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Functional Neurology 2017To better understand the effects of spasticity on peripheral nerves, we evaluated the electrodiagnostic and nerve ultrasonographic features of the median and ulnar... (Observational Study)
Observational Study
To better understand the effects of spasticity on peripheral nerves, we evaluated the electrodiagnostic and nerve ultrasonographic features of the median and ulnar nerves in adults with upper limb spasticity. Twenty chronic stroke patients with spastic hemiparesis underwent nerve conduction study and nerve ultrasonography of the median and ulnar nerves at both upper limbs. Affected versus unaffected upper limb comparisons showed significant differences in the median and ulnar nerve distal motor latencies, compound muscle action potentials and F-wave minimal latencies. Furthermore, we observed a significantly greater median nerve crosssectional area at the elbow of the affected upper limb compared with the unaffected one. Our findings confirmed electrodiagnostic asymmetries and nerve ultrasonographic abnormalities in the affected versus the unaffected upper limb after stroke. Slight changes in lower motor neuron activity and spasticity might contribute to these alterations.
Topics: Action Potentials; Electrodiagnosis; Humans; Median Nerve; Muscle Spasticity; Neural Conduction; Ulnar Nerve; Ultrasonography; Upper Extremity
PubMed: 29041999
DOI: 10.11138/fneur/2017.32.3.119 -
Scientific Reports Mar 2021This study took shear wave elastography (SWE) technology to measure the shear wave velocity (SWV) of peripheral nerve in healthy population, which represents the... (Clinical Trial)
Clinical Trial
This study took shear wave elastography (SWE) technology to measure the shear wave velocity (SWV) of peripheral nerve in healthy population, which represents the stiffness of the peripheral nerves, and research whether these parameters (location, age, sex, body mass index (BMI), the thickness and cross-sectional area(CSA) of the nerve) would affect the stiffness of the peripheral nerves. 105 healthy volunteers were enrolled in this study. We recorded the genders and ages of these volunteers, measured height and weight, calculated BMI, measured nerve thickness and CSA using high-frequency ultrasound (HFUS), and then, we measured and compared the SWV of the right median nerve at the middle of the forearm and at the proximal entrance of the carpal tunnel. The SWV of the median nerve of the left side was measured to explore whether there exist differences of SWV in bilateral median nerve. Additionally, we also measured the SWV of the right tibial nerve at the ankle canal to test whether there is any difference in shear wave velocity between different peripheral nerves. This study found that there existed significant differences of SWV between different sites in one nerve and between different peripheral nerves. No significant difference was found in SWV between bilateral median nerves. Additionally, the SWV of peripheral nerves was associated with gender, while not associated with age or BMI. The mean SWV of the studied male volunteers in median nerve were significantly higher than those of female (p < 0.05). Peripheral nerve SWE measurement in healthy people is affected by different sites, different nerves and genders, and not associated with age, BMI, nerve thickness or CSA.
Topics: Adolescent; Adult; Elasticity Imaging Techniques; Female; Humans; Male; Median Nerve; Middle Aged; Tibial Nerve
PubMed: 33692411
DOI: 10.1038/s41598-021-84900-8 -
Neuroscience Letters May 2019Defensive motor responses elicited by sudden environmental stimuli are finely modulated by their behavioural relevance to maximise the organism's survival. One such...
Defensive motor responses elicited by sudden environmental stimuli are finely modulated by their behavioural relevance to maximise the organism's survival. One such response, the blink reflex evoked by intense electrical stimulation of the median nerve (Hand-Blink Reflex; HBR), has been extensively used to derive fine-grained maps of defensive peripersonal space. However, as other subcortical reflexes, the HBR might also be modulated by lower-level factors that do not bear direct relevance to the defensive value of blinking, thus posing methodological and interpretive problems. Here, we tested whether HBR magnitude is affected by the muscular effort present when holding the hand in certain postures. We found that HBR magnitude increases with muscular effort, an effect most likely mediated by the increased corticospinal drive. However, we found strong evidence that this effect is substantially smaller than the well-known effect of eye-hand proximity on HBR magnitude. Nonetheless, care should be taken in future experiments to avoid erroneous interpretations of the effects of muscular effort as indicators of behaviour relevance.
Topics: Adult; Blinking; Electric Stimulation; Female; Hand; Humans; Male; Median Nerve; Muscle, Skeletal; Posture; Reflex; Young Adult
PubMed: 30528879
DOI: 10.1016/j.neulet.2018.11.046 -
BMC Anesthesiology Aug 2022The radial artery cannulation helps to maintain the stability of maternal hemodynamics and reduce complications, however, it is difficult for women with gestational... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The radial artery cannulation helps to maintain the stability of maternal hemodynamics and reduce complications, however, it is difficult for women with gestational hypertension. Ultrasound-guided median nerve block can cause arterial vasodilation, which may improve the success rate of radial artery cannulation.
METHODS
Ninety-two women with gestational hypertension and risks of intra-operative bleeding undergoing cesarean section following failed ultrasound-guided cannulation were identified and randomized into the median nerve block group and control group. Median nerve block was performed under the guidance of ultrasound in the middle forearm and 5 ml of 0.5% lidocaine was injected. Subcutaneous local block was administered in the control group. The ultrasound-guided radial artery cannulation was performed ten minutes after blocking. Baseline measurements (T1) were performed after 10 minutes of rest. All variables were measured again at 10 (T2) and 30 (T3) minutes after median nerve block or local block. The primary outcome was the success rate of radial artery cannulation within 10 minutes after blocking. The puncture time, number of attempts, the overall complications, and ultrasonographic measurements including radial artery diameter and cross-sectional area were recorded before (T1), 10 minutes (T2) after, and 30 minutes (T3) after block.
RESULTS
A total of 92 pregnant women were identified and completed the follow-up. As compared to control group, the first-attempt success rate of radial artery cannulation was significantly higher (95.7% vs78.3%, p = 0.027) and procedure time to success was significantly shorter (118 ± 19 s vs 172 ± 66 s, p < 0.001) in median nerve group. Median nerve group also had a significantly less overall number of attempts (p = 0.024). Compared with control group, the diameter and cross-sectional area of radial artery increased significantly at the T2 and T3 points in median nerve group (p < 0.001), as well as percentage change of radial artery diameter and CSA. No difference was observed in the overall complication at chosen radial artery, which including vasospasm (21.7% vs 28.3%; p = 0.470) and hematoma (4.3% vs 8.7%; p = 0.677).
CONCLUSIONS
Ultrasound-guided median nerve block can increase the first-attempt success rate of chosen radial artery cannulation in women with gestational hypertension and risks of intra-operative bleeding undergoing cesarean section following failed radial artery cannulation, and especially for those anesthesiologists with less experienced in radial artery cannulation.
TRIAL REGISTRATION
ChiCTR2100052862; http://www.chictr.org.cn , Principal investigator: MEN, Date of registration: 06/11/2021.
Topics: Catheterization, Peripheral; Cesarean Section; Female; Humans; Hypertension, Pregnancy-Induced; Median Nerve; Pregnancy; Radial Artery; Ultrasonography, Interventional
PubMed: 35931948
DOI: 10.1186/s12871-022-01793-4 -
Medical Ultrasonography Jun 2023Charcot-Marie-Tooth disease type 1A (CMT1A) is characterized by enlargement and stiffness of peripheral nerves due to edema with large numbers of "onion bulbs" in the...
AIMS
Charcot-Marie-Tooth disease type 1A (CMT1A) is characterized by enlargement and stiffness of peripheral nerves due to edema with large numbers of "onion bulbs" in the endoneurium. Ultrasound elastography seems to be an ideal method to detect this condition. The aim of this study was to analyze the shear wave elastography (SWE) features of peripheral nerves in patients with CMT1A.
MATERIAL AND METHODS
We included 24 CMT1A patients with a mean age of 28 years, along with 24 age- and gender-matched controls. All patients presented with mutations of the PMP22 gene and showed length-dependent polyneuropathy. The motor nerve conduction velocity (MNCV) of the median nerve ranged from 5.2 to 37.4 m/s. SWE and cross-sectional area (CSA) were used to evaluate the bilateral median nerves at predefined sites in both patients and con-trols.
RESULTS
The average elastography value (EV) of the median nerve was 73.5±11.7 kPa in patients with CMT1A and 37.5±6.1 kPa in control subjects. The difference between the two groups was statistically significant (P<0.05). In CMT1A pa-tients, the average EV at the proximal and distal parts of the median nerve were 81.4±9.4 kPa and 65.2±8.1 kPa, respectively. The average CSAs at the proximal and distal parts of the median nerve were 0.29±0.06 cm2 and 0.20±0.05 cm2, respectively. The EV on SWE was positively correlated with CSA (p< 0.01) and negatively correlated with MNCV in the median nerve (p< 0.01).
CONCLUSIONS
Peripheral nerve stiffness dramatically increases in CMT1A and is correlated with the severity of nerve involvement.
Topics: Humans; Adult; Charcot-Marie-Tooth Disease; Median Nerve; Elasticity Imaging Techniques; Peripheral Nerves
PubMed: 37369047
DOI: 10.11152/mu-3938 -
Folia Morphologica 2023The aim of the present work was to provide evidence about the anatomical variations as regard the origin, distribution, and branching pattern of the musculocutaneous...
BACKGROUND
The aim of the present work was to provide evidence about the anatomical variations as regard the origin, distribution, and branching pattern of the musculocutaneous nerve (MCN).
MATERIALS AND METHODS
Brachial plexus was dissected in 40 upper limbs of 20 male adult cadavers. The pattern of the MCN was photographed by a digital camera.
RESULTS
The location and length of the nerve branches between left and right arms were recorded and statistically analysed. In 90% of specimens the MCN originates from the lateral cord of the brachial plexus, in 5% it arose from the median nerve (MN), while in the remaining 5% specimen, it was absent. The MCN pierced the coracobrachialis muscle in 90% of specimens, and in the remaining 10% did not pierce it. The motor branches to biceps brachii muscle were categorised into: type 1 (90%): one branch that divides to supply the two heads of biceps; type 2 (5%): double branches, innervating each head of biceps separately. The motor branches to brachialis muscle were categorised into: type 1 (82.9%): one branch; type 2 (14.2%): double branches and type 3 (2.9%): three branches that innervating brachialis muscle. Communications between the MCN and the MN were observed in 35% of specimens.
CONCLUSIONS
The knowledge of the common and uncommon MCN variations is important especially to the surgeons for carrying out surgical procedures in axilla and arm.
Topics: Adult; Male; Humans; Musculocutaneous Nerve; Arm; Median Nerve; Muscle, Skeletal; Cadaver
PubMed: 35037697
DOI: 10.5603/FM.a2021.0139 -
PloS One 2015The course and branches of the median nerve (MN) in the wrist vary widely among the population. Due to significant differences in the reported prevalence of such... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND OBJECTIVE
The course and branches of the median nerve (MN) in the wrist vary widely among the population. Due to significant differences in the reported prevalence of such variations, extensive knowledge on the anatomy of the MN is essential to avoid iatrogenic nerve injury. Our aim was to determine the prevalence rates of anatomical variations of the MN in the carpal tunnel and the most common course patterns and variations in its thenar motor branch (TMB).
STUDY DESIGN
A systematic search of all major databases was performed to identify articles that studied the prevalence of MN variations in the carpal tunnel and the TMB. No date or language restrictions were set. Extracted data was classified according to Lanz's classification system: variations in the course of the single TMB--extraligamentous, subligamentous, and transligamentous (type 1); accessory branches of the MN at the distal carpal tunnel (type 2); high division of the MN (type 3); and the MN and its accessory branches proximal to the carpal tunnel (type 4). Pooled prevalence rates were calculated using MetaXL 2.0.
RESULTS
Thirty-one studies (n = 3918 hands) were included in the meta-analysis. The pooled prevalence rates of the extraligamentous, subligamentous, and transligamentous courses were 75.2% (95%CI:55.4%-84.7%), 13.5% (95%CI:3.6%-25.7%), and 11.3% (95%CI:2.4%-23.0%), respectively. The prevalence of Lanz group 2, 3, and 4 were 4.6% (95%CI:1.6%-9.1%), 2.6% (95%CI:0.1%-2.8%), and 2.3% (95%CI:0.3%-5.6%), respectively. Ulnar side of branching of the TMB was found in 2.1% (95%CI:0.9%-3.6%) of hands. The prevalence of hypertrophic thenar muscles over the transverse carpal ligament was 18.2% (95%CI:6.8%-33.0%). A transligamentous course of the TMB was more commonly found in hands with hypertrophic thenar muscles (23.4%, 95%CI:5.0%-43.4%) compared to those without hypertrophic musculature (1.7%, 95%CI:0%-100%). In four studies (n = 423 hands), identical bilateral course of the TMB was found in 72.3% (95%CI:58.4%-84.4%) of patients.
CONCLUSIONS
Anatomical variations in the course of the TMB and the MN in the carpal tunnel are common in the population. Thus, we recommend an ulnar side approach to carpal tunnel release, with a careful layer by layer dissection, to avoid iatrogenic damage to the TMB.
Topics: Cadaver; Carpal Tunnel Syndrome; Hand; Humans; Hypertrophy; Median Nerve; Prevalence; Wrist
PubMed: 26305098
DOI: 10.1371/journal.pone.0136477 -
Scientific Reports Jul 2021Before and immediately after passive upper limb neurodynamic mobilizations targeting the median nerve, grip ([Formula: see text]) and load ([Formula: see text]) forces...
Before and immediately after passive upper limb neurodynamic mobilizations targeting the median nerve, grip ([Formula: see text]) and load ([Formula: see text]) forces applied by the thumb, index and major fingers (three-jaw chuck pinch) were collected using a manipulandum during three different grip precision tasks: grip-lift-hold-replace (GLHR), vertical oscillations (OSC), and vertical oscillations with up and down collisions (OSC/COLL/u, OSC/COLL/d). Several parameters were collected or computed from [Formula: see text] and [Formula: see text]. Maximum pinch strength and fingertips pressure sensation threshold were also examined. After the mobilizations, [Formula: see text] max changes from 3.2 ± 0.4 to 3.4 ± 0.4 N (p = 0.014), d[Formula: see text] from 89.0 ± 66.6 to 102.2 ± 59.6 [Formula: see text] (p = 0.009), and d[Formula: see text] from 43.6 ± 17.0 to 56.0 ± 17.9 [Formula: see text] ([Formula: see text]0.001) during GLHR. [Formula: see text] SD changes from 0.9 ± 0.3 to 1.0 ± 0.2 N (p = 0.004) during OSC. [Formula: see text] peak changes from 17.4 ± 8.3 to 15.1 ± 7.5 N ([Formula: see text]0.001), [Formula: see text] from 12.4 ± 6.7 to 11.3 ± 6.8 N (p = 0.033), and [Formula: see text] from 2.9 ± 0.4 to 3.00 ± 0.4 N (p = 0.018) during OSC/COLL/u. [Formula: see text] peak changes from 13.5 ± 7.4 to 12.3 ± 7.7 N (p = 0.030) and [Formula: see text] from 14.5 ± 6.0 to 13.6 ± 5.5 N (p = 0.018) during OSC/COLL/d. Sensation thresholds at index and thumb were reduced (p = 0.001, p = 0.008). Precision grip adaptations observed after the mobilizations could be partly explained by changes in cutaneous median-nerve pressure afferents from the thumb and index fingertips.
Topics: Adult; Algorithms; Analysis of Variance; Female; Hand Strength; Healthy Volunteers; Humans; Male; Median Nerve; Models, Theoretical; Physical Therapy Modalities; Pinch Strength; Sensation; Students; Young Adult
PubMed: 34234161
DOI: 10.1038/s41598-021-93036-8 -
Biomedical Papers of the Medical... Jun 2023The aim of the study was to investigate the associations of cross-sectional area (CSA) of the median nerve measured by ultrasonography, the median to ulnar nerve ratio...
OBJECTIVE
The aim of the study was to investigate the associations of cross-sectional area (CSA) of the median nerve measured by ultrasonography, the median to ulnar nerve ratio (MUR), the median to ulnar nerve difference (MUD) and the ratio of CSA of the median nerve to height squared (MHS) in relation to electrodiagnostic classification of moderate and severe carpal tunnel syndrome (CTS) and thus to identify patients suitable for surgical treatment.
MATERIALS AND METHODS
A prospective study was conducted in patients aged ≥ 18 years who underwent both median and ulnar nerve ultrasonography and electrodiagnostic studies (EDS). 124 wrists of 62 patients were examined. The patients' characteristics were acquired through a questionnaire. CTS was diagnosed using EDS and classified according to the guidelines of the Czech Republic Association of Electrodiagnostic Medicine. The CSA of the median nerve and of the ulnar nerve were measured at the carpal tunnel inlet.
RESULTS
Median nerve CSA at the tunnel inlet ≥ 12 mm correlates with electrodiagnostic classification of moderate to severe carpal tunnel syndrome. At this cut-off value, the sensitivity of ultrasonography is 82.4%, its specificity is 87.7%, the positive predictive value is 82.4%, the negative predictive value is 87.7%. MUD, MUR and MHS perform worse than the median nerve CSA, as shown by their lower area under the receiver operating characteristic curve.
CONCLUSIONS
Ultrasound could help us indicate surgical treatment for CTS, especially in patients with clinical findings. Our results suggest a cut-off value of CSA at the tunnel inlet of ≥ 12mm.
Topics: Humans; Median Nerve; Carpal Tunnel Syndrome; Prospective Studies; ROC Curve; Ultrasonography; Sensitivity and Specificity
PubMed: 34897298
DOI: 10.5507/bp.2021.068 -
Hand (New York, N.Y.) Jan 2023Magnetic resonance diffusion tensor imaging (DTI) can detect microstructural changes in peripheral nerves. Studies have reported that the median nerve apparent diffusion... (Meta-Analysis)
Meta-Analysis Review
Magnetic resonance diffusion tensor imaging (DTI) can detect microstructural changes in peripheral nerves. Studies have reported that the median nerve apparent diffusion coefficient (ADC), a quantification of water molecule diffusion direction, is sensitive in diagnosing carpal tunnel syndrome (CTS). Five databases were searched for studies using ADC to investigate CTS. Apparent diffusion coefficient (measured in mm/s) were pooled in random-effects meta-analyses. Twenty-two studies met criteria yielding 592 patients with CTS and 414 controls. Median nerve ADC were measured at the level of the distal radioulnar joint (CTS ADC: 1.11, 95% CI: 1.07-1.15, I = 54%; control ADC: 1.04, 95% CI: 1.01-1.07, I = 57%), pisiform (CTS ADC: 1.39, 95% CI: 1.37-1.42, I = 0%; control ADC: 1.27, 95% CI: 1.23-1.31, I = 59%), hamate (CTS ADC: 1.40, 95% CI: 1.36-1.43, I = 58%; control ADC: 1.27, 95% CI: 1.25-1.28, I = 47%), and as an combination of several measurements (CTS ADC: 1.40, 95% CI: 1.37-1.47, I = 100%; control ADC: 1.39, 95% CI: 1.24-1.53, I = 100%). Median nerve ADC is decreased in individuals with CTS compared to controls at the levels of the hamate and pisiform. ADC cut-offs to diagnose CTS should be established according to these anatomic levels and can be improved through additional studies that include use of a wrist coil.
Topics: Humans; Carpal Tunnel Syndrome; Diffusion Tensor Imaging; Median Nerve; Magnetic Resonance Imaging; Wrist Joint
PubMed: 35695339
DOI: 10.1177/15589447221096706