Typical Chronic Inflammatory Demyelinating Polyradiculoneuropathy Research Articles

Typical CIDP: Update of the Pathogenesis, Diagnosis, and Treatment

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common chronic immune-mediated demyelinating neuropathy and includes several clinical subtypes. The major phenotype is "typical CIDP," which is characterized by symmetric polyneuropathy and "proximal and distal" muscle weakness. In typical CIDP, the nerve roots and distal nerve terminals, where the blood-nerve barrier is anatomically deficient, are preferentially affected, and therefore antibody-mediated immune pathogenesis is likely to have a major role. Currently, CIDP is considered a syndrome including typical CIDP and CIDP variants. In 2021, the European Academy of Neurology/Peripheral Nerve Society Guideline was published, whereas the Japanese CIDP/ Multifocal Motor Neuropathy Clinical Practice Guideline will be available in May 2024. This review article summarizes the immunopathogenesis, diagnosis, and treatment for typical CIDP.

Typical CIDP, distal variant CIDP, and anti-MAG antibody neuropathy: An ultra-high frequency ultrasound comparison of nerve structure

To date, little is known about the usefulness of ultra-high frequency ultrasound (UHF-US, 50–70 MHz) in clinical practice for the diagnosis of dysimmune neuropathies. We present a prospective study aimed at comparing UHF-US alterations of nerves and fascicles in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), distal CIDP (d-CIDP) and anti-MAG neuropathy and their relationships with clinical and electrodiagnostic (EDX) features. 28 patients were included (twelve CIDP, 6 d-CIDP and 10 anti-MAG) and ten healthy controls. Each patient underwent neurological examination, EDX and UHF-US study of median and ulnar nerves bilaterally. UHF-US was reliable in differentiating immune neuropathies from controls when using mean and/or segmental nerve and/or fascicle cross-sectional area (CSA); furthermore, fascicle ratio (fascicle/nerve CSA) was a reliable factor for differentiating d-CIDP from other types of polyneuropathies. The fascicle CSA appears to be more increased in CIDP and its variant than in anti-MAG neuropathy. UHF-US offers information beyond simple nerve CSA and allows for a better characterization of the different forms of dysimmune neuropathies.

Impact of 2021 European Academy of Neurology/Peripheral Nerve Society diagnostic criteria on diagnosis and therapy of chronic inflammatory demyelinating polyradiculoneuropathy variants.

There are different criteria for the diagnosis of different variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) guidelines provide specific clinical criteria for each CIDP variant even if their therapeutical impact has not been investigated. We applied the clinical criteria for CIDP variants of the 2021 EAN/PNS guidelines to 369 patients included in the Italian CIDP database who fulfilled the 2021 EAN/PNS electrodiagnostic criteria for CIDP. According to the 2021 EAN/PNS clinical criteria, 245 patients achieved a clinical diagnosis of typical CIDP or CIDP variant (66%). We identified 106 patients with typical CIDP (29%), 62 distal CIDP (17%), 28 multifocal or focal CIDP (7%), four sensory CIDP (1%), 27 sensory-predominant CIDP (7%), 10 motor CIDP (3%), and eight motor-predominant CIDP (2%). Patients with multifocal, distal, and sensory CIDP had milder impairment and symptoms. Patients with multifocal CIDP had less frequently reduced conduction velocity and prolonged F-wave latency and had lower levels of cerebrospinal fluid protein. Patients with distal CIDP more frequently had reduced distal compound muscle action potentials. Patients with motor CIDP did not improve after steroid therapy, whereas those with motor-predominant CIDP did. None of the patients with sensory CIDP responded to steroids, whereas most of those with sensory-predominant CIDP did. The 2021 EAN/PNS criteria for CIDP allow a better characterization of CIDP variants, permitting their distinction from typical CIDP and more appropriate treatment for patients.

Cutting edge of diagnosis and treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) based on the EAN/PNS guideline 2021

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a most common chronic immune-mediated demyelinating neuropathy, and includes a number of clinical subtypes. The major phenotype is "typical CIDP", which is characterized by symmetric polyneuropathy and "proximal and distal" muscle weakness. During the historical changes in the concept of CIDP, multifocal motor neuropathy, anti-myelin-associated glycoprotein (MAG) neuropathy, and autoimmune nodopathy have been excluded. Currently CIDP is considered as a syndrome including typical CIDP and CIDP variant such as distal CIDP and multifocal CIDP. In 2021, the international guideline of diagnosis and treatment for CIDP, European Academy of Neurology (EAN)/Peripheral Nerve Society (PNS) Guideline, was published. This review article introduces the putline of the guideline with medical-social situation in Japan. The diagnosis of CIDP is based on (1) phenotype of typical CIDP or variant, (2) electrophysiologic evidence of peripheral nerve demyelination, and (3) exclusion criteria. The first-line treatments are corticosteroids or immunoglobulin therapy, and plasma exchange should be considered if the 2 treatments were not effective sufficiently. This guideline recommends intravenous or subcutaneous immunoglobulin as a maintenance therapy, and suggests other immune-suppressive agents. In the near future, new treatment with biologics, such as monoclonal antibodies against neonatal Fc receptors, complements, and CD19/20 will be approved.

The distribution pattern of nerve enlargement in clinical subtypes of chronic inflammatory demyelinating polyneuropathy.

We aim to investigate nerve enlargement patterns and their correlation with clinical subtypes and treatment response using nerve ultrasound in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Between March 2015 and December 2021, 135 CIDP patients were recruited. Nerve ultrasound and electrophysiological studies were performed on the median and ulnar nerves. The responses to intravenous immunoglobulin (IVIg) or prednisone were evaluated with the disability score. There were 99 typical CIDP cases, 10 Lewis-Sumner syndrome (LSS) cases, 15 distal acquired demyelinating symmetric neuropathy (DADS) cases, nine pure motor CIDP cases, and two pure sensory CIDP cases. Sixty (61%) typical CIDP and seven (78%) pure motor CIDP patients had moderately increased or normal cross-sectional area (CSA), and 10 (67%) DADS and seven (70%) LSS patients had significantly increased CSA. The peripheral nerve showed a diffuse enlargement pattern in 46 (51%) typical CIDP, five (50%) LSS, three (25%) DADS, and three (33%) pure motor CIDP patients and a proximal regional enlargement pattern in 11 (12%) typical CIDP, one (10%) LSS, six (50%) DADS, and four (44%) pure motor CIDP patients. Patients with diffusely moderate enlargement patterns and those with proximal regional enlargement showed a higher response rate to glucocorticoids than to IVIg. Various distribution patterns of nerve enlargement existed in CIDP. Although almost all patterns could be detected in each CIDP subtype, diffusely moderate enlargement was more common in typical CIDP and LSS, while proximal regional enlargement was more common in DADS and pure motor CIDP. Different enlargement patterns might indicate different treatment responses.

Unclassified clinical presentations of chronic inflammatory demyelinating polyradiculoneuropathy

BackgroundTo assess the ability of the 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) clinical criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) to include within their classification the whole spectrum...

Chronic inflammatory demyelinating polyradiculoneuropathy-associated tremor: Phenotype and pathogenesis.

Tremor in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is underrecognized, and the pathophysiology remains incompletely understood. This study evaluated tremor in CIDP and tested the hypothesis, established in other demyelinating neuropathies, that tremor occurs due to mistimed peripheral inputs affecting central motor processing. Additionally, the tremor stability index (TSI) was calculated with the hypothesis that CIDP-related tremor is more variable than other tremor disorders. Consecutive patients with typical CIDP were prospectively recruited from neuromuscular clinics. Alternative causes of neuropathy and tremor were excluded. Cross-sectional clinical assessment and extensive tremor study recordings were undertaken. Pearson correlation coefficient was used to compare nerve conduction studies and tremor characteristics, and t-test was used for comparisons between groups. Twenty-four patients with CIDP were included. Upper limb postural and action tremor was present in 66% and was mild according to the Essential Tremor Rating Assessment Scale. Tremor did not significantly impact disability. Surface electromyography (EMG) found high-frequency spectral peaks in deltoid (13.73 ± 0.66 Hz), biceps brachii (11.82 ± 0.91 Hz), and extensor carpi radialis (11.87 ± 0.91 Hz) muscles, with lower peaks in abductor pollicis brevis EMG (6.07 ± 0.45 Hz) and index finger accelerometry (6.53 ± 0.42 Hz). Tremor was unchanged by weight loading but correlated with ulnar nerve F-wave latency and median nerve sensory amplitude. TSI (2.3± 0.1) was significantly higher than essential tremor. Postural tremor is a common feature in CIDP. Tremor was unaffected by weight loading, typical of centrally generated tremors, although there was a correlation with peripheral nerve abnormalities. The high beat-to-beat variability on TSI and gradation of peak frequencies further suggest a complex pathophysiology. These findings may assist clinicians with the diagnosis of neuropathic tremor.

Nerve enlargement differs among chronic inflammatory demyelinating polyradiculoneuropathy subtypes and multifocal motor neuropathy

ObjectiveWe aimed to evaluate differences in ultrasonographic nerve enlargement sites among typical chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), distal CIDP, multifocal CIDP and multifocal motor neuropathy (MMN) in a Japanese population. MethodsWe retrospectively reviewed medical records and selected 39 patients (14 with typical CIDP, 7 with multifocal CIDP, 4 with distal CIDP, and 14 with MMN) who underwent ultrasonography. Median and ulnar nerve cross-sectional areas (CSAs) were measured at the wrist, forearm, elbow, and upper arm. CSA ratios for each nerve were calculated as: wrist-to-forearm index (WFI) = wrist CSA/forearm CSA; elbow-to-upper arm index (EUI) = elbow CSA/upper arm CSA; and intranerve CSA variability (INCV) = maximal CSA/minimal CSA. ResultsSignificant differences were observed among typical CIDP, multifocal CIDP, distal CIDP, and MMN in CSA at the forearm and upper arm in the median nerves (p < 0.05). Patients with multifocal CIDP had lower WFI and EUI and higher INCV than the other groups (p < 0.05). ConclusionsRegardless of the untreated period, compared with other CIDP subtypes and MMN, multifocal CIDP showed a focal and marked nerve enlargement in the Japanese population. SignificanceDifferences in nerve enlargement site may be an underlying feature of multifocal CIDP.

Comparison of the diagnostic accuracy of the 2021 EAN/PNS and 2010 EFNS/PNS diagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy

ObjectivesTo compare the sensitivity and specificity of the 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) diagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with those of the 2010 European...

CIDP Refractory to Three Types of Mainstay Treatments: Differential Diagnosis and Treatment Strategies

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a syndrome constructed by several clinical phenotypes that share chronic inflammatory demyelination in the peripheral nervous system. While the detailed pathogenesis is not elucidated, mainstay induction therapies such as corticosteroids, IVIg, and plasma exchange, are effective for typical CIDP. However, most conventional treatments show inadequate responses in CIDP variants. Furthermore, patients with IgG4-predominant autoantibodies (anti-NF155 Ab, anti-CNTN1 Ab, and so on) show distal-predominant disability and are recognized as refractory CIDP (autoimmune nodopathy). Combining therapeutics with induction of plasma exchange following intermittent high-dose corticosteroids could be adequate for those patients. Besides, as a novel therapeutic option, rituximab is strongly expected to be a first-line for IgG4-positive autoimmune nodopathy. Some patients show relapses before the next IVIg maintenance. We can change from intravenous immunoglobulin per three weeks to weekly subcutaneous induction. Add on corticosteroids or immunosuppressants would also be helpful to the disease stability. Recently, serum NF-L has been a candidate biomarker for secondary axonal damage in CIDP. A high-level Nf-L suggests an active phase of the disease and could indicate the requirement for therapeutic intervention.

A diagnostic score for anti-myelin-associated-glycoprotein neuropathy or chronic inflammatory demyelinating polyradiculoneuropathy in patients with anti-myelin-associated-glycoprotein antibody.

A diagnostic score was developed to discriminate anti-myelin-associated-glycoprotein (MAG) neuropathy from chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and applied it to patients with atypical anti-MAG neuropathy. The clinical and electrophysiological features of patients with a diagnosis of typical anti-MAG neuropathy were compared to those of patients with a diagnosis of CIDP. The association of each feature with the diagnosis was assessed in the two groups. Features showing a significant association with the diagnosis were included in a multivariable logistic regression model and adjusted odds ratios were estimated for each feature. A score ranging from 1 to 3 was applied to each feature based on the magnitude of the estimated odds ratios. The score was then applied to patients with a clinical diagnosis of CIDP who also had high anti-MAG antibody titers (CIDP-MAG). Thirty-one anti-MAG neuropathy patients, 45 typical CIDP patients and 16 CIDP-MAG patients were included. Scores in anti-MAG antibody patients ranged from 1 to 5 and in CIDP patients from -7 to -1. Using the score, 4/16 CIDP-MAG patients were diagnosed to have anti-MAG neuropathy and 12/16 patients to have CIDP. Response to intravenous immunoglobulin in the CIDP-MAG patients classified as CIDP was similar to that of definite CIDP patients and higher than that of anti-MAG neuropathy patients. Our score allowed an accurate discrimination to be made, amongst patients with anti-MAG antibodies, of those affected by CIDP and the patients with anti-MAG neuropathy. This score may help proper treatment to be chosen for patients with anti-MAG antibodies with a CIDP-like presentation.

Axonal damage determines clinical disability in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): A prospective cohort study of different CIDP subtypes and disease stages

Monitoring of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is challenging in daily medical practice because the interrelationship between clinical disability, CIDP subtype, and neuronal degeneration is still elusive. The aim of this prospective cohort study was to investigate the role of different electrophysiological variables in CIDP monitoring. Comprehensive bilateral nerve conduction studies (NCS) and structured clinical examinations were performed in 95 patients with typical CIDP and CIDP variants (age at inclusion 58.6±11.6years; median [range] inflammatory neuropathy cause and treatment overall disability score (INCAT-ODSS) 3 [0-9]), at time of first diagnosis in 25 of these patients (based on data from the prospective Immune-mediated Neuropathies Biobank registry). After 12months, 33 patients underwent follow-up examination. Typical CIDP patients and patients with CIDP variants were characterized electrophysiologically and each individual NCS variable and the overall sum score for axonal damage and demyelination were then correlated to clinical disability scores (INCAT-ODSS, modified Medical Research Council (MRS) sum score, and INCAT sensory score). As opposed to demyelination markers, the NCS axonal damage variable correlated strongly with disability at both first diagnosis and advanced disease stages in cross-sectional and longitudinal analyses. Distal compound muscle action potential amplitudes of the upper limbs were found to have the strongest correlation with overall clinical function. Typical and atypical CIDP variants had distinct electrophysiological characteristics but, in typical CIDP, axonal degeneration markers were more strongly associated with clinical disability. Total disability is largely determined by the degree of axonal damage, especially in typical CIDP. Although most patients have symptoms predominantly in the legs, NCS of the upper limbs are essential for the monitoring of patients with CIDP and CIDP variants.

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision.

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs). Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

European Academy of Neurology/Peripheral Nerve Society guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force-Second revision.

To revise the 2010 consensus guideline on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Seventeen disease experts, a patient representative, and two Cochrane methodologists constructed 12 Population/Intervention/Comparison/Outcome (PICO) questions regarding diagnosis and treatment to guide the literature search. Data were extracted and summarized in GRADE summary of findings (for treatment PICOs) or evidence tables (for diagnostic PICOs). Statements were prepared according to the GRADE Evidence-to-Decision frameworks. Typical CIDP and CIDP variants were distinguished. The previous term "atypical CIDP" was replaced by "CIDP variants" because these are well characterized entities (multifocal, focal, distal, motor, or sensory CIDP). The levels of diagnostic certainty were reduced from three (definite, probable, possible CIDP) to only two (CIDP and possible CIDP), because the diagnostic accuracy of criteria for probable and definite CIDP did not significantly differ. Good Practice Points were formulated for supportive criteria and investigations to be considered to diagnose CIDP. The principal treatment recommendations were: (a) intravenous immunoglobulin (IVIg) or corticosteroids are strongly recommended as initial treatment in typical CIDP and CIDP variants; (b) plasma exchange is strongly recommended if IVIg and corticosteroids are ineffective; (c) IVIg should be considered as first-line treatment in motor CIDP (Good Practice Point); (d) for maintenance treatment, IVIg, subcutaneous immunoglobulin or corticosteroids are recommended; (e) if the maintenance dose of any of these is high, consider either combination treatments or adding an immunosuppressant or immunomodulatory drug (Good Practice Point); and (f) if pain is present, consider drugs against neuropathic pain and multidisciplinary management (Good Practice Point).

Atypical chronic inflammatory demyelinating polyradiculoneuropathy: recent advances on classification, diagnosis, and pathogenesis.

In recent years, there has been an intense debate in literature regarding the definition of the individual variants of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), their possible pathogenetic mechanisms, and impact in the diagnosis of CIDP. The 2021 European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) guidelines revised the definition of the individual CIDP variants and implemented their diagnostic criteria. Diagnosis of atypical CIDP is challenging and misdiagnosis is frequent, leading to diagnostic delay and consequent greater accumulation of disability and treatment dependency. Recent studies suggest that patients with typical CIDP have an antibody-mediated mechanism of neuropathy whereas in those with Lewis--Sumner syndrome (LSS) neuropathy is preferentially mediated by macrophages and T cells. Although the validity of the 2021 EFNS/PNS diagnostic criteria for atypical CIDP is unknown, they will hopefully lead to greater uniformity in the selection of patients to be enrolled in future studies and to a greater diagnostic accuracy. New data are emerging on the possible pathological mechanisms of individual variants and this could result in the discovery of specific diagnostic biomarkers and new therapies.

Patients who meet electrodiagnostic criteria for CIDP rarely present with a sensory predominant DSP phenotype.

It is unknown how often patients with electrodiagnostic evidence of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), a potentially treatable condition, present with a distal symmetric polyneuropathy (DSP) phenotype. We reviewed the records of patients who presented to our electrodiagnostic laboratory between January 1, 2011, to December 31, 2019, and fulfilled electrodiagnostic criteria for CIDP to identify those who presented with a sensory predominant DSP phenotype. One hundred sixty-two patients had a chronic acquired demyelinating neuropathy, of whom 138 met criteria for typical or atypical CIDP. Nine of these patients presented with a sensory predominant DSP phenotype, among whom six were eventually diagnosed with distal acquired demyelinating symmetric (DADS) neuropathy; one with Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein, Skin changes (POEMS) syndrome; and two with idiopathic DSP. The prevalence of acquired chronic demyelinating neuropathies among all patients presenting with a DSP phenotype was estimated to be 0.34%. Patients who meet electrodiagnostic criteria for CIDP rarely present with a sensory predominant DSP phenotype, and electrodiagnostic testing rarely identifies treatable demyelinating neuropathies in patients who present with a DSP phenotype.

Treatment response to cyclophosphamide, rituximab, and bortezomib in chronic immune-mediated sensorimotor neuropathies: a retrospective cohort study.

Background:Up to 20% of patients with chronic immune-mediated sensorimotor neuropathies (CIN) do not respond adequately to first-line therapies. However, studies on further treatment are scarce.Methods:We analyzed retrospectively 200 CIN patients regarding disease characteristics and response to therapy with cyclophosphamide (CYP), rituximab (RTX), and bortezomib (BTZ). Treatment response was defined as improvement or stabilization of inflammatory neuropathy cause and treatment overall disability score (INCAT-ODSS).Results:A total of 48 of 181 patients (26.5%) received therapy with CYP, RTX, or BTZ. The most frequently and first used therapy was CYP (69%). More than 40% of patients needed a second or third treatment. Overall, 71 treatments were applied in 48 patients. The combination of up to all three treatments enhanced the response-rate to 90%. Treatment within 24 months after initial diagnosis resulted in significantly higher response rate than late treatment (79% versus 50 %, p = 0.04, χ2-test, n = 46) and in lower disability in long-term follow up (INCAT-ODSS 3.8 versus 5.8, p = 0.02, t-test, n = 48). Patients with Lewis-Sumner syndrome (n = 9) and autoantibody mediated neuropathies (n = 13) had excellent response rates after treatment with RTX (90–100%). In contrast, typical chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) showed a response rate of 64% in CYP, 64% in RTX, and 75% in BTZ.Conclusion:Treatment with CYP, RTX, or BTZ was effective in this cohort of CIN refractory to first-line treatment. Our data increase evidence for an early use of these therapies. High efficacy of RTX in Lewis-Sumner syndrome in contrast to typical CIDP suggests a distinct pathophysiology.

Juvenile Chronic Inflammatory Demyelinating Polyneuropathy Epidemiology in Sardinia, Insular Italy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare and disabling immunomediated radiculoneuropathy. Its worldwide epidemiology is heterogeneous and, in adults, CIDP prevalence varies from 0.6 to 9 cases per 100,000 population. Juvenile CIDP (jCIDP) is even rarer, with age-specific prevalence rates varying from 0.23 to 1.26 owing to different diagnostic criteria (American Academy of Neurology [AAN] and European Federation of Neurological Societies/Peripheral Nerve Society [EFNS/PNS]), different age grouping or, genuine differences. We assessed jCIDP incidence and prevalence in Sardinia, an area at very-high risk for autoimmune diseases, using comparable methods. The study area was the northern Sardinia, insular Italy, with 491,571 inhabitants and a pediatric population (0-18 years) of 79,086 individuals. On prevalence day (December 31, 2019) the total crude, age-specific prevalence rate were 6.32 per 100,000 according with AAN criteria, 7.58 per 100,000 population with European Neuromuscular Center (ENMC) criteria, and 8.85 per 100,000 population with both 2006 and 2010 EFNS/PNS criteria. Crude mean incidence rate were 0.42 per 100,000 per year with AAN criteria, 0.50 per 100,000 per year with ENMC criteria, and 0.59 per 100,000 per year using 2006 and 2010 EFNS/PNS criteria. Of the eight patients, six had typical CIDP, one had multifocal-acquired demyelinating sensory and motor neuropathy (MADSAM), and one chronic immune sensory polyradiculopathy (CISP). Patient's disability was generally mild. Clinical course was progressive, monophasic, or relapsing. jCIDP prevalence and incidence rates in Sardinia were criteria-dependent, the lowest obtained when using AAN criteria, the highest using the EFNS/PNS. Nonetheless, even with the exclusion of the "possible" category, by using comparable methodology, prevalence rates in Sardinia are considerably higher than the range reported in all previous jCIDP studies.

The comparison of MRN, electrophysiology and progression among typical CIDP and atypical CIDP subtypes

We aimed to compare the electrophysiology and magnetic resonance neurography (MRN) results of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) subtypes and to explore the progression from atypical CIDP to typical CIDP. We collected the medical records of 45 CIDP patients to analyse the rate of progression from atypical CIDP to typical CIDP subtypes. The cerebrospinal fluid (CSF) protein (p = 0.024) and overall disability sum score (ODSS) (p = 0.000) differed among patients with typical CIDP, distal acquired demyelinating symmetric neuropathy (DADS) and Lewis-Sumner syndrome (LSS). The compound motor action potential (CMAP) of typical CIDP was lower than that of the other subtypes (p = 0.016, p = 0.022 and p = 0.012). The cross-sectional area (CSA) of nerve roots in typical CIDP was significantly thicker than that of nerve roots in DADS and LSS. There were fewer DADS and LSS patients who progressed to typical CIDP than those who progressed to pure motor and pure sensory CIDP (p = 0.000), and the progression from pure motor to typical CIDP required a significantly longer time than the progression from pure sensory to typical CIDP (p = 0.007). Typical CIDP was more severe than the other subtypes not only in terms of clinical and electrophysiology factors but also in terms of MRN factors.

The Noninvasive Diagnostic Value of MRN for CIDP: A Research from Qualitative to Quantitative.

We examined the chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients and non-CIDP patients who have similar symptoms and difficult to differential diagnosis with CIDP by magnetic resonance neurography to find the difference among them. To investigate the differential diagnostic value of magnetic resonance neurography (MRN) for CIDP and other peripheral neuropathies. Thirty-two consecutive patients with CIDP and 22 non-CIDP patients with symptoms similar to CIDP and difficult to be discriminate were recruited and imaged as a control group between May 2017 and May 2019. In this prospective study, the brachial plexus and lumbosacral plexus of 32 CIDP patients and 22 non-CIDP patients were examined by MRN. The clinical features and the nerve roots cross-sectional area (CSA) of the brachial plexus and lumbosacral plexus were measured. The CSA of nerve roots of CIDP, Charcot-Marie-Tooth disease type-1 and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome patients were all shown extensive by MRN. The sensitivity of MRN in diagnosing CIDP was 81.25% (26/32), the specificity was 68.18% (15/22), the positive predictive value was 78.79% (26/33), the negative predictive value was 71.43% (15/21), the accuracy was 75.93% (40/54), the misdiagnosis rate was 24.07% (13/54), and the kappa value was 0.498. Receiver operating characteristic analysis showed higher diagnostic accuracy for CIDP with the CSA of the lumbosacral plexus (area under the curve [AUC] = 0.762) and that of the brachial plexus (AUC = 0.762), and the combined of both examinations did not improve the diagnostic efficacy compared with either (AUC = 0.769). The nerve roots of CIDP, Charcot-Marie-Tooth disease type-1, and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome were difficult to distinguish by MRN. Atypical CIDP patients had less nerve root injury compared with typical CIDP patients. MRN of either the brachial plexus or the lumbosacral plexus had a high diagnostic accuracy for CIDP, and it is not necessary to perform both parts of the examination. 2.