Conduction Studies Research Articles

Promising predictors of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus

BackgroundDiabetic peripheral neuropathy (DPN) in children and adolescents with type 1 diabetes mellitus (T1DM) is a growing issue, with controversial data in the terms of prevalence and evaluation timelines. Currently, there are no clear standards for its early detection. Therefore, our aim was to assess the contribution of the Michigan neuropathy screening instrument (MNSI), lipid profile, serum neuron specific enolase (NSE), and serum heat shock protein 27 (HSP 27) to the prediction of DPN in children and adolescents with T1DM.MethodsIn this case-control study, fifty children diagnosed with T1DM for at least five years were enrolled and evaluated through complete neurological examination, MNSI, and nerve conduction study (NCS). Additionally, HbA1c, lipid profile, serum NSE, and serum HSP 27 levels were measured for patients and controls.ResultsThe prevalence of DPN in our study was 24% by NCS, and electrophysiological changes showed a statistically significant lower conduction velocity for the posterior tibial and sural nerves, as well as a prolonged latency period for the common peroneal and sural nerves in neuropathic patients. In these patients, older age, earlier age of diabetes onset, longer disease duration, higher total cholesterol, triglycerides, low density lipoprotein cholesterol, HbA1c, serum NSE, and HSP27 levels were observed. The MNSI examination score ≥ 1.5 cutoff point had an area under the curve (AUC) of 0.955, with 75% sensitivity and 94.74% specificity, according to receiver operating characteristic curve analysis. However, the questionnaire’s cutoff point of ≥ 5 had an AUC of 0.720, 75% sensitivity, and 63% specificity, with improved overall instrument performance when combining both scores. Regarding blood biomarkers, serum NSE had greater sensitivity and specificity in discriminating neuropathic patients than HSP27 (92% and 74% versus 75% and 71%, respectively). Regression analysis revealed a substantial dependency for MNSI and serum NSE in predicting DPN in patients.ConclusionsDespite limited research in pediatrics, MNSI and serum NSE are promising predictive tools for DPN in children and adolescents with T1DM, even when they are asymptomatic. Poor glycemic control and lipid profile changes may play a critical role in the development of DPN in these patients, despite conflicting results in various studies.

Gullian Barre syndrome secondary to heat stroke: a case report.

Heat waves are increasingly common in subcontinent countries, including Pakistan. Heat stroke (HS) is a critical condition resulting from extreme temperatures, often culminating in multiorgan dysfunction. Clinical manifestations of heat-related emergencies can include altered mentation, fever, and profound weakness. We present a compelling case of a previously healthy 49-year-old male who developed altered mentation, fever, and acute kidney injury following intense physical exertion amidst a severe heat wave. Although initially managed as heat stroke, the patient soon exhibited dysarthria, palatal weakness, and bilateral lower limb weakness with areflexia, prompting a detailed neurological assessment. Electromyography and nerve conduction studies revealed the acute motor-sensory axonal neuropathy (AMSAN) variant of Guillain-Barré Syndrome (GBS), an uncommon but severe sequel of heat stroke. GBS, an autoimmune disorder, typically presents with ascending bilateral lower limb flaccid paralysis, often following an acute infectious trigger. Treatment with plasmapheresis led to remarkable neurological recovery. This case represents the first documented instance of heat stroke-induced GBS in Pakistan, highlighting both the distinctive clinical features and the therapeutic complexities of this rare condition.

Case report: Encephalitis with Guillain-Barré Syndrome secondary to extensively multi-drug resistant Salmonella infection

Abstract Background This case report presents a highly unusual and challenging medical case involving a 16-month-old previously healthy boy who developed encephalitis followed by Guillain-Barré Syndrome (GBS) as complications of multi-drug resistant Salmonella infection, despite an initial misdiagnosis of gastroenteritis and outpatient treatment with Cefixime. Methods The patient initially experienced an increase in stool frequency, accompanied by low-grade fevers, which was initially attributed to gastroenteritis. Outpatient treatment with oral Cefixime was started, but the child’s symptoms worsened, ultimately leading to high-grade fevers and an increase in vomiting and loose stools. In light of his clinical deterioration, he was admitted to our hospital with signs of mild metabolic acidosis and elevated inflammatory markers. During his hospitalization, the patient’s condition worsened, with drowsiness, irritability, and a generalized tonic-clonic seizure, prompting concern for brain involvement. Consequently, he underwent lumbar puncture, and neuroimaging, and received high-dose intravenous steroids. Further medical investigations including lumbar puncture and brain Magnetic Resonance Imaging (MRI), which revealed normal cerebrospinal fluid (CSF) analysis and non-enhancing white matter changes in the occipital region, respectively. In addition, a collected blood culture confirmed the presence of extensively multi-drug resistant Salmonella typhi and prompted an adjustment of antibiotics to intravenous Meropenem. Due to autonomic dysfunction, the patient was transferred to the Pediatric Intensive Care Unit (PICU) for close monitoring and specialized care. While in the PICU, he developed flaccid limb weakness and axial hypotonia. A repeat lumbar puncture was normal, but nerve conduction studies showed features of axonal polyneuropathy diagnosis, consistent with the diagnosis of GBS. To treat the encephalopathy and polyneuropathy, high-dose dexamethasone and Intravenous Immunoglobulin (IVIG) treatments were initiated, without necessitating respiratory or inotropic support. After receiving these treatments, the patient’s autonomic instability and motor strength improved, prompting his transfer back to the general pediatrics wards. He was treated with a 21-day course of IV Meropenem. Upon discharge, his motor power had returned to normal, and he displayed progress in movement transitions, including the ability to stand and walk independently, albeit with mild gait abnormalities. Results The co-occurrence of encephalitis and Guillain-Barré Syndrome due to Typhoid fever is exceedingly rare. The patient’s origin, with recent travel to Pakistan where extensively drug-resistant Salmonella typhi prevails, necessitates heightened awareness among healthcare providers. Initial misdiagnosis and inadequate antibiotics treatment may have contributed to encephalitis and polyneuropathy. High-dose dexamethasone and IVIG were pivotal in the patient’s treatment. While Typhoid fever-related neurological complications are infrequent, high-dose dexamethasone offers promise in reducing mortality and mitigating typhoid-induced encephalopathy. Importantly, IVIG is not conventionally employed in Salmonella encephalopalitis but was used due to polyneuropathy and its role in GBS management. Conclusion This exceptional pediatric case serves as a striking example of the possibility simultaneous encephalitis and Guillain-Barré Syndrome as rare complications of Typhoid fever. This case report underscores the importance of early diagnosis, prompt management with appropriate antibiotics and caution of possible neurological complications. Furthermore, it calls for further research into the role of high-dose glucocorticoids and IVIG in the management of extensively multi-drug resistant Salmonella infection and its neurological complications.

Clinical and Video-Oculographic Characteristics of Spinocerebellar Ataxia Type 27B (GAA-FGF14 Ataxia): A Single-Center Retrospective Study

An intronic GAA repeat expansion in the FGF14 gene was recently identified as a common cause of autosomal dominant GAA-FGF14 ataxia (SCA27B). We aimed to characterize in detail the clinical and video-oculographic features in our cohort of SCA27B patients. We genotyped the FGF14 GAA repeat expansion in 52 patients with unsolved late-onset cerebellar ataxia. Brain MRI and nerve conduction study, as well as video-oculographic (VOG) assessment, were performed. Eight patients (15.4%) with pathogenic GAA repeat expansion in the FGF14 gene were found. The median age at onset was 51 years (range—23–63 years). Sensory axonal neuropathy was found in 5/8 patients. Cerebellar atrophy was observed in 5/8 patients, and in one case, pontocerebellar atrophy was found. All tested patients had impaired smooth pursuit, 5/6 patients had impaired vestibulo-ocular reflex suppression, nystagmus, and an increased number of square wave jerks, 4/6 patients had horizontal gaze-evoked nystagmus, 3/6 had spontaneous downbeat nystagmus, and 1/6 had an upbeat one. Video head impulse test gain was lower than 0.8 on both sides in 2/4 patients, along with the presence of overt saccades. Further studies in different cohorts are needed to complete the phenotype of the FGF14-related disorders.

Neurofilament light chain as a biomarker for hereditary ATTR amyloidosis − correlation between neurofilament light chain and nerve conduction study

Background Neurofilament light chain (NfL) is a biomarker of neuronal injury in hereditary ATTR (ATTRv) amyloidosis. However, the correlation between NfL and nerve conduction study (NCS), the standard test for ATTRv neuropathy, has not been investigated. Objective Elucidate the correlation between NfL and NCS parameters. Methods 227 serum NfL measurements were performed in 45 ATTRv patients, 5 asymptomatic carriers, and 12 controls. Among them, 177 simultaneous analyses of NCS and NfL were conducted in 45 ATTRv patients. Results NfL levels of symptomatic patients were significantly higher than those of asymptomatic carriers and controls. Serum NfL levels were correlated with NCS parameters, especially compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes, indicators of axonal damage. CMAP and/or SNAP amplitudes were undetectable in 9 patients (no-amplitude group) due to advanced neuropathy. NfL levels in the no-amplitude group were significantly higher than those in patients with detectable CMAP/SNAP. NfL levels significantly decreased with patisiran, although no significant changes were observed in CMAP and SNAP. Conclusions NfL levels are found to be correlated with CMAP/SNAP amplitudes. Compared with NCS, NfL can be a more sensitive biomarker for detecting treatment response and active nerve damage even in patients with advanced neuropathy.

A Study of Excess Conductivity for Hollow TSMG YBCO Welded With Solder Material Produced by Different Methods

A Study of Excess Conductivity for Hollow TSMG YBCO Welded With Solder Material Produced by Different Methods

Insights from volumetric, acoustic, conductance and spectroscopic studies to study the molecular interactions of drug Levocetirizine in aqueous and aqueous glucose solutions at varying temperatures

Levocetirizine, an antihistamine, has been analyzed in relation to temperature by volumetric, acoustic, and spectroscopic methods to investigate its interaction with glucose, the predominant carbohydrate. Density and ultrasonic velocity for LC (0–0.10 mol dm−3) at different temperature (298.15, 308.15 and 318.15 K) in water and in aqueous solution of glucose (0.05, 0.10 and 0.15 mol kg−1) have been recorded using Anton Paar DSA 5000 M. The apparent molar volume (Vϕ), limiting apparent molar volume (Vϕ0), apparent molar compressibility (Kϕ,S), limiting apparent molar compressibility (Kϕ,S0) were computed utilizing the experimental data. In addition, the transfer parameters of LC from water to aqueous glucose solutions were identified and elucidated using the co-sphere model. The transfer volumes have been utilized to estimate the interaction coefficients. Limiting apparent molar expansibility (ϕE0) and Hepler’s constant was obtained to throw light upon the structure-making or structure-breaking effect of solute. Multiple acoustical parameters like isentropic compressibility (KS), relaxation strength (r), intermolecular free length (Lf), specific acoustic impedance (Z), Wada’s constant (W), relative association (RA), Rao’s constant (Rm), molar volume (Vm), Van der Waals constant (b), and free volume (Vf) were determined to validate the thermodynamic results.

Optical, electrical, structural properties by of PFO-PMMA films loaded with TiO2 nanoparticles

The authors studied Poly (methyl methacrylate) also called PMMA films with different concentrations of Poly (9, 9′-di-n-octylfuorenyl-2, 7-diyl) also called PFO and concluded that 1% PFO blended with PMMA is the best choice for opto-electronic applications. In the present study, the authors prepared nanocomposite films of PMMA + 1% PFO + different concentrations of TiO2 nanoparticles. The resulting films were subjected to FTIR, XRD, UV–visible, fluorescence and electrical conductivity studies. The polymer matrix undergoes modifications in its molecular and microstructural characteristics as evidenced by FTIR and XRD results. The addition of TiO2 nanoparticles leads to a uniform dispersion and good interaction with the blend matrix resulting in homogeneous films. The additional peaks were found at a wavenumber of 3620 cm−1 in FTIR can be attributed to stretching vibration of TiO2. The presence of TiO2 nanoparticles is confirmed by the distinctive diffraction peaks observed at 25.4°, 37.8°, 48.3°, 54.3°, 55.2°, and 62.8°. With a shift in the absorption peak towards higher wavelengths, the nanocomposites show greater absorption in the UV and visible regions. As the concentration of TiO2 increases, the optical parameters such as absorption coefficient, extinction coefficient, Urbach energy, refractive index and optical conductivity also increase. The direct optical band gap of the PNC films decreases from 5.03 to 3.06 eV and indirect band gap decreases from 4.52 to 1.92 eV at 10 wt% of TiO2 concentration. The addition of TiO2 nanoparticles to the PFO/PMMA matrix resulted in an increase in fluorescence emission intensity. The AC electrical conductivity exhibits increasing trend with frequency in Audio-Frequency range. Thus TiO2 nanoparticles improve the overall optical, electrical, and structural properties of PFO-PMMA nanocomposites. This means that they can be used in a variety of optoelectronic and advanced optical devices.

LITERATURE REVIEW THE ROLE OF ACUPUNCTURE IN THE MANAGEMENT OF PERIPHERAL NEUROPATHY

Peripheral neuropathy (PN) is a condition characterized by damage to the peripheral nervous system, resulting in symptoms such as pain, numbness, and weakness in the hands and feet. The most common causes include diabetes, thyroid disorders, vitamin B12 deficiency, alcohol abuse, chemotherapy, and human immunodeficiency virus (HIV) infection. Despite the availability of various treatments, neurological disorders remain a significant therapeutic challenge. The therapeutic effects of acupuncture are attributed to several mechanisms, including stimulation of nerve fibers, restoration of blood flow, release of neurotransmitters and hormones, modulation of the autonomic nervous system, anti-inflammatory effects, and increased neuroplasticity. These mechanisms collectively contribute to the relief of symptoms associated with peripheral neuropathy. Evidence suggests that acupuncture is beneficial in treating peripheral neuropathy. Studies have shown that acupuncture can improve nerve conduction study parameters in sensory and motor nerves, reduce neuropathic pain, and improve overall nerve function. Certain acupuncture points such as ST-36, GB-34, SP-3, SP-8, and BI-56 have been identified as particularly effective in managing symptoms of peripheral neuropathy. Although more rigorous studies are needed to fully characterize the effects of acupuncture on peripheral neuropathy, the available evidence supports its use as a complementary therapy. Standardized acupuncture protocols that combine anatomical correlation with peripheral nerves and traditional approaches to neuropathic pain management appear to be effective. Further studies with larger sample sizes and randomized comparisons to sham acupuncture will help establish acupuncture as a guideline for treating peripheral neuropathy. This review outlines the potential of acupuncture as a complementary therapy in the management of peripheral neuropathy.

Validating ICD-10 Diagnosis Codes for Guillain-Barré Syndrome in Taiwan's National Health Insurance Claims Database.

To validate the International Classification of Diseases, 10th Revision (ICD-10) codes for Guillain-Barré syndrome (GBS) in Taiwan's insurance claims database. We identified adult patients hospitalized at any Chang Gung Memorial Foundation branch hospital between January 1st, 2017, and December 31st, 2022, with ICD-10 code G61.0 in any of the five discharge diagnosis positions, indicating possible Guillain-Barré syndrome. We then validated the possible GBS diagnosis using data from electronic medical records of the identified patients, based on the diagnostic criteria established by the National Institute of Neurological Disorders and Stroke. We determined the positive predictive values (PPV) of various operational definitions, including the position (primary or other) where the code was recorded in the discharge diagnosis, nerve conduction study (NCS) claims, and / or specific GBS treatments. The final validation cohort of 484 patients with ICD-10 code for GBS in the discharge diagnosis was found to include 368 true GBS patients. Identifying inpatients using only the ICD-10 code for GBS in any of the five positions for discharge diagnosis yielded a PPV of 76.0%. With more restrictive definitions (primary diagnosis only, or requiring additional claims for NCS and/or treatments), the PPV tended to increase, but with fewer true GBS patients identified. Using ICD-10 GBS code in the primary diagnosis plus NCS and treatment claims yielded the highest PPV (98.3%); however, 140 (38.0%) of the true GBS patients were missed using this definition. In contrast, using the ICD-10 GBS code in any position, plus claims for NCS, achieved a relatively good PPV (85.8%) with minimal loss of true GBS patients (13, ie, 3.5%). In Taiwan's NHI claims data, identifying true GBS patients using only the ICD-10 code yielded a PPV of 76.0%; however, adding claims for diagnostic procedure and GBS treatment increased the PPV to 98.3%.

Influence of nano industrial waste and short coir fiber filler on hybrid inter and intra yarn bio fiber composites

Bio-polymer composites are emerging as a feasible substitute for conventional polymers in various major fields of applications. In the current research, the impact of hybridization of inter and intra-woven natural engineering fibers namely, brown flax, white flax, and jute of different amalgamations along with commingled SCF and novel nano IW filler has been studied. The composites are manufactured by hand layup process and physical and thermomechanical characteristics of the composites are experimentally studied. The composites mingled with IW filler demonstrated better dimensional stability and mechanical properties such as maximum tensile strength of 36.74 MPa, bending strength of 82.53 MPa, and hardness of 84.89 D compared to other composites. However, elastic and flexural modulus are maximum for composite without any filler. The composites mingled with SCF filler demonstrated the highest impact strength, energy absorption, and elongation. Thermogravimetric analysis and thermal conductivity study demonstrated that the composite with SCF filler exhibited better thermal stability and thermal resistance than the other hybrid composites. Fourier transform infrared spectroscopy study confirms the interaction of hydrogen bonds with different polymers, matrices, and fillers. It is established that the weaving pattern and the filler types greatly influences the mechanical and thermal characteristics of the composites. Filler addition and fabric hybridization optimizes the catastrophic failures and enhances the thermal stability, hence becoming more suitable for small interior structural components in aerospace and automobile applications.

Game-Based Assessment of Peripheral Neuropathy Combining Sensor-Equipped Insoles, Video Games, and AI: Proof-of-Concept Study.

Detecting peripheral neuropathy (PNP) is crucial in preventing complications such as foot ulceration. Clinical examinations for PNP are infrequently provided to patients at high risk due to restrictions on facilities, care providers, or time. A gamified health assessment approach combining wearable sensors holds the potential to address these challenges and provide individuals with instantaneous feedback on their health status. We aimed to develop and evaluate an application that assesses PNP through video games controlled by pressure sensor-equipped insoles. In the proof-of-concept exploratory cohort study, a complete game-based framework that allowed the study participant to play 4 video games solely by modulating plantar pressure values was established in an outpatient clinic setting. Foot plantar pressures were measured by the sensor-equipped insole and transferred via Bluetooth to an Android tablet for game control in real time. Game results and sensor data were delivered to the study server for visualization and analysis. Each session lasted about 15 minutes. In total, 299 patients with diabetes mellitus and 30 with metabolic syndrome were tested using the game application. Patients' game performance was initially assessed by hypothesis-driven key capabilities that consisted of reaction time, sensation, skillfulness, balance, endurance, and muscle strength. Subsequently, specific game features were extracted from gaming data sets and compared with nerve conduction study findings, neuropathy symptoms, or disability scores. Multiple machine learning algorithms were applied to 70% (n=122) of acquired data to train predictive models for PNP, while the remaining data were held out for final model evaluation. Overall, clinically evident PNP was present in 247 of 329 (75.1%) participants, with 88 (26.7%) individuals showing asymmetric nerve deficits. In a subcohort (n=37) undergoing nerve conduction study as the gold standard, sensory and motor nerve conduction velocities and nerve amplitudes in lower extremities significantly correlated with 79 game features (|R|>0.4, highest R value +0.65; P<.001; adjusted R2=0.36). Within another subcohort (n=173) with normal cognition and matched covariates (age, sex, BMI, etc), hypothesis-driven key capabilities and specific game features were significantly correlated with the presence of PNP. Predictive models using selected game features achieved 76.1% (left) and 81.7% (right foot) accuracy for PNP detection. Multiclass models yielded an area under the receiver operating characteristic curve of 0.76 (left foot) and 0.72 (right foot) for assessing nerve damage patterns (small, large, or mixed nerve fiber damage). The game-based application presents a promising avenue for PNP screening and classification. Evaluation in expanded cohorts may iteratively optimize artificial intelligence model efficacy. The integration of engaging motivational elements and automated data interpretation will support acceptance as a telemedical application.

Median nerve conduction study findings in various arm positions.

To investigate the effects of various arm positions on median nerve conduction studies (NCSs). This prospective cohort study, conducted at Adana City Training and Research Hospital between January and July 2023, included 20 healthy participants. Median NCSs were performed on the participants in three different standing positions with the elbow as the stimulation point: 1) with the arm adducted (P1), 2) with the arm anteflexed (P2), and 3) with the arm raised upwards (P3). We obtained median nerve compound muscle action potential (CMAP) latency, duration, peak-to-peak (PP) amplitude, onset-to-negative peak (OP) amplitude, negative area/duration. Three CMAPs were obtained in each position, and the mean and minimum/maximum values at each position were analyzed. The mean age (minimum-maximum) of the participants (11 male, 9 female) was 28.5±6.5 (20-42) years. Median nerve CMAP means (median) of latency/negative duration in the P1, P2, and P3 positions were 6.82±0.59 (6.83)/5.50±0.76 (5.39) ms, 6.99±0.56 (7.02)/5.72±0.73 (5.73) ms, and 7.03±0.58 (7.12)/5.79±0.80 (5.83) ms. Median nerve CMAP mean/minimum latency and negative duration were lowest in the P1 position (p<0.05). The mean median nerve CMAP OP amplitude was highest in P3 than P1 or P2 (p=0.042 and p=0.048). Median NCS results differed based on the position of the arm.

Unveiling the Role of Nerve Conduction Studies (NCS) in Detecting Subclinical Peripheral Neuropathy in Autoimmune Disorders: A Cross-Sectional Study

Unveiling the Role of Nerve Conduction Studies (NCS) in Detecting Subclinical Peripheral Neuropathy in Autoimmune Disorders: A Cross-Sectional Study

Nerve Conduction Studies in Diabetic Polyneuropathy: A Comparative Analysis of Asymptomatic and Symptomatic Patients

Nerve Conduction Studies in Diabetic Polyneuropathy: A Comparative Analysis of Asymptomatic and Symptomatic Patients

Ionic Conductivity Studies on Proton Conducting Solid Biopolymer Electrolyte based on 2-Hydroxyethyl Cellulose (2HEC) Doped with Ammonium Chloride (NH4CL)

Solution casting techniques have been used to create a solid biopolymer electrolyte (SBEs) based on 2-hydroxyethyl cellulose (2HEC) doped with varying amounts of ammonium chloride (NH4Cl) to investigate the potential of NH4Cl in enhancing the ionic conductivity of SBE. Electrical impedance spectroscopy (EIS) was used to measure the impedance of the electrolytes between 50 Hz and 1 MHz in frequency. At room temperature, ionic conductivity was at its highest for 16% weight percent of NH4Cl which was 1.74 x 10-3 Scm-1. The temperature dependence data of 2HEC-NH4Cl SBEs abides Arrhenius behaviour. Complex electrical modulus and complex permittivity were used to assess the dielectric data for the sample at various temperatures.

Ultrasound vs Nerve Conduction Studies: A Comparative Analysis in Carpal Tunnel Syndrome Diagnosis

Background: Carpal tunnel syndrome (CTS) is a prevalent entrapment neuropathy. While nerve conduction studies (NCS) remain the gold standard for diagnosis, ultrasound (USG) offers a non-invasive alternative. This study aimed to compare the diagnostic accuracy of USG and NCS in CTS at Dr. Mohammad Hoesin General Hospital Palembang, Indonesia. Methods: A cross-sectional study was conducted on patients presenting with CTS symptoms. Demographic and clinical data were collected. NCS and USG assessments were performed, blinded to each other's results. USG measurements included the cross-sectional area at the carpal tunnel inlet (CSAc), proximal to the carpal tunnel (CSAp), and the difference between them (∆CSA). Diagnostic accuracy was calculated, and agreement was assessed using Cohen's kappa. Results: A total of 86 wrists from 49 patients were included. The mean age was 52 ± 11 years, with a female predominance (86%). The majority had mild CTS based on NCS (55.8%). USG measurements showed mean CSAc of 13.1 ± 3.5 mm², CSAp of 10.6 ± 3.0 mm², and ∆CSA of 2.5 ± 0.9 mm². ∆CSA had the highest sensitivity (92.2%), specificity (88.9%), and accuracy (91.9%), with substantial agreement with NCS (Kappa = 0.65). Conclusion: USG, particularly using ∆CSA, demonstrates high diagnostic accuracy in CTS, comparable to NCS. It can serve as a valuable tool, especially in settings with limited NCS availability.

Research of heat conductivity of quartz material

In the article the results of a study of heat conductivity and thermal resistance of quartz-containing materials were presented. The object of the study was a quartz mineral from the Aktas deposit, located in the Ulytau district of the Karaganda region. The initial size was a piece of quartz mineral measuring 5–10 mm, which was disassembled mechanically. To prepare the samples under study, quartz powder 0.2 mm thick, crushed by the electric pulse method, was used. Electropulse technology is one of the methods based on the influence of Yutkin, accompanied by the formation of a specially formed high-voltage pulsed electrical discharge inside a volume of liquid. The pulse discharge frequency of the electrohydropulse installation for grinding the mineral to the required fraction was f = 3 Hz, the pulse capacitor capacitance C = 0.4 μF, the pulse discharge voltage U = 18–37 kV. The samples under study were made in the following dimensions: width 100 mm, length 100 mm, height 25 mm. To evaluate the thermophysical properties of manufactured samples in a stationary mode, the ITP-МG4 “100” installation was used, which determines the heat conductivity and thermal resistance of materials for thermal insulation of industrial equipment and pipelines in accordance with GOST 7076, based on the thermoelectric method, and GOST 30256, based on the thermal probe method. As a result of the study, a graph of the temperature dependence of heat conductivity and thermal resistance of quartz-containing materials was obtained. Based on the results obtained, it was established that the thermophysical parameters of the sample containing quartz are lower compared to the sample consisting of cement.

Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS): a family with five affected sibs from Turkey

BackgroundCerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS), a relatively common cause of late-onset progressive ataxia, is a genetic disease characterised by biallelic pentanucleotide AAGGG repeat expansion in intron 2 of the replication factor complex subunit 1 gene. Herein, we describe the first molecularly confirmed CANVAS family with five affected siblings from Turkey.Case presentationThe family comprised seven siblings born from healthy non-consanguineous parents. CANVAS phenotype was present in five of them; two were healthy and asymptomatic. Chronic cough was the first symptom reported in all five siblings, followed by the development of sensory symptoms, oscillopsia and imbalance. Clinical head impulse test (HIT) was positive in all cases and video HIT performed on three patients revealed very low vestibulo-ocular reflex gains bilaterally. Magnetic resonance imaging and nerve conduction studies revealed cerebellar atrophy and sensory neuronopathy, respectively. RP-PCR confirmed the homozygous presence of the AAGGG repeat expansion in all five cases.ConclusionGenetic screening for CANVAS should be considered in all patients with late-onset ataxia, sensory disturbances and vestibular involvement, especially in the presence of chronic cough.

Early Electrophysiology in Suspected Acute Guillain-Barré Syndrome: A Prospective Study of Comprehensive Testing.

Electrophysiologic changes in early Guillain-Barré Syndrome (GBS) can be nondiagnostic. Improved testing paradigms may improve hyperacute treatment. This work prospectively evaluated consecutive patients admitted to a metropolitan teaching hospital in Melbourne, Australia, with suspected acute GBS. We performed extensive neurophysiology at three different time points. Novel tests, including cutaneous silent periods, long latency reflexes, and contraction-induced H reflexes, were assessed. Twenty-three participants were studied, including 13 cases of acute GBS. In total, 69% of acute cases of GBS were accurately diagnosed on the first nerve conduction study using published neurophysiologic criteria, with serial studies rarely altering the GBS subtype classification. Antidromic and orthodromic upper limb sensory studies were diagnostically equivalent. A sural sparing pattern was seen in 77% of cases of GBS at the first test. Long latency reflexes and contraction-induced H reflexes testing were abnormal in most participants but were limited by muscle weakness in some. Cutaneous silent periods testing was unobtainable in approximately 50% of cases because of weakness and did not discriminate from mimic disorders. Abnormalities of long latency reflexes and contraction-induced H reflexes may be helpful where initial electrophysiology is nondiagnostic but are nonspecific. Cutaneous silent periods testing seems of limited value. Comprehensive testing provides diagnostic certainty in most cases of GBS from the very first study.