European Federation of Neurological Societies/Peripheral Nerve Society guideline on management of chronic inflammatory demyelinating polyradiculoneuropathy: report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society - first revision

Compound muscle action potential duration ratio for differentiation between Charcot-Marie-Tooth disease and CIDP

OBJECTIVE

To elucidate the utility of the proximal to distal compound muscle action potential (CMAP) duration ratio to distinguish between demyelinating Charcot-Marie-Tooth disease (CMT) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) compared with nerve ultrasound.

METHODS

Thirty-nine demyelinating CMT patients and 19 CIDP patients underwent nerve conduction studies (NCS) and nerve ultrasound. NCS parameters including CMAP duration ratio calculated by dividing the value at the proximal site by that at the distal site and nerve cross-sectional area (CSA) measured by ultrasound were compared between the two groups. The diagnostic sensitivity and specificity of each parameter were analysed.

RESULTS

CMT patients showed a significantly lower CMAP duration ratio than CIDP patients (p < 0.05). The area under the curve (AUC) value of the CMAP duration ratio exceeded 0.95 when CMT was considered "positive", and a cut-off value of 1.13 resulted in high diagnostic sensitivity and specificity (84.6 and 100 % for median nerve, 97.4 and 85.7 % for ulnar nerve, respectively), whereas the AUC value of nerve CSA ranged from 0.70 to 0.81.

CONCLUSIONS

The CMAP duration ratio could effectively distinguish between demyelinating CMT and CIDP.

SIGNIFICANCE

Adding the CMAP duration ratio to a routine NCS may improve the accuracy of the diagnosis of demyelinating CMT.

Metabolic disorder and intestinal microflora dysbiosis in chronic inflammatory demyelinating polyradiculoneuropathy

OBJECTIVE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare acquired immune-mediated neuropathy. Although microbial infection is potentially a contributing factor, a causative link between CIDP and microbial infection remains unclear. There is also no definitive biomarker for CIDP diagnostics and therapies. The present study aimed to characterize the serum metabolic profile and gut microbiome structure in CIDP.

METHODS

Targeted metabolomics profiling of serum, using liquid chromatography-mass spectrometry, and metagenomics sequencing of stool samples from a cohort of CIDP and non-CIDP subjects were performed to evaluate serum metabolic profiles and gut microbiome structure in CIDP subjects relative to healthy controls.

RESULTS

Metabolome data revealed that the bile acids profile was perturbed in CIDP with bile acids and arachidonic acid enriched significantly in CIDP versus non-CIDP controls. Metagenome data revealed that opportunistic pathogens, such as Klebsiella pneumonia and Megamonas funiformis, and genes involved in bacterial infection were notably more abundant in CIDP subjects, while gut microbes related to biotransformation of secondary bile acids were abnormal in CIDP versus non-CIDP subjects. Correlation analysis revealed that changes in secondary bile acids were associated with altered gut microbes, including Bacteroides ovatus, Bacteroides caccae, and Ruminococcus gnavus.

CONCLUSION

Bile acids and arachidonic acid metabolism were disturbed in CIDP subjects and might be affected by the dysbiosis of gut microbial flora. These findings suggest that the combination of bile acids and arachidonic acid could be used as a CIDP biomarker and that modulation of gut microbiota might impact the clinical course of CIDP.

The Electrophysiological Findings in Spinocerebellar Ataxia Type 6: Evidence From 24 Patients

PURPOSE

Peripheral neuropathy has been reported commonly in several spinocerebellar ataxia (SCA) types. To date, there is a lack of robust evidence for neuropathy or neuronopathy in SCA type 6 (SCA6). Here, we aim to evaluate the presence of neuropathy or neuronopathy in a cohort of SCA6 patients.

METHODS

Twenty-four individuals with genetically confirmed SCA6 underwent detailed neurophysiological assessment. This included nerve conduction studies, and in some, cutaneous silent periods, blink reflexes, tilt table tests, quantitative sudomotor axon reflex tests, and somatosensory (median and tibial) evoked potentials.

RESULTS

Mean age was 56.1 years (range, 22-94 years) at the time of testing. Four patients were presymptomatic of SCA6 at recruitment. The mean disease duration of symptomatic patients was 11.9 years (range, 1-40 years). Most patients (79.2%, 19/24) had no neurophysiological evidence of a peripheral neuropathy. One with impaired glucose tolerance had mild, large, and small fiber sensorimotor polyneuropathy. One elderly patient had length-dependent axonal sensorimotor polyneuropathy. Two had minor sensory abnormalities (one had type II diabetes and previous chemotherapy). One other had minor small fiber abnormalities. Ten patients (41.7%) had median neuropathies at the wrist. All somatosensory evoked potential (15/15), and most autonomic function tests (13/14) were normal.

CONCLUSIONS

A large proportion of subjects (79.2%) in our cohort had no evidence of large or small fiber neuropathy. This study does not support the presence of neuropathy or neuronopathy as a common finding in SCA6 and confirms the importance of considering comorbidities as the cause of neurophysiological abnormalities.

On the path to evidence-based therapy in neuromuscular disorders

Neuromuscular disorders encompass a diverse group of acquired and genetic diseases characterized by loss of motor functionality. Although cure is the goal, many therapeutic strategies have been envisioned and are being studied in randomized clinical trials and entered clinical practice. As in all scientific endeavors, the successful clinical translation depends on the quality and translatability of preclinical findings and on the predictive value and feasibility of the clinical models. This chapter focuses on five exemplary diseases: childhood spinal muscular atrophy (SMA), Charcot-Marie-Tooth (CMT) disorders, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), acquired autoimmune myasthenia gravis (MG), and Duchenne muscular dystrophy (DMD), to illustrate the progress made on the path to evidenced-based therapy.

Chronic inflammatory demyelinating polyneurophaty: assessment of the cognitive function and quality of life

BACKGROUND

Studies were carried out with the objective of evaluating the quality of life (QoL) of patients affected by chronic inflammatory demyelinating polyradiculopathy (CIDP). However, the cognitive issue is still little addressed.

OBJECTIVES

To assess the QoL and cognitive impairment of patients with CIDP and to analyze whether there is a correlation between these parameters.

METHODS

Seven patients with CIDP and seven paired controls were subjected to: mini-mental state examination (MMSE); Montreal cognitive assessment (MoCA); digit symbol replacement/symbol copy test (DSST); fatigue severity scale (FSS); Beck depressive inventory-I (BDI-I), and a short-form of health survey (SF-36).

RESULTS

The mean age of the participants was 50 years (71.4% male). The MMSE and MoCA had no statistical difference between the groups. Patients showed superior results in the memory domain in the MoCA (5 vs. 2, p = 0.013). In the DSST, we observed a tendency for patients to be slower. There was a strong negative correlation between fatigue levels and vitality domain (SF-36). There was no significant correlation between depression levels and QoL, and there was no correlation between depression and the results obtained in the cognitive tests. The patients presented higher levels of depression (15.28 vs. 3.42, p < 0.001). A total of 57% had severe fatigue, 28.8% self-reported pain, and 57.1% complained of cramps.

CONCLUSION

There was no cognitive impairment in these patients. However, there was a tendency of slower processing speed. To better evaluate the alterations found, a study with a larger number of individuals would be necessary. Chronic inflammatory demyelinating polyradiculopathy affects the QoL of patients in different ways.

Tips in navigating the diagnostic complexities of chronic inflammatory demyelinating polyradiculoneuropathy

The 2021 guideline of the European Academy of Neurology/Peripheral Nerve Society on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) includes important revisions to the previous 2010 guideline. This article highlights the new criteria and recommendations for the differential diagnosis of CIDP. In the revised guideline, the CIDP spectrum has been modified to include typical CIDP and four well-characterized CIDP variants, namely distal, multifocal/focal, motor and sensory CIDP, replacing the term 'atypical' CIDP. To improve the diagnosis of CIDP, the revised guideline attempts to improve the specificity of the diagnostic criteria for typical CIDP and the four CIDP variants. Specific clinical and electrodiagnostic (including both motor and sensory conduction) criteria are provided for typical CIDP and each of the CIDP variants. The levels of diagnostic certainty have been changed to CIDP and possible CIDP, with the removal of probable CIDP (due to the lack of difference in the accuracy of the electrodiagnostic criteria for probable CIDP) and definite CIDP (due to the lack of a gold standard for diagnosis). If the clinical and electrodiagnostic criteria allow only for a diagnosis of possible CIDP, cerebrospinal fluid analysis, nerve ultrasound, nerve magnetic resonance imaging, objective treatment response, and nerve biopsy can be used as supportive criteria to upgrade the diagnosis to CIDP. Although the revised guideline needs to be validated and its strengths and weaknesses assessed, using the guideline will likely improve the accuracy of diagnosis of CIDP and variants of CIDP, and aid in distinguishing CIDP from conditions with similar features.

Sex differences in Guillain Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy and experimental autoimmune neuritis

Guillain Barré syndrome (GBS) and its variants, and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP and its variants, are regarded as immune mediated neuropathies. Unlike in many autoimmune disorders, GBS and CIDP are more common in males than females. Sex is not a clear predictor of outcome. Experimental autoimmune neuritis (EAN) is an animal model of these diseases, but there are no studies of the effects of sex in EAN. The pathogenesis of GBS and CIDP involves immune response to non-protein antigens, antigen presentation through non-conventional T cells and, in CIDP with nodopathy, IgG4 antibody responses to antigens. There are some reported sex differences in some of these elements of the immune system and we speculate that these sex differences could contribute to the male predominance of these diseases, and suggest that sex differences in peripheral nerves is a topic worthy of further study.

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

OBJECTIVES

To 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 Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS).

METHODS

Sensitivity and specificity of the two sets of criteria were evaluated in 330 patients with CIDP and 166 axonal peripheral neuropathy controls. Comparison of the utility of nerve conduction studies with different number of nerves examined and of the sensitivity and specificity of the two criteria in typical CIDP and its variants were assessed.

RESULTS

EFNS/PNS criteria had a sensitivity of 92% for possible CIDP and 85% for probable/definite CIDP, while the EAN/PNS criteria had a sensitivity of 83% for possible CIDP and 74% for CIDP. Using supportive criteria, the sensitivity of the EAN/PNS criteria for possible CIDP increased to 85% and that of CIDP to 77%, remaining lower than that of the EFNS/PNS criteria. Specificity of the EFNS/PNS criteria was 68% for possible CIDP and 84% for probable/definite CIDP, while the EAN/PNS criteria had a specificity of 88% for possible CIDP and 98% for CIDP. More extended studies increased the sensitivity of both sets of criteria by 4%-7% but reduced their specificity by 2%-3%. The EFNS/PNS criteria were more sensitive for the diagnosis of typical CIDP while the EAN/PNS criteria were more specific for the diagnosis of distal and sensory CIDP.

CONCLUSIONS

In our population, the EAN/PNS criteria were more specific but less sensitive than the EFNS/PNS criteria. With the EAN/PNS criteria, more extended nerve conduction studies are recommended to obtain an acceptable sensitivity while maintaining a high specificity.

Peripheral neuropathy and MOG-IgG: A clinical and neuropathological retrospective study

BACKGROUND

Myelin oligodendrocyte glycoprotein antibodies (MOG-Abs) may rarely be associated with peripheral nervous system involvement. We aimed to test MOG-Abs in patients with undetermined peripheral neuropathy (PN).

METHODS

Consecutive patients with available sural nerve biopsy and paired serum sample were retrospectively identified (January, 1st 2016-November, 1st 2021) and tested for MOG-Abs with live cell-based assay (CBA). Patients with antibody titre ≥1:160 (secondary H + L antibody) and selective MOG-IgG presence (IgG-Fc predominance) were considered MOG-IgG positive. All positive samples were analysed with immunohistochemistry and CBAs for antibodies against Neurofascin-155 and Contactin-1. Clinical and neuropathological data were collected through clinical reports.

RESULTS

Among 163 patients, 5 (3%) resulted positive for predominantly IgG MOG-Abs (median titer 1:320, range 1:160-1:5120), none showed other concomitant antibodies. Median age was 74 years-old (range 55-81), median disease duration was 60 months (range 1-167), 60% of patients were female. Of these, 4/5 cases had clinical features suggestive of acute (n = 1) or chronic (n = 3) inflammatory demyelinating neuropathy, 2/5 fulfilled the criteria of combined central and peripheral demyelination (CCPD) whilst 3/5 had isolated PNS involvement. Neuropathological findings showed mixed axonal-demyelinating features in 2/5, predominant demyelination in 3/5 cases. Other neuropathological hallmarks included paranodal demyelination (n = 3), myelin outfoldings (n = 4), slight inflammatory infiltrates (n = 3), onion bulbs (n = 3), and clusters of regeneration (n = 4).

DISCUSSION

MOG-IgG can be detected in patients with isolated PN or CCPD. Clinical and neuropathological features are suggestive for demyelination and slight inflammation. Further studies should include larger cohorts of patients to elucidate the utility of MOG-Abs testing in PN.

Application of the 2021 EAN/PNS criteria for chronic inflammatory demyelinating polyneuropathy

BACKGROUND

The diagnostic value of new criteria of the European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) for chronic inflammatory demyelinating polyneuropathy (CIDP) is unknown.

METHODS

We performed a retrospective study of fulfilment of EAN/PNS 2021 criteria on 120 consecutive patients with a clinical diagnosis of 'suspected CIDP' and objective treatment response, attending University Hospitals Birmingham, UK. Specificity was evaluated versus 100 consecutive controls.

RESULTS

The sensitivity of EAN/PNS criteria for 'CIDP' was 83.3%. The sensitivity for 'CIDP' or 'possible CIDP' was 93.3%. Specificity was of 94% for 'CIDP' and 79% for 'CIDP' or 'possible CIDP'. No sensitivity/specificity differences were ascertained with previous versions ('CIDP': sensitivity: 83.3% vs 81.3%, p=0.74, specificity: 94% vs 96.1%, p=0.38, respectively; 'CIDP' or 'possible CIDP': sensitivity: 93.3% vs 96.7%, p=0.25 and specificity: 79% vs 69.2 %, p=0.09, respectively). F-wave prolongation, proximal and distal temporal dispersion were the most likely parameters to contribute to false positives, whereas distal motor latency was the least likely. No impact of sensory electrophysiology could be ascertained. 'Typical CIDP' represented 79% of the CIDP cohort. The largest component of the 'variant CIDP' group was represented by focal/multifocal forms (14%). With new criteria, 6.7% of the cohort did not meet requirements, among whom the majority (75%) had paranodopathy or chronic immune sensory polyradiculopathy (CISP).

DISCUSSION

The sensitivity and specificity of new EAN/PNS criteria for CIDP is equivalent to that of previous versions. The exclusion of paranodopathies and CISP from the CIDP spectrum impacts on management of a non-negligible proportion of treatment-responsive patients.

Antibody response after COVID-19 vaccination in intravenous immunoglobulin-treated immune neuropathies

BACKGROUND AND PURPOSE

This study assessed the prevalence of anti-SARS-CoV-2 antibodies in therapeutic immunoglobulin and their impact on serological response to COVID-19 mRNA vaccine in patients with intravenous immunoglobulin (IVIg)-treated chronic immune neuropathies.

METHODS

Forty-six samples of different brands or lots of IVIg or subcutaneous IgG were analyzed for anti-SARS-CoV-2 IgG using enzyme-linked immunosorbent assay and chemiluminescent microparticle immunoassay. Blood sera from 16 patients with immune neuropathies were prospectively analyzed for anti-SARS-CoV-2 IgA, IgG, and IgM before and 1 week after IVIg infusion subsequent to consecutive COVID-19 mRNA vaccine doses and after 12 weeks. These were compared to 42 healthy subjects.

RESULTS

Twenty-four (52%) therapeutic immunoglobulin samples contained anti-SARS-CoV-2 IgG. All patients with immune neuropathies (mean age = 65 ± 16 years, 25% female) were positive for anti-SARS-CoV-2 IgG after COVID-19 vaccination. Anti-SARS-CoV-2 IgA titers significantly decreased 12-14 weeks after vaccination (p = 0.02), whereas IgG titers remained stable (p = 0.2). IVIg did not significantly reduce intraindividual anti-SARS-CoV-2 IgA/IgG serum titers in immune neuropathies (p = 0.69). IVIg-derived anti-SARS-CoV-2 IgG did not alter serum anti-SARS-CoV-2 IgG decrease after IVIg administration (p = 0.67).

CONCLUSIONS

Our study indicates that IVIg does not impair the antibody response to COVID-19 mRNA vaccine in a short-term observation, when administered a minimum of 2 weeks after each vaccine dose. The infusion of current IVIg preparations that contain anti-SARS-CoV-2 IgG does not significantly alter serum anti-SARS-CoV-2 IgG titers.

Association of plasma neurofilament light chain with disease activity in chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND AND PURPOSE

This study was undertaken to explore associations between plasma neurofilament light chain (pNfL) concentration (pg/ml) and disease activity in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and examine the usefulness of pNfL concentrations in determining disease remission.

METHODS

We examined pNfL concentrations in treatment-naïve CIDP patients (n = 10) before and after intravenous immunoglobulin (IVIg) induction treatment, in pNfL concentrations in patients on maintenance IVIg treatment who had stable (n = 15) versus unstable disease (n = 9), and in clinically stable IVIg-treated patients (n = 10) in whom we suspended IVIg to determine disease activity and ongoing need for maintenance IVIg. pNfL concentrations in an age-matched healthy control group were measured for comparison.

RESULTS

Among treatment-naïve patients, pNfL concentration was higher in patients before IVIg treatment than healthy controls and subsequently reduced to be comparable to control group values after IVIg induction. Among CIDP patients on IVIg treatment, pNfL concentration was significantly higher in unstable patients than stable patients. A pNFL concentration > 16.6 pg/ml distinguished unstable treated CIDP from stable treated CIDP (sensitivity = 86.7%, specificity = 66.7%, area under receiver operating characteristic curve = 0.73). Among the treatment withdrawal group, there was a statistically significant correlation between pNfL concentration at time of IVIg withdrawal and the likelihood of relapse (r = 0.72, p < 0.05), suggesting an association of higher pNfL concentration with active disease.

CONCLUSIONS

pNfL concentrations may be a sensitive, clinically useful biomarker in assessing subclinical disease activity.

Prevalence of chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy in two regions of Australia

INTRODUCTION/AIMS

Immune-mediated neuropathies such as chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) produce significant disability and often require maintenance treatment. There is a paucity of epidemiological data on these conditions in Australia.

METHODS

We undertook a prevalence study of CIDP and MMN in North Queensland and Tasmania, coinciding with a national census. Diagnoses were classified against the diagnostic criteria of the European Federation of Neurological Societies/Peripheral Nerve Society. Case ascertainment was undertaken via multiple methods, including survey of local neurologists across public and private clinics, search of neurophysiology, neurology and hospital databases, search of admitted hospital database collections using ICD codes and through immunoglobulin therapy prescription lists.

RESULTS

The crude prevalence of CIDP was 5.00 per 100,000 (95% confidence interval [CI] 3.79-6.62) and the crude prevalence of MMN was 1.33 per 100,000 (95% CI 0.78-2.27). Prevalence was also investigated using National Blood Authority numbers of cases prescribed immunoglobulin therapy, indicating a CIDP prevalence of 5.72 per 100,000 (95% CI 4.41-7.43) and MMN prevalence of 1.94 per 100,000 (95% CI 1.24-3.03). There was no significant difference between these numbers and those calculated through access of patient records locally. There was no significant difference in prevalence between Tasmania and North Queensland for any category.

DISCUSSION

This study updates the prevalence of CIDP and MMN in Australia. Understanding the distribution of CIDP and MMN patients and their need for treatment is essential for future resource planning and to enable monitoring and coordination of therapies such as immunoglobulin.

A first case of childhood chronic inflammatory demyelinating polyneuropathy associated with alopecia universalis

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired demyelinating disease of the peripheral nervous system with unknown etiology. Alopecia universalis, an advanced form of alopecia areata (AA), is a condition characterized by complete hair loss. Here we report the first case of childhood CIDP associated with AA who was successfully treated with a combination of intravenous immunoglobulin (IVIg) and corticosteroids. CASE REPORT: This case describes a nine-year-old Japanese girl who developed alopecia, progressive muscle weakness, and eventually loss of walking ability (at ages 2, 4, and 7, respectively). She was treated with IVIg and prednisolone combination therapy, which improved muscle weakness and alopecia. She was positive for serum IgG-GM2 type anti-glycolipid antibodies, which may be associated with this rare combination of diseases.

Granulocyte-colony-stimulating Factor-resistant Neutropenia and Polyneuropathy Presenting as Severe Complications of Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) has multi-dimensional manifestations, including neutropenia and polyneuropathy. We herein report a 76-year-old woman with pSS initially presenting as severe granulocyte-colony-stimulating factor (G-CSF)-refractory neutropenia and axonal sensorimotor polyneuropathies (SMP). Systemic glucocorticoid administration had reduced neutrophil-associated immunoglobulin G (NAIgG) on the neutrophil surface as detected using flow cytometry, resulting in the development of neutropenia. A patient with pSS concomitant with axonal SMP might show severe neutropenia as aggressive autoimmune disease. Neutropenia can be treated with systemic glucocorticoids based on the assessment of NAIgG on the neutrophil surface.

Combined Central and Peripheral Demyelination in a Case With Sjogren Syndrome

INTRODUCTION

Combined central and peripheral demyelination (CCPD) is a rare entity in which central and peripheral nervous system demyelination coexist. Herein, we present a patient with coexistence of Sjögren syndrome (SS) and CCPD.

CASE REPORT

A 58-year-old female patient was admitted to our neurology clinic with paraparesis, difficulty walking, imbalance, and paresthesia. Neurological examination showed paraparesis, absence of lower extremity deep tendon reflex, sensory deficit at the T8 level, loss of deep sensory position, and vibration. Spinal magnetic resonance imaging revealed multiple focal T2-hyperintense and contrast-enhancing cord lesions. Fat-suppressed imaging disclosed T2 hyperintensity in lumbar nerve roots, diffuse linear enhancement of the cauda equina, and diffuse increased enhancement in lumbar nerve roots. Electrodiagnostic findings fulfilled the diagnostic criteria for chronic inflammatory demyelinating polyneuropathy. Extensive laboratory workup excluded all possible pathologies. The Schirmer test detected positive in both eyes and minor salivary gland biopsy resulted in grade 3. These results were consistent with SS. The patient received intravenous methylprednisolone, azathioprine hydroxychloroquine. Approximately 2 years later, her complaints had completely disappeared, except for mild sensory complaints.

CONCLUSION

It is unclear whether the association of central nervous system and peripheral nervous system demyelination and SS is a coincidence or a consequence. Our patient shows that patients with SS can have CCPD, and a significant clinical response can be obtained with early treatment. We hope that this unique case sheds light on the pathophysiology of CCPD.

Case report: Immunoadsorption therapy for anti-caspr1 antibody-associated nodopathy

Background and objectives

Several autoantibodies against proteins located at the node of Ranvier has been identified in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) in the last few years. Then a new concept, autoimmune nodo-paranodopathies was proposed. Cases of Caspr1 autoantibodies are the most rare. Here we describe an anti-Caspr1 nodopathy patient, summarized his clinical, physiological and pathological features.

Case presentation

We present the case of a 56-year-old male patient with proprioceptive loss, ataxia, coarse tremor and distal limb weakness without any painess and cranial involvement. Electrophysiological studies showed prolonged distal motor latencies, conduction slowing and reduced amplitude distal compound muscle action potential (CMAP) amplitude. Antibodies against the nodes of Ranvier in serum samples revealed a positive finding for the anti-Caspr1 antibody (1:10).Myelinated fiber loss could be revealed in nerve biopsy. Longitudinal ultrathin sections of the nodal region was discovered in electron microscope, the paranodal/nodal architecture was destructed. It was lack of transverse bands and enlargement of the space between the axon and the paranodal loops was seen. The patient improved obviously after three times immunoadsorption(IA) therapy.

Conclusion

Anti-Caspr1 nodopathy patient may present atypical symptoms without any neuropathic pain and cranial palsy. The destruction of paranodal/nodal architecture could be observed in nerve biopsy, which may be caused by the lost of axoglial complex formed by NF155, CNTN1 and Caspr1. Antibodies detection is important for the diagnosis, while IA therapy could be regarded as an option for the patients allergic to rituximab (RTX).

Relapsing MRI-negative myelitis associated with myelin-oligodendrocyte glycoprotein autoantibodies: a case report

Background

Serum antibodies to myelin-oligodendrocyte glycoprotein (MOG) are biomarkers of MOG-IgG-associated disorder (MOGAD), a demyelinating disease distinct from both multiple sclerosis and aquaporin-4-IgG neuromyelitis optica spectrum disorder. The phenotype of MOGAD is broad and includes optic neuritis, transverse myelitis, and acute demyelinating encephalomyelitis. Myelitis is common with MOGAD and typically results in acute and severe disability, although prospects for recovery are often favorable with prompt immunotherapy.

Case presentation

This contribution presents a unique case report of a young male patient exhibiting relapsing myelitis with normal spinal cord and brain magnetic resonance imaging. Comprehensive diagnostic assessment revealed myelin-oligodendrocyte glycoprotein-IgG-associated disorder.

Conclusion

MOGAD is one of the conditions which should be considered in MRI-negative myelitis. The diagnosis, however, may prove difficult, especially if the patient is not exhibiting other neurological symptoms of MOGAD. Conus or epiconus involvement is common in MOGAD; the patient reported herein exhibited incomplete rostral epiconus symptoms which, together with somatosensory evoked potential abnormalities, led to the diagnosis.

Versorgungssituation von CIDP-Patienten in neun deutschen Zentren des Neuritis Netzes

Hintergrund

Die Diagnose und Behandlung von Patienten mit immunvermittelten Polyneuropathien ist aufgrund der Heterogenität der Erkrankungen herausfordernd.

Ziel der Arbeit

Ein aktueller epidemiologischer Überblick über die Versorgungssituation von Patienten mit immunvermittelten Polyneuropathien innerhalb des deutschen Neuritis-Netzwerks „Neuritis Netz“.

Material und Methoden

Es erfolgte eine Umfrage in neun deutschen neurologischen Zentren, die auf die Betreuung von Patienten mit Immunneuropathie spezialisiert sind. Wir erfassten Diagnose, Vorgehen in der Diagnostik und Nachsorge, typische Symptome bei Manifestation und im Krankheitsverlauf sowie Therapiedaten.

Ergebnisse

Die Erhebung umfasst Daten von 1529 jährlich behandelten Patienten mit Immunneuropathien, 1320 davon mit chronisch inflammatorisch demyelinisierender Polyneuropathie (CIDP). Die Diagnostik umfasste fast immer Lumbalpunktionen sowie Elektroneuro- und -myografien entsprechend den aktuellen Leitlinien. Der Einsatz von Ultraschall, Biopsie und MRT war unterschiedlich. Wichtigster klinischer Parameter zum Therapiemonitoring in allen Zentren war die motorische Funktion in den klinischen Nachuntersuchungen. Zur Erhaltungstherapie wurde bei rund 15 % der Patienten ein breites Spektrum unterschiedlicher Immunsuppressiva eingesetzt.

Diskussion

Die Studie liefert wichtige epidemiologische Daten zur aktuellen Versorgungsituation von Patienten mit Immunneuropathien in Deutschland. Die Weiterentwicklung spezifischer Empfehlungen zur Therapie und Nachverfolgung von CIDP-Patienten ist notwendig, um einen einheitlichen Standard der Patientenversorgung zu gewährleisten. Dieses wird durch die strukturierte Zusammenarbeit von Exzellenzzentren wie dem deutschen Neuritis Netz erheblich unterstützt.

ALSUntangled #65: glucocorticoid corticosteroids

ALSUntangled reviews alternative and off-label treatments for people with amyotrophic lateral sclerosis (PALS). Here we review glucocorticoids. Neuroinflammation plays a prominent role in amyotrophic lateral sclerosis (ALS) pathogenesis, so some hypothesize that glucocorticoids might be an effective ALS therapy through their immunosuppressive effects. In this paper, we review the available evidence for glucocorticoids in ALS, including one pre-clinical study with a genetic mouse model of ALS, nine case reports (ranging from 1 to 26 patients each), and four clinical trials. We also review the possible side effects (including steroid myopathy) and the costs of therapy. We graded the level of evidence as follows: Mechanism, D; Pre-Clinical, F; Cases, B; Trials, F; Risks, C. Our review of the current evidence concludes that glucocorticoids do not offer clinical benefit in ALS and confer serious risks. Thus, ALSUntangled does not recommend glucocorticoids as a treatment for ALS.

Anti-disialosyl-IgM chronic autoimmune neuropathies: a nationwide multicenter retrospective study

BACKGROUND & PURPOSE

In this retrospective study involving 14 University Hospitals from France and Switzerland, we aimed at defining the clinicopathologic features of chronic neuropathies with anti-disialosyl ganglioside IgM antibodies (CNDA).

RESULTS

Fifty-five patients with a polyneuropathy evolving for more than 2 months and with at least one anti-disialosyl ganglioside IgM antibody, i.e., anti-GD1b, -GT1b, -GQ1b, -GT1a, -GD2 and -GD3 were identified. Seventy-eight percent of patients were male, mean age at disease onset was 55 years (30-76), and disease onset was progressive (82%) or acute (18%). Patients presented with limb sensory symptoms (94% of cases), sensory ataxia (85%), oculomotor weakness (36%), limb motor symptoms (31%), and bulbar muscles weakness (18%). Sixty-five percent of patients had a demyelinating polyradiculoneuropathy electrodiagnostic profile, and 24% a sensory neuronopathy profile. Anti-GD1b antibodies were found in 78% of cases, while other anti-disialosyl antibodies were each observed in less than 51% of patients. Other features included nerve biopsy demyelination (100% of cases), increased cerebrospinal fluid protein content (75%), IgM paraprotein (50%), and malignant hemopathy (8%). Eighty six percent of CNDA patients were intravenous immunoglobulins (IVIg)-responsive, and rituximab was successfully used as second-line treatment in 50% of cases. Fifteen percent of patients had mild symptoms and were not treated. CNDA course was progressive (55%) or relapsing (45%), and 93% of patients still walked after a mean disease duration of 11 years.

CONCLUSION

CNDA have a recognizable phenotype, are mostly IgIV-responsive, and present with a good outcome in a majority of cases.

Zuverlässigkeit der Elektroneuro-, myografie: Aspekte zur neurologischen Begutachtung

Von einem Gutachten wird eine zuverlässige Bewertung erwartet. Aspekte der Zuverlässigkeit der Elektroneuro-, myografie werden vorgestellt. Ihre Bedeutung für die Begutachtung wird mit Blick auf Diagnostik und das Ausmaß eines ggf. vorhandenen funktionellen Defizits besprochen.

Protocol of comparison of the effects of single plasma exchange and double filtration plasmapheresis on peripheral lymphocyte phenotypes in patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy: a monocentric prospective study with single-case experimental design

BACKGROUND

Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP), a rare disorder affecting young adults, causes gradual weakness of the limbs, areflexia and impaired sensory function. New CIDP phenotypes without pathogenic antibodies but with modified cell profiles have been described. Treatments include corticotherapy, intravenous immunoglobulins, and plasmapheresis but the latter's action mechanisms remain unclear. Plasmapheresis supposedly removes toxic agents like antibodies from plasma but it is uncertain whether it has an immune-modulating effect. Also, the refining mechanisms of the two main plasmapheresis techniques-single plasma exchange and double filtration plasmapheresis (DFPP) - are different and unclear. This study aims to compare the evolution of peripheral lymphocyte profiles in patients with CIDP according to their treatment (single centrifugation plasmapheresis or DFPP) to better grasp the action mechanisms of both techniques.

METHOD

In this proof-of-concept, monocentric, prospective, Single-Case Experimental Design study, 5 patients are evaluated by alternating their treatment type (single plasma exchange or DFPP) for 6 courses of treatment after randomization to their first treatment type. Each course of treatment lasts 2-4 weeks. For single plasma exchange, 60 ml/kg plasma will be removed from the patient and replaced with albumin solutes, with a centrifugation method to avoid the immunological reaction caused by the membrane used with the filtration method. For DFPP, 60 ml/kg plasma will be removed from the patient with a plasma separator membrane, then processed via a fractionator membrane to remove molecules of a greater size than albumin before returning it to the patient. This technique requires no substitution solutes, only 20 g of albumin to replace what would normally be lost during a session. The primary outcome is the difference between the two plasmapheresis techniques in the variation of the TH1/TH17 ratio over the period D0H0-D0H3 and D0H0-D7. Secondary outcomes include the variation in lymphocyte subpopulations at each session and between therapeutic plasmapheresis techniques, the clinical evolution, tolerance and cost of treatments.

DISCUSSION

Understanding the action mechanisms of single plasma exchange and DFPP will help us to offer the right treatment to each patient with CIPD according to efficacy, tolerance and cost.

TRIAL REGISTRATION

ClinicalTrials.gov under the no. NCT04742374 and date of registration 10 December 2020.

Effect of low-dose rituximab treatment on autoimmune nodopathy with anti-contactin 1 antibody

Background

Autoimmune nodopathy with anti-contactin-1 (CNTN1) responds well to rituximab instead of traditional therapies. Although a low-dose rituximab regimen was administered to patients with other autoimmune diseases, such as myasthenia gravis and neuromyelitis optica spectrum disorders, and satisfactory outcomes were obtained, this low-dose rituximab regimen has not been trialed in anti-CNTN1-positive patients.

Methods

Anti–CNTN1 nodopathy patients were enrolled in this prospective, open-label, self-controlled pilot study. A cell-based assay was used to detect anti-CNTN1 antibodies and their subclasses in both serum and cerebrospinal fluid. Clinical features were evaluated at baseline, 2 days, 14 days, and 6 months after single low-dose rituximab treatment (600 mg). The titers of the subclasses of anti-CNTN1 antibody and peripheral B cells were also evaluated at baseline, 2 days, and 6 months after the rituximab regimen.

Results

Two patients with anti–CNTN1 antibodies were enrolled. Both patients had neurological symptoms including muscle weakness, tremor, sensory ataxia, numbness and mild nephrotic symptoms. In the field of neurological symptoms, sensory ataxia markedly improved, and the titer of anti-CNTN1 antibody as well as CD19+ B cells decreased only two days following low-dose rituximab treatment. Other neurological symptoms improved within two weeks of rituximab treatment. At the 6-month follow-up, all neurological symptoms steadily improved with steroid reduction, and both the anti-CNTN1 antibody titer and CD19+ B cells steadily decreased. No adverse events were observed after this single low-dose rituximab treatment.

Conclusions

We confirmed the clinical efficacy of low-dose rituximab by B cell depletion in autoimmune nodopathy with anti-CNTN1 antibody. This rapid and long-lasting response suggests that low-dose rituximab is a promising option for anti-CNTN1 nodopathy.

Cyclophosphamide for Treatment of Refractory Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Systematic Review and Meta-analysis

PURPOSE

This study evaluates the tolerability and efficacy of cyclophosphamide (CYC) for the treatment of refractory chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

We searched PubMed, Embase, Cochrane Library, and 2 Chinese databases (Chinese National Knowledge Infrastructure and SinoMed) for studies published between database inception and September 30, 2021. Articles obtained using the appropriate keywords were independently selected by 2 reviewers on the basis of the established inclusion and exclusion criteria.

FINDINGS

In total, 240 records that were eventually curtailed to 13 studies with 83 patients were retrieved and subsequently included in this evaluation. All 13 studies were included in the systematic review, 7 of which were included in the meta-analysis. The pooled estimate of the response rate was 68% (95% CI, 45%-90%). The pooled estimate of the adverse reaction rate was 8% (95% CI, 0%-15%). The disease duration before the first CYC treatment was negatively correlated with the reduction in the modified Rankin Scale score (r = -0.76, P < 0.001). However, the response rates did not differ significantly between patients of different sexes (P = 0.716) or between patients who received and those who did not receive concurrent glucocorticoids (P = 0.617).

IMPLICATIONS

CYC might be a recommended therapeutic option for patients with refractory CIDP, especially those who are unable to accept rituximab treatment. Earlier CYC treatment yields better therapeutic outcomes in patients with refractory CIDP without CYC-related contraindications.

The diversity of hereditary neuromuscular diseases: Experiences from molecular diagnosis

BACKGROUND

Hereditary neuromuscular diseases (NMDs) are a group of rare disorders, and the diagnosis of these diseases is a substantial burden for referral centers. Although next-generation sequencing (NGS) has identified a large number of genes associated with hereditary NMDs, the diagnostic rates still vary across centers.

METHODS

Patients with a suspected hereditary NMD were referred to neuromuscular specialists at the National Taiwan University Hospital. Molecular diagnoses were performed by employing a capture panel containing 194 genes associated with NMDs.

RESULTS

Among the 50 patients referred, 43 had a suspicion of myopathy, and seven had polyneuropathy. The overall diagnostic rate was 58%. Pathogenic variants in 19 genes were observed; the most frequent pathogenic variant found in this cohort (DYSF) was observed in only four patients, and 10 pathogenic variants were observed in one patient each. One case of motor neuron disease was clinically mistaken for myopathy. A positive family history increased the diagnostic rate (positive: 72.7% vs. negative: 56.3%). Fourteen patients with elevated plasma creatine kinase levels remained without a diagnosis.

CONCLUSION

The application of NGS in this single-center study proves the great diversity of hereditary NMDs. A capture panel is essential, but high-quality clinical and laboratory evaluations of patients are also indispensable.

A rare presentation of POEMS syndrome on magnetic resonance neurography: a case series

Polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS) syndrome is a multisystem disease associated with underlying plasma cell neoplasm. Here, we present two cases of POEMS syndrome that manifested on magnetic resonance neurography as an increasing bone mass with cortical disruption, direct invading nerve roots and lumbar gluteal muscles. These features have not been previously reported. We also report a case with diffuse hypertrophy and enhancement of the brachial and lumbosacral plexus, which mimics the most common chronic inflammatory demyelinating polyradiculoneuropathy. Moreover, we detected perineurium effusions in the plexus, coupled with a variety of myofascitis and atrophy in denervated muscle. The case series is of concern to atypical magnetic resonance imaging findings of POEMS syndrome in the bone and peripheral nerve system as critical attacked target organs, which would be facilitating diagnosis.

Rituximab Responsive Relapsing-Remitting IgG4 Anticontactin 1 Chronic Inflammatory Demyelinating Polyradiculoneuropathy Associated With Membranous Nephropathy: A Case Description and Brief Review

ABSTRACT

Nodal/paranodal IgG4-related chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) rarely involves anticontactin (CNTN1) subtype and exceptionally complicates with nephrotic syndrome. A 65-year-old man developed weakness, facial palsy, and balance impairment; after spontaneous recovery, he severely relapsed 1 month later. Electroneuromyography confirmed CIDP. Proteinorachy (462 mg/dL; N < 45), proteinuria (3.5 g/g creatine), and biopsy-proven membranous nephropathy were identified. Intravenous immunoglobulins, corticosteroids, and plasmaphereses did not allow recovery. Anti-CNTN1 immunoglobulin G4 (IgG4) assay was positive. Rituximab (375 mg/m2/week, 4 weeks) provided obvious improvement. Relapsing-remitting anti-CNTN1-CIDP co-occurring with nephrotic syndrome is exceptional, and its identification is essential because efficient therapies such as rituximab are available for this severe condition.

Nerve ultrasound characteristics of immunoglobulin M neuropathy associated with anti-myelin-associated glycoprotein antibodies

INTRODUCTION/AIMS

Immunoglobulin M neuropathy associated with anti-myelin-associated glycoprotein antibody (IgM/anti-MAG) neuropathy typically presents with chronic, distal-dominant symmetrical sensory or sensorimotor deficits. Ultrasonographic studies of IgM/anti-MAG neuropathy are limited, and were all performed on Western populations. We aimed to characterize the nerve ultrasonographic features of IgM/anti-MAG neuropathy in the Japanese population and evaluate whether they differ from the findings of the common subtypes of chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

In this cross-sectional study, we retrospectively reviewed medical records and extracted the cross-sectional areas (CSAs) of C5-C7 cervical nerve roots and median and ulnar nerves of 6 IgM/anti-MAG neuropathy patients, 10 typical CIDP (t-CIDP) patients, 5 multifocal CIDP (m-CIDP) patients, and 17 healthy controls (HCs).

RESULTS

Cervical nerve root CSAs were significantly larger at every examined site on both sides in IgM/anti-MAG neuropathy than in m-CIDP and HCs but were comparable to those in t-CIDP. Peripheral nerve enlargements were greatest at common entrapment sites (ie, wrist and elbow) in IgM/anti-MAG neuropathy, a pattern shared with t-CIDP but not with m-CIDP. The degree of nerve enlargement at entrapment sites compared to non-entrapment sites was significantly higher in IgM/anti-MAG neuropathy than in t-CIDP.

DISCUSSION

Our study delineated the ultrasonographic features of IgM/anti-MAG neuropathy in the Japanese population and observed similar characteristics to those of t-CIDP, with subtle differences. Further studies comparing results from various populations are required to optimize the use of nerve ultrasound worldwide.

Neurofilament light chain and total tau in the differential diagnosis and prognostic evaluation of acute and chronic inflammatory polyneuropathies

Background and Purpose

To investigate the diagnostic and prognostic value of axonal injury biomarkers in patients with inflammatory polyneuropathies.

Methods

Neurofilament light chain (NfL) and total tau (T‐tau) were measured in the cerebrospinal fluid (CSF) and plasma in 41 patients with Guillain–Barré syndrome (GBS), 32 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 10 with paraproteinemia‐related demyelinating polyneuropathy (PDN), and 8 with multifocal motor neuropathy (MMN), in comparison with 39 disease‐free controls and 59 other controls. Outcome was measured with the GBS‐disability score (GBS‐ds) or Inflammatory Neuropathy Cause and Treatment (INCAT) disability score.

Results

Neurofilament light chain levels in CSF and plasma were higher in GBS, CIDP, and PDN vs. disease‐free controls. Patients with MMN had higher NfL levels in plasma vs. disease‐free controls, but lower levels in CSF and plasma vs. patients with amyotrophic lateral sclerosis (ALS).

T‐tau levels in plasma were higher in GBS, CIDP, PDN, and MMN vs. all control groups.

Neurofilament light chain levels in CSF and plasma in patients with GBS correlated with GBS‐ds, as higher levels were associated with inability to run after 6 and 12 months. NfL levels in CSF and plasma in CIDP did not correlate significantly with outcome.

Conclusions

Acute and chronic inflammatory neuropathies are associated with an increase in levels of NfL in CSF and plasma, but NfL is validated as a prognostic biomarker only in GBS. NfL could be used in differentiating patients with MMN from ALS. T‐tau in plasma is a novel biomarker that could be used in a diagnostic assessment of patients with acute and chronic inflammatory polyneuropathies.

Nerve Echogenicity in Polyneuropathies of Various Etiologies-Results of a Retrospective Semi-Automatic Analysis of High-Resolution Ultrasound Images

Echogenicity of peripheral nerves in high-resolution ultrasound (HRUS) provides insight into the structural damage of peripheral nerves in various polyneuropathies. The aim of this study was to compare nerve echogenicity in different primarily axonal or demyelinating polyneuropathies to examine the significance of this parameter. Performing semi-automated echogenicity analysis and applying Image J, we retrospectively used HRUS images of 19 patients with critical illness polyneuropathy (CIP), and 27 patients with chemotherapy-induced polyneuropathy (CIN) and compared them to 20 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). The fraction of black representing echogenicity was measured after converting the images into black and white. The nerves of patients with progressive CIDP significantly differed from the hyperechogenic nerves of patients with other polyneuropathies at the following sites: the median nerve at the forearm (p < 0.001), the median nerve at the upper arm (p < 0.004), and the ulnar nerve at the upper arm (p < 0.001). The other polyneuropathies showed no notable differences. Altogether, the comparison of echogenicity between different polyneuropathies supports the assumption that there are differences depending on the genesis of the structural nerve damage. However, these differences are slight, and cannot be used to show clear differences between each polyneuropathy form.

Identification and clinical characterization of Charcot-Marie-Tooth disease type 1C patients with LITAF p.G112S mutation

BACKGROUND

Charcot-Marie-Tooth disease type 1C (CMT1C) is a rare subtype associated with LITAF gene mutations. Until now, only a few studies have reported the clinical features of CMT1C.

OBJECTIVE

This study was performed to find CMT1C patients with mutation of LITAF in a Korean CMT cohort and to characterize their clinical features.

METHODS

In total, 1,143 unrelated Korean families with CMT were enrolled in a cohort. We performed whole exome sequencing to identify LITAF mutations, and examined clinical phenotypes including electrophysiological and MRI features for the identified CMT1C patients.

RESULTS

We identified 10 CMT1C patients from three unrelated families with p.G112S mutation in LITAF. The frequency of CMT1C among CMT1 patients was 0.59%, which is similar to reports from Western populations. CMT1C patients showed milder symptoms than CMT1A patients. The mean CMT neuropathy score version 2 was 7.7, and the mean functional disability scale was 1.0. Electrophysiological findings showed a conduction block in 22% of affected individuals. Lower extremity MRIs showed that the superficial posterior and anterolateral compartments of the calf were predominantly affected.

CONCLUSIONS

We found a conduction block in Korean CMT1C patients with p.G112S mutation and first described the characteristic MRI findings of the lower extremities in patients with LITAF mutation. These findings will be helpful for genotype-phenotype correlation and will widen understanding about the clinical spectrum of CMT1C.

Amyotrophic lateral sclerosis mimics

Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disorder characterized by progressive degeneration of cortical, bulbar, and spinal motor neurons. When a patient presents with a progressive upper and/or lower motor syndrome, clinicians must pay particular attention to any atypical features in the history and/or clinical examination suggesting an alternate diagnosis, as up to 10% percent of patients initially diagnosed with ALS have a mimic of ALS. ALS is a clinical diagnosis and requires the exclusion of other disorders that may have similar presentations but a more favorable prognosis or an effective therapy. Because there is currently no specific diagnostic biomarker that is sensitive or specific for ALS, understanding the spectrum of clinical presentations of ALS and its mimics is paramount. While true mimics of ALS are rare, the clinician must correctly identify these disorders to avoid the misdiagnosis of ALS and to initiate effective treatment where available.

Clinical Course and Diagnostic Findings of Biopsy Controlled Presumed Immune-Mediated Polyneuropathy in 70 European Cats

There is a paucity of information on the clinical course and outcome of young cats with polyneuropathy. The aim of the study was to describe the clinical features, diagnostic investigations, and outcome of a large cohort of cats with inflammatory polyneuropathy from several European countries. Seventy cats with inflammatory infiltrates in intramuscular nerves and/or peripheral nerve biopsies were retrospectively included. Information from medical records and follow up were acquired via questionnaires filled by veterinary neurologists who had submitted muscle and nerve biopsies (2011-2019). Median age at onset was 10 months (range: 4-120 months). The most common breed was British short hair (25.7%), followed by Domestic short hair (24.3%), Bengal cat (11.4%), Maine Coon (8.6%) and Persian cat (5.7%), and 14 other breeds. Male cats were predominantly affected (64.3%). Clinical signs were weakness (98.6%) and tetraparesis (75.7%) in association with decreased withdrawal reflexes (83.6%) and, less commonly, cranial nerve signs (17.1%), spinal pain/hyperesthesia (12.9%), and micturition/defecation problems (14.3%). Onset was sudden (30.1%) or insidious (69.1%), and an initial progressive phase was reported in 74.3%. Characteristic findings on electrodiagnostic examination were presence of generalized spontaneous electric muscle activity (89.6%), decreased motor nerve conduction velocity (52.3%), abnormal F-wave studies (72.4%), pattern of temporal dispersion (26.1%) and unremarkable sensory tests. The clinical course was mainly described as remittent (49.2%) or remittent-relapsing (34.9%), while stagnation, progressive course or waxing and waning were less frequently reported. Relapses were common and occurred in 35.7% of the cats' population. An overall favorable outcome was reported in 79.4% of patients. In conclusion, young age at the time of diagnosis and sudden onset of clinical signs were significantly associated with recovery (p < 0.05). Clinical and electrodiagnostic features and the remittent-relapsing clinical course resembles juvenile chronic inflammatory demyelinating polyneuropathy (CIDP), as seen in human (children/adolescents), in many aspects.

Neurological complications in adult allogeneic hematopoietic stem cell transplant patients: Incidence, characteristics and long-term follow-up in a multicenter series

Neurological complications (NCs) represent a diagnostic and clinical challenge in allogeneic hematopoietic stem cell transplant (alloHSCT) patients. We retrospectively analyzed NC incidence, etiology, timing, characteristics, outcome, and long-term effects in 2384 adult patients transplanted in seven Italian institutions between January 2007 and December 2019. Ninety-three (3.9%) patients were affected by 96 NCs that were infectious (29.2%), immune/inflammatory (26%), drug-related (12.5%), cerebrovascular (5.2%), metabolic (3.1%), related to central nervous system disease relapse (11.5%) and malignancy (3.1%), or undefined (9.4%). Six patients (6.4%) had neurological manifestations of chronic graft-versus-host disease (GVHD). NCs occurred on average at day +128 (from -5 to +4063). Early (< day +120) and late NCs had similar frequencies (46.9% vs 53.1%, p = 0.39). Thirty-one patients (33.3%) were affected by acute or chronic GVHD at the NC onset. With a median follow-up of 25.4 (0.4-163) months, the overall mortality due to NCs was 22.6%. The median time between NC onset and death was 36 (1-269) days. Infectious NCs were the main cause (61.9%) of NC-related mortality. A persistent neurological impairment occurred in 20.4% patients, 57.9% of whom being affected by immune/inflammatory NCs. This study highlights the rare, yet severe impact of alloHSCT-associated NCs on patient survival and long-term functional ability.

Inflammatory demyelinating polyneuropathy after the ChAdOx1 nCoV-19 vaccine may follow a chronic course

Background

Methods

Conclusions

Diabetes Mellitus Is a Possible Risk Factor for Nodo-paranodopathy With Antiparanodal Autoantibodies

Background and Objectives

Nodo-paranodopathies are peripheral neuropathies with dysfunction of the node of Ranvier. Affected patients who are seropositive for antibodies against adhesion molecules like contactin-1 and neurofascin show distinct clinical features and a disruption of the paranodal complex. An axoglial dysjunction is also a characteristic finding of diabetic neuropathy. Here, we aim to investigate a possible association of antibody-mediated nodo-paranodopathy and diabetes mellitus (DM).

Methods

We retrospectively analyzed clinical data of 227 patients with chronic inflammatory demyelinating polyradiculoneuropathy and Guillain-Barré syndrome from multiple centers in Germany who had undergone diagnostic testing for antiparanodal antibodies targeting neurofascin-155, pan-neurofascin, contactin-1–associated protein 1, and contactin-1. To study possible direct pathogenic effects of antiparanodal antibodies, we performed immunofluorescence binding assays on human pancreatic tissue sections.

Results

The frequency of DM was 33.3% in seropositive patients and thus higher compared with seronegative patients (14.1%, OR = 3.04, 95% CI = 1.31–6.80). The relative risk of DM in seropositive patients was 3.4-fold higher compared with the general German population. Seropositive patients with DM most frequently harbored anti–contactin-1 antibodies and had higher antibody titers than seropositive patients without DM. The diagnosis of DM preceded the onset of neuropathy in seropositive patients. No immunoreactivity of antiparanodal antibodies against pancreatic tissue was detected.

Discussion

We report an association of nodo-paranodopathy and DM. Our results suggest that DM may be a potential risk factor for predisposing to developing nodo-paranodopathy and argue against DM being induced by the autoantibodies. Our findings set the basis for further research investigating underlying immunopathogenetic connections.

A Retrospective Study of Ultrasound Accuracy for the Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy

INTRODUCTION

Ultrasound is emerging as a useful tool for the evaluation of immune-mediated neuropathies because it can provide high-resolution anatomic information to complement electrodiagnostic data. Nerve enlargements are commonly found in chronic inflammatory demyelinating polyneuropathy (CIDP), and their presence likely useful in diagnosis, particularly if multifocal.

METHODS

In this study, the authors undertook a retrospective chart review to identify ultrasound findings in patients with CIDP previously studied in a single busy neurodiagnostic laboratory.

RESULTS

Of the 50 cases identified from 2000 to 2017, individuals with a confirmed diagnosis of CIDP (21 cases) were more likely to have multiple sites of enlargement, as well as more pronounced nerve enlargement, than patients who were subsequently found to have an alternate cause of neuropathy (22 cases). The presence of any moderately enlarged nerve segment predicted definite CIDP with sensitivity of 81% and specificity 77%.

CONCLUSION

This study demonstrates that ultrasound can be of diagnostic utility in patients with suspected CIDP, even when conducted in a nonstandardized real-world setting.

Temporal Dispersion and Duration of the Distal Compound Muscle Action Potential Do Not Distinguish Diabetic Sensorimotor Polyneuropathy From Chronic Inflammatory Demyelinating Polyneuropathy

Objective

To investigate the contribution of duration and temporal dispersion (TD) of the distal compound muscle action potential (CMAP) in discriminating chronic inflammatory demyelinating polyneuropathy (CIDP) from diabetic sensorimotor polyneuropathy (DSP) and from CIDP+DSP.

Methods

We performed a retrospective review of patients diagnosed with CIDP, DSP and CIDP+DSP (responsive to immunotherapy) and examined differences in CMAP duration and TD at baseline.

Results

We included 59 subjects: 17 CIDP, 21 DSP and 21 CIDP+DSP. Of these, 16 (94.1%) CIDP, 18 (85.7%) CIDP+DSP and 1 (4.7%) DSP fulfilled the 2010 EFNS/PNS criteria for definite CIDP. There was no difference in CMAP duration or TD in all nerves (compound outcome) or in individual motor nerves. Patients with CIDP/CIDP+DSP had more conduction blocks, slower conduction velocities and more prolonged F wave latencies than those with DSP.

Conclusion

Measures of CMAP duration and TD were not helpful in distinguishing CIDP, DSP or CIDP+DSP patients; however, parameters such as F-wave latencies, conduction blocks or the number of demyelinating parameters were useful in this separation.

Significance

There are no definite nerve conduction criteria to distinguish patients with CIDP+DSP from DSP alone. Further studies focusing on measures of demyelination may provide stronger evidence to guide treatment decisions in CIDP + DSP patients.

Prevalence and determinants of pain in chronic inflammatory demyelinating polyneuropathy: results from the German INHIBIT registry

INTRODUCTION

Pain, fatigue and depression in chronic inflammatory demyelinating polyneuropathy (CIDP) are often underestimated, as the focus lies on sensorimotor dysfunction and gait instability. The aim of this study was to investigate their prevalence, characteristics and contribution to disability in a prospective cohort of 84 patients with CIDP.

METHODS

Pain, fatigue, depression and quality of life were measured using Pain Detect Questionnaire, Krupp's Fatigue Severity Scale, Beck Depression Inventory-II and German Short-Form-36 Health Survey. Sensorimotor deficits and disability were assessed using the Inflammatory Neuropathy Cause and Treatment overall disability score, the Rasch-built Overall Disability Scale, the Medical Research Council Sum Score and the INCAT-sensory sum-score. The interrelation between the five factors was assessed using analysis of variance and linear regression analysis.

RESULTS

Pain was reported in 62%, mostly of moderate and severe intensity, whereas pain characteristics indicated of neuropathic pain (NP) in 29%. Sensory dysfunction was stronger in NP-patients compared to pain-free patients (p=0.001). Pain of any type, especially NP, was associated with more pronounced fatigue symptoms (p=0.010). Depressive symptoms were more frequent in patients with pain compared to the pain-free patients (61% vs. 33%, p=0.02) and were more severe and frequent in NP-patients than in non-NP (p=0.005). Patients with pain had a worse physical quality of life than pain-free patients (p=0.001).

CONCLUSION

Pain, depression and fatigue are relevant disability factors in CIDP affecting quality of life. Sensory dysfunction is associated with NP. Therefore, evaluation of CIDP-related disability should include pain and sensory function for adequate monitoring of therapeutic interventions.

[65 years old man of chronic inflammatory demyelinating polyneuritis (CIDP) which presented radicular swelling and was able to confirm image progress before the onset]

The case is a 65 years old man. He noticed muscle weakness of lower limbs from 3 years ago. Dysesthesia was developed, He came in our hospital in X year. He was detected muscle weakness, sensory disturbance in distal lower limbs predominance and detected radicular significant swelling in spinal cord MRI and diagnosed it with chronic inflammatory demyelinating polyneuritis (CIDP). In the follow-up purpose of other diseases regularly, it was confirmed that nerve root was gradually swelling from around 7 years before the onset. The radicular swelling is one of the characteristics in CIDP, supports the diagnosis. This case was the valuable case that was able to chase image progress before the onset.

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): Current Therapies and Future Approaches

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated polyradiculoneuropathy leading to disability via inflammatory demyelination of peripheral nerves. Various therapeutic approaches with different mechanisms of action are established for the treatment of CIDP. Of those, corticosteroids, intravenous or subcutaneous immunoglobulin, or plasma exchange are established first-line therapies as suggested by the recently revised EAN/PNS guidelines for the management of CIDP. In special cases, immunosuppressants or rituximab may be used. Novel therapeutic approaches currently undergoing clinical studies include molecules or monoclonal antibodies interacting with Fc receptors on immune cells to alleviate immune-mediated neuronal damage. Despite various established therapies and the current development of novel therapeutics, treatment of CIDP remains challenging due to an inter-individually heterogeneous disease course and the lack of surrogate parameters to predict the risk of clinical deterioration.

Nerve Ultrasound Performances in Differentiating POEMS Syndrome from CIDP

Chronic inflammatory demyelinating polyneuropathy (CIDP) and polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome are both acquired demyelinating polyneuropathies. We aim to explore the different features of ultrasonographic changes between CIDP and POEMS syndrome. Nerve ultrasonographic studies were performed in 120 patients with CIDP and 34 patients with POEMS syndrome. Cross-sectional areas (CSAs) were measured on the bilateral median nerve, ulnar nerve, and brachial plexus. Nerve conduction studies were performed on median and ulnar nerves to detect motor conduction blocks (CBs). CSAs at all sites were larger in patients with CIDP and POEMS syndrome than in healthy controls. Maximal CSA (median (min to max)) was 14 (6-194) mm2 for median nerve, 9 (4-92) mm2 for ulnar nerve, and 14 (7-199) mm2 for brachial plexus in CIDP and 11 (8-16) mm2 for median nerve, 8.5 (6-13) mm2 for ulnar nerve, and 14 (10-20) mm2 for brachial plexus in POEMS syndrome. The ratio of maximum/minimum CSA of the median nerve was significantly larger in CIDP (2.8 ± 2.8) than in POEMS syndrome (1.7 ± 0.3). CBs or probable CBs were detected in 60 out of 120 CIDP patients but in none of the POEMS syndromes. For distinguishing CIDP and POEMS syndrome, a two-step protocol using CB and maximum/minimum CSA of the median nerve yields a sensitivity of 93% and a specificity of 79%. In conclusion, compared with CIDP, nerve CSA enlargement was more homogeneous along the same nerve in individual POEMS patients, as well as among different POEMS patients. The addition of nerve ultrasound to nerve conduction studies significantly improves the differential diagnosis between the two diseases.

Microstructural Alteration of Lumbosacral Nerve Roots in Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Insights From DTI and Correlations with Electrophysiological Parameters

RATIONALE AND OBJECTIVES

To detect the diffusion characteristics of lumbosacral nerve roots in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and further to explore their correlations with electrophysiological parameters of lower extremity nerves.

MATERIALS AND METHODS

Eighteen CIDP patients and 18 age and sex-matched healthy volunteers were enrolled in this study from August 2019 to August 2020. Axial diffusion tensor imaging (DTI) of lumbosacral plexus was performed in all subjects and fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) of lumbosacral nerve roots were measured. Two-sample t test or Mann-Whitney U test was used to compare the difference of DTI parameters between two groups. Receiver operating characteristic curves were plotted to determine the diagnostic accuracy. All patients also underwent nerve conduction studies. Correlations between DTI parameters of lumbosacral nerve roots and electrophysiological parameters were analyzed with Pearson or Spearman coefficients.

RESULTS

CIDP patients showed significantly lower FA as well as higher AD, RD, and MD values of lumbosacral nerve roots (FA:0.24±0.054, 0.32±0.044; AD:2.31±0.256, 2.11±0.230 (×10^-3mm²/s); RD:1.28±0.189, 1.13±0.106 (×10^-3mm²/s); MD:1.68±0.268, 1.45±0.186 (×10^-3mm²/s) in CIDP and control group, respectively, all p < 0.05). Receiver operating characteristic analysis showed among all DTI parameters, FA had the best diagnostic accuracy with an area under the curve of 0.914 and optimal cut-off value of 0.27. FA showed a positive correlation while RD showed a negative correlation with a conduction velocity of tibial and common peroneal nerves. RD also correlated positively with F-wave minimal latency of tibial nerves.

CONCLUSION

DTI can be used to assess the microstructure alterations of lumbosacral nerve roots in CIDP patients. FA and RD may serve as potential markers reflecting the conduction function of tibial and common peroneal nerves.