Distal Arm Research Articles

Single-Stage Decompression for Triple Nerve Entrapment of the Distal Upper Limb

Peripheral nerve injuries have a significant negative impact on daily activities and quality of life. Considering that the compression of more than one peripheral nerve may have an increased negative emotional impact, it is, therefore, important to make a thorough diagnosis and speed up the surgical treatment. We present the case of a 71-year-old male patient with multiple simultaneous compression neuropathies of the distal right arm involving the posterior interosseous, median and ulnar nerves, who sought medical care during the first year of the COVID-19 outbreak.

31. Rare familial rearrangement with acrocentric satellite material on Yp relocating to Xp in a female fetus

The short (p) arms of acrocentric chromosomes contain chromatin material described as stalks and satellites made up of repetitive DNA sequences including those encoding ribosomal RNA, and correspond to the nucleolar organizer regions (NOR). Satellites observed on non-acrocentric chromosomes are rare aberrations, typically resulting from translocation between the p-arm of an acrocentric chromosome and the distal arm of another chromosome. The phenotypic consequences of such unbalanced rearrangements can vary significantly depending on the size and gene content of the non-acrocentric chromosome involved.

P178 Advising workers with distal arm pain to remain active: a secondary analysis of the ARM trial, a multicentre randomised controlled trial

Abstract Background/Aims Pain in the distal arm (elbow/forearm/wrist/hand) is common amongst working-aged adults and causes substantial work disability. The best strategy for managing arm pain is uncertain and patients are often referred to physiotherapy. We have recently shown in a randomised controlled trial (the ARM trial) that long-term disability was reduced among patients advised to remain active while awaiting physiotherapy, compared to advice to rest. The aim of the current study was to determine whether this approach is effective among workers, who may have to continue activities that are causing or exacerbating their pain; and whether there was any differential effect between workers doing manual versus non-manual work, and exposed versus not exposed to a range of physically demanding activities involving the upper limb. Methods The ARM trial (ISRCTN79085082) recruited patients with distal arm pain from 14 outpatient physiotherapy departments across the UK. Eligible consenting patients were randomised equally to: Advice to remain active, while awaiting physiotherapy; Advice to rest, while awaiting physiotherapy; or Immediate physiotherapy. This was done using a mixed randomisation/minimisation algorithm, maintaining treatment balance regarding treatment centre, gender, laterality, a broad categorisation of diagnosis, and baseline arm function. The primary outcome was freedom from disability at 26wks, as determined using the modified DASH (Disabilities of the Arm, Shoulder and Hand) questionnaire. In the current study, an intention-to-treat analysis was undertaken for the sub-group of trial participants in paid employment > =20hrs/wk at the start of the study. Results are presented as odds ratios, with 95% confidence intervals, for the probability of recovery. Results We have previously shown, among persons awaiting physiotherapy for distal arm pain, that advice to remain active is associated with improved long-term outcomes. Although not powered as a trial for workers, our findings suggest that these results also hold true for people in paid work - and there is certainly no evidence that this advice is detrimental. We have also shown that fast-track physiotherapy seems to confer no benefit, over and above therapy delivered after a period on a waiting list which calls into question the benefit of rapid access rehabilitation programmes. Conclusion We have previously shown, among persons awaiting physiotherapy for distal arm pain, that advice to remain active is associated with improved long-term outcomes. Although not powered as a trial for workers, our findings suggest that these results also hold true for people in paid work who may have to continue activities that are causing or exacerbating their pain. Certainly, there is no evidence that this advice is detrimental. We have also shown that fast-track physiotherapy seems to confer no benefit, over and above therapy delivered after a period on a waiting list which calls into question the benefit of rapid access rehabilitation programmes. Disclosure G.T. Jones: None. G.J. Macfarlane: None. K. Burton: Royalties; Was involved in the development of The Arm Book (ISBN: 978-0117069145) to which the experimental leaflet in this trial is related, and may receive future royalties on the booklet. K. Walker-Bone: None.

The outcomes of a novel two-stage proximal brachial artery to proximal basilic/brachial vein arteriovenous graft extension for dialysis access.

We describe a technique to mature a basilic/brachial vein in the mid-arm in preparation for a second stage loop proximal brachial artery to basilic/brachial vein arteriovenous graft (BBAVG). This can occur after a failed basilic/brachial vein transposition or a lack of adequate veins in the distal arm. This allows a mature vein to be used in an end-to-end configuration as an outflow to a BBAVG while preserving proximal vessels for the future. This single-center retrospective study was performed from 2015 to 2021, including 104 AVG patients divided into three groups: (1) Patients who failed a basilic vein transposition and had an enlarged vein suitable for an AVG outflow; (2) Patients who had a small caliber basilic/brachial vein after the transposition, requiring a mid-arm brachial artery to brachial/basilic arteriovenous fistula (AVF) creation with a subsequent AVG extension; (3) and lastly, patients who had no distal arm veins available and required a primary brachial artery to basilic/brachial AVF with AVG extension. A survival analysis was performed looking at time to loss of primary and secondary patency, calculated with Kaplan-Meier estimates and Cox regression models adjusted for covariates. The median follow-up time was 11 months (IQ = 11-30 months). The survival analysis showed 28% lost primary patency at a median time of 9 months, and 14% lost secondary patency at a median time of 61 months. Overall secondary patency of the vascular access measured at 12 months was 85.6%. Loss of primary (p = 0.008) and secondary patency (p = 0.017), as well as patency during the first 12 months (p = 0.036), were all significantly associated with increased age when adjusting for covariates. Our results suggest that the graft extension technique using a mature vein from a previous fistula can result in reliable and durable access. This is important for patients with limited access for hemodialysis, as the axillary vein is preserved for future use if needed.

Median and ulnar nerve fascicle imaging using MR microscopy and high-resolution ultrasound.

Understanding nerve microanatomy is important as different neuropathies and some nerve neoplasms present with fascicle enlargement. The aim of our study was to gain clinically oriented knowledge on nerve fascicular anatomy using imaging modalities. On a cadaveric upper extremity, high-resolution ultrasound (HRUS) scan with 22MHz probe was performed. Sections of the median and ulnar nerves were excised at the level of the distal arm and after magnetic resonance microscopy (MRM), histological cross-sections (HCS) were prepared. Cross-referencing of the MRM and HRUS images with HCS was performed. Fascicle and nerve contouring was performed with morphometric software in order to assess nerve and fascicular cross-sectional area (CSA), fascicle count, and interfascicular distances. Based on fascicle differentiation, factual fascicle (FF) group and fascicular cluster (FC) group were defined. On the cross-referenced imaging material, fascicles were differentiated in 92.7% on MRM and in 57.3% on HRUS. High to very high positive correlation among imaging material was observed for the fascicle CSA. FF depiction was 30.1% on HRUS. In comparison to the FF group, the FC group had significantly larger fascicle CSA and shorter interfascicular distances. The findings of our study contribute to understanding of fascicle depiction on imaging modalities. HRUS offers good visualization of fascicles. The capability of differentiating fascicles is modality specific and depends on the fascicle CSA and the amount of interfascicular epineurium.

Sensorimotor Outcomes of Upper Extremity End-to-Side Nerve Transfers: A Meta-analysis.

End-to-side nerve transfer (ETSNT) for treatment of peripheral nerve injuries is controversial given the myriad anatomic locations, injury types, and indications. Efficacy of ETSNT remains debated. We hypothesized differences in age, sex, transfer location, and time to surgery influence outcomes. We performed a search of the PubMed database for ETSNT in the upper extremity from 1988 to 2018. Age, sex, transfer location, time to surgery, donor and recipient axons, and strength and sensation outcomes as measured by Medical Research Council scale were extracted from articles. Meaningful recovery was classified as Medical Research Council Grade 3 or greater. Association between meaningful recovery and younger (<25) and older (≥25) patients, injury mechanism, sex, transfer location, donor axons, and recipient axons were calculated using a χ 2 or Fisher exact test. A logistic mixed effect model was used with time to surgery, age (categorical), transfer location, and injury type as a fixed effect, and a random paper effect was included to account for correlation among patients from the same paper. One hundred fifteen patients from 11 studies were included. Neither age (continuous variable, P = 0.68) nor time to surgery ( P = 0.28) affected meaningful recovery. Injury mechanism, sex, and younger age (<25 vs ≥25 years) were not associated with meaningful recovery. Within the brachial plexus ETSNT demonstrated median M4 ± 1 postoperative strength, with trunks/cords as the primary axon donor ( P = 0.03). The musculocutaneous nerve demonstrated promising but variable results in 31 patients with median strength M3 ± 4. Digital nerves consistently demonstrated meaningful sensory recovery as both donor and recipient axons (15 of 15, 100%). Logistic regression analysis demonstrated that odds of meaningful recovery after ETSNT are significantly greater for transfers within the brachial plexus compared with the distal arm (odds ratio, 41.9; 95% CI, 1.1-1586.7, P = 0.04), but location does not significantly affect meaningful recovery ( P = 0.22). Patients undergoing ETSNT for digital nerve injury demonstrated meaningful recovery. End-to-side nerve transfer seems to be more efficacious when performed within the brachial plexus. This study did not find sex, injury mechanism, or time to surgery to significantly affect meaningful recovery. Additional study is needed to better evaluate the effectiveness of ETSNT in the upper extremity.

Sonographic normal values for the cross-sectional area of the ulnar nerve: a systematic review and meta-analysis

PurposeNerve size is a commonly used sonographic parameter when assessing suspected entrapment of the ulnar nerve. We aimed to create a robust set of normal values, based on a critical review of published normal values.MethodsWe performed a systematic evaluation of studies on normal ulnar nerve sizes, identified in PubMed, Embase, and Cochrane databases. Using meta-analyses, we determined pooled mean cross-sectional area (CSA) values for different anatomical locations of the ulnar nerve throughout the arm. Subgroup analyses were performed for gender, probe frequency, in- or exclusion of diabetic patients, position of the elbow and Asian versus other populations.ResultsWe identified 90 studies of which 77 studies were included for further analyses after quality review, resulting in data from 5772 arms of 3472 participants. Subgroup analyses show lower CSA values at at the wrist crease and proximal to the wrist crease when using low frequency probes (< 15 MHz) and at the wrist crease, proximal to the wrist crease, proximal forearm and the distal upper arm in Asians. CSA values were lower when in flexed position compared to extended position for the cubital tunnel inlet only. No difference was found for gender.ConclusionsOur systematic review provides a comprehensive set of normal values at sites along the entire length of the ulnar nerve. This provides a foundation for clinical practise and upon which future studies could be more systematically compared.

Outcome of human amniotic membrane wrap around neurorrhaphy in high radial nerve injury - a case report following monkey bite

IntroductionPeripheral nerve injury due to animal bite is a rare phenomenon. Most animal bites are from dogs. Monkey bites constitute a common risk, second only to dog bites, among travelers. Peripheral nerve injuries may occur due to a combination of monkey's strong jaws and sharp long teeth penetrating deep into the soft tissues. Such injuries are associated with increased perineural fibrosis. Human amniotic membrane (HAM) wrap around the nerve repair site reduces fibrotic response, prevents adhesions and scar formation thereby improving outcome. We report a case of “High Radial nerve palsy due to monkey bite, treated by neurorrhaphy with HAM wrap”. MethodA 3-year old boy presented with wrist drop, and inability to extend the fingers and thumb of his right dominant hand, following a monkey bite over the distal arm. The diagnosis of high radial nerve injury was corroborated by high frequency ultrasound and electrodiagnostic studies. On exploration the radial nerve was found to be transected. An end to end repair was performed, with HAM wrap around the neurorrhaphy. ResultsWrist dorsiflexion recovered at 2.5 months followed by active finger and thumb extension at 4 months with no infection or immune rejection. ConclusionNerve regeneration in our patient occurred at a faster rate as compared to the conventional 1 mm/day. This could be attributed to decreased perineural fibrosis, improved neurotropism due to the HAM wrap and neuronal plasticity in young brain in addition, the patient being a small child having better regenerative ability in comparison to an adult.

Abstract WMP38: The Functional Significance Of Distal Arm Motor Deficits After Stroke

Background: Much of human behavior revolves around use of the hand, yet distal arm motor deficits are not part of the NIH Stroke Scale (NIHSS), and so their measurement is omitted from many guidelines and care pathways. We examined the frequency of distal arm motor deficits and their functional implications. Methods: Patients in the STRONG Study were examined 1-10d and again 90 d post-stroke. Grip force, expressed as the ratio of paretic/nonparetic hands, and the NIHSS were measured serially. The modified Rankin (mRS) and Fugl-Meyer arm motor (FM) scales were measured at d90. Results: There were 763 patients, with age = 62.5±15.0 (mean±SD), acute NIHSS = 4 [2-9] (median [IQR]), and day 90 mRS median = 2 [1-3]. Grip force was available in 748 acutely and in 439 at d90. Weakness in grip strength was present in 60.2% acutely and 52.2% at d90. Acutely, grip force was not related to NIHSS total score (r=.04, p=.3) after accounting for proximal motor deficits (NIHSS Q5); at d90, there was a weak relationship (r= -0.15, p&lt;.0001). Proximal weakness was only partially related to distal motor deficits at both timepoints (r = -0.48 to -0.53, p&lt;.0001). At d90, grip force explained 24.6% of the variance in mRS score (p&lt;.0001). D90 grip force showed convergent validity, correlating strongly with the distal arm motor FM score (r=.64, p&lt;.0001). Conclusions: In this mild-moderate stroke population, distal arm motor deficits were common, were poorly captured by the NIHSS total score, and did not simply echo proximal arm motor deficits. Distal arm motor deficits were strongly related to level of global disability at d90. These findings argue that measurement of distal arm motor deficits should be included in guidelines and care pathways after stroke.

Air Cuff Transducer Design for Occlusion-Based Hemodynamic Measurements—An Experimental and Simulation Study

In standard clinical practice, cuff devices are widely used for non-invasive blood pressure measurements (NIBP). However, cuff-based NIBP is prone to large errors especially in cases of hypo- and hypertension. In addition to this, the cuff measurement principle allows for estimation of a number of other hemodynamic parameters (e. g. cardiac output, arterial stiffness, augmentation index) by means of analysis of the pulse waveform and/or pulse amplitude recorded in the cuff pressure. However, in standard practice, the cuff is still only used for the measurement of BP.A key reason for the observed measurement errors and the limited set of extracted parameters lies in our poor understanding of the cuff device as a transducer; the cuff pressure response to arm volume pulsations (the cuff transfer function <i>TF</i>_cuff) depends on a large number of factors. It is not yet clear to what extent the cuff contributes to the NIBP error, or if the cuff in its current format is reliable for measurement of arterial pulse waveform/amplitude. In this study, we investigate the isolated cuff in order to gain a better understanding of the main sources of measurement errors. By using an experimental setup which measures the cuff response to mechanically simulated arm pulsations, we find that the cuff can explain part of the NIBP errors in cases of hypotension. Also, we find that pulse waveforms can be estimated using a standard cuff; however, measurement of the pulse volume amplitude is unfeasible. We demonstrate that the observed inaccuracies can be eliminated by usage of a calibrator device which obtains real-time information on <i>TF</i>_cuff. These findings will enable further investigation of the effects related to the pulse travel along the compressed limb and the interaction between cuff, arm tissue, distal arm hemodynamics and arterial walls for the development of improved occlusion-based measurement strategies.

Efficacy and safety of istradefylline in patients with Parkinson's disease presenting with postural abnormalities: Results from a multicenter, prospective, and open-label exploratory study in Japan

Postural abnormalities in Parkinson's disease (PD) can devastatingly impair the quality of life, especially in patients with advanced disease, and are generally refractory to dopaminergic agents. The objective of this exploratory study was to investigate the efficacy and safety of istradefylline for the treatment of postural abnormalities in PD. In this open-label, 24-week, single-arm prospective trial, PD patients with postural abnormalities experiencing the wearing-off phenomenon on levodopa-containing therapies were enrolled and received a starting dose of 20 mg/day istradefylline orally for 4 weeks, which was then increased to 40 mg/day. The primary endpoint was the change from baseline to week 24 in the 14-item Unified Dystonia Rating Scale (UDRS) total score. Pivotal secondary endpoints were changes in the sub-items of UDRS, Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III, and adverse drug reactions (ADRs). Overall, 24/31 enrolled patients completed the study; mean (standard deviation) age and duration of motor complications were 73.3 (7.7) years and 3.2 (4.4) years, respectively. Mean (95% confidence interval [CI]) change in the UDRS total score was 4.84 (1.97, 7.71; P = 0.002), with significant improvements in the neck, right distal arm and hand, and trunk severity scores. Mean (95% CI) change in the MDS-UPDRS part III score was 7.84 (4.34, 11.34; P < 0.001). The most common ADRs were malaise, dyskinesia exacerbation, and visual hallucinations in 2 (6.5%) patients each. This exploratory study demonstrated that istradefylline could be efficacious for postural abnormalities and was generally well tolerated in patients with PD experiencing the wearing-off phenomenon with levodopa-containing therapies.

“A COMPARATIVE STUDY OF ULTRASOUND GUIDED TECHNIQUE VERSUS PERIPHERAL NERVE STIMULATOR GUIDED TECHNIQUE IN INFRA-CLAVICULAR BRACHIAL PLEXUS BLOCK FOR UPPER LIMB SURGERIES.”

Background: Extensive use of ultrasonography for block execution has increased the success of procedure due to direct visualization of anatomical structures. Infra-clavicular brachial plexus block can be an attractive alternative to supraclavicular nerve block for upper limb surgeries. The objective of our study was to assess and compare the efcacy and success rate of USG guided technique versus PNS technique in Infra-clavicular brachial plexus block. Material And Methods: 70 adult patients with age in the range of 18-60 years, weight 50-80 Kg, ASA Grade I &amp; II posted for elective upper limb surgeries of hand, wrist, forearm and distal arm under infra-clavicular brachial plexus block. Group P (PNS)– Nerve stimulator guided Infraclavicular brachial plexus block. Group U (USG)– Ultrasound guided Infraclavicular brachial plexus block. Block execution time, sensory blockade, motor blockade and success rate were assessed. Assessment of sensory blockade was done by Hollmen scale whereas motor block assessment was done by Bromage Scale. Results: There was statistically signicant difference between the groups for block execution time, onset of sensory and motor blockade, time for complete sensory and motor block and success rate(p&lt;0.05). Conclusion: We conclude that, Ultrasound guided infraclavicular nerve block has shorter block execution time, faster sensory and motor block onset, signicantly earlier complete sensory and motor blockade, higher success rate with lesser pricks and minimal complications and should be preferred over PNS technique.

The role of ultrasonography in diagnosing hourglass-like fascicular constriction(s) of the anterior interosseous nerve.

In the past, the diagnosis of hourglass-like fascicular constriction(s) of the anterior interosseous nerve mostly depended on electrophysiological examination, by which the location could not be diagnosed. There are few studies on the evaluation of hourglass-like fascicular constriction(s) by ultrasonography. To evaluate the role of ultrasonography in the diagnosis of hourglass-like fascicular constriction(s) of the anterior interosseous nerve. A retrospective analysis of 12 patients with hourglass-like fascicular constriction(s) of the anterior interosseous nerve was carried out, and the characteristics of the high-frequency ultrasonographic images were summarized and compared with surgical exploration. The 12 cases of hourglass-like fascicular constriction(s) of the anterior interosseous nerve were all located in the median nerve of the distal upper arm, including nine cases of single hourglass-like fascicular constriction and three cases of multiple hourglass-like fascicular constrictions. High-frequency ultrasonography can accurately locate the hourglass-like fascicular constriction(s) of the anterior interosseous nerve and the extent of neuropathy. The ultrasonographic images of hourglass-like fascicular constriction(s) of the anterior interosseous nerve showed single or multiple hourglass-like change(s) in the median nerve of the distal upper arm. The nerve fascicles on both sides of the affected nerve with hourglass-like change thickened. High-frequency ultrasonography could be a reliable, convenient, and non-invasive diagnostic imaging method for hourglass-like fascicular constriction(s) of the anterior interosseous nerve.

A Rare Case of Sporadic Inclusion Body Myositis with Atypical Presentation

AbstractSporadic inclusion body myositis (IBM) is the most common acquired inflammatory myopathy that occurs after the age of 50 years. IBM typically involves wrist and finger flexors and quadriceps, but all sporadic IBM may not have the classic presentation of distal arm and proximal leg involvement. Treating physicians must be aware of this atypical presentation to avoid the misdiagnosis of IBM, leading to treatment with immunosuppressive agents. The aim of this study is to increase the awareness among physicians about the atypical presentation of IBM and to emphasize the importance of muscle biopsy in such cases. Here we report a case of 52 years old male diagnosed with sporadic IBM by muscle biopsy presented with atypical presentation.

Modulation of pulse travel and blood flow during cuff inflation- An experimental case study.

The blood pressure (BP) cuff can be used to modulate blood flow and propagation of pressure pulse along the artery. In our previous work, we researched methods to adapt cuff modulation techniques for pulse transit time vs. BP calibration and for measurement of other hemodynamic indices of potential interest to critical care, such as arterial compliance. A model characterized the response of the vasculature located directly under the cuff, but assumed that no significant changes occur in the distal vasculature.This study has been tailored to gain insights into the response of distal BP and pulse transit time to cuff inflation. Invasive BP data collected downstream from the cuff demonstrates that highly dynamic processes occur in the distal arm during cuff inflation. Mean arterial pressure increases in the distal artery by up to 20 mmHg, leading to a decrease in pulse transit time of up to 20 ms. Clinical Relevance: Such significant changes need to be taken into account in order to improve non-invasive BP estimations and to enable inference of other hemodynamic parameters from vasculature response to cuff inflation. A simple model is developed in order to reproduce the observed behaviors. The lumped-parameter model demonstrates opportunities for cuff modulation measurements which can reveal information on parameters such as systemic resistance, distal arterial, venous compliances and artery-vein interaction.

Sustained strong blood pressure lowering and preserved renal function during 3 year after anatomically optimized distal renal denervation according to the double blind randomized controlled study

Abstract Aim To evaluate long-term safety and efficacy of anatomically optimized distal renal denervation (RDN). Methods We assessed major adverse cardiovascular and renal events; changes in BP (office, ambulatory), and renal function (serum creatinine, eGFR) over 3 year follow-up extension of our double blind, randomized controlled study of the efficacy and safety of distal RDN versus conventional main trunk treatment in patients with true resistant hypertension (NCT02667912). Results Of 55 randomized patients (28/27, distal/main trunk RDN, respectively), 47 (23/24) were assessed at 1 year, and 39 (21/18) - at 3-year post-procedure. During 3-year follow-up 2 fatal and 2 non-fatal strokes were observed in distal RDN group versus one heart failure death and 2 non-fatal strokes in group of main trunk treatment. In distal RDN arm BP remained powerfully and significantly lowered both at 1 and 3 years post-procedure: −18.0 (95% CI −27.6; −8.5) and −16.9 (95% CI −27.3; −6.5) mmHg, 24h ambulatory systolic. During 1st year this potent BP lowering effect was accompanied by moderate eGFR decrease: −8.9 (95% CI −14.8; −3.1) ml/min/sq.m, however, this decrease was later reduced to non-significant −6.5 (95% CI −13.2; 0.3) ml/min/sq.m at 3 year post-procedure signaling some improvement in renal function after 1st year despite sustained strong BP lowering. In group of main trunk intervention BP only moderately decreased at 1 year −12.1 (95% CI −19.2; −5.0) mmHg, in parallel with small non-significant change in eGFR: −1.3 (95% CI −6.6; 4.0) ml/min/sq.m. Subsequently, BP lowering effect weakened and lost significance at 3 years post-procedure: −8.5 (95% CI −19.7; 2.2) mmHg. In contrast, eGFR continued to decline and reached significant −5.0 (95% CI −9.6; −0.3) ml/min/sq.m at the end of the study. Five patients developed new onset chronic kidney disease after main trunk RDN versus 3 patients – after distal RDN. The number of concomitant antihypertensive medications did not significantly changed in either group. Conclusion Our data demonstrate strong long-term BP lowering efficacy of distal RDN and, also, the potential of this procedure to prevent the decline of renal function in patients with resistant hypertension. Funding Acknowledgement Type of funding sources: None.

A Unique Case of Unilateral Distal Arm Weakness as a Presentation of Myasthenia Gravis

Background: Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder which typically presents with fluctuating ocular, bulbar or proximal limbs weakness. Case Presentation: A 71-year-old woman was admitted to our Neurology department with sudden onset of right distal hand weakness which exacerbated within days and subsequently involved also the proximal limbs and ocular muscles following treatment with high-dose steroids (admitted due to suspicion of myelitis). After a broad neurological work up, she was diagnosed with MG, based on the findings of a typical decremental pattern on Repetitive Nerve Stimulation (RNS) test and the presence of Acetylcholine Receptor Antibodies (AChRAbs). Treatment with 5 cycles of plasma exchange induced a dramatic clinical improvement. Conclusion: This case represents an atypical presentation of MG, simulating Cerebrovascular Accident (CVA) or myelitis and unmasking of signs by treatment with high dose of steroids.

National Electronic Injury Surveillance System sports-related arm fractures in the USA: thrower's fractures.

Humerus fractures are common in the USA. The purpose of this study was to utilize the National Electronic Injury Surveillance System: 1) to compare overall and age stratified incidence rates of proximal and distal arm fractures presenting to USA emergency departments; 2) to compare relative humerus fracture locations by age; and 3) to compare anatomical humerus fracture locations stratified by sports between 2005-2009 and 2015-2019. The National Electronic Injury Surveillance System was used to obtain estimated proximal and distal arm fractures between 2005-2009 and 2015-2019. Fracture rates were normalized using USA census estimates and stratified by age. Case summaries were filtered for anatomical and non-specific (proximal, middle, distal third) humerus fractures. Relative humerus fractures, inclusive of anatomical and non-specific fractures, were stratified by age and compared between 2005-2009 and 2015-2019. Anatomical fractures were stratified by sports. χ2 tests were used to compare fracture rates between time periods. There was a decrease (P<0.0001) in proximal and distal arm fracture rates and a difference (P<0.0001) in fracture rates with respect to age between 2005-2009 and 2015-2019. There was a significant difference in reported relative humeral fractures (P<0.0001) between the two periods. Impact related sports trauma accounted for most fracture cases for both periods. Non-impact related sports trauma consisted entirely of thrower's fractures. USA proximal and distal arm fracture rates decreased, and distributions differed by age between 2005-2009 and 2015-2019. Relative humerus fractures differed by time periods. One major non-impact sports related humerus fracture was extreme external rotational torque from throwing.

Effects of two grip force levels and forearm postures on hand‐arm transmitted vibration and physiological responses

AbstractVibration transmitted to the upper limb is the primary source of occupational musculoskeletal disorder. Transmissibility is not just caused by vibration magnitude but is also directly influenced by the applied force and posture. This study investigated the effects of two forearm postures and grip force levels, when using dual‐handle guided equipment, on hand‐arm transmitted vibration and physiological responses. Sixteen young male adults were recruited. Pre‐task and post‐task assessments including grip strength and perceived discomfort were measured. The task was to hold a vibrating handlebar for 5 ‐min under four randomly sequenced conditions: N/PM/H—neutral/pronated forearm and mild/hard grip. Transmissibility and forearm muscle activities were recorded during each task. It was discovered that neutral posture led to higher wrist and elbow transmissibility, whereas hard grip resulted in higher elbow transmissibility, forearm muscle activities, grip strength reduction, and distal arm discomfort. Furthermore, the interaction between the effects of posture and force significantly influenced wrist extensor activity (NH &gt; PH; NM = PM), proximal arm discomfort (NH &lt; PH; NM = PM), and wrist transmissibility (PH &gt; PM; NH = NM). Essentially, with constant vibration and exposure duration, the application of sustained hard grip had more negative physiological effects because of the greater physical workload toward the hands and forearms. Moreover, gripping hard during pronation led to higher discomfort that reached the proximal arm because a greater effort was required. Hence, a neutral forearm posture is recommended when the tasks require forceful movements and either posture is suggested when less powerful movements are involved.

Advance of research on Phelan-McDermid syndrome

Phelan-McDermid syndrome (PMS)(OMIM#606232) is a rare genetic disorder caused by a deletion of the distal long arm of chromosome 22q13 involving a variety of clinical features with considerably heterogeneous degrees of severity. This syndrome is characterized by global developmental delay, intellectual disability, hypotonia, absent or severely delayed speech, minor dysmorphic features and autism spectrum disorder. PMS is easy to be misdiagnosed due to the lack of specific clinical manifestations. SHANK3 has been identified as the critical candidate gene for the neurological features of this syndrome. However, some studies have shown that other genes located in the 22q13 region may have a role in the formation of symptoms in individuals with PMS. This article provides a review for recent progress made in research on PMS including etiology, clinical manifestation, diagnosis, and treatment, with a particular emphasis on clinical diagnosis and treatment.