Nerve Conduction Studies Research Articles

A novel variant of biallelic MME gene associated with autosomal recessive late-onset distal hereditary motor neuropathy in Chinese families

Distal hereditary motor neuropathies (dHMN) are a group of heterogeneous diseases and previous studies have reported that the compound heterozygous recessive MME variants cause dHMN. Our study found a novel homozygous MME variant and a reported compound heterozygous MME variant in two Chinese families, respectively. Next-generation sequencing and nerve conduction studies were performed for two probands. The probands in two families presented with the muscle weakness and wasting of both lower limbs and carried a c.2122 A > T (p.K708*) and c.1342 C > T&c.2071_2072delinsTT (p.R448*&p.A691L) variant, respectively. Prominently axonal impairment of motor nerves and slight involvement of sensory nerves were observed in nerve conduction study. Our study reported a “novel” nonsense mutation and a missense variant of autosomal recessive late-onset dHMN and reviewed reported MME variants associated with dHMN phenotype.

Screening tools for diabetic foot ulcers: a narrative review.

The prevalence of diabetic foot ulcers (DFUs) is 4 to 10% among people with diabetes mellitus. DFUs are associated with increased morbidity and mortality as well as reduced quality of life and have a significant impact on overall healthcare expenditure. The main predisposing factors for DFU are diabetic neuropathy, peripheral arterial disease, and trauma. The fact that a range of tests can be used to identify patients at risk for DFU often causes confusion among practitioners regarding which screening tests should be implemented in clinical practice. Herein we sought to determine whether tests of somatic nerve function, such as pinprick sensation, thermal (cold/hot) test, ankle reflexes, vibration perception, 10-g monofilament, Ipswich touch test, neuropathy disability score, and nerve conduction studies, predict the development of DFUs. In addition, we examined whether sudomotor function screening tests, such as Neuropad, sympathetic skin response, and other tests, such as elevated plantar pressure or temperature measurements, can be used for DFU screening. If not treated properly, DFUs can have serious consequences, including amputation, early detection and treatment are vital for patient outcomes.

Dorsal ulnar cutaneous nerve conduction study based on nerve ultrasound

This study investigates the impact of the anatomical separation point of the dorsal ulnar cutaneous nerve (DUCN) on nerve conduction studies (NCS). Involving 25 subjects with DUCN NCS findings, it utilizes ultrasound to mark the DUCN's divergence from the ulnar nerve. NCS was performed at four points relative to the separation point. The findings indicate the maximal amplitudes occurred 2 cm distal to the separation point. The study suggests it is ideal when the stimulation is performed between the seperation point and 2 cm distal to it.

A revised electrodiagnosis-based severity classification for carpal tunnel syndrome

BACKGROUND: An electrodiagnostic evaluation is conducted to diagnose carpal tunnel syndrome (CTS) and evaluate its severity. OBJECTIVE: This study proposes a revised approach for classifying the severity of electrophysiological findings for patients with CTS. METHODS: This retrospective cross-sectional study included patients with CTS confirmed through electrodiagnostic evaluations. Based on the Stevens’ classification, the patients were divided into three groups (mild/moderate/severe). A new intermediate group was defined to identify patients with normal motor nerve conduction studies and abnormal electromyographic results. CTS pain was evaluated using a numeric rate scale. Physical examinations and sonographic evaluation were performed to detect anatomical abnormalities. RESULTS: Overall, 1,069 CTS hands of 850 CTS patients were included. The mean age was 57.9 ± 10.8 years, and 336 (39.5%) were men. There were 522 (48.8%) mild cases; 281 (26.3%) moderate cases; and 266 (24.9%) severe cases. In the severe group, 49 cases were reclassified into the intermediate group. The median cross-sectional area in the intermediate group significantly differed from that in the severe group. However, the pain score significantly differed from that of the moderate group. CONCLUSION: The intermediate CTS group showed clinical features that were intermediate to those of the moderate and severe CTS groups.

T2-relaxometry in a large cohort of hereditary transthyretin amyloidosis with polyneuropathy

Background Previously, T2-relaxation time (T2app) and proton spin density (ρ) detected nerve injury in a small group of ATTRv amyloidosis. Here, we aim to quantify peripheral nerve impairment in a large cohort of symptomatic and asymptomatic ATTRv amyloidosis and correlate T2-relaxometry markers with clinical parameters and nerve conduction studies (NCS). Methods Eighty participants with pathologic variants of the transthyretin gene (TTRv) and 40 controls prospectively underwent magnetic resonance neurography. T2-relaxometry was performed, allowing to calculate tibial ρ, T2app and cross-sectional-area (CSA). Detailed clinical examinations and NCS of tibial and peroneal nerves were performed. Results Forty participants were classified as asymptomatic TTRv-carriers, 40 as symptomatic patients with polyneuropathy. ρ, T2app and CSA were significantly higher in symptomatic ATTRv amyloidosis (484.2 ± 14.8 a.u.; 70.6 ± 1.8 ms; 25.7 ± 0.9 mm2) versus TTRv-carriers (413.1 ± 9.4 a.u., p < 0.0001; 62.3 ± 1.3 ms, p = 0.0002; 19.0 ± 0.8 mm2, p < 0.0001) and versus controls (362.6 ± 7.5 a.u., p < 0.0001; 59.5 ± 1.0 ms, p < 0.0001; 15.4 ± 0.5 mm2, p < 0.0001). Only ρ and CSA differentiated TTRv-carriers from controls. ρ and CSA correlated with NCS in TTRv-carriers, while T2app correlated with NCS in symptomatic ATTRv amyloidosis. Both ρ and T2app correlated with clinical score. Conclusion ρ and CSA can detect early nerve injury and correlate with electrophysiology in asymptomatic TTRv-carriers. T2app increases only in symptomatic ATTRv amyloidosis in whom it correlates with clinical scores and electrophysiology. Our results suggest that T2-relaxometry can provide biomarkers for disease- and therapy-monitoring in the future.

Role of ultrasound and magnetic resonance neurography in the detection of median nerve abnormalities in carpal tunnel syndrome

BackgroundThe most prevalent cause of peripheral nerve entrapment is carpal tunnel syndrome, which is characterized by compression of the median nerve at the wrist as a result of nearby or localized microvascular interference as well as structural alterations to the median nerve or adjacent tissues. However, no special information regarding the median nerve or its surroundings is provided by clinical examination or electrophysiological testing. The purpose of this study is to evaluate the effectiveness of magnetic resonance neurography (MRN) and ultrasound in identifying changes and abnormalities of the median nerve in carpal tunnel syndrome.MethodsThe twenty-five patients in this study ranged in age from 27 to 63 years old, with a mean age of 47. There were 18 female patients and seven male patients. All patients were sent to the radiology department from the orthopedics, neurology, outpatient clinic, and neurology department, at Ain Shams Hospital, Faculty of Medicine, Ain Shams University. All of the patients had clinically manifested pain along the median nerve distribution, each of the sixteen patients had hand paresthesia, and four had thenar muscle atrophy.ResultsIn the current study, Ultrasound exhibits low negative predictive value of 67% and specificity of 67%, but high positive predictive value of 95%, sensitivity of 95%, and overall accuracy of 92%. On the other hand, (MRN) exhibits a low negative predictive value of 60% and a high specificity of 75% in the diagnosis of nerve entrapment, but it also displays a high positive predictive value of 95%, sensitivity of 90%, and overall accuracy of 88%. Regarding the assessment of the recurrence cause and post-surgical evaluation is more reliable by Magnetic Resonance Neurography examination.ConclusionsMagnetic resonance neurography and high-resolution ultrasonography can be utilized to diagnose patients with median nerve entrapment and patients who cannot be diagnosed electrophysiologically.MRN is a more accurate method for detecting the exact location of nerve entrapment and evaluating nerve recovery after surgical intervention than nerve conduction studies and electromyography. Additionally, MRN can be used to identify causes that were not previously recognized based on physical examination and electrophysiological tests.

Sural sparing reversible sensorimotor abnormalities in hypokalemia: A close mimic of GBS

Nerve conduction studies (NCS) in hypokalemic paralysis usually show decreased compound muscle action potential (CMAP) which improves with correction of hypokalemia and normalizes in between the attacks. Inactivity of Na+ K+ ATPase pump due to hypokalemia results in decreased excitability of muscle fibers resulting in reduced CMAP on NCS. Sensory symptoms, as well as abnormalities in sensory NCS is a rare phenomenon. Here we describe a 40-year-old male who presented with acute onset rapidly progressive ascending quadriparesis with type 2 respiratory failure due to hypokalemia following hepatorenal dysfunction. NCS done before hypokalemia correction, suggested sural sparing with generalized reduced CMAPs, nonrecordable median and ulnar nerves sensory nerve action potential (SNAP) and abnormal F waves. After hypokalemia correction there was improvement in CMAPs as well as SNAPs. Thus, hypokalemia can present as an axonal sensorimotor involvement with sural sparing on NCS study similar to Guillain-Barré syndrome subtype.

Prevalence of Subclinical Peripheral Neuropathy in Patients With Autoimmune Connective Tissue Disorders: An Observational Cross-Sectional Study.

Background Autoimmune connective tissue disorders (AICTDs) are a group of chronic inflammatory diseases characterized by immune responses targeting the body's own tissues. Peripheral neuropathy, which can be symmetrical or asymmetrical, is a common complication in AICTD patients. Early detection of subclinical peripheral neuropathy remains challenging, as nerve conduction studies are not routinely performed. This study aimed to determine the prevalence of subclinical peripheral neuropathy among patients with AICTD and to assess its association with potential predictor variables, including laboratory parameters and autoimmune markers. Materials and methods This observational cross-sectional study included 100 patients undergoing treatment for AICTDs for over three years, conducted over 15 months. Ethical approval and informed consent were obtained before detecting subclinical peripheral neuropathy through nerve conduction studies on bilateral ulnar, radial, sural, peroneal, and tibial nerves at a tertiary-level medical college hospital. Inclusion criteria encompassed patients treated at the tertiary hospital, not on immunosuppressants other than steroids, with at least three years of treatment, while exclusions were made for established peripheral neuropathy and other specified conditions. Descriptive statistics, Chi-square/Fisher's exact tests, independent samples t-tests, and logistic regression were used for data analysis at a 0.05 significance level, with IBM SPSS Statistics for Windows, Version 20 (Released 2011; IBM Corp., Armonk, NY, USA). Results Subclinical peripheral neuropathy was present in 18% (n = 18) of the study participants, while 82% (n = 82) did not exhibit neuropathy. Patients with subclinical neuropathy had a significantly higher mean age (49.66 ± 4.77 years) compared to those without neuropathy (46.02 ± 12.7 years, p = 0.047). The majority of the study population was female, 79 (79%), and there was no significant gender difference between the groups (p = 0.513). There was no significant association between inflammatory markers (C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)) and neuropathy. However, patients with subclinical neuropathy were more likely to test positive for rheumatoid factor (RF) (8 (66.7%) vs. 71 (58.5%), p = 0.011) and anti-cyclic citrullinated peptide (Anti-CCP) antibodies (11 (78.5%) vs. 32 (47%), p = 0.032). Steroid use did not significantly affect the presence of neuropathy (p = 0.769). Conclusion The study found a high prevalence of subclinical peripheral neuropathy in AICTD patients, detectable only by nerve conduction studies. RF and Anti-CCP antibodies were associated with subclinical neuropathy, suggesting these markers could guide early detection, and inform treatment intensification to reduce neuropathy prevalence among AICTD patients.

Correlation of Clinical and Electrophysiological Criteria in the Diagnosis of Guillain-Barré Syndrome: A Prospective Observational Study.

There are many criteria for diagnosing Guillain-Barré syndrome (GBS), and the yield of these diagnostic criteria varies. Each criterion requires some laboratory data and nerve conduction studies (NCS). Although supportive laboratory data are reassuring when present in suspected cases of GBS, when absent, they can potentially cause further delay in diagnosis and treatment. There is no gold standard test for the diagnosis of GBS, and there are multiple diagnostic criteria for GBS to date. The aim of the study is to know the sensitivity of different criteria, clinical and electrophysiological, for the diagnosis of GBS and to study the clinical spectrum and electrophysiological spectrum of GBS in our cohort of patients. We studied a total of 43 cases who presented with one or more of the following symptoms: relatively symmetrical and progressive flail-type weakness of more than one limb, with or without ataxia and/or ophthalmoplegia, and were diagnosed with GBS according to clinical criteria at the time of admission to Government Stanley Medical College Hospital. GBS mimics were ruled out. In all patients, the demographic data, cerebrospinal fluid (CSF) analysis (if done), and electrophysiological findings fitting into the diagnostic criteria of National Institute of Neurological Disorders and Stroke (NINDS), Dutch, and Brighton criteria were recorded. The need for assisted mechanical ventilation, neurology intensive care unit (NICU) stay, any complications, and treatment outcome details were recorded in a structured proforma. Most of the patients in our study were in their fourth decade of life, with a mean age of 41.37 years, similar to previous studies from India. Men are more frequently affected compared to women, similar to what has been observed in most studies done previously worldwide. In our study, electrophysiological criteria by Dutch criteria (87.5%), Brighton criteria (87.5%), and NINDS criteria (85.6%) had low sensitivity compared to the clinical criteria. In the present study, electrophysiological criteria proposed by the NINDS, Dutch, and Brighton criteria are less sensitive compared to clinical criteria in diagnosing GBS at early stages. Clinical criteria alone may be useful in resource-poor countries and at peripheral healthcare systems where NCS are not always readily available.

Evaluation of the Dysfunctional Scapula.

Periscapular pain and dysfunction are relatively common complaints in the practice of upper extremity surgeons. However, evaluation of the dysfunctional scapula is intimidating for most. Physical examination of the periscapular muscles is very rich, and a systematic approach provides the opportunity to establish a diagnosis for most patients. Conditions underlying scapular dysfunction include trapezius palsy, serratus palsy, brachial plexus injuries, muscular dystrophy, snapping scapula, pectoralis minor syndrome, congenital undescended scapula, and functional scapular dyskinesis, among others. Patients should be examined with their torso uncovered and assessed from the front and back. Inspection, evaluation of motion, and strength testing may be followed by certain examination maneuvers specific for each condition. The scapular assistance test may help predict the outcome of treatment for certain conditions. Plain radiographs oftentimes need to be complemented with magnetic resonance of the chest to capture periscapular muscles as well as an electromyogram with nerve conduction studies. Computed tomography is particularly helpful for skeletal abnormalities. Ultrasound is used to assess certain peripheral nerve injuries and to guide diagnostic and therapeutic injections. A focused evaluation of the scapula followed by a more specific and directed approach for each condition suspected will allow upper extremity surgeons to approach the evaluation of the dysfunctional scapula with much more confidence.

Electrodiagnostic subtyping in Guillain-Barré syndrome patients in the International Guillain-Barré Outcome Study.

Various electrodiagnostic criteria have been developed in Guillain-Barré syndrome (GBS). Their performance in a broad representation of GBS patients has not been evaluated. Motor conduction data from the International GBS Outcome Study (IGOS) cohort were used to compare two widely used criterion sets and relate these to diagnostic amyotrophic lateral sclerosis criteria. From the first 1500 patients in IGOS, nerve conduction studies from 1137 (75.8%) were available for the current study. These patients were classified according to nerve conduction studies criteria proposed by Hadden and Rajabally. Of the 1137 studies, 68.3% (N = 777) were classified identically according to criteria by Hadden and Rajabally: 111 (9.8%) axonal, 366 (32.2%) demyelinating, 195 (17.2%) equivocal, 35 (3.1%) inexcitable and 70 (6.2%) normal. Thus, 360 studies (31.7%) were classified differently. The areas of differences were as follows: 155 studies (13.6%) classified as demyelinating by Hadden and axonal by Rajabally; 122 studies (10.7%) classified as demyelinating by Hadden and equivocal by Rajabally; and 75 studies (6.6%) classified as equivocal by Hadden and axonal by Rajabally. Due to more strictly defined cutoffs fewer patients fulfilled demyelinating criteria by Rajabally than by Hadden, making more patients eligible for axonal or equivocal classification by Rajabally. In 234 (68.6%) axonal studies by Rajabally the revised El Escorial (amyotrophic lateral sclerosis) criteria were fulfilled; in axonal cases by Hadden this was 1.8%. This study shows that electrodiagnosis in GBS is dependent on the criterion set utilized, both of which are based on expert opinion. Reappraisal of electrodiagnostic subtyping in GBS is warranted.

The prevalence and clinical features of leflunomide-associated peripheral neuropathy in patients with rheumatic disease in a New Zealand cohort.

To identify the prevalence and clinical features of leflunomide-associated peripheral neuropathy in patients with rheumatic disease over a 42-month observational period between January 1, 2016 and June 30, 2019. A retrospective observational study was conducted using regional prescription data identifying all patients treated with leflunomide for rheumatic diseases in the Southern District Health Board of New Zealand. Medical records were used to identify patients who developed peripheral neuropathy while receiving treatment with leflunomide. Demographic characteristics, co-therapies, and additional risk factors for peripheral neuropathy were also recorded. A total of 482 patients were identified as receiving leflunomide for the treatment of rheumatic during the study period. In total, 23 patients developed leflunomide-induced peripheral neuropathy within the cohort giving a prevalence of 4.7%. Nerve conduction studies (NCS) performed in 18 (78.2%) of these patients confirmed a distal axonal, sensory, or sensorimotor peripheral neuropathy. The majority of patients (n = 22; 95.6%) either improved, stabilized, or resolved on cessation of the drug, with or without medication washout. Adverse symptoms were reported in association with peripheral neuropathy in 15 of the 23 patients (65.2%): these included pain, poor sleep, compromised skin integrity, poor balance, and a Charcot-like arthropathy. Additional treatment was required to manage symptoms of peripheral neuropathy including nine patients (39%) who received pain relief. This study supports the previously reported association between leflunomide treatment and the development of a peripheral neuropathy. However, our findings suggest that this is more common than the previous estimates. In patients with psoriatic arthritis and previous tarsitis, there appeared to be an association with a Charcot's-like arthropathy, a complication not previously noted in the literature.

The importance of medial plantar nerve conduction study in detectıon of polyneuropathy in inflammatory bowel disease

Background &amp; Objective: Peripheral neuropathy is the most frequent neurologic complication of inflammatory bowel disease (IBD). We aimed to evaluate the clinical utility of medial plantar nerve conduction study (NCS) in the detection of distal sensory polyneuropathy in IBD patients. Methods: The study was performed with 21 Crohn’s disease (Group 1) patients, 24 Ulcerative Colitis (Group 2) patients without clinical peripheral neuropathy and 28 healthy participants (Group 3). Each patient group underwent electrophysiological conduction studies. The findings were analyzed statistically. Results: Abnormal medial plantar nerve conduction was present on both sides in 11 (24.4 %) patients with IBD; 5 (11.1 %) patients had low sural nerve amplitude, and 5 (11.1 %) had low superficial peroneal nerve amplitude bilaterally. There were significant differences between the IBD groups (Group 1 and 2) and Group 3 in the mean sensory nerve action potential amplitude of the right medial plantar nerve (p&lt;0.024), and in the mean sensory nerve action potential amplitude of the left medial plantar nerve (p&lt;0.025). The polyneuropathy pattern was mostly of the sensory axonal type in patients with IBD. Conclusions: These electrophysiologic findings indicate that peripheral neuropathy is more prevalent in IBD. In IBD patients the amplitudes of the medial plantar nerve were abnormal more than in the sural and superficial peroneal nerves.

"Voriconazole-Associated Motor Neuropathy In Acute Myeloid Leukemia: A Case Report And Literature Review"

Introduction: Voriconazole, a commonly used antifungal in immunocompromised patients is effective against various fungal pathogens. Despite its efficacy, it is associated with numerous adverse effects, including the less frequently documented motor neuropathy. Case Presentation: We report a case of a 60-year-old male with acute myeloid leukemia (AML) who developed motor neuropathy following voriconazole administration. Initially treated with standard chemotherapy and prophylactic antifungals, he developed febrile neutropenia and was subsequently administered voriconazole. Within a week, he presented with bilateral foot drop. The neurological assessment revealed severe motor weakness without sensory loss. MRI indicated lumbar disc protrusion and nerve conduction studies confirmed severe demyelinating polyneuropathy. Upon cessation of voriconazole, the patient's symptoms completely resolved, as confirmed by follow-up electromyography. Discussion: Voriconazole-associated neuropathy, though rare, can present as motor neuropathy, contrary to the more commonly reported sensory neuropathy. The exact mechanism remains unclear, and while symptoms often resolve after discontinuation, some cases may result in permanent damage. Conclusion: This case highlights the importance of recognizing voriconazole-induced motor neuropathy in AML patients. Early identification and discontinuation of the drug are crucial for symptom resolution. Further research is needed to understand the underlying mechanisms and to develop preventive and management strategies.

The Association between the Severity of Distal Sensorimotor Polyneuropathy and Increased Carotid Atherosclerosis in Individuals with Type 2 Diabetes.

Diabetes contributes to a spectrum of complications encompassing microvascular and macrovascular disorders. This study aimed to explore the correlation between distal sensorimotor polyneuropathy (DSPN) severity and heightened carotid atherosclerosis among individuals with type 2 diabetes mellitus (T2DM). Method: Participants underwent comprehensive assessments including nerve conduction studies (NCS), Toronto Clinical Neuropathy Score (TCNS) evaluations, assessment of cardiometabolic risk factors, and carotid sonography studies covering dynamic and morphological parameters. The resistance index (RI), pulsatility index (PI), peak systolic velocity (PSV), and end-diastolic velocity (EDV) in both the common carotid artery (CCA) and internal carotid artery (ICA), carotid intima-media thickness (IMT), and carotid plaque score (CPS) were also measured. Peripheral nerve function severity was assessed using composite amplitude scores (CAS) derived from NCS. Individuals with DSPN exhibited lower EDV in the CCA and ICA (p < 0.0001 and p = 0.002), higher PI and RI in both CCA and ICA (all p < 0.0001), and higher CPS (p = 0.002). They also demonstrated a higher prevalence of retinopathy as an underlying condition, higher index HbA1c, and reduced estimated glomerular filtration rate (eGFR) (all p < 0.0001). Multiple linear regression analysis revealed significant associations where eGFR, ICA-PI, index HbA1c, waist circumference, and age were correlated with CAS. Meanwhile, diabetes duration, waist circumference, age, and index HbA1c showed significant associations with TCNS. Our study suggests that individuals with T2DM who exhibit more severe carotid atherosclerosis may not only be at increased risk of developing DSPN but also may experience greater severity of DSPN. PI in both the CCA and ICA, along with the CPS, serve as surrogate biomarkers for DSPN severity.

Role of minimal F-wave latency in the electrodiagnosis of polyneuropathy

Background and objective: Polyneuropathy is a debilitating condition that causes damage to more than two peripheral nerves in the body. The objective of this research was to detect the role of minimal F-wave latency as compared with other nerve conduction parameters for the electro-diagnosis of polyneuropathies. Methods: In this descriptive, prospective cross-sectional study, 80 consecutive patients with clinical diagnosis of polyneuropathy (both acute and chronic) between July and December 2023, presenting to the Neurology Department at King Edward Medical University were enrolled. Patients with clinical diagnosis of cervical/lumbar radiculopathies, plexopathies, compressive myelopathy , neuromuscular junction diseases, motor neuron disorders, or localized neuropathies were excluded from this research. NCS and EMG were carried out using conventional procedure. The results were recorded in the predesigned pro forma along with the history and demographic information. Statistical software SPSS 25.0 was used for the analysis of the recorded data. Results: F-wave abnormality was detected in 57 (71.3%) for median nerve, 57 (71.3%) for ulnar nerve, 79 (98.7%) for tibial nerve and in 79 (98.7%) patients for peroneal nerve. Nerve-specific motor nerve conduction study (MNCS) abnormality was found in 47 (58.8%) for median nerve, 43/80 (53.8%) for ulnar nerve, 59 (73.7%) for tibial nerve and in 57(71.3%) patients for peroneal nerve. Nerve-specific sensory nerve conduction study (SNCS) abnormality was present in 43 (53.3%) for median nerve, 43 (53.3%) for ulnar nerve, 50 (62.5%) for sural nerve, and in 49 (61.3%) patients for superficial peroneal nerve. Overall rate of abnormality was 85% for F-wave minimal latencies in comparison with 64% for MNCS and 56% for SNCS. Conclusion: Minimal F-wave latency can be an effective diagnostic parameter for detection of polyneuropathy. This can facilitate in early detection and management of polyneuropathy.

Adherence to Non-operative Clinical Quality Measures in Carpal Tunnel Syndrome.

Background: Clinical quality measures exist for non-operative management of carpal tunnel syndrome (CTS). Factors predicting adherence are unclear. Methods: A retrospective cohort study of patients with chronic CTS using MarketScan Research Database (2015-2020) was conducted. Six logistic regression models were designed to study adherence to quality measures within 1 year after diagnosis. Results: Of 782,717 patients identified, 514,073 (65.7%) were female with an average (SD) age of 51.4 (13.4) years. Only 88 patients (0.01%) met all quality measures. Greatest compliance observed with receipt of nerve conduction study (NCS; 283,959 [36.3%]), no prescription of medications (336,297 [43.0%]) and no laser therapy (772,979 [98.8%]); 294,305 patients (37.6%) received hand surgeon referral. Hand surgeon referral predicted higher likelihood of NCS and splinting (OR, 1.83; 95% CI: 1.81-1.84; OR, 2.53; 95% CI: 2.50-2.56) and medication over-prescription (OR, 1.05; 95% CI: 1.00-1.10). Females were more likely to be referred to a hand surgeon and be referred for splinting (OR 1.02; 95% CI: 1.01-1.03; OR 1.19; 95% CI: 1.18-1.21) but less likely to have no prescriptions or avoid laser therapy (OR 0.85, 95% CI: 0.84-0.85; OR 0.82, 95% CI: 0.79-0.86). Medicare recipients adhered less to quality measures compared to patients with fee-for-service insurance. As comorbidities increased, patients were less likely to receive hand surgeon referral and carpal tunnel release. Conclusions: Findings suggest that hand surgery referrals increased adherence to quality measures. Females, Medicare recipients and multimorbid patients should be targeted for improved care. Future quality care efforts should incentivise adherence for Medicare beneficiaries and improve guideline recognition amongst physicians. Level of Evidence: Level III (Therapeutic).

The difference in nerve ultrasound and motor nerve conduction studies between autoimmune nodopathy and chronic inflammatory demyelinating polyneuropathy.

Nerve enlargement has been described in autoimmune nodopathy and chronic inflammatory demyelinating polyneuropathy (CIDP). However, comparisons of the distribution of enlargement between autoimmune nodopathy and CIDP have not been well characterized. To fill this gap, we explored differences in the ultrasonographic and electrophysiological features between autoimmune nodopathy and CIDP. Between March 2015 and June 2023, patients fulfilling diagnostic criteria for CIDP were enrolled; among them, those with positive antibodies against nodal-paranodal cell-adhesion molecules were distinguished as autoimmune nodopathy. Nerve ultrasound and nerve conduction studies (NCS) were performed. Overall, 114 CIDP patients and 13 patients with autoimmune nodopathy were recruited. Cross-sectional areas (CSA) at all sites were larger in patients with CIDP and autoimmune nodopathy than in healthy controls. CSAs at the roots and trunks of the brachial plexus were significantly larger in patients with anti-neurofascin-155 (NF155), anti-contactin-1 (CNTN1), and anti-contactin-associated protein 1 (CASPR1) antibodies than in CIDP patients. The patients with anti-NF186 antibody did not have enlargement in the brachial plexus. NCS showed more frequent probable conduction block at Erb's point in autoimmune nodopathy than in CIDP (61.9% vs. 36.6% for median nerve, 52.4% vs. 39.5% for ulnar nerve). Markedly prolonged distal motor latencies were also present in autoimmune nodopathy. Patients with autoimmune nodopathies had distinct distributions of peripheral nerve enlargement revealed by ultrasound, as well as distinct NCS patterns, which were different from CIDP. This suggests the potential utility of nerve ultrasound and NCS to supplement clinical characteristics for distinguishing nodopathies from CIDP.

New phenotyping questionnaire for diagnosing sarcoidosis-associated small fiber neuropathy.

Small fiber neuropathy is a common complication in patients with sarcoidosis and its prevalence is estimated at 40-86%. The underlying mechanism influences the presentation of small fiber neuropathy. For example, patients with metabolic diseases are often associated with a classic length-dependent small fiber neuropathy pattern, while patients with inflammatory diseases are more often present with a non-length-dependent small fiber neuropathy. Detailed phenotyping may be useful to improve diagnostic efficiency, as a clue to underlying mechanisms and as a precondition for personalized medicine. This study examined four phenotypes distinguishing between length-dependent and non-length-dependent presentation with a new subdivision for continuous and intermittent presentation. Forty-eight sarcoid patients with symptoms and at least two clinical signs of small fiber neuropathy and normal nerve conduction studies were classified as having probable small fiber neuropathy. A new small fiber neuropathy phenotyping questionnaire has been developed that allows patients to mark the anatomical locations of pain at three different levels: the skin, muscles, and joints. The location of symptoms was used to define length dependence, and two colors were used to distinguish continuous (red) from intermittent (blue) symptoms. In addition, skin biopsy, corneal confocal microscopy, Sudoscan and water immersion skin wrinkling were used to investigate a correlation between the four phenotypes, sensory function, nerve fiber density, and autonomic nerve function. Overall, 35% of patients with probable small fiber neuropathy showed length-dependent symptoms and 44% showed non-length-dependent symptoms while 21% suffered from non-neuropathic musculoskeletal pain. The distinction between intermittent and continuous symptoms showed significantly less continuous than intermittent non-length-dependent symptoms (odds ratio = 0.3, P = 0.01). Moreover, continuous length-dependent symptoms were the only phenotype that correlated with thermal threshold testing (R = 0.3; P = 0.02) and the small fiber neuropathy screening list (R = 0.3; P = 0.03). In addition, thermal threshold testing (TTT) also correlated with the small fiber neuropathy (SFN) screening list (R = 0.3; P = 0.03). Other diagnostic methods showed no correlation with any of the four defined phenotypes. A novel finding is that TTT is only associated with continuous length-dependent pain, suggesting that TTT could result in more false negatives in patients with other pain phenotypes. Determining the pathophysiologic mechanisms could help develop new diagnostic methods. If patients suspected of SFN show symptoms without a length-dependent continuous presentation, the diagnosis should focus less on the diagnostic methods used.

Use of a remote assessment pathway for diagnosis of carpal tunnel syndrome.

We undertook a retrospective cohort study of a remote carpal tunnel syndrome assessment pathway created in response to limitations caused by the COVID-19 pandemic. Between July 2020 and September 2021, 702 patients referred from primary care (general practice) were assessed in a nurse-led telephone clinic using the carpal tunnel questionnaire of Kamath and Stothard (2003). Depending on their questionnaire score, patients were referred either for nerve conduction studies or a consultant hand surgeon review for diagnosis and treatment planning. Questionnaire scores of 3 and above accurately predicted a likely diagnosis of carpal tunnel syndrome in 83% of patients, and a diagnosis was unlikely in 90% of those with a score below 3. The pathway resulted in an estimated cost savings of £24,436 (€28,862, US$30,945) in comparison with the pre-pandemic service. However, some limitations in the pathway may have impacted effective patient management and we suggest possible improvements.Level of evidence: III.