Distal Amplitude Research Articles

Normative data of upper limb nerve conduction in North Kerala population

Objectives: The objective of this study was to detect the normal motor amplitude, distal latency, conduction velocity, sensory amplitude, sensory latency and F-wave latency of upper limb nerves (Median nerve, ulnar nerve and radial nerve). Materials and Methods: It was a cross-sectional study conducted in the Department of Neurology, Government Medical College, Kozhikode, between 1 January 2022 and 31 December 2022. Nerve conduction studies (NCSs) were performed prospectively in the upper limbs of 311 carefully screened, healthy individuals of either sex, who were between the ages of 13 and 60 years, belonging to the North Kerala population, using the standardised technique. Results: The study population consisted of 54% males and 46% females. The mean age, height, weight and body mass index (BMI) of the study population were 39 ± 15 years, 163 ± 12 cm, 58 ± 11 Kgs and 22 ± 2.7 Kg/m2, respectively. The motor, sensory parameters and F-wave latency of median ulnar and radial nerves were established. We obtained a significant positive correlation between motor distal latency, sensory distal latency and F-wave latency of median and ulnar and radial nerves with age, height and weight. We obtained a significant negative correlation between motor distal amplitude, sensory distal amplitude and conduction velocity of median, ulnar, and radial nerves with age, height and weight. In our study, females had faster conduction velocity, shorter F-wave latency, motor distal latency, sensory latency and higher motor amplitude and sensory amplitude than males. BMI did not have a significant correlation with nerve conduction parameters in our study. Conclusion: Normative conduction parameters of commonly tested peripheral nerves of the upper limb were established for our electrophysiology laboratory. While performing NCS, it is essential to adapt values based on physiological factors such as age, gender, height, weight and BMI, which enhance the diagnostic sensitivity of the procedure and, thus, avoid misdiagnosis and mistreatment of various demyelinating and axonal disorders.

Relationships between the global symptom score and electrophysiological findings after surgical release for carpal tunnel syndrome: Indications and outcomes.

Regarding surgical indications for carpal tunnel syndrome (CTS), the hypothesis that the recovery processes of subjective symptoms differ among pain, sensory, and motor symptoms and correlate with recovery in objective nerve conduction studies was examined in the present study. The global symptom score (GSS) is a method used to assess clinical outcomes and covers subjective symptoms, including pain (pain and nocturnal awakening), sensory (numbness and paresthesia), and motor (weakness/clumsiness) symptoms. The relationships between long-term changes in GSS and recovery in nerve conduction studies were investigated. Forty patients (40 hands) were included (mean age 65years; 80% female; 68% with moderate CTS: sensory nerve conduction velocity < 45m/s and motor nerve distal latency > 4.5ms). Pain and nocturnal awakening rapidly subsided within 1month after surgery and did not recur in the long term (median 5.6years). Paresthesia significantly decreased 3months after surgery and in the long term thereafter. Weakness/clumsiness significantly decreased at 1year. Sensory nerve distal latency, conduction velocity, and amplitude significantly improved 3months and 1year after surgery, and correlated with nocturnal awakening in the short term (3months) in moderate CTS cases. The patient satisfaction rate was 91%. Rapid recovery was observed in pain and nocturnal awakening, of which nocturnal awakening correlated with the recovery of sensory nerve conduction velocity. Patients with pain symptoms due to moderate CTS may benefit from surgical release.

Mapping Neurophysiological Patterns in Carpal Tunnel Syndrome: Correlations With Tinel's and Phalen's Signs.

Background This study aimed to observe the neurophysiological severity grading of carpel tunnel syndrome (CTS) using nerve conduction studies (NCSs) and the correlation between Tinel's and Phalen's signs. Methodology In this cross-sectional study, 240 patients of CTS were enrolled. NCSs were conducted in 480 hands. Various variables such as distal latency, amplitude, and nerve conduction velocity in both sensory and motor median nerves were recorded. The provocative tests capable of reproducing patients' symptoms such as Phalen's test and Tinel's test were performed on all 480 hands studied. Results Neurophysiological variables were affected in 449 out of 480 hands. Tinel's sign was observed in 59% of cases (265 hands) while Phalen's sign was positive in 37.2% (167 hands) of cases. Severity grading of CTS based on neurophysiological variables resulted in Grade I (mild) in 202 hands, Grade II (mild to moderate) in 56 hands, Grade III (moderate) in 39 hands, and Grade IV (severe) in 152 hands. Provocative tests (Tinel's and Phalen's) used for the diagnosis of CTS were positive in 68 hands (36.66%) and 26 hands (12.8%), respectively, in mild Grade I. However, as the CTS severity grade increased, the provocative test success rate also increased simultaneously. In severe Grade IVCTS, Tinel's and Phalen's tests were positive in 134 (88.1%)hands and 94 (61.8%) hands, respectively. Conclusions This study underscores the unreliability of Tinel's and Phalen's signs as screening methods for CTS severity. With moderate sensitivity and specificity, NCSs are deemed essential for confirming CTS diagnosis and assessing severity, especially in mild cases that might be mistakenly perceived as normal hands by consultants.

Outcome measures in pediatric chronic inflammatory demyelinating polyradiculoneuropathy.

Objective outcome measures in children undergoing treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are lacking. The aim of the study was to record serial grip strength and motor nerve conduction studies to assess interval change. This was a retrospective review of 16 children (8 females and 8 males; median age, 9.7 years; interquartile range, 6-13 years) with CIDP followed at a tertiary children's hospital from 2013 to 2021. Subjects were treated with intravenous immunoglobulin (IVIG). Right and left grip strength measurements were obtained at each clinic visit using a handheld dynamometer. Annual right median motor nerve conduction study data were recorded during the study period. Mean duration of follow-up was 2.9 years. Grip strength (right: 0.19 kg/month, p < 0.001; left 0.23 kg/month, p < 0.001) and median F-wave latencies (-0.23/month, p = 0.015) showed significant improvement over time. Akaike information criterion showed time + IVIG frequency <21 days as best fit for grip strength and distal compound muscle action potential amplitude. Our study results indicate serial grip strength measurements are a feasible and objective way to assess motor strength improvement in children with CIDP receiving immunotherapy.

Electrophysiological Evaluation of Common Peroneal Nerve in Chronic Cigarette Smokers.

Background: Researchers have identified multiple negative health effects of smoking on the respiratory and cardiovascular systems. It was recently reported that substances in cigarette smoke also have pathological effects on peripheral nerves, which causes neuronal impairment. The common peroneal nerve conduction study is an essential electrodiagnostic test of the lower limb for the detection of peripheral motor nerve dysfunction.Objectives: To assess the potential influence of smoking on the electrophysiological status of common peroneal nerve in young male chronic cigarette smokers.Materials and Methods: This case-control study was conducted in the Department of Physiology, Sir Salimullah Medical College, Dhaka, from July 2017 to June 2018, including thirty male cigarette smokers aged 25 to 40 years. For comparison, another thirty age and BMI-matched healthy male non-smoker subjects were selected in the control group. The electrophysiological parameters (distal latency, amplitude, and motor nerve conduction velocity) of the left common peroneal nerve were evaluated by standard methods in the Department of Neurology, Dhaka Medical College Hospital. For the statistical analysis, an independent t-test was performed.Result: In this study, the mean distal latency of the common peroneal nerve was slightly prolonged, while the mean amplitude was slightly reduced in smokers. However, these changes were not statistically significant. However, the motor nerve conduction velocity was significantly (p ˂ 0.05) slower in cigarette smokers compared to non-smokers.Conclusion: Chronic cigarette smoking causes significant impairment of common peroneal motor nerve conduction, while it does not affect the amplitude in young individuals. KYAMC Journal Volume: 14, No: 03, October 2023: 111-115.

Normative parameters of motor nerve conduction studies in infants

Introduction. Electromyography (EMG) is a modern method of instrumental neurophysiological diagnostics, which includes two main techniques as nerve conduction studies and needle EMG. Parameters of motor nerve conduction studies have been used in a number of clinical studies to evaluate the effectiveness of treatment in children with spinal muscular atrophy (SMA) during the use of pathogenetic therapy (nusinersen). Now, in our country there are no verified normative parameters of motor nerve conduction studies in infants. It is also worth saying that neonatal screening for identifying SMA patients started in 2023 in our country, and currently gene therapy for this disease is increasingly used, so improving methods for instrumental assessment of the dynamics of the condition during treatment, including using EMG, is relevant. &#x0D; Objective: to determine the normative parameters of motor nerve conduction studies in 1–6 months, 7–12 months, and 13–24 months infants without neurological pathology.&#x0D; Materials and methods: The motor nerve conduction studies were carried out using a 2-channel electromyograph Neuro-MVP-Micro (Russia) with electrical stimulation of the ulnar nerve and registration of the compound muscle action potential (CMAP) from the abductor digiti minimi muscle. This made it possible to determine the main parameters of the negative peak of the CMAP — distal latency, amplitude and area, and calculate the motor nerve conduction velocity (MNCV) along the distal part of the ulnar nerve. The obtained data for each parameter were subject to normal distribution and presented in the form of mean and standard deviation (M±SD), minimum and maximum values (min – max).&#x0D; Results: In the age range of 1–6 months, the amplitude of the CMAP (mV) was 5.0±1.0 (3.0–8.0); CMAP area (ms∙mV) — 9.1 ± 2.1 (5.5–12.9); distal latency (ms) — 2.2 ± 0.2 (1.6–2.5), MNCV (m/s) — 37.5 ± 5.4 (27.5–48.9).&#x0D; In the age range of 7–12 months, the amplitude of the CMAP (mV) was 6.2 ± 1.3 (3.8-9.3); CMAP area (ms∙mV) — 11.7 ± 3.0 (6.5–18.6); distal latency (ms) — 2.0 ± 0.2 (1.4–2.4), MNCV (m/s) – 48.4 ± 4.1 (42.1–55.2).&#x0D; In the age range of 13-24 months, the amplitude of the CMAP (mV) was 6.4 ± 0.6 (5.0-7.3); CMAP area (ms∙mV) — 13.3 ± 2.8 (9.8–18.2); distal latency (ms) — 2.2 ± 0.2 (1.8–2.5), MNCV (m/s) – 52.6 ± 3.8 (41.8–57.3).&#x0D; Conclusion. For the first time, normative parameters of motor nerve conduction studies were obtained in 1–6, 7–12, and 13–24 months infants without neurological pathology. This will make it possible to objectify neurophysiological parameters in neuromuscular diseases in infants.

OGBN O06 Enhancing Surgical Decision-Making with High-Resolution Manometry and Distal Contractile Integral in Preoperative Assessment for Magnetic Sphincter Augmentation (LINX)

Abstract Background Preoperative assessment for magnetic sphincter augmentation (MSA) (LINX) involves evaluating the Mean Distal Amplitude (MDA) on conventional manometry to assess the patient suitability and risk of post-operative dysphagia. In the last decade high-resolution manometry (HRM) has superseded conventional manometry owing to obtaining more clinical information on the oesophageal motility, including the Distal Contractile Integral (DCI) that incorporates contractile amplitude, duration and contractility propagation length within the oesophageal body. The purpose of this study is to translate the MDA to modern DCI as preoperative marker to MSA. Methods This retrospective study includes patients referred to oesophageal laboratory at Guy’s Hospital between March and May 2023. Patients underwent HRM with ten 5ml water swallows that provided manometric information to compute mean DCI and MDA (MDA waveforms at 11cm, 7cm and 3cm above the GOJ were used). Statistical analysis investigated the relationship between MDA and mean DCI using Pearson correlation, Student t-test, ROC curve analysis and relevant metrics assess the cut-off threshold accuracy and reliability in classifying normal MDA. Results 270 patients were included in the study (female:male=190:80 males, mean age 52.1 years). There was strong direct correlation between MDA and mean DCI (r=0.71, p&amp;lt;0.0001) (Figure 1). Patients with normal MDA had a significantly higher mean DCI compared with weak MDA at 11cm (601mmHgscm vs 167.15mmHgscm, p&amp;lt;0.0001) 7cm (286.4mmHgscm vs 741mmHgscm, p&amp;lt;0.001), 3cm (592mmHgscm vs 192.6mmHgscm, p&amp;lt;0.0001) and overall MDA (714.2mmHgscm vs 259mmHgscm, p&amp;lt;0.001) (Figure 2). ROC curve analysis revealed the mean DCI thresholds for normal MDA to be 615mmHgscm at 11cm, 419mmHgscm at 7cm, 318mmHgscm at 3cm and 453mmHgscm for the overall MDA (Table 1). Conclusions The findings of this study show HRM and the clinical measurement DCI may be a suitable preoperative assessment for MSA. This translation of MDA to modernisation in manometry may assist surgeons adopt DCI which is regarded as more robust assessment that offers more detailed clinical information of the oesophageal motility health and disorder.

Relationship Between Clinical Outcomes and Nerve Conduction Studies Before and After Viral Infections in Healthy Individuals: Case Series.

The neurological effect of viral respiratory infections has been acknowledged in many studies.However, patients who recovered from this infection show neurological manifestations and are not being routinely transferred for electrodiagnostic evaluation. This study aimed to examine the neurological effect of viral respiratory infections on the nerve function using electrophysiology in patients fully recovered from viral respiratory infections. To limit bias in the results, the authors decided to choose patients who recovered from one virus in all participants (coronavirus).Medical records were screened for patients who performed nerve conduction studies (NCSs) before the coronavirus pandemic.Thirty patients met our inclusion criteria, and only 10 showed up to perform NCS.Data of the NCS was compared before and after the coronavirus infection for motor and sensory NCS parameters. An increase in both the median and ulnar sensory nerve latencies and a decrease in the sensory nerve amplitude was observed.Also, there was a decrease in the motor conduction velocity (MCV) of the ulnar nerves and motor amplitude in the median nerve.In the lower limbs, there was a decrease in the sural nerve latency, increased MCV in the tibial nerves, and decreased MCV in the peroneal nerves.The proximal amplitudes of the tibial and peroneal nerves were increased, but the distal amplitude was increased only in the peroneal nerves and decreased in the tibial nerves. There is a significant impact of viral infections on the peripheral nerves.Large-scale prospective studies are required to investigate the pathogenesis of the neuropathy and myopathy after viral infections.

Clinical efficacy of electroacupuncture-like magnetic therapy compared to conventional transcutaneous electrical nerve stimulation in individuals with carpal tunnel syndrome

This study aimed to evaluate the clinical efficacy of an electroacupuncture-like magnetic therapy (ELMT) and conventional transcutaneous electrical nerve stimulation (TENS) in patients with carpal tunnel syndrome (CTS). A prospective randomized controlled trial in single-centre was conducted. Thirty-four CTS patients confirmed by electrodiagnostic study were randomized into TENS or ELMT group and completed a six-week treatment program. TENS or ELMT treatment was applied on acupuncture point PC-6 (Neiguan) and one selected hand acupoint. Therapeutic exercises were also included after the electrophysical modality. Their physical signs, motor and sensory performances, Boston Carpal Tunnel Questionnaire (BCTQ) scores, and results of electrodiagnostic study were evaluated. After treatments, both groups demonstrated significantly decreased BCTQ scores and positive rate of Tinel’s sign in the major symptomatic side, which indicated improvements in the symptom severity and physical functions. Significant increases in distal sensory amplitude and nerve conduction velocity of the median nerve were only found in the ELMT group. Our study found either conventional TENS or ELMT plus therapeutic exercises could improve the symptomatology and physical provocation sign of CTS. The ELMT has additional improvement in the nerve conduction in patients with CTS.

The effect of aging on nerve conduction study of median nerve and ulnar nerves in healthy individuals

Background: Nerve conduction studies (NCS) are known to be influenced by various physiological and environmental factors. Region and population-specific normative reference values of NCS required for comparison and evaluation of results have been published in many research studies but the age-group-specific significant pattern of reference values is not available for the same. Researchers have agreed that results are variable by chronological age, the present study was carried out to determine the effect of aging on nerve conduction velocity (NCV) of two commonly tested median and ulnar nerves of upper limb in individuals of different age groups. Furthermore, the motive was to collect reference data that can be used during clinically significant diagnostic testing of nerves. Aims and Objectives: The study aimed to study the effect of aging on nerve conduction velocities of the median and ulnar nerve, as well as to observe the correlation of age and changes in NCS of the median and ulnar nerve. Materials and Methods: A cross-sectional (observational) study was conducted on 110 healthy individuals (count of males-60, females-50). The subjects for the study were taken up amongst the volunteers (medical students, teaching and nonteaching staff members in the Government Medical College and Rajindra Hospital, Patiala, and healthy volunteers who were willing to participate in the study). The subjects were grouped according to their age: Group I (18–30 years) (n = 38), Group II (31–45 years) (n = 38), and Group III (46–60 years) (n = 34). The motor and sensory distal latencies, amplitudes, and NCVs of median and ulnar nerves were recorded, and data were evaluated. Results: The mean and standard deviation of the median and ulnar nerve was studied for latencies, amplitude, and velocities for both sensory and motor components. Patients with older age had longer latencies (median: Motor and sensory P &lt; 0.001, ulnar: Motor = 0.013 and sensory = 0.006), smaller amplitudes (median: Motor P = 0.013 and sensory &lt;0.001, ulnar: Motor P = 0.014, and sensory = 0.008), and slower conduction velocities (median: Motor P &lt; 0.001 and sensory = 0.006, ulnar: Motor P = 0.003 and sensory = 0.069) compared with the younger age group, and the change was well observed in the age group of ≥46 years. The change with age was greater in sensory nerve conduction of the median and ulnar nerves. Conclusion: Our study results demonstrate that age is significantly correlated with all three nerve conduction parameters recorded from both nerves. An age-matched comparison of the results obtained during routine testing should be made to increase the diagnostic sensitivity of NCS.

Clinical and Neurophysiological Follow-Up of Chronic Inflammatory Demyelinating Polyneuropathy Patients Treated with Subcutaneous Immunoglobulins: A Real-Life Single Center Study.

chronic idiopathic demyelinating polyneuropathy (CIDP) is an acquired, immune-mediated neuropathy characterized by weakness, sensory symptoms and significant reduction or loss of deep tendon reflexes evolving over 2 months at least, associated with electrophysiological evidence of peripheral nerve demyelination. Recently, subcutaneous immunoglobulins (SCIg) have been introduced in clinical practice as a maintenance therapy for CIDP; nevertheless, electrophysiological and efficacy data are limited. to evaluate SCIg treatment efficacy, we retrospectively reviewed data from 15 CIDP patients referring to our clinic, receiving SCIg treatment and who performed electrophysiological studies (NCS) and clinical scores (MRC sumscore, INCAT disability score and ISS) before starting the treatment and at least one year after. NCS showed no significant changes before and during treatment for all the nerves explored. Clinical scores did not significantly change between evaluations. Correlation analysis evidenced a positive correlation of cMAPs distal amplitude with MRC sumscore and a trend of negative correlation with the INCAT disability score. SCIg maintenance therapy preserves nerve function in CIDP with a good efficacy and safety. Treatment effectiveness can be assessed with ENG, which represents a useful instrument in the follow-up and prognostic assessment of CIDP.

Conduction block and positive sharp waves/fibrillation potentials in entrapment neuropathies of the ulnar, radial, and peroneal nerves

Introduction: Entrapment mononeuropathies can cause motor conduction block, positive sharp waves, and fibrillation potentials. Aim: The study aims to find whether there is a relationship between positive sharp waves/fibrillation potentials and conduction block observed in entrapment mononeuropathies. Materials and methods: Patients with ulnar neuropathy at the elbow, radial neuropathy at the spiral groove, and peroneal neuropathy at the fibular head were included in this retrospective study. Nerve conduction study and needle electromyography results of the patients were analysed. Results: The study included a total of patients with 67 ulnar neuropathy, 8 radial neuropathy, and 27 peroneal neuropathy. All radial and peroneal neuropathy patients and 30 ulnar neuropathy patients had positive sharp waves/fibrillation potentials in at least one muscle. Twenty-three ulnar neuropathy patients with these potentials, 6 radial neuropathy patients, and 18 peroneal neuropathy patients had conduction block (p &lt; 0.001). The reduction of compound muscle action potential amplitude in percentage recorded from the abductor digiti quinti/first dorsal interosseous across the elbow segment in ulnar neuropathy patients with and without positive sharp waves/fibrillation potentials was 41.9 ± 35.9/46.6 ± 36.1% and 7.6 ± 16.5/10.4 ± 16.5%, respectively (p &lt; 0.001/p &lt; 0.001). The distal compound muscle action potential amplitudes of ulnar neuropathy patients with these potentials were lower than those of ulnar neuropathy patients without these potentials (p = 0.029 – abductor digiti quinti, p = 0.017 – first dorsal interosseous). No correlation was found between the severity of positive sharp waves/fibrillation potentials and muscle strength in patients with these potentials (p &gt; 0.05). Conclusions: Positive sharp waves/fibrillation potentials and motor conduction block can be seen together in patients with entrapment mononeuropathies. We concluded that there may be no relationship between the severity of these potentials and muscle strength.

Clinical and Electrophysiological Changes in Pediatric Spinal Muscular Atrophy after 2 Years of Nusinersen Treatment.

In the new therapeutic era, disease-modifying treatment (nusinersen) has changed the natural evolution of spinal muscular atrophy (SMA), creating new phenotypes. The main purpose of the retrospective observational study was to explore changes in clinical evolution and electrophysiological data after 2 years of nusinersen treatment. We assessed distal compound motor action potential (CMAP) on the ulnar nerve and motor abilities in 34 SMA patients, aged between 1 and 16 years old, under nusinersen treatment, using specific motor scales for types 1, 2 and 3. The evaluations were performed at treatment initiation and 26 months later. There were registered increased values for CMAP amplitudes after 2 years of nusinersen, significantly correlated with motor function evolution in SMA type 1 patients (p < 0.005, r = 0.667). In total, 45% of non-sitters became sitters and 25% of sitters became walkers. For SMA types 1 and 2, the age at the treatment initialization is highly significant (p < 0.0001) and correlated with treatment yield. A strong negative correlation (r = −0.633) was observed for SMA type 1 and a very strong negative correlation (r = −0.813) for SMA type 2. In treated SMA cases, the distal amplitude of the CMAP and motor functional scales are important prognostic factors, and early diagnosis and treatment are essential for a better outcome.

Patterns of facial and blink reflex abnormalities in type 2 diabetes mellitus patients with short disease duration: a clue to subclinical cranial neuropathy

Abstract Background Cranial neuropathies occur in 3 to 14% of diabetic patients. Motor conduction study of the facial nerve and blink reflex study are electrophysiologic techniques used to assess the facio-trigeminal pathway in diabetic patients. The patterns of facial and blink reflex abnormalities are inconsistent among studies. This study aimed to assess the subclinical facial nerve and blink reflex abnormalities patterns in short-duration type 2 diabetes mellitus patients. This cross-sectional study included 30 type 2 diabetic patients with disease duration ≤ 5 years. We included only patients with the Toronto clinical neuropathy score ≤ 5. We enrolled 30 age- and sex-matched healthy subjects as a control group. We performed facial nerve motor conduction and blink reflex studies. Patients with prior history of cranial nerve lesions, stroke, or any other disease-causing polyneuropathy or drug-induced neuropathy were excluded from the study. Results Thirty diabetic patients were included, 20 females (66.7%) and ten males (33.3%). Their mean age was 52.63 ± 8.94 years. None of the patients had clinical evidence of neuropathy. There were significant differences between patients and controls in the distal latencies and amplitudes of facial nerve compound muscle action potentials and contralateral R2 late response latencies of the blink reflex. We detected subclinical cranial abnormalities in 6 diabetic patients (20%). One of them (3.3%) had facial nerve conduction abnormalities, four of them (13.4%) had blink reflex abnormalities, and one of them (3.3%) had both facial nerve and blink reflex abnormalities. Conclusion Subclinical cranial neuropathy can occur in short-duration type 2 diabetes mellitus patients. We detected different blink reflex patterns and facial conduction study abnormalities. We recommend blink reflex and facial nerve conduction studies as simple tests for the early evaluation of neurological subclinical affection in patients with short disease duration of T2DM as they may appear in the absence of peripheral neuropathy.

Nerve Conduction and Surface Electromyography of Physically Active Healthy Medical Undergraduates of Nepal

Introduction: Physical activity is defined as any bodily movement produced by skeletal muscles that requires energy expenditure. Nerve conduction studies and surface EMG provides a comprehensive evaluation of nerve, muscle or neuromuscular impairment. However, such studies are mostly done on professional athletes. Methods: Healthy physically active (n=17) and non-active (n=17) medical undergraduate students from B.P. Koirala Institute of Health Sciences (BPKIHS), Nepal were enrolled in the study using convenient sampling technique. Anthropometric and motor nerve conduction parameters of common peroneal nerves and surface EMG of gastrocnemius muscle were recorded using standard technique in Neurophysiology Lab II, BPKIHS. Descriptive analysis was done. Unpaired t-test was applied for comparing the nerve conduction and surface EMG variables between the groups. Pearson’s correlation was applied between anthropometric and nerve conduction &amp; surface EMG variables. Objectives: To compare nerve conduction parameters of common peroneal nerve and surface EMG of Gastrocnemius muscle between active and non-active individuals. Results: The distal and proximal amplitudes of left common peroneal nerve were significantly higher in physically active compared to non-active individuals (LCPDA-p value: 0.026, LCPPA-p value: 0.009). Anthropometric parameters showed significant correlation with nerve conduction parameters. Conclusion: Nerve conduction parameters are affected in the physically active individuals. Anthropometric variables showed significant relation with the nerve conduction parameters. Keywords: Nerve Conduction Velocity, Surface Electromyography, Peroneal Nerve, Gastrocnemius.

A Young Man With Acute-Onset Bilateral Arm Weakness After Traumatic Sciatic Neuropathy: A Clinical Vignette.

A Young Man With Acute-Onset Bilateral Arm Weakness After Traumatic Sciatic Neuropathy: A Clinical Vignette.

Mean Motor Nerve Conduction Velocity of Right Ulnar Nerve among Physically Trained Adult Males in a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Neural adaptation to physical training allows a person to better coordinate the activation of all relevant muscles producing maximum force. Nerve conduction velocity measures the speed of impulse along the motor neuron and is strongly associated with muscle contraction time. This study aimed to find out the mean motor nerve conduction velocity of the right ulnar nerve among physically trained adult males in a tertiary care centre. This descriptive cross-sectional study was conducted in the Neurophysiology Laboratory of a tertiary care centre from 3rd November, 2019 to 2nd November, 2020. Thirty young adult males who were engaged in the physical training at a training centre for more than 3 months were studied after receiving ethical approval from the Institutional Review Committee (Reference number: 1578/019). Motor nerve conduction parameters of the right ulnar nerve were measured and data were entered in Microsoft Excel. Statistical analysis was done using the Statistical Packages for the Social Sciences version 25.0. Point estimate at 95% Confidence Interval was calculated along with frequency and percentages for binary data, and mean and standard deviation for continuous data. Among 30 males studied, the mean motor nerve conduction velocity of the ulnar nerve was found to be 61.02±5.86 m/sec (58.92-63.11 at 95% Confidence Interval). The mean distal latency and amplitude of the muscle action potential were 2.33±0.53 ms and 8.08±1.17 mv respectively. Our study found that the mean nerve conduction velocity of the ulnar nerve was similar when compared to studies conducted in similar settings. Nepal; nerve conduction; ulnar nerve.

Nodopathies in the Early Diagnosis of Axonal Forms of Guillain-Barré Syndrome.

Introduction:Guillain-Barré syndrome (GBS) has been classified into demyelinating and axonal subtypes or forms, such as acute motor axonal neuropathy (AMAN) and regional pharyngeal-cervical-brachial variant (PCBv).ObjectiveTo study the relationship between motor nerve conduction blocks (CBs) and prognosis in AMAN and PCBv.Patients and MethodsWe retrospectively analyzed six cases of AMAN and PCBv with serial nerve conduction studies (NCS) and electromyography (EMG).ResultsThe serial NCS (1st−2nd and 3rd week) showed, as the most constant data, a decreased amplitude of the compound muscle action potential (CMAP) in 100% of cases. CBs were present in 66.6% of cases. EMG (3rd week) showed signs of severe denervation in 33.3%. All patients were treated from the 1st−2nd week of evolution with intravenous immunoglobulins (IVIGs). Patients with CBs (1st−2nd and 3rd week), showed reversible CBs or reversible conduction failure (RCF) and complete recovery at 1 month. Patients without CBs, with persistent reduced distal CMAP amplitude (dCMAP), showed severe acute denervation due to axonal degeneration (3rd week and 1st−3rd month) and a slow recovery of several months.ConclusionsNot all axonal forms of GBS have a poor prognosis. This study of AMAN and PCBv shows that patients with CBs can have reversible CBs or RCF, and good prognosis. Patients without CBs, with persistent reduction of dCMAP amplitude decrement, have severe acute denervation, and a worse prognosis. AMAN and PCBv have a continuous spectrum ranging from CBs due to dysfunction/disruption of Nodes of Ranvier, called nodopathies, with reversible CBs or RCF and good prognosis, to axonal degeneration with worse prognosis.

Anatomic and Manometric Abnormalities of the Upper and Lower Esophageal Sphincters in Patients With Reflux Disease

Laryngopharyngeal reflux (LPR) may cause inflammation of the laryngeal and pharyngeal mucosa. Gastroesophageal reflux disease (GERD) involves retrograde flow of gastric content into the esophagus below the upper esophageal sphincter (UES). The goal of this study was to investigate the esophageal anatomical and manometric variations of the esophagus in patients with LPR and/or GERD. Adult voice center patients who underwent diagnostic workup for reflux complaints with 24-hour multichannel intraluminal pH-impedance testing and esophageal manometry were included in this retrospective study. Subjects were classified as having LPR (>10 proximal reflux events), LPR + GERD (>10 proximal reflux events plus >73 distal reflux events) or were assigned to a control group (≤10 proximal events and ≤73 distal reflux events) based on pH study results. Anatomic and manometric parameters were evaluated between groups. There were 169 cases (65 male, 104 female) included in this study. The average age was 50.50 ± 17.29. Subjects in the LPR group had significantly higher UES relaxation pressures and greater UES length compared with the control group. Lower esophageal sphincter relaxation pressure was significantly higher in the control group compared with the LPR group or the GERD + LPR group. Subjects in the GERD + LPR group had a significantly shorter intra-abdominal portion of the lower esophageal sphincter compared with the LPR only group and the control group. Intrabolus pressure was significantly lower in both the LPR group and the LPR + GERD group compared with the control group. Distal wave amplitude was significantly lower in the LPR + GERD group compared to both the LPR group and the control group. The percentage of swallows with incomplete clearance was significantly greater in the LPR + GERD group than both the control group and the LPR group. The LPR group had significantly fewer swallows with incomplete clearance than the control group. Anatomic and manometric abnormalities are present in subjects with LPR with or without GERD and may contribute to the pathogenesis of reflux disease. Further research is needed to confirm or refute these findings.

Comparison of Motor Nerve Conduction Velocity between Football Players and Sedentary Individuals: A Cross-sectional Study

Introduction: Athletic training improves the cardiovascular, pulmonary and musculoskeletal performance. A number of studies have also suggested an improvement in neural capabilities. Nerve Conduction Study (NCS) helps in learning about various electrophysiological parameters of the nerve such as Nerve Conduction Velocity (NCV), latency, amplitude, duration, etc. They influence co-ordination and speed of voluntary activity. Aim: To study the Motor Nerve Conduction Velocities (MNCV) of trained athletes and compare their values with untrained individuals. Materials and Methods: A cross-sectional study was conducted in the Department of Physiology, Government Medical College, Trissur, Kerala, India, from January 2016 to January 2017. The sample consisted of 60 male subjects who included 30 athletes and 30 non athletes between ages 18 to 25. MNCV, latency, amplitude and duration of median, ulnar, and tibial nerves of both sides of the subjects were measured. These were compared using independent t-test, and p-value &lt;0.05 was taken as significant. Results: The MNCV in athletes were found to be faster than non athletes. The mean MNCV of left and right median nerves were 61.5±2.60 m/s and 61.45±2.52 m/s in athletes, and 56.48±2.70 m/s and 56.73±2.51 m/s in non athletes respectively. The mean MNCV of the left and right ulnar nerves were 61.28±2.64 m/s and 61.58±3.15 m/s in athletes, and 57.87±3.42 m/s and 58.05±3.94 m/s in non athletes. The mean MNCV of the left and right tibial nerves were 46.34±3.44 m/s and 46.37±3.60 m/s in athletes, and 44.74±3.46 m/s and 44.86±3.58 m/s in non athletes. In both tibial nerves, the proximal and distal amplitude was higher, and the proximal and distal duration was lower in athletes. Conclusion: The results indicated MNCV of athletes were higher which could be beneficial in their sports performance.