OBJECTIVE: To analyze and compare the characteristics and causes of F wave changes in patients with Charcot-Marie-Tooth1A (CMT1A) and chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: Thirty patients with CMT1A and 30 patients with CIDP were enrolled in Peking University Third Hospital from January 2012 to December 2018. Their clinical data, electrophysiological data(nerve conduction velocity, F wave and H reflex) and neurological function scores were recorded. Some patients underwent magnetic resonance imaging of brachial plexus and lumbar plexus, and the results were analyzed and compared. RESULTS: The average motor conduction velocity (MCV) of median nerve was (21.10±10.60) m/s in CMT1A and (31.52±12.46) m/s in CIDP. There was a significant difference between the two groups (t=-6.75, P < 0.001). About 43.3% (13/30) of the patients with CMT1A did not elicit F wave in ulnar nerve, which was significantly higher than that of the patients with CIDP (4/30, 13.3%), χ²=6.65, P=0.010. Among the patients who could elicit F wave, the latency of F wave in CMT1A group was (52.40±17.56) ms and that in CIDP group was (42.20±12.73) ms. There was a significant difference between the two groups (t=2.96, P=0.006). The occurrence rate of F wave in CMT1A group was 34.6%±39%, and that in CIDP group was 70.7%±15.2%. There was a significant difference between the two groups (t=-5.13, P < 0.001). The MCV of median nerve in a patient with anti neurofascin 155 (NF155) was 23.22 m/s, the latency of F wave was 62.9-70.7 ms, and the occurrence rate was 85%-95%. The proportion of brachial plexus and lumbar plexus thickening in CMT1A was 83.3% (5/6) and 85.7% (6/7), respectively. The proportion of brachial plexus and lumbar plexus thickening in the CIDP patients was only 25.0% (1/4, 2/8). The nerve roots of brachial plexus and lumbar plexus were significantly thickened in a patient with anti NF155 antibody. CONCLUSION The prolonged latency of F wave in patients with CMT1A reflects the homogenous changes in both proximal and distal peripheral nerves, which can be used as a method to differentiate the CIDP patients characterized by focal demyelinating pathology. Moreover, attention should be paid to differentiate it from the peripheral neuropathy caused by anti NF155 CIDP. Although F wave is often used as an indicator of proximal nerve injury, motor neuron excitability, anterior horn cells, and motor nerve myelin sheath lesions can affect its latency and occurrence rate. F wave abnormalities need to be comprehensively analyzed in combination with the etiology, other electrophysiological results, and MRI imaging.
Humans ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/pathology* ; Median Nerve/pathology* ; Ulnar Nerve/pathology* ; Brachial Plexus/pathology* ; Magnetic Resonance Imaging/methods*

BACKGROUND: Multifocal motor neuropathy (MMN), Lewis-Sumner syndrome (LSS), and many chronic inflammatory demyelinating polyradiculoneuropathies (CIDPs) are representative of acquired multifocal polyneuropathy and are characterized by conduction block (CB). This retrospective study aimed to investigate the demyelinating distribution and the selective vulnerability of MMN, LSS, and CIDP with CB (CIDP-CB) in nerves. METHODS: Fifteen LSS subjects (107 nerves), 24 MMN subjects (176 nerves), and 17 CIDP-CB subjects (110 nerves) were included. Their clinical information was recorded, blood and cerebrospinal fluid tests were conducted, and nerve conductions of the median, ulnar, radial, peroneal, and tibial nerves were evaluated. CB, temporal dispersion, distal motor latency (DML), and F-wave latency were recorded, and nerve conduction velocity, terminal latency index, and modified F-wave ratio were calculated. RESULTS: CB was more likely to occur around the elbow in CIDP-CB than in MMN (78.6% vs. 6.8%, P < 0.01) but less likely to occur between the wrist and the elbow than in LSS (10.7% vs. 39.3%, P < 0.05). Tibial nerve CB was most frequently observed in MMN (47.4%, P < 0.05). CIDP-CB was characterized by a prolonged DML in all nerves, and slow motor nerve velocity of the upper limb was significant when CB nerves were excluded (P < 0.05). CONCLUSIONS We report the different distributions of segmental and diffuse demyelination of the ulnar and tibial nerves in LSS, MMN, and CIDP-CB. These distinct distributions could help in differentiating among these conditions.
Humans ; Neural Conduction ; Peripheral Nerves ; Polyneuropathies ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; Retrospective Studies

Electrodiagnostic tests (EDX) is essential for the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP). EDX could provide information about demyelinating pathology in the peripheral nerves. According to phenotypes, CIDP could be classified several phenotypes, which has different clinical manifestations, EDX could present a different distribution pattern of demyelinating lesions. In addition, EDX could be useful markers for predicting treatment response of prognosis of CIDP.
Classification ; Diagnosis ; Electrodiagnosis ; Neural Conduction ; Pathology ; Peripheral Nerves ; Phenotype ; Polyneuropathies ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; Prognosis

Intravenous immunoglobulin (IVIG) is used in treating many cases of autoimmune and inflammatory conditions thanks to its multiple anti-inflammatory and immunomodulatory properties. The clinical use of IVIG has been for the patients with primary immunodeficiencies, but lately it is expanding its usage to the realms of treating patients with neurological conditions. Both the efficacy and safety of IVIG treatment in chronic inflammatory demyelinating polyradiculoneuropathy and Guillain–Barré syndrome have been studied successfully. However, the use of IVIG treatment in other neurological conditions still remains investigational despite several successful reports. Considerable numbers of mechanisms have been suggested in order to explain the effects of IVIG, but the exact mechanisms are not understood yet. This review covers the new developments in clinical fields and the possible ways in which IVIG could help in the future.
Humans ; Immunoglobulins* ; Immunoglobulins, Intravenous ; Neurology ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated progressive or relapsing demyelinating peripheral neuropathy. Other autoimmune diseases may be associated with CIDP. A 38-year-old man developed CIDP, which was subsequently associated with membranous glomerulonephritis (MGN) and tendinitis. He was treated with intravenous immunoglobulin, rituximab, and prednisone, which resulted in improvement of the clinical symptoms. This is a case report of CIDP associated with MGN and tendinitis.
Adult ; Autoimmune Diseases ; Glomerulonephritis ; Glomerulonephritis, Membranous* ; Humans ; Immunoglobulins ; Peripheral Nervous System Diseases ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating* ; Prednisone ; Rituximab ; Tendinopathy*

OBJECTIVETo investigate the role of short-latency somatosensory evoked potential (SSEP) in the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODSA total of 48 children with a confirmed or suspected CIDP and 40 healthy children were enrolled. Nerve electrophysiological examination and/or SSEP examination was performed (the children in the healthy control group only underwent SSEP examination). Four-lead electromyography was used for nerve electrophysiological examination, including at least 4 motor nerves and 2 sensory nerves. N6 (elbow potential), N13 (cervical cord potential), and N20 (cortex potential) of the median nerve and N8 (popliteal fossa potential), N22 (lumbar cord potential), and P39 (cortex potential) of the tibial nerve were observed by SSEP examination.

RESULTSAmong the 48 children with CIDP, 35 had demyelination in both motor and sensory nerves, 8 had demyelination in sensory nerves, and 5 had axonal degeneration. SSEP examination showed that 7 had conduction abnormality in the trunk of the brachial plexus and/or the posterior root and 33 had damage in the lumbosacral plexus and/or the posterior root. The 40 children with abnormal findings of SSEP examination included 8 children with affected sensory nerves and 5 children with secondary axonal degeneration who did not meet the electrophysiological diagnostic criteria for CIDP. Compared with the healthy control group, the CIDP group had significantly prolonged latency periods of N13 and N22 (P<0.05).

CONCLUSIONSSSEP can be used for the auxiliary diagnosis of CIDP, especially in CIDP children with affected sensory nerves or secondary axonal degeneration.

Axons ; physiology ; Child ; Child, Preschool ; Evoked Potentials, Somatosensory ; Female ; Humans ; Male ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; diagnosis ; physiopathology ; Reaction Time

A 77-year-old man developed diplopia, gait ataxia, and paresthesia. A clinical examination also revealed ophthalmoplegia, facial palsy, ataxia of the limbs and trunk, and reduced deep tender reflexes. Laboratory and electrophysiological studies revealed albuminocytological dissociation and demyelination. He was diagnosed as Miller-Fisher syndrome and received intravenous immunoglobulin therapy. His clinical symptoms deteriorated at 12 weeks after onset. We diagnosed acute-onset chronic inflammatory demyelinating polyradiculoneuropathy, and which the patient recovered from following corticosteroid therapy.
Aged ; Ataxia ; Demyelinating Diseases ; Diplopia ; Extremities ; Facial Paralysis ; Gait Ataxia ; Guillain-Barre Syndrome ; Humans ; Immunization, Passive ; Miller Fisher Syndrome* ; Ophthalmoplegia ; Paresthesia ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating* ; Reflex

A 77-year-old man developed diplopia, gait ataxia, and paresthesia. A clinical examination also revealed ophthalmoplegia, facial palsy, ataxia of the limbs and trunk, and reduced deep tender reflexes. Laboratory and electrophysiological studies revealed albuminocytological dissociation and demyelination. He was diagnosed as Miller-Fisher syndrome and received intravenous immunoglobulin therapy. His clinical symptoms deteriorated at 12 weeks after onset. We diagnosed acute-onset chronic inflammatory demyelinating polyradiculoneuropathy, and which the patient recovered from following corticosteroid therapy.
Aged ; Ataxia ; Demyelinating Diseases ; Diplopia ; Extremities ; Facial Paralysis ; Gait Ataxia ; Guillain-Barre Syndrome ; Humans ; Immunization, Passive ; Miller Fisher Syndrome* ; Ophthalmoplegia ; Paresthesia ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating* ; Reflex

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronically progressive or relapsing symmetric sensorimotor disorder presumed to occur because of immunologic antibody-mediated reactions. To understand the clinical courses of CIDP, we report variable CIDP courses in children with respect to initial presentation, responsiveness to medical treatment, and recurrence interval. Four patients who were diagnosed with acute-onset and relapsing CIDP courses at Severance Children's Hospital, Seoul, Korea, were enrolled in this retrospective study. We diagnosed each patient on the basis of the CIDP diagnostic criteria developed in 2010 by the European Federation of Neurological Societies/Peripheral Nerve Society Guidelines. We present the cases of four pediatric patients diagnosed with CIDP to understand the variable clinical course of the disease in children. Our four patients were all between 8 and 12 years of age. Patients 1 and 2 were diagnosed with acute cerebellar ataxia or Guillain-Barre syndrome as initial symptoms. While patients 1 and 4 were given only intravenous dexamethasone (0.3 mg/kg/day) for 5 days at the first episode, Patients 2 and 3 were given a combination of intravenous immunoglobulin (2 g/kg) and dexamethasone (0.3 mg/kg/day). All patients were maintained with oral prednisolone at 30 mg/day, but their clinical courses were variable in both relapse intervals and severity. We experienced variable clinical courses of CIDP in children with respect to initial presentation, responsiveness to medical treatment, and recurrence interval.
Cerebellar Ataxia ; Child* ; Dexamethasone ; Electromyography ; Guillain-Barre Syndrome ; Humans ; Immunoglobulins ; Korea ; Neural Conduction ; Polyneuropathies* ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; Prednisolone ; Recurrence ; Retrospective Studies ; Seoul

To present a case of cauda equina syndrome (CES) caused by chronic inflammatory demyelinating polyneuropathy (CIDP) which seemed clinically similar to Charcot-Marie-Tooth disease type1 (CMT1). CIDP is an immune-mediated polyneuropathy, either progressive or relapsing-remitting. It is a non-hereditary disorder characterized by symmetrical motor and sensory deficits. Rarely, spinal nerve roots can be involved, leading to CES by hypertrophic cauda equina. A 34-year-old man presented with low back pain, radicular pain, bilateral lower-extremity weakness, urinary incontinence, and constipation. He had had musculoskeletal deformities, such as hammertoes and pes cavus, since age 10. Lumbar spine magnetic resonance imaging showed diffuse thickening of the cauda equina. Electrophysiological testing showed increased distal latency, conduction blocks, temporal dispersion, and severe nerve conduction velocity slowing (3 m/s). We were not able to find genetic mutations at the PMP 22, MPZ, PRX, and EGR2 genes. The pathologic findings of the sural nerve biopsy revealed thinly myelinated nerve fibers with Schwann cells proliferation. We performed a decompressive laminectomy, intravenous IgG (IV-IgG) and oral steroid. At 1 week after surgery, most of his symptoms showed marked improvements except foot deformities. There was no relapse or aggravation of disease for 3 years. We diagnosed the case as an early-onset CIDP with cauda equine syndrome, whose initial clinical findings were similar to those of CMT1, and successfully managed with decompressive laminectomy, IV-IgG and oral steroid.
Adult ; Biopsy ; Cauda Equina ; Charcot-Marie-Tooth Disease* ; Congenital Abnormalities ; Constipation ; Foot Deformities ; Humans ; Immunoglobulin G ; Laminectomy ; Low Back Pain ; Magnetic Resonance Imaging ; Nerve Fibers, Myelinated ; Neural Conduction ; Polyneuropathies* ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; Polyradiculopathy* ; Recurrence ; Schwann Cells ; Spinal Nerve Roots ; Spine ; Sural Nerve ; Urinary Incontinence