.9%). This contrasts with the significantly greater vestibular modulation of SSNA with nausea (41.1±2.0 vs. 28.7±3.1%) and indicates an organ-specific modulation of sympathetic outflow via the vestibular system during motion sickness.