Sensory Nerve Action Potentials Research Articles

Effect of Platelet-Rich Plasma Injection on Mild or Moderate Carpal Tunnel Syndrome: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Objective To evaluate efficacy of platelet-rich plasma (PRP) injection in carpal tunnel syndrome (CTS), we conducted this meta-analysis, as well as proposed a protocol for its application in curative processes. Methods All randomized controlled trials (RCTs) of PRP for the management of mild or moderate CTS were included in this study. Database search was conducted from study inception to July 2020, including PubMed, Embase, Web of Science, and Cochrane Library. We used visual analogue scores (VAS) and the Boston Carpal Tunnel Questionnaire (BCTQ) as evaluation tools for primary outcomes. Second outcomes comprised cross-sectional area (ΔCSA) and electrophysiological indexes including distal motor latency (DML), sensory peak latency (SPL), motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNCV), compound muscle action potential (CMAP), and sensory nerve action potential (SNAP). The pooled data were analyzed using RevMan 5.3. Subgroup and sensitivity analyses were conducted with the evidence of heterogeneity. Egger' test was used to investigate publication bias. Results 9 RCTs were finally screened out with 434 patients included. Control groups comprised corticosteroid injection in 5 trials, saline injection in 1 trial, and splint in 3 trials. At the 1st month after follow-up, only ΔCSA between the PRP group and the control group showed significant difference (P < 0.05). In the 3rd month, there were statistically significant differences in VAS, BCTQ, SPL, SNCV, and ΔCSA between two groups (P < 0.05), while no statistically significant differences were found in the remaining outcomes. In the 6th month, there were statistically significant differences at BCTQ (P < 0.05) in primary outcomes and ΔCSA (P < 0.05) in secondary outcomes between two groups. As to adverse events in PRP injection, only one study reported increased pain sensation within 48 h after injections. Conclusion This systematic review and meta-analysis demonstrates that the PRP could be effective for mild to moderate CTS and superior to traditional conservative treatments in improving pain and function and reducing the swelling of the median nerve for a mid-long-term effect. To some extent, the electrophysiological indexes also improved after PRP injection compared with others conservative treatments.

Clinical predictors of surgical outcomes of severe carpal tunnel syndrome patients: utility of palmar stimulation in a nerve conduction study

BackgroundCarpal tunnel syndrome is a common peripheral nerve compression disorder. However, there is no established opinion regarding the predictors of symptom improvement after surgery. This study aimed to identify the predictors of surgical outcomes of severe carpal tunnel syndrome patients.MethodsIn the patients who underwent a carpal tunnel syndrome surgery, we selected the patients who had a preoperative Bland’s classification of grade 5 or 6, and assessed for the changes in Bland’s classification grade before and after surgery. Those who showed improvement from preoperative grades 5–6 to postoperative grades 1–4 comprised the improvement group. In contrast, those who did not show improvement and had postoperative grades 5 or 6 comprised the non-improvement group. In a nerve conduction study, amplitudes of the compound muscle action potential and sensory nerve action potential of the palms were assessed between the improvement and non-improvement groups.ResultsAmong the 60 hands of 46 patients who had a preoperative Bland’s classification of grade 5 or 6, 49 hands of 37 patients comprised the improvement group, and 11 hands of 9 patients comprised the non-improvement group. The amplitudes of the compound muscle action potential and sensory nerve action potential of the palms before surgery were significantly higher in the improvement group. The degree of improvement in Bland’s classification grade was correlated with the degree of clinical symptom improvement.ConclusionsAmplitudes of compound muscle action potential and sensory nerve action potential before surgery induced by palmar stimulation can predict improvements in nerve conduction study scores and clinical findings after surgical treatment.

Associations between hand function and electrophysiological measurements in hand osteoarthritis patients of different ages with or without carpal tunnel syndrome

Osteoarthritis is a common degenerative disease that most frequently involves the hand. The objective was to compare clinical functional outcome measures including hand grip, pinch strength, and dexterity with various electrophysiological measures in patients of different ages with hand osteoarthritis with or without the presence of carpal tunnel syndrome (CTS). Patients with hand osteoarthritis (208 patients, 404 hands) who underwent hand-function tests and motor and sensory nerve conduction studies (NCS) between June 2015 and June 2016 were enrolled. The patients’ hands were assigned to carpal tunnel syndrome (CTS) (206 hands; mean age, 56.37 ± 10.52; male:female, 46:160) or control groups (198 hands; mean age, 57.88 ± 9.68; male:female, 55:143). The strength of hand grip and lateral pinch, the time required to complete the nine-hole pegboard test (9HPT), and motor and sensory nerve conduction parameters were measured and compared across age groups and between hands with or without CTS. The CTS group showed significantly lower hand grip and lateral pinch strength, and a longer time to complete the 9HPT in comparison with the control group. Female patients showed significantly lower hand grip and lateral pinch strength than male patients. However, there was no difference in the 9HPT completion time between genders. Multivariate regression analysis identified the amplitude of the median compound muscle action potential (CMAP), age, and male gender as independent predictors of grip strength (adjusted R2 = 0.679), and amplitude of median CMAP and male gender as independent predictors of KP strength (adjusted R2 = 0.603). Velocity of median CMAP, amplitude of median sensory nerve action potential, and age were identified as independent predictors of 9HPT time (adjusted R2 = 0.329). Nerve conduction measurements were significantly related to hand-function test results, and CTS induced significant deficits in strength and performance of the affected hand.

Vibratory testing with the 64 Hz Rydel-Seiffer tuning fork and its relation to the sural nerve action potential.

Despite its widespread use, little is known regarding the ability of the semi-quantitative Rydel-Seiffer tuning fork to designate peripheral nerve function. We sought to determine in a large sample of normal and abnormal nerves the relationship between vibration sense and compound sensory nerve action potential (SNAP) parameters recorded in a corresponding innervation area. Vibratory thresholds were determined on a scale of 0 to 8 with a 64 Hz Rydel-Seiffer tuning fork placed on the lateral malleolus of 303 subjects. Sural nerve sensory neurography was employed to derive SNAP parameters, which were related to vibration sense by means of multiple linear regression. ROC curve analysis was performed to determine the classification efficacy of the tuning fork in distinguishing normal from abnormal sural nerve responses. SNAP amplitude was the most significant predictor in the whole subjects group and in the subgroup of subjects with normal SNAPs, whereas conduction velocity played a major role in subjects with abnormal SNAPs. Age was significantly associated with vibration perception, particularly in subjects with normal SNAPs. With an area under the curve of 0.730, vibration sense was a fair classifier for decreased SNAP amplitudes. The optimal vibratory cutoff was 4.2. Age is a major determinant of vibratory test results, highlighting the importance of aging of central and peripheral pathways in mediating vibration sense. Hence, neurophysiological testing cannot be omitted in the context of polyneuropathy work-up, since even at the optimal cutoff threshold, vibratory examination still displays 40% false negative test results.

Intensive Care Unit-Acquired Weakness in Children: A Prospective Observational Study Using Simplified Serial Electrophysiological Testing (PEDCIMP Study).

BackgroundTo study the incidence and time of onset of intensive care unit—acquired weakness in a prospective cohort of children (2–12 years) by serial simplified electrophysiological assessment (Pediatric Critical Illness Myopathy Polyneuropathy study, PEDCIMP).MethodsA single-center, prospective cohort study (Trial Registry Number: NCT02763709; PEDCIMP2016) was conducted at the pediatric intensive care unit of a tertiary care hospital in North India. A complete electrophysiological evaluation (4 motor nerves and 2 sensory nerves) was performed at baseline in children (2–12 years) admitted to the ICU with a pediatric risk of mortality (PRISM) of > 20 with more than 24-h stay. Following the entry evaluation, a minimal alternate day simplified electrophysiological testing of the unilateral common peroneal nerve and the sural nerve was assessed. A 25% reduction in compound muscle action potential (CMAP) and sensory nerve action potential from baseline was considered significant for ICUAW and was confirmed by complete electrophysiological re-evaluation.ResultsOf the total 481 children assessed for eligibility, 97 were enrolled. The median age of the cohort was 7 years. Sepsis (81%); need for vasoactive support (43%); multiorgan dysfunction (26%) were the common reasons for admission. Of the 433 eligible patient ICU days, 380 electrophysiological observations were done. A significant decrease of > 25% in CMAP of common peroneal nerve was not detected in any of the 380 observations. However, two children unfit for inclusion were diagnosed with ICUAW during the study period.ConclusionsChildren admitted with PRISM > 20 have a very low incidence of intensive care unit—acquired weakness by serial clinical and abbreviated electrophysiological evaluation.Electronic supplementary materialThe online version of this article (10.1007/s12028-020-01123-x) contains supplementary material, which is available to authorized users.

Reverse End-to-Side Anterior Interosseous Nerve-to-Ulnar Motor Transfer for Severe Ulnar Neuropathy.

Reverse end-to-side anterior interosseous nerve transfer has been reported to enhance treatment of severe, proximal ulnar neuropathy. The authors report on patients with severe neuropathy treated with ulnar nerve transposition and distal reverse end-to-side anterior interosseous nerve transfer. Thirty patients with severe ulnar neuropathy at the elbow were reviewed. Clinical parameters included preoperative and postoperative Medical Research Council muscle strength, clawing, and degree of wasting. Electrodiagnostic data included compound motor action potential and sensory nerve action potential amplitudes. Summary statistics were used for demographic and clinical data. The t test and Wilcoxon signed rank test were used where appropriate. Average follow-up was 18.6 months. Preoperatively, 20 patients had Medical Research Council less than or equal to grade 1 in hand intrinsics, small finger sensory nerve action potentials were absent in all patients except for three, and average compound motor action potentials were severely reduced (absent in nearly 40 percent) confirming severity. All groups had a statistically significant increase in strength. More than three-quarters of patients noted partial or complete resolution of clawing and intrinsic muscle wasting. Seventy-three percent of patients regained Medical Research Council greater than or equal to grade 3 and 47 percent achieved Medical Research Council greater than or equal to grade 4. Mean time to observation of nascent units was 8.5 months, and 77 percent of patients demonstrated an augmentation of motor unit numbers with forearm pronation on needle electromyography CONCLUSION:: Proximal subcutaneous ulnar nerve transposition when combined with reverse end-to-side anterior interosseous nerve-to-ulnar nerve transfer demonstrates significant clinical and electrodiagnostic improvement of intrinsic muscle function. Therapeutic, IV.

Sensory Nerve Conduction Study with Inching Test in Palmar Digital Neuropathy.

Mild palmar digital neuropathy may be underestimated because selective nerve conduction studies (NCS) of the palmar digital nerve are challenging. We herein report two cases of palmar digital neuropathy. We performed sensory NCS in each finger using the standard approach. Both cases showed a decrease in the amplitude of sensory nerve action potential (SNAP) in the localized finger. Furthermore, the sensory nerve inching test identified the lesion site. When performing NCS in patients with finger sensory impairment, we recommend recording the SNAP in each finger using standard NCS at the wrist, as well as sensory nerve inching testing.

Gluten neuropathy: electrophysiological progression and HLA associations.

Gluten neuropathy (GN) is the term used to describe peripheral neuropathy that occurs in patients with gluten sensitivity (GS) or coeliac disease (CD) in the absence of other risk factors. We aimed to describe the neurophysiological progression rate of GN across time and look into the potential role of genetic susceptibility in its development. This is a cohort study of 45 patients with GN with a mean follow-up period of 8 ± 5years. The assessments included clinical and neurophysiological data and HLA-DQ genotyping. The mean age at diagnosis was 60 ± 12years. The majority of patients had a length-dependent neuropathy (75.6%), whereas the rest were diagnosed with sensory ganglionopathy (SG). DQA1*02-positive patients were more likely to suffer with SG compared to the DQA1*02 negative patients (60% versus 13.8%, p = 0.009). There was also a trend for statistical significance regarding the DQB1*06 allele and the DQA1*01/DQB1*06 haplotype were found more frequently in patients with GN than in healthy controls (p = 0.026 and p = 0.047, respectively). A linear effect of time on the neurophysiological findings was found in radial sensory nerve action potential (1.9% mean annual decrement, p = 0.036), sural sensory nerve action potential (3.3% mean annual decrement, p = 0.013) and tibial nerve motor compound action potential (6.5% mean annual decrement, p < 0.001) amplitudes, independently from age or gender. GN is a late manifestation of GS and CD. The majority of patients have the length-dependent neuropathy with a linear deterioration over time. HLA genotyping of GS and CD patients who suffer from neuropathic symptoms is recommended as it can help identifying patients at risk for developing SG.

Implanted High Density Cuff Electrodes Functionally Activate Human Tibial and Peroneal Motor Units Without Chronic Detriment to Peripheral Nerve Health

Peripheral nerve stimulation via multi-contact nerve cuff electrodes (NCEs) has proved effective in restoring function to individuals with lower-extremity paralysis. This study investigates clinical measures of nerve health over one year post-implantation of a composite flat-interface nerve electrode (C-FINE) on the tibial and peroneal nerves above the knee in a human volunteer. This represents the first deployment of a novel NCE on new neural targets in a uniquely challenging location prone to prolonged externally applied forces, making acute and chronic postoperative observation critical. A 27-year-old man with an incomplete spinal cord injury (AIS C) at the C3 to C4 level received eight-contact C-FINEs bilaterally on the tibial and peroneal nerves, proximal to the knee. Access to four contacts per cuff exhibiting the most desirable responses was externalized via temporary percutaneous leads. Percutaneous leads were later removed, with contacts generating the best dorsiflexion (two of four) and plantar flexion (one of four) reconnected to a permanently implanted pulse generator. For 13 months post-implantation, nerve health and cuff performance were assessed through motor nerve conduction velocity (MNCV) studies, clinical needle electromyography, compound motor action potential (CMAP), sensory nerve action potential (SNAP), stimulation-evoked tetanic moment collection, and lower-limb circumference measurements. Tibial and peroneal MNCVs remained stable bilaterally above 40 m/sec, with CMAPs increased or stable after six months. SNAPs remained stable across all measurements. CMAP initial charge thresholds remained below 50 nC, with minimal changes to muscle recruitment order in three of four externalized contacts per cuff. Peak tetanic moments remained stable, with bilateral increases in thigh and calf circumferences of 5% and 14% over one year. Above-knee tibial and peroneal NCEs can restore stimulated ankle-joint function without chronic nerve health detriments. Alongside previous femoral nerve data, this study demonstrates the ability of NCEs to enhance lower-extremity function with limited neuromuscular impact.

Electrophysiological evaluation in 4 patients with diabetic pseudotabes

BACKGROUNDResearches on diabetic nervous system lesion are mainly focus on peripheral nerve and vegetative nerve, so there are few investigations on diabetic pseudotabes. OBJECTIVETo investigate the electrophysiological examinations on the diagnosis of diabetic pseudotabes. DESIGNCase study. SETTINGDepartment of Electrophysiology and Department of Neurology, Zhongshan Hospital Affiliated to Xiamen University. PARTICIPANTSA total of 4 patients with type 2 diabetes mellitus, including 3 males and 1 female aged from 50 to 72 years, were selected from Department of Neurology, Zhongshan Hospital Affiliated to Xiamen University from March 2002 to February 2005. All accepted subjects met the modified diagnostic criteria of diabetes mellitus, which was set by American Diabetes Mellitus Association (ADA) in 1997. Otherwise, the subjects had typical symptoms and physical signs of spinal posterior funiculus damage. However, patients with spinal cord lesion which was caused by other factors were excluded. All accepted subjects provided the confirmed consent. METHODSNicolet NT electromyography (EMG)/evoked potential meter (made in the USA) was used to detect spinal cord conduction velocity (SCCV), somatosensory evoked potential (SEP) of lower limbs, motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) of extremities. Determining criteria: Measurements were performed based on the laboratory standards. SCCV, which was less than lower limit of normal value (T2–12: 40 – 55 m/s, T12 – L4: 20 – 41 m/s, T2 – L4: 36 – 45 m/s), was regarded as abnormal. SEP value of lower limbs: P40, P60 and PF, which were more than standard deviation of normal value (x+2.5), were regarded as the abnormality. Normal value of P40, P60 and PF latencies (x±s) in this study: P40, P60 and PF in males were (37.6±1.9) ms, (59.8±3.9) ms and (7.6±0.9) ms, respectively; meanwhile, those in females were (35.5±1.7) ms, (55.2±2.7) ms and (6.3±0.7) ms, respectively. MNCV and SNCV, which were less than 50 m/s in upper limbs and 40 m/s in lower limbs, were regarded as the abnormality. MAIN OUTCOME MEASURESElectrophysiological examinations. RESULTSAll 4 patients with type 2 diabetes mellitus were involved in the final analysis. (1) SCCV: Among 4 patients, SCCV of three patients was decreased in T2 – 12, T12 – L4 and T2 – L4, and that of the other one was decreased in T2–12 and T2 – L4; however, SCCV in T12 – L4 was normal. There was significant difference as compared with normal value (P < 0.01). (2) SEP of lower limbs: SEP values of lower limbs were abnormal in all 4 patients. Among them, P40, P60 and PF latencies of two patients were delayed; P40 of one patient was delayed and PF was not drained out; P40 and P60 of the last one were delayed and PF was normal. (3) MNCV and SNCV: The MNCV and SNCV were normal in one patient and abnormal in three patients. The results demonstrated that MNCV and SNCV of extremities decreased; especially, sensory nerve action potential (SNAP) of both lower extremities of one patient were not drained out. CONCLUSIONDetections of SCCV, SEP of lower limbs, MNCV and SNCV of extremities are helpful to investigate whether peripheral nerve and deep sensory passage are damaged or not and determine whether deep sensory damage is caused by peripheral nerve and spinal posterior funiculus.

Comparison of Corticosteroid Injection Dosages in Mild to Moderate Idiopathic Carpal Tunnel Syndrome: A Randomized Controlled Trial

ObjectivesTo evaluate whether the therapeutic effect of ultrasound-guided injections with 10 mg or 40 mg triamcinolone acetonide (TA) was dose-dependent in patients with idiopathic mild to moderate carpal tunnel syndrome (CTS). DesignProspective, double-blind, randomized controlled study with 12 weeks of follow-up. SettingRehabilitation outpatient clinic of a single medical center. ParticipantsPatients with CTS (N=56). InterventionParticipants were randomly assigned to 2 treatment groups for injection: (A) 40 mg TA+2% lidocaine hydrochloride or (B) 10 mg TA+2% lidocaine hydrochloride. Main Outcome MeasuresParticipants were evaluated using visual analog scale (VAS) and Boston Carpal Tunnel Questionnaire (BCTQ, including Symptom Severity Scale [SSS] and Functional Status Scale [FSS]) at baseline and 6 and 12 weeks after injection). Nerve conduction studies, including parameters of distal motor latency, amplitude of compound motor action potential, amplitude of sensory nerve action potential and sensory nerve conduction velocity of median nerve, and the patient’s subjective impression of improvement, were recorded before injection and 6 and 12 weeks after injection. ResultsNo significant differences were observed in baseline demographic characteristics and clinical evaluations. The parameters in group A and B at baseline, 6 weeks, and 12 weeks were (1) SSS: 2.17±0.14, 1.19±0.04, and 1.34±0.09 and 1.87±0.11, 1.21±0.07, and 1.26±0.04; (2) FSS: 1.63±0.07, 1.27±0.06, and 1.33±0.08 and 1.50±0.10, 1.18±0.05, and 1.26±0.05; (3) VAS: 6.4±0.3, 2.2±0.3, and 3.0±0.1 and 6.7±0.3, 2.0±0.3, and 3.1±0.3, respectively, and significantly decreased after 6 and 12 weeks in both treatment groups (P<.05). All parameters of nerve conduction studies improved in both groups after 12 weeks (P<.05). VAS, BCTQ, and nerve conduction studies did not show significant intergroup differences after 6 and 12 weeks. ConclusionIn patients with idiopathic mild to moderate CTS, ultrasound-guided injection with 10 and 40 mg TA yield similar improvements in BCTQ, VAS, and nerve conduction studies at the 12-week follow-up.

Normal neurophysiologic parameters of the median nerve among adult healthy Sudanese population

Background: Nerve conduction studies (NCSs) help in delineating the extent distribution of neural lesion, and the diagnosis of peripheral nerve disorders. Because normative nerve conduction parameters were not yet established in Sudan EMG laboratories, this study aims towards having our own reference values, as we are using the American and British parameters. This will allow avoiding the discrepancies that might be induced by many factors. Methods: NCSs were performed in 200 Median nerves of 100 adult healthy Sudanese subjects using standardized techniques. Results: The median SNAP (sensory nerve action potential) values were as follows: distal latency, 2.6±3 ms with a range of (2.3-2.9); peak latency, 3.5±0.5 ms (3.0-4.0); amplitude, 47.7±18.0μV (29.7-65.7); conduction velocity, 53.0±7.8 m/s (45.2-60.8). The following values were obtained for the Median nerve CMAP (compound muscle action potential) at wrist stimulation: distal latency, 3.5±0.5 ms with a range of (3.0-4.0); peak latency, 9.4± 1.0 ms (8.4-10.4); duration, 5.9±0.9 ms (5.0-6.8); amplitude, 12.3±2.5 mV (9.8-14.8); area, 43.0±10.4 mVms (32.6-53.4); conduction velocity, 63.6±6.2 m/s (57.4-69.8). The F wave was 28.4±1.8 ms (26.6-30.2). Conclusion: The overall mean sensory and motor nerve conduction parameters for the tested nerve compared favorably with the existing literature with some discrepancies that were justified.

Median and ulnar nerve functions in taxi/microbus drivers and helpers in Kathmandu

Background: Occupational drivers are exposed to various stressors such as ergonomic restriction, whole body vibration, vehicle exhaust and dust exposure. Drivers are reported to have higher rates of morbidities, especially of the musculoskeletal and peripheral nervous systems. Reports on drivers’ nerve functions by specific electrodiagnostic methods are lacking.&#x0D; Objectives: To compare electrophysiologic parameters of median and ulnar nerves in drivers with other population.&#x0D; Methodology: In a cross-sectional comparative study, nerve conduction study was performed in median and ulnar nerves in three groups of participants – Drivers (driving taxi/microbus for at least six months), Helpers (microbus conductors for at least six months) and Controls (college staff/students). Parameters for sensory nerve action potentials and compound motor action potentials were compared among groups by ANOVA and right versus left sides within groups by paired t test.&#x0D; Results: The study involved 145 male participants – 51 Drivers, 34 Helpers and 60 Controls. Compared to drivers and helpers, conduction velocity of nerves was significantly higher in controls for sensory component of all nerves (p values for right median = 0.001, left median = &lt;0.001, right ulnar = &lt;0.001 and left ulnar = 0.019) and motor component of right ulnar nerve (p=0.002). In right-left comparisons, conduction was slower in left median sensory than right (p=0.001) and right ulnar sensory than left (p=0.015) in the helpers but not significant in other groups.&#x0D; Conclusion: Electrophysiological evidences of afflictions of median and ulnar nerves are detectable in urban taxi/ microbus drivers and helpers with at least six months’ occupational duration.

Clinical and neurophysiological correlation in axonal and demyelinating polyneuropathy

BackgroundThe neurophysiological examination provides valuable pathophysiological information for the diagnosis, prognosis, and therapy of patients with polyneuropathy (Fuglsang- Fredriksen A., Pugdahl K. Clin Neurophysilogy 122:440–455, 2011). Nerve conduction study (NCS) is the most objective and reliable measure of peripheral nerve function and is considered the gold standard for the diagnosis of most neuropathies.Aim of the studyTo evaluate the clinical usefulness of nerve conduction study (NCS) in the differentiation between axonal and demyelinating polyneuropathies.MethodsIn the present study, 125 patients with polyneuropathy were studied ranging age from 9 to 79 years. Thirty-six patients were classified as axonal polyneuropathy, 23 patients as demyelinating, and 9 as mixed, while 57 patients were classified as neuropathic. Nerve conduction study (NCS) and electromyography (EMG) were performed using Nihon Kochden electromyography machine with surface recording and stimulating electrodes.ResultsThere is statistically significant linear correlation between reduction in sensory nerve action potential (SNAP) amplitude and decrease in sensory conduction velocity (SCV) of median and ulnar nerves. Also, there is statistically significant inverse correlation between reduction in compound motor action potential (CMAP) amplitude and increase in distal motor latency (DML). There is statistically significant linear correlation between reduction in compound motor action potential (CMAP) amplitude and decrease in motor conduction velocity (MCV). There is statistically significant linear correlation between reduction in compound motor action potential (CMAP) amplitude and decreased grade of power in both axonal and demyelinating polyneuropathy; statistically significant linear correlation was found between decrease in conduction velocity and decrease in grade of power.ConclusionThe present study demonstrates significant correlation between amplitude reduction and conduction slowing in demyelinating as well as axonal polyneuropathy.

Systemic lupus erythematosus may have an early effect on peripheral nerve function in patients without clinical or electrophysiological neuropathy: comparison with age- and gender-matched controls.

Asymptomatic electrophysiological peripheral neuropathy is described in systemic lupus erythematosus (SLE) patients. To determine if SLE could have an even earlier effect on peripheral nerve function even before the development of electrophysiological abnormalities, we compared nerve conduction studies (NCS)of SLE patients without electrophysiological or clinical peripheral neuropathy with healthy controls. Consecutive SLE patients without clinical neuropathy (or other known causes of neuropathy) underwent sensory and motor NCS of all four limbs. Results of 61 patients without electrophysiological criteria of neuropathy were compared with age- and gender-matched controls. Although still within the laboratory's range of normal values, significant differences were found in several NCS parameters between patients and controls. SLE patients had lower amplitudes for ulnar, fibular, and tibial compound muscle action potentials (CMAP) and sural sensory nerve action potentials (SNAP); slower conduction velocities for median, ulnar, and fibular motor nerves, and median, ulnar and sural sensory nerves. SLE patients also had longer minimum F-wave latencies for median, ulnar, fibular, and tibial nerves. H reflexes were more often absent in patients. Correlations were found between the number of disease relapses and motor conduction velocities of the fibular and tibial nerves. SLE may have early effect on peripheral nerve function in patients even before they develop electrophysiological or clinical neuropathy.

P0267CLINICAL MANIFESTATIONS, PREVALENCE AND PREDICTORS OF PERIPHERAL NEUROPATHY IN NON DIABETIC CHRONIC KIDNEY DISEASE PATIENTS. A CROSS SECTIONAL STUDY FROM TERTIARY CARE CENTRE

Abstract Background and Aims There is a progressive increase in the prevalence of chronic kidney disease (CKD). The impairment of functions of kidney secondary to CKD leads to uraemia. Peripheral neuropathy is one of the common manifestations of uraemia. The present study focuses on the prevalence, clinical manifestations and predictors of peripheral neuropathy in patients with non-diabetic CKD. Method This was a cross sectional study conducted in the Department of General Medicine, Maharaja Krishna Chandra Gajapathi Medical College and Hospital, Berhampur, Odisha, India from October 2015 to October 2017. Patients with serum creatinine &amp;gt;2 mg/dl, estimated glomerular filtration rate &amp;lt;60 ml/min (calculated by using Modification of Diet in Renal Disease equation), kidney size &amp;lt; 8.5cm on ultrasound abdomen were included in the study and patients with age less than 18 years, patients with diabetes mellitus and other recognizable risk factors for peripheral neuropathy (Alcoholism, Drugs, Connective tissue disorders, Sarcoidosis, Vasculitis, Thyroid dysfunction, HIV, Hansen’s disease, Paraneoplastic disease etc.) and patients on dialysis were excluded. Peripheral neuropathy was assessed by both clinical methods and nerve conduction studies (NCS). Reduced motor nerve conduction velocity, delayed distal latency, fall in the amplitude of compound muscle action potential on Motor Nerve Conduction Study (MNCS) and delay in the peak latencies, reduced sensory nerve action potential on Sensory Nerve Conduction study (SNCS) were considered as evidence for peripheral neuropathy. From upper limb, median nerve and ulnar nerve were selected for MNCS and SNCS. From lower limb, common peroneal and posterior tibial nerves were selected for MNCS and sural nerve was selected for SNCS. Results Total 109 patients were included in the study and 75(68.8%) were proved to have peripheral neuropathy. Majority of the affected patients were in 40 to 50 years age group (n=24;32%). Forty four of 75 (58.6%) were males and 31(41.33%) were females. Patients with both sensory and motor neuropathy were 35(32.1%), 26(23.9%) were affected with only sensory neuropathy, while 14(12.8%) were affected with only motor neuropathy. Patients with clinical neuropathy (patients who have clinical symptoms and signs of neuropathy and also evidence on NCS) were 35(46.6%) and with subclinical neuropathy (only evident on NCS) were 40(53.3%).On univariate analysis, age (p-0.015), hypertension (p-0.031), duration of disease (p&amp;lt;0.0001), serum creatinine (p&amp;lt;0.0001), eGFR (p&amp;lt;0.0001), serum uric acid (p&amp;lt;0.0001), serum parathyroid (p&amp;lt;0.0001), serum phosphorus (p&amp;lt;0.0001), serum calcium (p-0.0003), serum magnesium (p-0.0002) and serum potassium (p-0.0028) were significantly correlated with peripheral neuropathy however on logistic regression analysis, sex [OR-0.058;95%CI(0.004-0.831)], serum parathyroid hormone [OR-1.032;95%CI(2.708-6043.5)], serum phosphorus[OR3.881;95%CI(1.114-13.524)], serum magnesium [OR-127.28;95%CI(0.901-1.113)] and duration of CKD[OR1.109;95%CI(1.005-1.224)] were shown to be independent predictors. Conclusion Peripheral neuropathy is one of the frequent complications of uremia. Subclinical presentation is most common. Serum parathyroid, serum phosphorus, serum magnesium and duration of disease are independent predictors of uremia induced peripheral neuropathy

Disulfiram induced bilateral foot drop; an under-recognised cause for peripheral neuropathy

Disulfiram is commonly used in chronic alcoholics as an effective treatment. We report a case of a 50 years old Irishman who was on disulfiram for the last nine years. He developed progressive bilateral foot drop, which started with one foot and later on progressed to bilateral involvement over a period of eight months. Our case report highlights the need to take into consideration disulfiram as one of the possible causes of peripheral neuropathy, which is a rare side effect of this drug.&#x0D; Abbreviations: Abductor Digiti Minimi – ADM; Extensor Digitorum Brevis – EDB, Abductor Hallucis – AH; Antinuclear antibodies - ANA; Ribonucleoprotein – RNP; Cerebrospinal fluid – CSF; Non-recordable – NR; Electromyography – EMG; Flexor digitorum indicis – FDI; Sensory nerve action potential - SNAP&#x0D; Citation: Mansoor S, Murphy K, Kelly S. Disulfiram induced bilateral foot drop; an under-recognised cause for peripheral neuropathy. Anaesth pain intensive care 2020;24(1):__&#x0D; DOI: https://doi.org/10.35975/apic.v24i1.&#x0D; Received – 28 December 2019;&#x0D; Reviewed – 10 January 2020;&#x0D; Accepted - 10 January 2020;

A nerve conduction study predicts the prognosis of sporadic amyotrophic lateral sclerosis.

To clarify the relationship between nerve conduction study (NCS) and prognosis in patients with amyotrophic lateral sclerosis (ALS). We included 190 patients with sporadic ALS. We used onset age, sex, onset site (bulbar vs. spinal), revised El Escorial criteria category (definite vs. others), and the King's clinical systems, and the Milano-Torino (MiToS) functional staging systems, and decline rates of revised ALS functional rating scale (ALSFRS-R) as known prognostic factors. An NCS was performed on the median, ulnar, tibial, and sural nerves. The endpoint was death or the introduction of tracheostomy positive-pressure ventilation. Multivariate analysis for each NCS variable, known prognostic factors was performed using Cox stepwise proportional hazards analysis. Univariate analysis was performed for NCS variables that showed a significant association with prognosis in multivariate analysis. Survival was analyzed with a Kaplan-Meier curve and log-rank test. The Cox model identified the compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes of the median nerve as prognostic factors. In the log-rank test, patients with higher median nerve CMAP amplitude had a significantly better prognosis than those with lower amplitude, regardless of age. And prognosis was better in the group with lower median nerve SNAP amplitude only in patients younger than the 25th percentile (~ 57years). CMAP and SNAP amplitudes of the median nerve are considered to be independent prognostic factors of sporadic ALS.

Sciatic neuropathy with preserved sensory nerve action potentials, a case series

Background: Sciatic neuropathy is differentiated from lumbosacral radiculopathy based on the finding of abnormal sensory nerve action potentials (SNAPs). Cases of sciatic neuropathy with intact SNAPS have not been well described.&#x0D; Methods: A retrospective analysis of 12 patients with sciatic neuropathy in a single institution.&#x0D; Results: We describe 12 patients in whom a sciatic neuropathy was diagnosed based on a combination of history, physical exam, radiological and electrodiagnostic (EDX) findings. Lower extremity SNAPs were found to be within normal range in all patients, although SNAP amplitude asymmetry between both sides was observed in 3. Included patients were young (mean age of 40.3 years) and mostly female (9 patients).&#x0D; Conclusions: Sciatic neuropathy may occur with a relative sparing of sensory fibers. Recognition of this group of patients should help to avoid making a misdiagnosis of lumbosacral radiculopathy.

Frequency of Electrodiagnostically Measurable Berrettini Anastomosis.

Ulnar sensory palmar crossover to digit three (D3), the Berrettini anastomosis, is measurable in routine electrodiagnostic nerve conduction studies. The crossover is reported as occurring in 60% of anatomic dissections, but the frequency of measurable ulnar crossover to D3 and its potential as a nerve conduction pitfall is not established. The purpose of this article was to present descriptive statistics regarding the frequency of measurable Berrettini anastomosis in nerve conduction studies. A retrospective chart review and data analysis was completed on 248 patients representing 411 extremities with a main outcome measure of ulnar sensory stimulated nerve conduction simultaneous waveform recording on D3 and digit four (D4). Consistent electrodiagnostic technique with waveform recording data analysis in a private practice and independent university waveform verification was completed on sequential patients referred for upper extremity electrodiagnostic testing. Measurable ulnar stimulated D3 sensory nerve action potentials were demonstrated in 34% of patients with amplitudes of 27%, the simultaneously recorded corresponding ulnar D4 amplitudes representing electrophysiological evidence of ulnar sensory crossover. The Berrettini anastomosis can frequently be seen as a small amplitude sensory nerve action potential response, but at times can be observed with an amplitude greater than 10 μV. It is possible that patients with an absent or significantly delayed median nerve response may have simultaneous inadvertent spread of stimulus to ulnar axons measurable on D3 that may be interpreted as a falsely normal response. All electromyographers need to be aware of this potential pitfall.