Peripheral Nerve Abnormalities Research Articles

A neuromuscular clinician's guide to magnetic resonance neurography.

Magnetic resonance neurography (MRN) is increasingly used in clinical practice for the evaluation of patients with a wide spectrum of peripheral nerve disorders. This review article discusses the technical aspects of MRN highlighting the core sequences performed for clinical care. A robust, high-resolution, heavily T2-weighted fluid-sensitive sequence performed on a 3.0 Tesla magnet system remains the main workhorse MRN sequence. In specific clinical scenarios, adjunct techniques such as diffusion-weighted imaging can be added to a protocol for disease characterization. In addition, gadolinium-based contrast material can also be administered for the purposes of image optimization (suppress adjacent vascular signal) and disease characterization. Technical modifications to field of view and planes of imaging can be made based on the clinical question and discussion with the radiologist(s). On fluid-sensitive MRN sequences, a normal peripheral nerve exhibits iso- to minimally hyperintense signal relative to skeletal muscle with a predictable trajectory, preserved "fascicular" architecture, and tapered caliber from proximal to distal. Peripheral nerve abnormalities on MRN include alterations in signal, caliber, architecture, diffusion characteristics as well as enhancement and provide information regarding the underlying etiology. Although some MRN findings including nerve hyperintensity and long-segmental enlargement are nonspecific, there are certain diagnoses that can be made with high certainty based on imaging including benign peripheral nerve tumors, high-grade peripheral nerve injury, and intraneural ganglia. The purpose of this article is to familiarize a neuromuscular clinician with fundamentals of MRN acquisition and interpretation to facilitate communication with the neuromuscular radiologist and optimize patient care.

Role of Ultrasonography in the Evaluation of Peripheral Nerve Pathologies: A Study of 200 Cases.

The aim of this study is to ascertain the role of ultrasonography in appraising the structural intricacies of peripheral nerve pathologies. (1) To scrutinize the anatomy of both normal and abnormal peripheral nerves. (2) Assess different parameters like continuity of the nerve, echotexture, vascularity, cross-sectional area, and thickness of the nerve in various pathologies. In a prospective observational study conducted at the Department of Radio Diagnosis, Tertiary Care Centre, the study design focused on the examination of 200 cases utilizing a high-resolution 9-14 Mhz and 17 Mhz linear array transducer, integrated into the Aplio 400 Canon Ultrasound System. Among the total cases, 62 were identified as traumatic neuropathy cases, 52 as entrapment neuropathy cases, 14 as infective neuropathy cases, 54 as thermal neuropathy cases, 14 as metabolic neuropathy cases, and 4 as nerve-tumor cases. In conclusion, this investigation illuminates the dynamic role of ultrasonography as an invaluable diagnostic instrument in appraising peripheral nerve pathologies. The noninvasive attributes, widespread availability, and economic viability of ultrasonography render it a pragmatic choice for clinicians. This inquiry buttresses the escalating significance of ultrasonography within neurology, emphasizing its potential to revolutionize the terrain of peripheral nerve pathology assessment.

The role of high-resolution ultrasound and MRI in the evaluation of peripheral nerves in the lower extremity.

Lower extremity peripheral neuropathy is a commonly encountered neurologic disorder, which can lead to chronic pain, functional disability, and decreased quality of life for a patient. As diagnostic imaging modalities have improved, imaging has started to play an integral role in the detection and characterization of peripheral nerve abnormalities by non-invasively and accurately identifying abnormal nerves as well as potential causes of neuropathy, which ultimately leads to precise and timely treatment. Ultrasound, which has high spatial resolution and can quickly and comfortably characterize peripheral nerves in real time along with associated denervation muscle atrophy, and magnetic resonance neurography, which provides excellent contrast resolution between nerves and other tissues and between pathologic and normal segments of peripheral nerves, in addition to assessing reversible and irreversible muscle denervation changes, are the two mainstay imaging modalities used in peripheral nerve assessment. These two modalities are complimentary, and one may be more useful than the other depending on the nerve and location of pathology. Imaging must be interpreted in the context of available clinical information and other diagnostic studies, such as electrodiagnostic tests. Here, we offer a comprehensive overview of the role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of the peripheral nerves of the lower extremity and their associated neuropathies.

Novel insights into the nervous system affected by prolonged hyperglycemia

Multiple molecular pathways including the receptor for advanced glycation end-products-diaphanous related formin 1 (RAGE-Diaph1) signaling are known to play a role in diabetic peripheral neuropathy (DPN). Evidence suggests that neuropathological alterations in type 1 diabetic spinal cord may occur at the same time as or following peripheral nerve abnormalities. We demonstrated that DPN was associated with perturbations of RAGE-Diaph1 signaling pathway in peripheral nerve accompanied by widespread spinal cord molecular changes. More than 500 differentially expressed genes (DEGs) belonging to multiple functional pathways were identified in diabetic spinal cord and of those the most enriched was RAGE-Diaph1 related PI3K-Akt pathway. Only seven of spinal cord DEGs overlapped with DEGs from type 1 diabetic sciatic nerve and only a single gene cathepsin E (CTSE) was common for both type 1 and type 2 diabetic mice. In silico analysis suggests that molecular changes in spinal cord may act synergistically with RAGE-Diaph1 signaling axis in the peripheral nerve.Key messagesMolecular perturbations in spinal cord may be involved in the progression of diabetic peripheral neuropathy.Diabetic peripheral neuropathy was associated with perturbations of RAGE-Diaph1 signaling pathway in peripheral nerve accompanied by widespread spinal cord molecular changes.In silico analysis revealed that PI3K-Akt signaling axis related to RAGE-Diaph1 was the most enriched biological pathway in diabetic spinal cord.Cathepsin E may be the target molecular hub for intervention against diabetic peripheral neuropathy.

Utilising clinical parameters to improve the selection of nerve biopsy candidates.

Peripheral nerve biopsy is a valuable final diagnostic tool; however, histopathological results can be non-diagnostic. We aim to identify quality improvement measures by evaluating the pre-biopsy assessment and diagnostic yield of specific histopathological diagnosis. This was a retrospective study based on 10 years of experience with peripheral nerve biopsies at a single centre. Clinical data were obtained regarding pre-biopsy history, examination, serum and cerebrospinal fluid (CSF) investigations, neurophysiology and peripheral nerve imaging. Based upon a histopathological outcome, patients were grouped into vasculitis, granulomatous and infiltrative (diagnostic) group, or a comparison group of non-specific axonal neuropathy and normal (non-specific/normal) group. From a cohort of 64 patients, 21 (32.8%) were included in the diagnostic group and 30 (46.9%) in the non-specific/normal group. Clinical parameters associated with the diagnostic group were shorter history (mean 10.2 months vs 38.1), stepwise progression (81% vs 20%), neuropathic pain (85.7% vs 56.7%), vasculitic rash (23.8% vs 0%), mononeuritis multiplex (57.1% vs 10%), asymmetry (90.5% vs 60%), raised white cell count (47.6% vs 16.7%), myeloperoxidase antibody (19.1% vs 0%) and abnormal peripheral nerve imaging (33.3% vs 10%). Selection of patients undergoing nerve biopsy requires careful consideration of clinical parameters, including peripheral nerve imaging. Several quality improvement measures are proposed to improve yield of clinically actionable information from nerve biopsy.

Biallelic pathogenic variants in the mitochondrial form of phosphoenolpyruvate carboxykinase cause peripheral neuropathy.

Phosphoenolpyruvate carboxykinase (PCK) plays a critical role in cytosolic gluconeogenesis, and defects in PCK1 cause a fasting-aggravated metabolic disease with hypoglycemia and lactic acidosis. However, there are two genes encoding PCK, and the role of the mitochondrial resident PCK (encoded by PCK2) is unclear, since gluconeogenesis is cytosolic. We identified three patients in two families with biallelic variants in PCK2. One has compound heterozygous variants (p.Ser23Ter/p.Pro170Leu), and the other two (siblings) have homozygous p.Arg193Ter variation. All three patients have weakness and abnormal gait, an absence of PCK2 protein, and profound reduction in PCK2 activity in fibroblasts, but no obvious metabolic phenotype. Nerve conduction studies showed reduced conduction velocities with temporal dispersion and conduction block compatible with a demyelinating peripheral neuropathy. To validate the association between PCK2 variants and clinical disease, we generated a mouse knockout model of PCK2 deficiency. The animals present abnormal nerve conduction studies and peripheral nerve pathology, corroborating the human phenotype. In total, we conclude that biallelic variants in PCK2 cause a neurogenetic disorder featuring abnormal gait and peripheral neuropathy.

Ultrasound-based Neuropathy Diagnosis in COVID-19 Patients in Post-intensive Care Rehabilitation Settings: A Retrospective Observational Study

ObjectivesUsing ultrasound (US) scanning to examine the correlation between increase of common fibular nerve's (CFN) cross sectional area (CSA) and functional impairment of foot dorsiflexor muscles as an early sign of peripheral neuropathy. DesignRetrospective observational study. SettingIn-patient rehabilitation unit between November 2020 and July 2021. ParticipantsTwenty-six inpatients who underwent prolonged hospitalization in intensive care units (ICUs) and were diagnosed with critical illness myopathy and polyneuropathy after SARS-COV-2 infection (N=26). Physical examination and US scanning of the CFN and EMG/ENG were carried out on each patient. InterventionsNot applicable. Main Outcome Measure(s)CFN's CSA at the peroneal head. ResultsWe verified a significant increase in the CSA of the CFN measured at the peroneal head in more than 90% of the nerves tested. A cut off value of CFN's CSA of 0.20 cm was used to identify pathologic nerves. No correlations with other variables (body mass index, ICU days) were found. ConclusionUS scanning of the CFN appears to be an early and specific test in the evaluation of CPN's abnormalities in post COVID-19 patients. US scanning is a reproducible, cost effective, safe, and easily administered bedside tool to diagnose a loss of motor function when abnormalities in peripheral nerves are present.

Chronic inflammatory demyelinating polyradiculoneuropathy-associated tremor: Phenotype and pathogenesis.

Tremor in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is underrecognized, and the pathophysiology remains incompletely understood. This study evaluated tremor in CIDP and tested the hypothesis, established in other demyelinating neuropathies, that tremor occurs due to mistimed peripheral inputs affecting central motor processing. Additionally, the tremor stability index (TSI) was calculated with the hypothesis that CIDP-related tremor is more variable than other tremor disorders. Consecutive patients with typical CIDP were prospectively recruited from neuromuscular clinics. Alternative causes of neuropathy and tremor were excluded. Cross-sectional clinical assessment and extensive tremor study recordings were undertaken. Pearson correlation coefficient was used to compare nerve conduction studies and tremor characteristics, and t-test was used for comparisons between groups. Twenty-four patients with CIDP were included. Upper limb postural and action tremor was present in 66% and was mild according to the Essential Tremor Rating Assessment Scale. Tremor did not significantly impact disability. Surface electromyography (EMG) found high-frequency spectral peaks in deltoid (13.73 ± 0.66 Hz), biceps brachii (11.82 ± 0.91 Hz), and extensor carpi radialis (11.87 ± 0.91 Hz) muscles, with lower peaks in abductor pollicis brevis EMG (6.07 ± 0.45 Hz) and index finger accelerometry (6.53 ± 0.42 Hz). Tremor was unchanged by weight loading but correlated with ulnar nerve F-wave latency and median nerve sensory amplitude. TSI (2.3± 0.1) was significantly higher than essential tremor. Postural tremor is a common feature in CIDP. Tremor was unaffected by weight loading, typical of centrally generated tremors, although there was a correlation with peripheral nerve abnormalities. The high beat-to-beat variability on TSI and gradation of peak frequencies further suggest a complex pathophysiology. These findings may assist clinicians with the diagnosis of neuropathic tremor.

Electroneurological changes in peripheral nerves in patients post-COVID.

Various neurological manifestations are observed in about 36.4% of patients infected with SARS-CoV-2 and post-COVID neuropathy is one of them. There is lack of studies describing neurophysiological abnormalities in peripheral nerves in case of patients who had SARS-CoV-2 infection. The aim of this study was to analyze the changes in peripheral nervous system in case of COVID-19 survivors. In the presented study, 45 COVID-19 survivors who had nerve conduction study (NCS) were involved. Results were compared with control group consisting of healthy patients who had nerve conduction study before the COVID-19 pandemic. In our study group, neurophysiological abnormalities were present in the case of both sensory and motor nerve fibers. The most significant reduction of NCS parameters was observed in the case of sensory action potential amplitude of sural nerve. Moreover, that correlation was the most significant in the case of amplitude and conduction velocity in sensory and motor neuron fibers both in arms and legs. Those abnormalities were observed even 6 mo after COVID-19. Further investigation needs to be done regarding the polyneuropathies associated with human coronaviruses, and we should answer the question whether the virus directly damages peripheral nerves or factors mediating inflammatory response are responsible for the neural damage.NEW & NOTEWORTHY Various neurological manifestations are observed in about 36.4% of patients infected with SARS-CoV-2 and post-COVID neuropathy is one of them. There is lack of studies describing neurophysiological abnormalities in peripheral nerves in case of patients who had SARS-CoV-2 infection. The aim of this study was to analyze changes in peripheral nervous system in case of COVID-19 survivors.

O.08 Biallelic variants in the mitochondrial form of phosphoenolpyruvate carboxykinase (PCK2) cause a recessive form of Charcot-Marie-Tooth disease

Mutations in over 100 genes have been associated with Charcot-Marie-Tooth disease (CMT). Despite testing availability, many patients remain genetically unresolved. In this study, a new cause of CMT was identified in <i>PKC2</i>. Phosphoenolpyruvate carboxykinase (PCK) plays a critical role in cytosolic gluconeogenesis. PCK is encoded by <i>PCK1</i>, the cytosolic gene associated with hypoglycemia during fasting, and <i>PCK2</i>, the mitochondrial gene not yet associated with human disease. Whole exome sequencing (WES) and nerve conduction studies (NCS) were performed. PCK enzymatic activity and protein production were assessed from patient fibroblasts. To validate the association, a mouse knockout model of <i>PCK2</i> deficiency was generated. Three patients from 2 families were identified with biallelic variants in <i>PCK2</i> via WES. Compound heterozygous variants (p.Ser23Ter/p.Pro170Leu) were identified in one patient and a homozygous variant (p.Arg193Ter) in two siblings. All 3 patients presented with weakness and gait abnormalities. Fibroblast cultures showed a reduction or absence of <i>PCK2</i> protein and profound reduction in <i>PCK2</i> activity with no obvious metabolic phenotype. NCS showed reduction in conduction velocities with temporal dispersion and conduction block, consistent with a demyelinating peripheral neuropathy. Corroborating the human phenotype, the mouse model had abnormal NCS and peripheral nerve pathology. In all, this study suggests a new cause of CMT, biallelic variants in <i>PCK2</i>. This supports the growing evidence for the importance of mitochondrial dysfunction in CMT which may inform future therapeutic targets.

Higher frequency of cardiovascular autonomic neuropathy in youth with type 2 compared to type 1 diabetes: Role of cardiometabolic risk factors.

Cardiovascular autonomic neuropathy (CAN) is an overlooked but common and serious diabetes complication. We examined CAN in youth with diabetes and associations with cardiovascular risk factors. This was a prospective cohort of youth aged <20 years with type 2 or type 1 diabetes (n=66/1153, median age 15.4/16.5 years, duration 1.7/8.0 years), assessed between 2009 and 2020. CAN was defined as ≥2 abnormal heart rate variability measures across time, geometric, and frequency domains. Obesity was defined as BMI ≥ 95th percentile and severe obesity as ≥120% of 95th percentile. Multivariable generalized estimating equations (GEE) were used to examine putative risk factors for CAN, including diabetes type, obesity, and HbA1c . At most recent assessment, youth with type 2 versus type 1 diabetes had median: HbA1 c 7.1% (54 mmol/mol) versus 8.7% (72 mmol/mol) and BMI SDS (2.0 vs. 0.7); frequency of CAN (47% vs. 27%), peripheral nerve abnormality (47% vs. 25%), hypertension (29% vs. 12%), albuminuria (21% vs. 3%), and severe obesity (35% vs. 2%). In multivariable GEE, CAN was associated with type 2 diabetes: Odds Ratio 2.53, 95% CI 1.46, 4.38, p=0.001, higher BMI SDS: 1.49, 95% CI 1.29, 1.73, p < 0.0001, and obesity: 2.09, 95% CI 1.57, 2.78, p < 0.0001. Youth with type 2 diabetes have a higher frequency of CAN, peripheral nerve abnormality, hypertension, albuminuria and severe obesity despite shorter diabetes duration and younger age. Our findings highlight the importance of targeting modifiable risk factors to prevent cardiovascular disease in youth with diabetes.

High-frequency Ultrasonography of the Digital and Palmar Nerve Branches of the Hand in Peripheral Nerve Diseases.

Peripheral nerve ultrasound is a well-established imaging technique to evaluate certain peripheral nerve pathologies. However, there is a poor correlation between ultrasound abnormalities of peripheral nerves and electrodiagnostic or clinical evidence of axonal loss. This is a significant limitation of peripheral nerve ultrasound, as many peripheral nerve diseases encountered in clinical settings are related to axonal loss. Furthermore, clinical and electrodiagnostic evidence of axonal loss directly correlates with disability in all peripheral nerve diseases. However, due to the floor effects often encountered in electrodiagnostic studies, these correlations, as well as definitive diagnoses, are often challenging. Thus, imaging techniques that correlate with axonal loss are essential for expanding the utility of peripheral nerve ultrasound as a potential biomarker for peripheral nerve diseases. With new technological advancements and the ever-increasing imaging capabilities of high-frequency ultrasound, the palmar and digital nerve branches of the hand can be imaged with exceptionally high resolution even using point-of-care ultrasound devices. Their superficial and distal-most anatomic locations are ideal for evaluating polyneuropathies, as these branches degenerate earliest during axonal loss. However, no studies have systematically evaluated these nerve branches to determine if they can be reproducibly measured with ultrasound. The current protocol was adapted for the systematic assessment of cross-sectional areas of the median and ulnar nerves in the palmar surface and digits of the hand. This protocol provides reference data for a subset of nerves that demonstrate high intraclass correlation coefficients between three separate ultrasonographers. Finally, as a proof of concept and to demonstrate the clinical applications of this protocol, representative data from individuals with genetically confirmed inherited polyneuropathies are compared with established normative data to examine cross-sectional area differences.

Neuronal Intranuclear Inclusion Disease with Abnormal Peripheral Nerve Conduction

A 70-year-old female presented with progressive gait disturbance. Neurologic examination revealed sensory impairment, hyporeflexia, and sensory ataxia. Nerve conduction study demonstrated mildly decreased velocity in motor nerves. Brain magnetic resonance imaging showed high signal intensities in the corticomedullary junction on diffusion weighted imaging. Neurocognitive function test implied mild cognitive impairment. Based on eosinophilic intranuclear inclusions in pathology, neuronal intranuclear inclusion disease was confirmed. Neuronal intranuclear inclusion needs to be considered when abnormal nerve conduction studies are consistent with abnormal brain imaging findings.

Multicenter real world study on the efficacy and safety of eribulin for the treatment of advanced breast cancer

Objective: To explore the efficacy and safety of real-world eribulin in the treatment of metastatic breast cancer. Methods: From December 2019 to December 2020, patients with advanced breast cancer were selected from Beijing Chaoyang District Sanhuan Cancer Hospital, Shandong Cancer Hospital, Peking University Cancer Hospital, Baotou Cancer Hospital, Shengjing Hospital Affiliated to China Medical University, and Cancer Hospital of Chinese Academy of Medical Sciences. Kaplan-Meier method and Log rank test were used for survival analysis, and Cox regression model was used for multivariate analysis. Results: The median progression-free survival (PFS) of 77 patients was 5 months, the objective response rate (ORR) was 33.8%, and the disease control rate (DCR) was 71.4%. The ORR of patients with triple-negative breast cancer was 23.1%, and the DCR was 57.7%; the ORR of patients with Luminal breast cancer was 40.0%, and the DCR was 77.8%; the ORR of patients with HER-2 overexpression breast cancer was 33.3%, and the DCR was 83.3%. ORR of 50.0% and DCR of 66.7% for patients treated with eribulin as first to second line treatment, ORR of 29.4% and DCR of 76.5% for patients treated with third to fourth line and ORR of 28.6% and DCR of 71.4% for patients treated with five to eleven line. The ORR of patients in the eribulin monotherapy group was 40.0% and the DCR was 66.0%; the ORR of patients in the combination chemotherapy or targeted therapy group was 22.2% and the DCR was 81.5%. Patients with a history of treatment with paclitaxel, docetaxel, or albumin paclitaxel during the adjuvant phase or after recurrent metastasis had an ORR of 32.9% and a DCR of 69.9% when treated with eribulin. The treatment efficacy is an independent prognostic factor affecting patient survival (P<0.001). The main adverse reactions in the whole group of patients were Grade Ⅲ-Ⅳ neutrophil decline [29.9% (23/77)], and other adverse reactions were Grade Ⅲ-Ⅳ fatigue [5.2% (4/77)], Grade Ⅲ-Ⅳ peripheral nerve abnormality [2.6% (2/77)] and Grade Ⅲ-Ⅳ alopecia [2.6% (2/77)]. Conclusions: Eribulin still has good antitumor activity against various molecular subtypes of breast cancer and advanced breast cancer that has failed multiple lines of chemotherapy, and the adverse effects can be controlled, so it has a good clinical application value.

Role of electromyography and ultrasonography in the diagnosis of double crush lumbar radiculopathy and common fibular injury: illustrative cases.

BACKGROUNDDouble crush syndrome consists of two compression sites along a peripheral nerve and is rare in the lower extremities. Electrodiagnostic and ultrasound (US) studies may be helpful in evaluating foot drop involving overlapping pathologies.OBSERVATIONSCase 1 involved a man who presented with left dorsiflexor weakness and left foot numbness. Electromyography (EMG) revealed a left common fibular nerve entrapment neuropathy and left L5 radiculopathy. US and magnetic resonance imaging (MRI) revealed a large cystic lesion of the left common fibular nerve treated by cyst removal. The left foot drop persisted postoperatively. Lumbar computed tomography myelography revealed severe left foraminal stenosis at L5–S1. Multilevel lumbar laminectomies and facetectomies with an L5–S1 fusion were performed. Within 1 month postoperatively, the left foot drop had improved. Case 2 involved a man who developed a right foot drop caused by right lumbar foraminal stenosis at L4–5 and L5–S1. EMG and US of the right common fibular neuropathy showed large fascicles involving the right common fibular nerve. MRI revealed a hyperintense signal of the right common fibular nerve. Spontaneous improvement occurred within 6 months without surgery.LESSONSSpine surgeons should recognize double crush in the lower extremities. EMG and US are valuable in detecting peripheral nerve abnormalities, especially in cases with overlapping lumbar pathology.

Plasma 1,5-anhydro-d-glucitol is associated with peripheral nerve function and diabetic peripheral neuropathy in patients with type 2 diabetes and mild-to-moderate hyperglycemia

BackgroundPlasma 1,5-anhydro-d-glucitol (1,5-AG) may be a easily accessible marker for glycemic variability under mild-to-moderate hyperglycemia. The present study was to investigate the association of 1,5-AG with peripheral nerve function and diabetic peripheral neuropathy (DPN) in patients with T2D and mild-to-moderate hyperglycemia.MethodsWe recruited 574 T2D patients with mild-to-moderate hyperglycemia (HbA1c < 8.0%) for this cross-sectional study, with plasma 1,5-AG synchronously detected. All patients were questioned for neurologic symptoms, examined for neurologic signs and screened for peripheral nerve function. Nerve function included the latency, amplitude and nerve conduction velocity (NCV) of limbs nerves (median, ulnar nerve, common peroneal, superficial peroneal, tibial and sural nerve). Besides, composite Z-score of latency, amplitude and NCV were calculated. DPN was identified as both at least a neurologic symptom/sign and an abnormality of peripheral nerve function.ResultsAmong the recruited patients, 23.9% (n = 137) were identified to be with DPN, and the prevalence of DPN decreased from 36.6%, 24.5%, 21.2%, 13.3% from first (Q1), second (Q2), and third (Q3) to fourth quartile (Q4) of 1,5-AG. Moreover, multivariable linear regression analysis showed 1,5-AG was associated with composite Z-score of nerve latency (β = − 0.18, t = − 3.84, p < 0.001), amplitude(β = 0.26, t = 5.35, p < 0.001) and NCV (β = 0.24, t = 5.61, p < 0.001), respectively. Furthermore, compared to Q4 of 1,5-AG as reference, the adjusted odds ratios and 95% CIs for DPN of Q3, Q2, and Q1 were 1.29(0.59–2.81), 1.85(0.87–3.97), and 2.72(1.16–6.34), respectively. Additionally, receiver operating characteristic analysis revealed that optimal cutoff value of 1,5-AG to indicate DPN was ≤ 30.8 μmol/L, with sensitivity of 56.20% and specificity of 66.36%.ConclusionsLow plasma 1,5-AG is closely associated with impaired peripheral nerve function and DPN in T2D patients under mild-to-moderate hyperglycemia.

Relapsing inflammatory neuropathy with normal peripheral nerve conduction studies – a paradoxical phenomenon in two patients

The diagnosis of Guillain Barre Syndrome and Chronic Inflammatory Demyelinating Polyneuropathy depends on an appropriate history, examination, CSF cyto-protein dissociation and abnormal peripheral nerve conduction studies (PNCS). We present two cases suggestive of GBS but with repeatedly normal PNCS, a paradoxical phenomenon.

Protective and therapeutic effect of (S)-ginsenoside F1 on peripheral nerve degeneration targeting Schwann cells: a pharmaco-neuroanatomical approach.

Damaged peripheral nerves undergo peripheral neurodegenerative processes that are essential for the nerve regeneration. Peripheral neurodegenerative diseases, including diabetic peripheral neuropathy, are induced by irreversible nerve damage caused by abnormal peripheral nerve degeneration. However, until now, there have been no effective therapeutic treatments for these diseases. Ginsenosides are the most pharmacologically active compounds in Panax ginseng, and are being actively studied. Ginsenosides have a variety of effects, including neuroprotective, antioxidative, anti-cytotoxic, and anti-inflammatory effects. Here, we investigated the efficacy of 18 ginsenosides. We then tested the ability of the most effective ginsenoside, (S)-ginsenosides F1 (sF1), to inhibit peripheral neurodegenerative processes using mouse sciatic ex vivo culture, and several morphological and biochemical indicators. Our results suggest that sF1 could effectively protect Schwann cells against peripheral nerve degeneration.

Normative Values for the Sonographic Measurement of the Pediatric Median and Ulnar Nerves

Ultrasound investigation of peripheral nerves, long used in the adult population, has been shown to be of value in diagnosing a variety of peripheral nerve abnormalities. More recently, nerve sonography has also been shown to be of use in pediatrics. However, normative values for nerve size in children have been lacking. As such, the goal of this research was to establish normative data for cross sectional area (CSA) measurements of the median and ulnar nerves in children. The median and ulnar nerves of 48 children ranging in age from 2 years to 17 years were imaged by ultrasound. CSA measurements were made at 2 separate sites for each nerve and measured independently by 6 pediatric radiologists. Reliability of ultrasound measurements between the radiologists was assessed by calculating intraclass correlation coefficients. Linear mixed-effects modeling was performed to develop prediction models for nerve cross sectional area for each nerve segment; 95% prediction values were generated from these models to approximate normal ranges. Agreement in nerve cross-sectional area measurements among the 6 radiologists for all nerve segments was good (ICC 0.82, 95% CI 0.78 to 0.85). CSA for both the median and ulnar nerves is larger in older children. However, statistical models to predict CSA using height perform better rather than those using a child's age. The range of normal nerve segment CSA using these prediction models based on child height are reported. Median and ulnar nerve CSA can be reliably measured with ultrasound. Normal reference values for ulnar and median nerve CSA correlate with patient age but may be more optimally determined based on a child's height.

Associations of nerve conduction parameters and OCT angiography results in adolescents with type 1 diabetes.

AimTo evaluate dependence of abnormalities in peripheral nerves and retina in children with type 1 diabetes (T1D) using optical coherence tomography angiography (OCTA) and nerve conduction studies (NCS).Material and methods50 adolescents with T1D without any signs and symptoms of diabetic retinopathy and neuropathy (mean age 16.92±1.6 years, diabetes duration 6.88 ±4.34years) were included. In OCTA capillary plexuses superficial (SCP) and deep (DCP) vessel density: whole, foveal and parafoveal, ganglion cell complex (GCC), loss volume focal (FLV) and global loss volume (GLV) were analyzed in relation to NCS parameters (motor nerves median and tibial potential amplitude (CMAP), velocity (CV), distal latency (DML) and F wave and sensory nerves median and sural potential amplitude (SNAP), CV and distal latency (DSL).ResultsWe detected the correlations between median sensory SNAP and GCC (r = -0.3, p <0.04), motor nerves tibial DML and CV and FLV (respectively r = -0.53, p<0.001, and r = -0.34, p<0.05), and median DML and GLV (r = 0.47, p<0.001). Vessel densities were related to changes in motor nerves tibial velocity (whole SCP r = 0.43, p <0.01, parafoveal SCP r = 0.41, p <0.01), CMAP (parafoveal SCP r = -0.35, p<0.03), median DML (whole DC r = 0.36, p<0.03, foveal DCP r = 0.37, p<0.02) and in sensory median SNAP (whole SCP r = -0.31, p<0.05).ConclusionsIn adolescents with T1D without diabetic neuropathy and retinopathy we detected associations between NCS and OCT and OCTA parameters, regarding decreased GCC and density of superficial and deep vessel plexuses in relation to DML and CV and amplitudes of sensory and motor potential.