Nerve Conduction Study Findings Research Articles

Subscapularis integrity, function and EMG/nerve conduction study findings following reverse total shoulder arthroplasty

BackgroundDuring reverse total shoulder arthroplasty, the functionality of the subscapularis remains unknown. The purpose of this study was to determine the integrity and function of the repaired subscapularis after reverse total shoulder arthroplasty using ultrasound, electromyography (EMG), and nerve conduction studies (NCS) to assess postoperative tendon healing, muscle, and nerve function.Materials and methodsPatients who underwent reverse total shoulder arthroplasty and repair with minimum 6-month follow-up were included in the study. Patient-reported outcome, physical examination, ultrasound examination of the subscapularis tendon, subscapularis EMG, and lower subscapular NCS were performed. In addition, contralateral subscapularis ultrasound, EMG, and lower subscapular nerve nerve NCS were performed to establish normative values (abnormal defined at >20% increased latency or >50% decreased amplitude). Phi coefficients of association and point biserial coefficients were used to correlate the ultrasound examination, EMG, and NCS results with the functional outcomes.ResultsA total of 20 patients were included. Four patients had abnormal but intact subscapularis tendons on ultrasound. Nine patients had abnormal lower subscapular NCS compared with the contralateral shoulder. All patients had normal subscapularis EMGs. No significant correlation was found between the ultrasound and NCS results. No significant correlations were found between the ultrasound or the NCS results and any of the independent outcome variables.ConclusionThis study demonstrates that the subscapularis remains neurologically functional after reverse total shoulder arthroplasty, based on EMG and NCS findings. Although side-to-side differences in lower subscapular NCS were identified in 45% of the postoperative shoulders, these abnormalities did not correlate with functional outcomes.

Characteristics of forearm mixed nerve conduction study in carpal tunnel syndrome: Comparison with ultrasound assessments

This study aimed to characterize forearm mixed nerve conduction study (NCS) findings in carpal tunnel syndrome (CTS). Eighty-two patients with CTS and 48 healthy controls were enrolled. We directly compared the forearm mixed NCS and ultrasonography results from CTS patients with those from the controls. Correlation analyses were performed to identify the relationship between forearm mixed NCS parameters and ultrasound measurements in CTS. We observed reduced forearm mixed nerve amplitude and increased cross-sectional area (CSA) of the median nerve at the proximal carpal tunnel (CT) inlet in CTS. The forearm mixed nerve amplitude negatively correlated with the CSA at the proximal CT inlet. We found a negative correlation between Bland's neurophysiological grade and the forearm mixed nerve amplitude as well as a positive correlation between the CSA of the median nerve at the proximal CT inlet and Bland's neurophysiological grade. We confirmed that the reduced median mixed nerve amplitude is the distinguishing feature of forearm mixed NCS in CTS. Our findings suggest that the forearm mixed NCS is potentially useful in evaluating its severity.

Potential Risk of Developing Peripheral Neuropathy in Heavy Motor Vehicle Driving: A Cross-sectional Study

Introduction: There is a growing concern regarding increasing road traffic accidents due to overburdened drivers, which also affect their general health. Drivers maintain the extreme position of arm, forearm, and legs which during distant journeys may put increased constraint on nerves passing in forearm and legs in addition to the vibrations transmission i.e., Hand Arm Vibration Syndrome (HAVS) and Foot Transmitted Vibration (FTV). Aim: To find out if chronic repeated movements at wrist and foot along with vibration transmitted from steering wheel and pedals influence the nerve conduction parameters and to find out which nerves are more prone to neurological conduction defects. Materials and Methods: A cross-sectional study was conducted over a period of two years in Neurophysiology Lab, Department of Physiology, JN Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India. Mean peak sensory and motor latency, mean motor and sensory Nerve Conduction Velocity (NCV), Sensory Nerve Action Potential (SNAP) and Compound Muscle Action Potential (CMAP) of median, ulnar and common peroneal nerve in Professional Heavy Vehicle Drivers (PHVD) was compared with non-drivers using Medicaid System’s (Electromyography) EMG/ (Nerve Conduction Velocity) NCV equipment with Neuroperfect Software. Student’s unpaired t-test was used to assess the significance of difference in nerve conduction study findings. Results: Heavy vehicle drivers showed slow Sensory Nerve Conduction Velocity (SNCV) (drivers: 51.40±3.30, non-drivers: 53.66±3.60 in right hand p-value 0.0001) and (drivers: 52.51±3.78, non-drivers: 53.87±3.61 in left hand p-value=0.0145) and increase in sensory latency (drivers: 3.71±0.72, non-drivers: 2.89±0.56 in right hand p-value<0.0001 and drivers: 3.4±0.81 non-drivers: 2.76±0.70 in left hand p-value <0.0001) of median nerve. Ulnar nerve sensory latency was prolonged (drivers: 2.98±0.52, non-drivers: 2.76±0.42 in right hand p-value 0.0021 and drivers: 2.97±0.42, non-drivers: 2.80±0.65 in left hand p-value 0.0386) and sural nerve sensory latency was prolonged (drivers: 3.05±0.55, non-drivers: 2.78±0.54 in right leg p-value=0.0011 and drivers: 2.92±0.45, non-drivers: 2.69±0.40 in left leg p-value 0.0004).There was no significant difference in Motor Nerve Conduction Velocity (MNCV), motor latency, SNAP and CMAP of median, ulnar and common peroneal nerve among heavy vehicle drivers in comparison to non-drivers. Conclusion: We conclude that pressure and vibrations transmitted at hand and foot along with repeated movements at forearm wrist and pedals leads to more neurological conduction defects in median nerve than in ulnar and sural nerve. Flexibility in delivery time, incorporating judicious breaks in duty, better ergonomics design may help in improving work conditions of drivers.

Effect of Age and Body Mass Index on Surgical Treatment Outcomes in Patients with Carpal Tunnel Syndrome.

To investigate the effect of age, diabetes mellitus, and body mass index (BMI) on the outcomes of carpal tunnel syndrome (CTS) surgery in patients with moderate CTS according to neurophysiological classification. Postsurgical outcomes were evaluated via a nerve conduction study (NCS) six to nine months after the surgery. Patients were divided into two groups according to neurophysiological classification based on the findings of postsurgical NCS: patients with mild CTS (partial recovery) or normal NCS (complete recovery) were classified as surgical success, and patients with moderate to more severe CTS were defined as surgical failure. Forty-seven patients who underwent surgery for moderate CTS were included in the study. The mean age of the patients with surgical success (47.3 ± 10.9 years) was significantly lower than that of patients with surgical failure (54.3 ± 12.6 years; p=0.048). The mean BMI of the patients with surgical success (31.3 ± 4.03 kg/m2) was significantly lower than that of patients with surgical failure (36.75 ± 5.5 kg/m2; p < 0.001). Multivariate logistic regression analysis demonstrated that higher BMI (p=0.003) and older age (p=0.031) were independent prognostic factors for surgical failure. In addition, there was a statistically significant and strong correlation between postoperative CTS severity and BMI (rho=0.606, p < 0.001). Advanced age and high BMI negatively affect the success of surgical treatment in patients with CTS. Ensuring weight loss before surgery in CTS patients who have high BMI may increase the probability of treatment success.

Electrodiagnostic findings in myotonic dystrophy: A study on 12 patients.

Myotonic dystrophy (DM) is a complex multisystem disease with specific clinical and electrodiagnostic findings. Myotonia can be seen in the distal and proximal muscle groups in upper and lower limbs. There is no established guideline to demonstrate the sensitivity of muscles in the diagnosis of myotonic dystrophy. The aims of this study are to describe common electrodiagnostic findings in patients with DM; and to assess the electrodiagnostic sensitivity of muscles in the diagnosis of DM. In this retrospective study, patients’ age, sex, nerve conduction study findings including common upper and lower limbs nerve functions, and needle examination findings were collected and analyzed. A descriptive analysis (with percentage) was performed on the data obtained from the charts. NCS analysis showed more than half of patients had normal sensory and motor NCS findings. In 11 over 12 patients, sensory NCSs were within normal limits. Only one patient showed abnormal sensory responses. The most common abnormal NCS findings were decreased amplitude with normal latency and normal conduction velocity. The needle analysis showed distal muscles including first dorsal interosseous, abductor policies brevis, tibialis anterior, medial gastrocnemius and peroneal longus muscles are more sensitive in detecting myotonic discharges than proximal muscles including deltoid, triceps, vastus medialis and vastus lateralis. Our findings showed sensory nerve responses were usually within normal limits. The most common NCS abnormality showed decreased motor nerve amplitudes. The needle test showed myotonic discharges were more prominent in the distal muscles in upper and lower limbs.

Electrophysiological findings of acroparesthesia: A single center experience

Acroparesthesia is abnormal sensory experiences in the extremities, especially in hands and feet, and is one of the most common symptoms encountered in the neurology outpatient clinic. It is caused by diverse medical conditions and even in a normal situation. Because exact diagnosis is very important to manage it properly, a variety of tests including nerve conduction study (NCS) should be considered. The purpose of this study is to know the electrophysiological findings in patients with acroparesthesia. 159 patients with acroparesthesia were recruited from January 2018 to December 2018 at the neurology outpatient clinic of a tertiary hospital. Demographics, clinical manifestations, associated medical conditions and laboratory findings including NCS were analyzed. NCS was normal in 98 patients (61.6%). Predictive factors of normal NCS findings were younger age, female gender, partial involvement of symptom, symptom onset after cold exposure, intermittent symptom episodes and emotional anxiety (p<0.05). In contrast, fine motor symptoms, a history of diabetes or renal disease were significantly associated with abnormal NCS in the patients with acroparesthesia. A thorough understanding of clinical history and symptom patterns in the patients with acroparesthesia would be able to afford valuable information regarding to the necessity of NCS to find a cause

Ultrasonography Provides a Diagnosis Similar to That of Nerve Conduction Studies for Carpal Tunnel Syndrome.

Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy. Its diagnosis is based on clinical symptoms and neurophysiological evaluation. Recently, ultrasonography has been introduced as a promising noninvasive diagnostic alternative. In this study, the authors compared ultrasonography with neurophysiological findings for the diagnosis of CTS in 96 patients/hands with clinical symptoms of CTS. The latency, amplitude, distance, and velocity of the median and ulnar nerves were measured. Needle electromyography was performed in the abductor pollicis brevis, in addition to muscles of the arm and forearm, to exclude proximal median nerve, brachial plexus, or radicular abnormalities. Ultrasonography was based on the morphologic/anatomic changes of the median nerve cross-sectional area in the sagittal plane of the wrist at the level of the pisiform bone, the changes of its regional echogenicity, and the identification of coexisting pathologies, such as tenosynovitis, space-occupying lesions, supplementary muscles, and vessels, that may provoke indirectly an increase of the pressure in the carpal tunnel. Eighty-seven (90%) of the 96 patients/hands with clinical symptoms of CTS showed positive findings in both ultrasonography and nerve conduction studies. Six (6%) patients showed positive findings only in nerve conduction studies, and 3 (3%) patients showed positive findings only in ultrasonography; the difference was not statistically significant. The sensitivity and the specificity of nerve conduction studies compared with ultrasonography was 97% and 89% compared with 94% and 55%, respectively. A positive correlation and proportional increase of the ultrasonography measurements compared with the increase of the nerve conduction studies severity was observed. [Orthopedics. 2019; 42(5):e460-e464.].

Hallazgos clínico-neurofisiológicos en neuropatías hereditarias sensibles a la presión con deleción del cromosoma 17p11.2

IntroductionHereditary neuropathy with liability to pressure palsy (HNPP) is an autosomal dominant disorder, typically presenting with recurrent episodes of mononeuropathy in nerves susceptible to compression, with similar neurophysiological characteristics. However, other clinical and neurophysiological presentations have been reported. MethodsWe retrospectively analysed the clinical and neurophysiological characteristics of 20 patients with genetically confirmed HNPP. Sixteen patients were studied in our department between 1996 and 2016. ResultsIn addition to the typical characteristics of HNPP, we found atypical forms including recurrent positional sensory symptoms in 3 patients, chronic sensorimotor polyneuropathy in one, and non-progressive mononeuropathy in one. Onset was early in 2 patients: one at the age of 7 years, with common peroneal nerve injury, and another at birth, with brachial plexus involvement. By frequency, the main pathological findings in the nerve conduction study were: decreased sensory nerve conduction velocity in the sural (84%) and the median and superficial peroneal nerves (94%); decreased motor nerve conduction velocity in the ulnar nerve through the elbow (97%), and increased motor distal latency of the median and deep peroneal nerves (74%). ConclusionOur results confirm the clinical variability of HNPP, with the most frequent nerve conduction study findings being the generalised decrease in sensory nerve conduction velocity, in addition to motor involvement, mainly in locations susceptible to nerve compression. The nerve conduction study can detect typical, atypical, and asymptomatic cases of HNPP.

Can we accurately predict nerve conduction study outcome using a carpal tunnel syndrome questionnaire?

NCS are often routinely performed for CTS despite recommendations from the BOA, BSSH and NICE that they are associated with increased costs and prolonged waiting times. This prospective study aimed to assess if the Kamath and Stothard clinical questionnaire could accurately predict nerve conduction study (NCS) results when diagnosing carpal tunnel syndrome (CTS).Eighty-eight patients referred with signs and symptoms of CTS from September 2016 to February 2017 were included. All patients were assessed by specialist hand therapists using the Kamath and Stothard carpal tunnel questionnaire (CTQ) and all patients independently underwent NCS by neurophysiologists. We compared results of CTQ score versus NCS findings. Results showed that a CTQ score of less than 3 correlated 100% to negative NCS. When the CTQ score was more than or equal to 5, 90% of patients had a positive NCS result. For patients with a CTQ score of 3 or 4, the NCS could not be reliably predicted. These findings suggest that the Kamath and Stothard CTQ is a useful tool in determining which patients may require NCS. We suggest that only patients with a CTQ score of 3 or 4 and with equivocal signs and symptoms should undergo NCS. The questionnaire has the potential to be used as a primary tool for diagnosing CTS, with significant cost savings and reduction in waiting times for NCS.

Role of superficial peroneal sensory potential and high-resolution ultrasonography in confirmation of common peroneal mononeuropathy at the fibular neck

BackgroundCommon peroneal mononeuropathy at the fibular neck (CPN) is one of the most frequent neuropathies of the lower extremities. Nerve conduction studies (NCS) have been used to confirm the diagnosis of CPN and localize common peroneal nerve abnormalities. High-resolution ultrasonography (HRUS) can aid in assessing the size of the common peroneal nerve.AimWas to evaluate the superficial peroneal sensory potential (SPSP) and HRUS role in the confirmation of CPN.MethodsThis study was conducted on 70 patients presented with clinical and motor electrophysiological evidence of common peroneal neuropathy at the fibular neck and 70 controls. Clinical assessment, electrophysiological evaluations, and HRUS at the fibular neck were done.ResultsAll the patients were electrophysiologically proven to have common peroneal motor neuropathy at the fibular neck, and seven of them showed abnormalities in nerve conduction studies only. The patients showed smaller common peroneal nerve motor and sensory responses and much larger cross-sectional area (CSA) of the common peroneal nerve at the fibular neck when compared with the controls. NCS and EMG positive findings are the most significant factor related to the increased HRUS CSA. Affected SPSP is significantly detected in patients with axonal affection. CSA of common peroneal nerve at the fibular neck showed a significant positive correlation with body mass index, motor, and sensory latencies. Also, it showed a significant negative correlation with motor and sensory amplitudes. HRUS CSA localized the lesion at the fibular neck with sensitivity and specificity 83% and 53% respectively. CSA plus SPSP affection sensitivity and specificity in confirming CPN were 91.9% and 89%.ConclusionHRUS CSA plus affected SPSP improve the diagnosis of CPN compared to standard electrophysiological criteria.RecommendationFurther studies on a wider scale for detection of their role in the prediction of prognosis in CPN.Trial registrationClinicalTrials.gov NCT03753178 (26-11-2018)

Prevention of chemotherapy-induced peripheral neuropathy with classical massage in breast cancer patients receiving paclitaxel: An assessor-blinded randomized controlled trial.

This assessor-blinded, prospective, randomized controlled clinical trial aimed at investigating the effect of classical massage on chemotherapy induced peripheral neuropathy and the quality of life (QOL) in breast cancer patients receiving adjuvant paclitaxel. A total of 40 female breast cancer patients were randomly allocated to the classical massage group (CMG) or the control group (CG). Classical massage was applied to the patients in the CMG before each paclitaxel infusion. The CG received only usual care. Presence of peripheral neuropathic pain and QOL were assessed at baseline and weeks 4, 8, 12, and 16. Nerve conduction studies (NCS) findings were also recorded at baseline and week 12. The peripheral neuropathic pain was lower in the CMG compared to the CG at week 12 (p < 0.05). The sensory and motor sub-scale scores of the QOL measure showed statistically significant differences over time in favor of the CMG (p < 0.05). Sensory action potential amplitude of the median nerve was significantly higher and the tibial nerve latency was significantly shorter in the CMG compared to the CG at week 12. This study suggested that classical massage successfully prevented chemotherapy-induced peripheral neuropathic pain, improved the QOL, and showed beneficial effects on the NCS findings.

Relation between Findings of Nerve Conduction Study and Hand Function in Carpal Tunnel Syndrome

Relation between Findings of Nerve Conduction Study and Hand Function in Carpal Tunnel Syndrome

Severe painful lower limbs and refusal of the leg reliance as atypical presentation of Gullain Barre syndrome

Introduction. Guillain?Barre syndrome (GBS) is the most common cause of acute flaccid paralysis in healthy infants and children. Acute motor axonal neuropathy (AMAN) is a type of GBS characterized by motor syndrome with no sensory symptoms. Case outline. Authors describe a six-and-a-half year old girl with atypical clinical presentation of AMAN with severe painful lower limbs and refusal of the leg reliance with typical findings on nerves conduction studies. Conclusion. Despite the nerve conduction study findings, atypical forms of AMAN and GBS are possible. Pain symptoms must be taken very seriously and treated careful by the clinicians.

Chapter 17 - Normal and abnormal spontaneous activity

Assessment of spontaneous waveforms recorded in a resting muscle during needle electromyography is important to determine the type of underlying neuromuscular disorder, temporal course of a disease, and severity and prognosis. A variety of different spontaneous waveforms may be recorded. Some waveforms may be recording in patients without neuromuscular disorders, such as end-plate activity or fasciculation potentials, while others occur only in abnormal muscles. Fibrillation potentials are the most common abnormal spontaneous waveform and are encountered in a wide variety of neuromuscular disorders causing denervation or damage to muscle fibers. Myotonic discharges, when diffuse, are seen in a small number of myopathies or muscle channelopathies. Complex repetitive discharges are nonspecific spontaneous waveforms that may be encountered in chronic or longstanding neurogenic or myopathic disorders. Myokymic and neuromyotonic discharges are rare spontaneous waveforms that suggest either focal or diffuse peripheral nerve hyperexcitability. When interpreted in conjunction with voluntary motor unit potentials as well as nerve conduction study findings, spontaneous waveforms are useful to fully assess the types of disorders of patients with neuromuscular complaints.

Impact of impaired glucose regulation on the functions of large and small fibers of peripheral nerves

This article analyzes the incidence and characteristics of peripheral neuropathy in patients with impaired glucose regulation (IGR). A total of 120 IGR patients and 60 healthy controls were enrolled. All subjects underwent nerve conduction study (NCS) of large fibers and skin sympathetic response (SSR) and contact heat pain evoked potential (CHEP) testing of small fibers with a Medtronic Keypoint machine (Medoc Ltd., Israel). IGR patients were evaluated using the Michigan Neuropathy Screening Instrument (MNSI). The abnormal rates (MNSI >2) in IGR patients and NCS and SSR evaluations were 18.3%, 22.5%, and 39.2%, respectively. All abnormal NCS findings were accompanied with abnormal SSR findings. Compared with the control group, the sensory nerve action potential wave of the posterior tibial and sural nerve was decreased in the IGR group (P = 0.01, P = 0.00), the SSR wave was reduced in the upper and lower limbs (P = 0.002, P = 0.00), and the CHEP wave was decreased in opisthenar and shank (P = 0.00). Compared with the control group, the CHEP wave was decreased in the shank in the normal SSR group (P < 0.05) and in the opisthenar and shank in the normal NCS group (P < 0.05). IGR patients have peripheral neuropathy characterized by impaired functions of large and small fibers focused on small fiber and lower limb sensory nerves. CHEP can detect small fiber damage earlier than SSR and NCS.

Tafamidis improves bladder function in hereditary ATTR amyloidosis

AbstractA 71‐year‐old man with a family history of hereditary ATTR (ATTRm) amyloidosis, began to have sensory disturbance in his extremities at age 65. Although he had no cardiac or gastrointestinal symptoms, a head‐up tilt test, ultrasound echography, myocardial scintigraphy, and upper gastric biopsy showed abnormality. This, together with the findings of nerve conduction study and gene analysis, confirmed a diagnosis of ATTRm. He was started on 20 mg/day tafamidis meglumine, a transthyretin tetramer stabilizer, and 0.5 mg/day clonazepam, a GABAergic drug. Somatic nerve functions were unchanged or slightly worsened. However, his bladder autonomic nerve function, as assessed by a urodynamic test, showed mild improvements characterized by recovery of bladder sensation and contractility.

SCN11A Arg225Cys mutation causes nociceptive pain without detectable peripheral nerve pathology

ObjectiveThe SCN11A gene encodes the NaV1.9 sodium channel found exclusively in peripheral nociceptive neurons.MethodsAll enrolled participants were evaluated clinically by electrophysiologic studies, DNA sequencing, and punch skin biopsies.ResultsAll affected family members are afflicted by episodes of pain. Pain was predominantly nociceptive, but not neuropathic in nature, which led a diagnosis of fibromyalgia in some patients. All patients had normal findings in nerve conduction studies for detecting large nerve fiber neuropathies and skin biopsies for detecting small nerve fiber pathology.ConclusionsUnlike those patients with missense mutations in SCN11A, small fiber sensory neuropathy, and neuropathic pain, the Arg225Cys SCN11A in the present study causes predominantly nociceptive pain with minimal features of neuropathic pain and undetectable pathophysiologic changes of peripheral neuropathy. This finding is consistent with dysfunction of nociceptive neurons. In addition, since nociceptive pain in patients has led to the diagnosis of fibromyalgia, this justifies a future search of mutations of SCN11A in patients with additional pain phenotypes such as fibromyalgia to expand the clinical spectrum beyond painful small fiber sensory neuropathy.

Guillain-barré Syndrome after Multiple Bee Stings

Severe systemic responses including neurologic complications such as myasthenia gravis, myeloradiculopathy, optic neuropathy, parkinsonism, stroke and Guillain-$barr{acute{e}}$ syndrome can occur after bee stings. This case describes a 78-year-old female who presented with symptoms of acute progressive bilateral symmetrical weakness in both lower legs after multiple bee stings. Nerve conduction study findings were consistent with acute sensorimotor axonal neuropathy and recovered by treatment with intravenous immunoglobulin. This case highlights that bee stings can result in acute onset Guillain-$barr{acute{e}}$ syndrome, although the pathophysiologies of bee venoms need to be investigated accurately.

Correlative study between C-reactive protein, clinical severity, and nerve conduction studies in Guillain-Barr\xe8 syndrome

BackgroundGuillain-Barre' syndrome (GBS) is a serious autoimmune disorder in which the immune system attacks healthy nerve cells of the peripheral nervous system causing polyradiculoneuropathy which leads to weakness, numbness, and tingling, and can eventually cause paralysis. Autoimmune conditions like GBS can induce a high level of inflammation resulting in an increase in the C-reactive protein( CRP) production. The aim of this study is to assess the relationship between CRP level and the clinical severity as well as the electrophysiological findings of nerve conduction studies in patients with GBS.MethodsTwenty- four patients (10 males &14 females) with ages ranged from 14 to 50 years and a mean age of 33.46 ±12.25 years who fulfilled the clinical criteria for diagnosing GBS were recruited within the first 2 weeks of onset of illness, in a cross- section study. They underwent general and neurological examination. Nerve conduction studies as well as assessment of serum CRP level were done.ResultsThere was a statistically significant positive correlation between clinical severity assessed by (Hughes disability scale) and serum CRP level in GBS patients. Multivariate logistic regression analysis showed that both gastroenteritis, cranio-bulbar affection, need for mechanical ventilation (MV), disability score >4, and absent motor and sensory responses were significantly associated with high serum CRP level >6mg/dl.ConclusionsThe results of this study support the hypothesis that in GBS patients, gastroenteritis, craniobulbar affection, need for MV, disability score >4, and absent motor and sensory nerve responses were significantly related to high serum CRP level. This reflects the negative impact of the inflammatory response elicited by high CRP level on clinical severity in GBS patients, and so it may be used as a prognostic marker of clinical severity of GBS and this can help in therapeutic decision making.

O-3-1. Sequential electrodiagnosis can contribute to differentiating subtypes of Guillain-Barré syndrome

Guillain-Barre syndrome (GBS) is divided into two subtypes, which are acute motor axonal neuropathy (AMAN) and acute inflammatory demyelinating polyneuropathy (AIDP), and anti-ganglioside antibodies are considered to be strongly associated with axonal form of GBS. To differentiate subtypes of GBS exactly, utility of sequential electrodiagnosis has been proposed. This is a prospective multi-center study, which was conducted as a part of JET-GBS (Japanese Eculizumab Trial for GBS). To investigate validation of sequential electrodiagnosis for GBS, nerve conduction study (NCS) was conducted twice. First assessment was conducted at within two weeks from onset (first electrodiagnosis). Second assessment was conducted at four weeks later from first assessment, and diagnosis was made by considering sequential changes of NCS findings (sequential electrodiagnosis). Anti-ganglioside antibodies were measured by ELISA. We evaluated the correlation between electrodiagnosis and anti-ganglioside antibody. Thirsty-three patients were analyzed. Although antibody-positive patients were 65% in AMAN and 38% in AIDP at first electrodiagnosis (P = 0.27), sequential electrodiagnosis showed 74% of antibody-positive patients in AMAN and 15% of those in AIDP (P = 0.003). The correlation between electrodiagnosis and anti-ganglioside antibody were increased by sequential electrodiagnosis, which suggests that sequential electrodiagnosis can contribute to differentiating subtype of GBS.