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

Incomplete Presentations in Typical Chronic Inflammatory Demyelinating Polyneuropathy: A Single-Center, Retrospective Study

INTRODUCTION/AIMS

Incomplete forms of typical chronic inflammatory demyelinating polyneuropathy (CIDP) have recently been described, but their frequency and clinical characteristics are uncertain. This study aimed to describe a cohort of patients with incomplete typical CIDP.

METHODS

We retrospectively analyzed 64 consecutive treatment-naïve patients with CIDP. Phenotypes were classified based on detailed motor examinations, and clinical, electrophysiological, and therapeutic characteristics were compared.

RESULTS

Nineteen (30%) subjects with typical CIDP presented with an incomplete phenotype; 12 (63.2%) exhibited a proximal arm-sparing pattern, 3 (15.8%) a distal arm-sparing pattern, 3 (15.8%) a pure paraparetic form, and 1 (5.2%) had a pure proximal form. In cases without full motor recovery, 11 (68.8%) maintained their original phenotype, while the rest transitioned to the complete (18.8%) or to another incomplete form (12.5%) due to involvement of previously unaffected segments. Subjects with incomplete typical CIDP had milder pre-treatment disability and weakness compared to those with the complete form, while other clinical and electrodiagnostic features were comparable. As opposed to the complete form, disability in incomplete typical CIDP at diagnosis showed no correlation with muscle strength.

DISCUSSION

Incomplete forms were observed in nearly one-third of subjects with typical CIDP. Incomplete typical CIDP represents a milder form of complete typical CIDP; however, its other disease characteristics, including treatment response, are similar, highlighting the importance of its proper prompt recognition as CIDP. Impairments beyond motor weakness, such as more diffuse proprioceptive loss, might play a role in the disability of patients with incomplete typical forms of CIDP.

Exploring the role of altered oxi-inflammasome activity in the immunobiology of inflammatory neuropathies

OBJECTIVES

Inflammasome plays a significant role in inflammatory responses. The role of inflammasome and its interactions with oxidative stress markers has not been examined in inflammatory neuropathies like Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). This study aims to explore the roles of inflammasome and oxidative stress pathways in inflammatory neuropathies.

METHODS

This case-controlled study comprised patients with inflammatory neuropathies (n = 60, GBS = 44, CIDP = 16) and age- and gender-matched healthy controls (n = 60). The expressions of inflammasome-related genes (Nlrp3, Casp1, and Il1b) were quantified along with the plasma levels of malondialdehyde (MDA), the end product of lipid peroxidation in all study participants.

RESULTS

The expressions of Nlrp3 (p = 0.0083) and Casp1 (p = 0.0007) genes were significantly up-regulated in GBS patients compared to controls. The plasma MDA levels were also markedly higher in GBS patients than in controls (p = 0.029). The gene expression levels of Nlrp3, Casp1, and Il1b and plasma MDA levels were comparable between CIDP patients and healthy controls. There were no correlations between the expressions of the studied genes and MDA levels with the clinical scores of GBS.

CONCLUSION

The up-regulated expression of Nlrp3 and Casp1 genes and increased levels of MDA suggest the presence of an activated oxi-inflammatory pathway in GBS. These findings provide a new dimension to the current understanding of the immuno-pathogenesis of GBS.

Clinical Reasoning: A 19-Year-Old Woman With Progressive Weakness and Numbness in Her Arms and Legs

Acute worsening of chronic weakness and numbness can have diagnostic challenges when trying to distinguish between acquired and hereditary conditions. We present the case of a 19-year-old patient who had acute worsening of chronic symmetric sensory and motor neuropathy with no response to intravenous immunoglobulin. Her story highlights the diagnostic approach for patients with atypical features of acquired vs genetic neuropathies and the importance of interpreting a "pathogenic" gene variant in this clinical context. Readers will explore the diagnostic steps our group has considered to reach our final diagnosis and the management of patients with complex neuropathy.

Basic Pathological Mechanisms in Peripheral Nerve Diseases

Pathological changes and the cellular and molecular mechanisms underlying axonopathy and myelinopathy are key to understanding a wide range of inherited and acquired peripheral nerve disorders. While the clinical indications for nerve biopsy have diminished over time, its diagnostic value remains significant in select conditions, offering a unique window into the pathophysiological processes of peripheral neuropathies. Evidence highlights the symbiotic relationship between axons and myelinating Schwann cells, wherein disruptions in axo-glial interactions contribute to neuropathogenesis. This review synthesizes recent insights into the pathological and molecular underpinnings of axonopathy and myelinopathy. Axonopathy encompasses Wallerian degeneration, axonal atrophy, and dystrophy. Although extensively studied in traumatic nerve injury, the mechanisms of axonal degeneration and Schwann cell-mediated repair are increasingly recognized as pivotal in non-traumatic disorders, including dying-back neuropathies. We briefly outline key transcription factors, signaling pathways, and epigenetic changes driving axonal regeneration. For myelinopathy, we discuss primary segmental demyelination and dysmyelination, characterized by defective myelin development. We describe paranodal demyelination in light of recent findings in nodopathies, emphasizing that it is not an exclusive indicator of demyelinating disorders. This comprehensive review provides a framework to enhance our understanding of peripheral nerve pathology and its implications for developing targeted therapies.

Rituximab versus placebo for chronic inflammatory demyelinating polyradiculoneuropathy: a randomized trial

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) often requires prolonged ongoing treatment to prevent worsening. The efficacy of rituximab in preventing worsening after the discontinuation of immunoglobulin therapy in patients with CIDP was assessed. In this randomized, double-blind, placebo-controlled study, conducted at seven Italian hospitals, CIDP patients under immunoglobulin therapy were assigned to receive either rituximab (1 g on Days 1, 15 and 180 ± 7) or placebo. Both groups continued their regular immunoglobulin doses for 6 months post-intervention. The primary end point was the proportion of patients who worsened in any of the following three measures at Month 12, within 6 months after immunoglobulin discontinuation: a decrease of at least one point on the adjusted INCAT score, two points on the MRC sum score, or four points on the RODS centile score. Secondary end points included the proportion of patients deteriorating at Month 18 (within 12 months after immunoglobulin discontinuation), treatment cessation due to adverse events or voluntary reasons, and the time until deterioration after immunoglobulin discontinuation. This study was registered with ClinicalTrials.gov (NCT06325943) and EUDRACT (number 2017-005034-36), and is now complete. From April 2019 to March 2022, 39 patients were recruited; two withdrew consent. The remaining 37 patients were assigned to rituximab (n = 19) or placebo (n = 18). Median age was 53 (interquartile range 45-64), with 11 (30%) females. A similar proportion of patients in both the rituximab (12/19, 63.2%) and placebo (12/18, 66.6%) groups worsened at Month 12 [odds ratio (OR) 0.86; 95% confidence interval (CI) 0.22-3.32]. No significant differences were noted at Month 18 (OR 0.62; 95% CI 0.14-2.70), or in the mean scores of each scale at Months 6, 12 and 18. The median time to worsening was 5 months for rituximab and 2 months for placebo (Log-rank P = 0.4372). Treatment was suspended due to adverse events in one rituximab patient. In this study, rituximab was not more effective than placebo in preventing clinical deterioration following the discontinuation of immunoglobulin therapy in CIDP. Further studies might evaluate the efficacy of more frequent or earlier administration of rituximab.

Effectiveness and safety of therapeutic plasma exchange in neurological diseases: An 11-year report from a tertiary care center

BACKGROUND

Therapeutic plasma exchange has been a well-known treatment method for many years and is widely available. It leads to the improvement of neurological symptoms in autoimmune neurological diseases by the removal of antibodies. The aim of this study was to present therapeutic plasma exchange responses and procedure-related adverse events in patients with autoimmune neurological diseases based on our 11-year experience.

METHOD

A retrospective evaluation was conducted on adult patients who underwent a therapeutic plasma exchange procedure due to neurological diseases between January 2013 and January 2024. Data were gathered from electronic and written hospital and apheresis unit records.

RESULTS

A total of 265 patients underwent 1274 procedures with a preliminary diagnosis of autoimmune neurological disease. Five patients were excluded from the analysis due to their final diagnoses. The most common clinical indications were Guillain-Barré syndrome (45.4%), myasthenia gravis (26.1%), and multiple sclerosis (19.2%). The overall response rate was 81.3%, with 21.7% exhibiting a complete response and 59.6% demonstrating a partial response. With the exception of one patient (hypertensive crisis), no complications necessitating the termination of the procedure were observed. The most prevalent complication was an easily manageable allergic reaction.

CONCLUSION

Therapeutic plasma exchange has been demonstrated to be an efficacious and safe treatment option in autoimmune neurological diseases, with a favorable overall response rate and a manageable mild-to-moderate side effect profile.

Dantrolene for the Treatment of Chronic Inflammatory Demyelinating Polyneuropathy-Induced Painful Muscle Spasms: A Case Report

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder that causes progressive weakness, sensory dysfunction, and often debilitating muscle spasms and pain. A man in his early 30s with a history of Hodgkin's lymphoma treated with chemotherapy developed neurologic symptoms initially misdiagnosed as chemotherapy-induced neuropathy. A diagnosis of CIDP was subsequently confirmed by nerve conduction studies. Despite treatment with muscle relaxants, benzodiazepines, botulinum toxin injections, and opioids, the patient's muscle spasms remained refractory. Dantrolene was then introduced at 25 mg orally 4 times/d, resulting in a significant reduction in the frequency and intensity of muscle spasms.

Neuropathy with anti-myelin-associated glycoprotein antibodies: update on diagnosis, pathophysiology and management

Antimyelin-associated glycoprotein (MAG) neuropathy is a rare autoimmune demyelinating peripheral neuropathy caused by IgM autoantibodies targeting MAG. The typical presentation is that of a slowly progressive, distal, length-dependent, predominantly sensory, sometimes ataxic neuropathy, frequently accompanied by upper limb tremor. Distal motor weakness may subsequently occur. The clinical presentation may vary and rarely be consistent with that of typical chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), as well as have an aggressive and rapidly disabling course. The diagnosis of anti-MAG neuropathy is based on the detection of anti-MAG antibodies through ELISA or western blot analysis, primarily in presence of an IgM monoclonal gammopathy. Anti-MAG neuropathy may occur without or with haematological malignancy. Electrophysiology is characteristic of a predominantly distal demyelinating neuropathy. Intravenous immunoglobulins and plasma exchange have unproven benefits, but may provide short-term effects. Cytotoxic therapies are commonly used, although without an evidence base. Rituximab, an anti-B-cell monoclonal antibody was studied in two randomised controlled trials, neither of which achieved their primary outcome. However, a meta-analysis of these two studies demonstrated improvement of disability at 8-12 months. A recent trial with lenalidomide was interrupted prematurely due to a high rate of venous thromboembolism. There are currently two ongoing trials with Bruton's tyrosine kinase inhibitors. Symptom control is otherwise frequently needed. Outcome measures used for other inflammatory neuropathies present limitations in anti-MAG neuropathy. International registries such as the planned IMAGiNe study may, in future, provide answers to the many remaining questions.

Usefulness of serum neurofilament light chain in chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

The development of new biomarkers is essential to improve diagnostic accuracy and guide treatment decisions in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The aim of this study was to investigate the utility of the serum neurofilament light chain (sNfL) level as a marker for disability and response to immunomodulatory treatment in patients with CIDP.

METHODS

This prospective, single-center, observational study included 38 patients with CIDP: 19 treatment-naive (CIDP-I) patients assessed before and after the initiation of immunomodulatory therapy and 19 stable patients on maintenance immunoglobulins (CIDP-M). Clinical scales (INCAT, I-RODS, MRC-SS and grip strength) were used to assess disability and treatment response. Nerve conduction study data were collected.

RESULTS

The median sNfL level (pg/mL) was greater in CIDP-I patients than in CIDP-M patients (23.4 vs. 7.7; p = 0.002). A reduction in sNfL levels was observed in CIDP-I patients after 5 months of immunomodulatory treatment (23.4 vs. 15.0; p = 0.001). sNfL levels were correlated with greater disability as assessed by the INCAT (p = 0.007), I-RODS (p = 0.004), and MRC-SS (p = 0.016) in treatment-naive patients but not in those receiving maintenance therapy. sNfL levels correlated with the average amplitude of the distal compound muscle action potential of the median, ulnar, peroneal and tibial nerves from the most affected limb (p = 0.043).

CONCLUSIONS

sNfL levels are significantly reduced in patients with CIDP who respond to immunomodulatory treatment and are positively correlated with disability. These findings highlight the utility of sNfL as a marker of disease activity and treatment response in patients with CIDP.

Diagnosis of hereditary transthyretin amyloidosis in patients with suspected chronic inflammatory demyelinating polyneuropathy unresponsive to intravenous immunoglobulins: results of a retrospective study

BACKGROUND AND AIMS

Hereditary transthyretin amyloidosis (ATTRv) should be considered in patients diagnosed with intravenous immunoglobulin (IVIg)-resistant chronic inflammatory demyelinating polyradiculoneuropathy (IVIg-NR CIDP). In this 1-year long, retrospective, multicentric study, an online questionnaire was sent to 1100 French healthcare professionals (HCPs) investigating: (i) how many IVIg-NR CIDP patients they followed; (ii) how many IVIg-NR CIDP patients had undergone TTR gene analysis; and (iii) how many IVIg-NR CIDP patients were eventually diagnosed with ATTRv. The questionnaire was sent every 3 months for 1 year and contained information on ATTRv clinical manifestations and diagnosis.

RESULTS

One-hundred and ten (10%) HCPs responded. A total of 2131 patients with CIDP were identified, including 315 (22.1%) with IVIg-NR CIDP. TTR gene analysis was performed in 144 patients and was positive in 43 cases (29.9%).

CONCLUSIONS

This study demonstrates that ATTRv should be investigated systematically in patients diagnosed with IVIg-NR CIDP. HCP-directed information campaigns are useful for modifying diagnostic practices.

International Consensus Guidance for the Management of Glucocorticoid Related Complications in Neuromuscular Disease

INTRODUCTION/AIMS

Glucocorticoid (GC)-related adverse reactions and risks are commonly seen during the treatment of immune-mediated and inflammatory neuromuscular disorders. There is wide variation in the management of associated complications. The aim of this study is to develop international consensus guidance on the management of GC-related complications in neuromuscular disorders.

METHODS

Through the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM), an international task force of 15 experts was convened to develop clinical guidance for the management of GC-related complications in neuromuscular patients. The RAND/UCLA appropriateness method (RAM) was used to develop consensus guidance statements. Initial guidance statements were crafted after a thorough literature review and were modified after anonymous panel input, with up to three rounds of voting via email to achieve consensus.

RESULTS

Statements were developed and achieved consensus for general care, monitoring of patients while on GC, osteoporosis prevention, vaccinations, infection screening, and Pneumocystis jiroveci pneumonia prophylaxis. A multidisciplinary approach to the management of GC-related complications was emphasized.

DISCUSSION

These formal consensus statements provide guidance to clinicians who use GC in the treatment of neuromuscular diseases regarding prevention and management of the more common associated adverse events and risks that arise with long and short-term GC use and serve as a springboard for investigation and updates.

Neuromuscular Ultrasound Training in Neuromuscular Fellowship Programs in Canada: Minding the Gap

INTRODUCTION/AIMS

Neuromuscular ultrasound (NMUS) is gaining prominence as a valuable tool for diagnosing neuromuscular disorders at the point of care. Neuromuscular disorder diagnostic criteria guidelines have begun incorporating NMUS findings. As interest grows, fellowship programs must consider incorporating training into their curricula. This study evaluated the current state of NMUS training, potential barriers, and interest in training across Canadian neuromuscular fellowship programs.

METHODS

A 23-question online survey was developed and distributed via email to all 10 neuromuscular fellowship program directors across Canada.

RESULTS

Seven (70%) programs responded to the survey. There was general agreement among programs on the value of NMUS, however, only one (14.3%) program reported they would consider recent graduates to be competent in NMUS. Critical barriers to incorporation of NMUS training included lack of a formalized curriculum, faculty expertise and time, and equipment. Two (28.6%) programs reported that accessibility of equipment and one (14.3%) that faculty expertise was not a barrier to NMUS training. Two (28.6%) programs have local NMUS training options available to fellows (in only one program is NMUS training mandatory). All programs expressed interest in additional training opportunities, and three (43%) programs reported taking steps toward incorporating NMUS training into their curricula.

DISCUSSION

NMUS training is in its infancy in Canada, with several common barriers identified across programs. There is universal interest in further NMUS training opportunities for fellows, highlighting the importance of a common approach to addressing the educational gap to support development of formalized NMUS training mechanisms in Canada.

The relevance of combined testing of cerebrospinal fluid glial fibrillary acidic protein and ubiquitin C-terminal hydrolase L1 in multiple sclerosis and peripheral neuropathy

INTRODUCTION

This study investigates the significance of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCHL-1) in cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and peripheral neuropathy (PN).

METHODS

We included 41 MS patients, 35 PN patients, and 36 controls across 5 sites. MS patient data included lesion counts, disease activity, albumin quotient, and Expanded Disability Status Scale (EDSS) scores. PN patients included those with acute and chronic inflammatory demyelinating polyneuropathy and sensorimotor neuropathy based on nerve conduction studies. CSF concentrations of GFAP and UCHL-1 were measured using the MILLIPLEX Map Human Neuroscience Magnetic Bead Panel 1.

RESULTS

Both GFAP and UCHL-1 levels were significantly higher in the two patient groups compared to controls. In the MS group, GFAP showed a strong correlation with disease duration, EDSS score, non-enhancing lesions, and the CSF/blood albumin quotient. UCHL-1 levels were significantly higher in patients with active disease (gadolinium-enhancing lesions). The combination of UCHL-1 and GFAP improved diagnostic accuracy (AUC 0.895, 95% CI 0.780-1.000) compared to the independent measurement of either marker for indicating Gd-negative lesions. In the PN group, CSF GFAP levels were significantly lower in patients with purely demyelinating neuropathy compared to those with axonal or mixed neuropathy.

CONCLUSION

GFAP serves as a sensitive marker for axonal damage in PN, while UCHL-1 closely correlates with disease activity in MS patients.

Chronic inflammatory demyelinating polyneuropathy associated with active systemic lupus erythematous: Anifrolumab as a potentially successful add-on therapy to intravenous immunoglobulins

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired, autoimmune peripheral neuropathy, rarely reported as being associated with systemic lupus erythematous (SLE). We report the case of 53-year-old women with a long history of SLE, diagnosed with CIDP during a lupus flare beginning with progressive muscle weakness of lower and upper limbs, without affection of the central nervous system. She received treatment with steroids, intravenous immunoglobulins and anifrolumab and showed clinical and immunological improvement. It is important to take into account the presence of peripheral neurological disorders in patients with SLE, considering CIDP as an uncommon manifestation. Controlling severe active disease is an imperative issue to manage this neurological manifestation which has a serious impact on health-related quality of life and physical function.

Validation of the Korean version of inflammatory Rasch-built Overall Disability Scale in patients with inflammatory neuropathy

BACKGROUND AND AIMS

The Inflammatory Rasch-built Overall Disability Scale (I-RODS) is an effective activity measure for use in inflammatory peripheral neuropathy. The aim of this study was to validate the Korean version of the I-RODS in patients with chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain-Barré syndrome (GBS), anti-myelin-associated glycoprotein (MAG) neuropathy, and autoimmune nodopathy.

METHODS

A total of 120 patients underwent clinical evaluations, which included the I-RODS, Inflammatory Neuropathy Cause and Treatment (INCAT) assessment, and Jamar grip strength (kg) measurement. Follow-up assessments were performed for 83 patients during their regular clinic visits. To estimate the test-retest reliability of the I-RODS, the scale was reapplied to a subset of 16 patients within 2-7 days of the initial test. Overall, reliability, validity, and responsiveness of the I-RODS were evaluated.

RESULTS

Internal consistency was good, as indicated by a person separation index of 0.966. The raw and standardized Cronbach's alpha values were both 0.974. The test-retest reliability analyzed using the intraclass correlation coefficient (ICC) was also high (ICC = 0.972). The I-RODS showed a strong correlation with INCAT scores (ρ = -0.81, p < .001) and a moderate correlation with grip strength (ρ = 0.61, p < .001). Furthermore, the sensitivity for detecting clinically meaningful improvement was highest for grip strength (60.4%) followed by I-RODS (52.1%), while for capturing deterioration, it was highest for I-RODS (80.0%).

INTERPRETATION

The Korean version of the I-RODS is a reliable and valid tool for measuring disability in patients with inflammatory neuropathy. The I-RODS is useful for both clinical practice and research applications.

Safety and Cost Analysis of Immunoglobulin Cessation Trials in Chronic Inflammatory Demyelinating Polyradiculoneuropathy

BACKGROUND AND AIMS

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common chronic autoimmune neuropathy worldwide. A significant proportion of CIDP patients enter spontaneous or medication-related remission, remaining stable without immunotherapy. Overtreatment of CIDP has clinical and financial implications. We examined performance of IVIg cessation trials in our CIDP cohort and report safety and cost analysis outcomes.

METHODS

In individuals with CIDP on maintenance IVIg treatment, a cessation trial was proposed in clinically stable patients with a static IVIg regimen over a 12-month period. We explored the proportion who were stable off treatment for 12 or more months and the time to recovery in those who declined and were re-treated. We examined cost implications of this approach.

RESULTS

45/125 individuals met criteria for clinical stability, with median age 58 years, I-RODS 37/48, MRC-SS 69/70 and annual treatment costs £107 000/person. Nine individuals had cessation trials resulting in decline within 2 years prior and were not re-challenged, leaving 36 eligible individuals. 12 of 36 (33.3%) consented to cessation trial and eight of those (66.7%) remained stable off treatment for ≥ 12 months. The successful cessation trials resulted in a cost saving of £855 000/year, with a potential further saving of £1.7 million/year if all the eligible individuals had consented. All patients who deteriorated were rescued to previous baseline on retreatment.

INTERPRETATION

Individuals with CIDP should be counselled about the natural history of the disease and future scheduled, targeted cessation trials. A dedicated clinical infrastructure is vital to safely perform cessation trials.

A Multicenter Study of Hereditary Transthyretin Amyloidosis in China

OBJECTIVE

Hereditary transthyretin amyloidosis (ATTRv) is an autosomal dominant genetic disease characterized by the misfolding and deposition of the transthyretin (TTR) protein. This study aimed to describe the clinical and genetic characteristics of ATTRv in a large multicenter Chinese cohort.

METHODS

Patients from 14 centers were included in the study. The clinical and genetic characteristics of all patients were summarized. The peripheral blood white blood cell mitochondrial DNA (mtDNA) was detected in offspring from different genders.

RESULTS

A total of 202 individuals with ATTRv from 148 families were identified. The average age of onset was 50.6 ± 12.4 years. Among these cases, 117 (57.9%) were classified as late-onset (≥50 years) and 85 (42.1%) as early-onset. Overall, the length dependent axonal sensorimotor peripheral neuropathy was the predominant phenotype (89.1%). A total of 42 heterozygous missense variants and 1 deletion variant were identified. The most common variants were Val30Met (19.8%) and Ala97Ser (15.8%) and patients with Val30Met and Ala97Ser were mostly late-onset in our cohort. Thirty-nine of these patients died with a mean age of 56.1 ± 13.5 years. Anticipation according to gender groups of offspring-parent pairs was different, and mother-son pairs showed the largest anticipation. The copies of mtDNA in the mother's offspring outnumbered those of the father's offspring (p < 0.001).

INTERPRETATION

This study highlights that ATTRv patients in China exhibit high heterogeneity in their initial symptoms. The most common variants observed in this cohort is Val30Met. The mtDNA copy number shows gender-linked effects. These results can impact ATTRv diagnosis and patient care strategies. ANN NEUROL 2025.

Maintenance Intravenous Immunoglobulin Therapy for Chronic Inflammatory Demyelinating Polyneuropathy: 18-Month Post-marketing Surveillance in 103 Patients

Objective The efficacy of maintenance intravenous immunoglobulin (IVIg) therapy has been established to prevent relapse in chronic inflammatory demyelinating polyneuropathy (CIDP). This prospective post-marketing surveillance study evaluated the treatment duration, efficacy, and safety of maintenance IVIg therapy in Japanese patients with CIDP. Methods Patients were registered between June 2017 and December 2018. After induction of IVIg therapy (0.4 g/kg/day for 5 consecutive days), patients received maintenance IVIg (1.0 g/kg every 3 weeks). The observation period was 18 months. Efficacy in preventing relapse was assessed using the Inflammatory Neuropathy Cause and Treatment (INCAT) disability score. Relapse was defined as a worsening of the INCAT score by ≥1 from baseline. Patients The efficacy population comprised 103 patients (80 with typical CIDP and 23 with CIDP variants). Results During the observation period, 86 (83%) patients were scheduled to continue maintenance IVIg therapy during the observation period, and the relapse rate was 24% (21/86). In the remaining 17 patients who showed continuous remission, maintenance IVIg therapy was stopped (mean, 136 days after the start), and the relapse rate was 24% (4/17). One serious adverse drug reaction of cardiac failure was reported. Conclusion In this post-marketing surveillance, most (83%) patients with CIDP were scheduled to continue maintenance IVIg for 18 months, with a relapse rate of 24%, indicating long-term efficacy. Maintenance IVIg therapy was rarely withdrawn, and the relapse rate after withdrawal was 24%. Further studies are required to determine the optimal maintenance IVIg dose and duration.

The overlap of diabetic and inflammatory neuropathies: Epidemiology, possible mechanisms, and treatment implications

Diabetic polyneuropathy is the common neuropathy of diabetes. However, several inflammatory neuropathies may occur during diabetes. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represents the most treatable example. There has been uncertainty about a higher risk of CIDP in subjects with diabetes. Contradicting earlier reports, subsequent epidemiological studies failed to confirm an association. However, more recent studies from different populations have shown a two-fold relative risk of concurrent diabetes with CIDP. Recognition of CIDP is important in diabetes as treatment response rates have been reported as comparable with or without diabetes. However, with diabetes, the clinical presentation of CIDP and the resulting disability may be more severe due to additional axonal loss from pre-existing diabetic polyneuropathy and delayed diagnosis. An association of nodo-paranodopathy has similarly been described with a three-fold relative risk of concurrent diabetes in seropositive subjects, particularly those harbouring anti-contactin 1 antibodies. Although rare, recognition of nodo-paranodopathy, with characteristic clinical features, in the context of diabetes is likewise important in view of treatment implications. Other inflammatory neuropathies in diabetes are the painful or painless, cervical, or lumbar, radiculoplexus neuropathies. These need distinguishing from variant, multifocal forms of CIDP, as are not treatable, although remit spontaneously over months or years. There are reports of possible association of Guillain-Barré syndrome (GBS), and particularly of greater GBS severity, with diabetes. Finally, vasculitic neuropathy may also occur in diabetes and requires early suspicion, urgent investigations and immunosuppressant treatment. As the worldwide prevalence of diabetes rises, prompt recognition of its concurrent inflammatory neuropathies, is essential.

Immune-Mediated Neuropathies: Top 10 Clinical Pearls

Immune-mediated neuropathies encompass a range of neurological disorders, including chronic inflammatory demyelinating polyradiculoneuropathy, Guillain-Barré syndrome, multifocal motor neuropathy, autoimmune autonomic neuropathies, and paranodal nodopathies. Recognizing clinical patterns is key to narrowing the broad range of differential diagnoses in immune-mediated neuropathies. Electrodiagnostic testing is a useful tool to support the diagnosis of immune-mediated neuropathies. Our understanding of autoimmune demyelinating neuropathies is rapidly advancing, particularly with the discovery of nodal and paranodal antibodies. Recent advances in neuropathy treatment include the utilization of neonatal Fc receptors to reduce antibody recycling, and the development of complement inhibitors to reduce inflammatory damage, offering promising new therapeutic avenues. Timely identification of immune-mediated neuropathies is imperative as delay in diagnosis and treatment may lead to irreversible disability.

Early therapy initiation is crucial in chronic inflammatory demyelinating polyneuropathy: prospective multimodal data from the German INHIBIT registry

BACKGROUND

Diagnosing chronic inflammatory demyelinating polyneuropathy (CIDP) can be challenging, leading to delays in initiating therapy. As disability in CIDP is mainly dependent on axonal damage, the impact of delayed immunotherapy remains unclear. We multimodally investigated the clinical outcomes of patients with early CIDP regarding different treatment strategies and time points.

METHODS

Patients with CIDP diagnosis within 1 year before study inclusion were systematically selected from the prospective Immune-mediated Neuropathies Biobank (INHIBIT) registry. Clinical and therapeutic data, and findings from nerve conduction study (NCS), and nerve and muscle ultrasound were correlated at inclusion and 12 months later. The patient outcomes were compared between immunotherapies. The effect of timing immunotherapy on clinical outcomes was determined using regression analysis.

RESULTS

In total, 30 patients were included (time from diagnosis to inclusion 22 ± 19 weeks). Low amplitudes of compound muscle potential were significantly associated with pathological spontaneous activity (PSA, r = 0.467) and correlated with the Heckmatt scale (rSp = 0.391). All three parameters were significantly associated with higher overall disability sum scores (NCS score rSp = 0.581, PSA r = 0.385, Heckmatt scale rSp = 0.472). The delays in initiating therapy resulted in progression of axonal damage (rSp = 0.467) and disability (R2 = 0.200). The combination of first-line therapies led to reduced disability progression (r = 0.773), while second-line therapies resulted in improved overall axonal damage (r = 0.467).

CONCLUSIONS

Axonal damage occurs early and is the main cause of clinical disabilities. Prompt initiation of therapy is crucial to prevent axonal damage and thereby disability progression. A comprehensive therapeutic approach, including a combination of first- or second-line therapies, may improve long-term outcomes.

Report on the 6th Ottawa International Conference on Neuromuscular Disease & Biology - September 7-9, 2023, Ottawa, Canada

The 6th Ottawa International Conference in Neuromuscular Disease and Biology was held on September 7-9, 2023 in Ottawa, Canada. The goal of the conference was to assemble international experts in fundamental science, translational medicine and clinical neuromuscular disease research. Speakers provided attendees with updates on a wide range of topics related to neuromuscular disease and biology, including methods to identify novel diseases, recent developments in muscle, motor neuron and stem cell biology, expanded disease pathogenesis of known diseases, and exciting advances in therapy development. A summary of the major topics and results presented by these speakers is provided.

Chronic Inflammatory Demyelinating Polyneuropathy: A Narrative Review of a Systematic Diagnostic Approach to Avoid Misdiagnosis

Chronic inflammatory demyelination polyradiculoneuropathy (CIDP) is a rare autoimmune neuropathy generated by cellular and humoral immune responses. Its course can be chronic, progressive, monophasic, or relapsing-remitting. Misdiagnosis and inappropriate therapy are common in CIDP. Given the scarcity of integrative information, we aimed to briefly summarize the epidemiology, pathophysiology, clinical phenotypes, diagnostic tools, and diagnostic criteria and provide a systematic diagnostic approach. We reviewed articles on Medline (PubMed) from 2018 to 2023, using Google Scholar to summarize the topics. The results are presented as a narrative review, in accordance with recommendations of the Scale for the Assessment of Narrative Review Articles (SANRA) guidelines. The included evidence showed that CIDP is a challenging neuropathy to diagnose and treat. Pathologic factors initiating typical CIDP and atypical CIDP are still clearly unknown. CIDP is diagnosed using the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria, which combine clinical features with electrophysiological evidence of demyelination. However, some patients need to fulfill the requirements. Another challenge is monitoring the disease progression and recognizing patients who do not respond to evidence-based first-line therapy to individualize their treatment. Based on the evidence, we conclude that 2021 EFNS/PNS guidelines allow for a more accurate diagnosis and treatment of CIDP and its variants. New diagnostic tools and molecular approaches are helpful in the diagnosis process but cannot replace clinical and electrodiagnostic criteria.

Don't be perplexed by the plexus! A practical approach to brachial plexus ultrasound

Ultrasound is as accurate as MRI in the detection of most brachial pathologies but tends to be underutilized in clinical practice compared to MRI. The main reason for this under-usage is a relative lack of knowledge regarding how to perform brachial plexus ultrasound and a lack of awareness of the ultrasound appearances of brachial pathologies. This review serves to re-address this imbalance by providing a practical overview on how to perform brachial plexus ultrasound as well as highlighting the ultrasound appearances of common pathologies likely to be encountered in everyday clinical practice.

Real-life experience with disease-modifying drugs in hereditary transthyretin amyloid polyneuropathy: A clinical and electrophysiological appraisal

INTRODUCTION

New treatments have dramatically improved the prognosis for Hereditary Transthyretin Amyloid Polyneuropathy (ATTRv-PN). However, there is a lack of routine follow-up studies outside of therapeutic trials. Our aim was to report the long-term clinical and electrophysiological evolution of a cohort of ATTRv-PN patients and to determine which biomarkers are most sensitive to change.

METHODS

We retrospectively collected neuropathy impairment scale (NIS), polyneuropathy disability scale (PND), overall neuropathy limitation scale (ONLS), rash built overall disability scale (RODS), electrodiagnostic data, motor unit number index (MUNIX), troponin and N-terminal pro-brain natriuretic peptide levels. Electrophysiological worsening was defined as a 20% decrease in previous values.

RESULTS

Thirty-five patients, with a median age of 58 (interquartile ranges 42-71) years, were followed for a median of 36 (24-48) months. All patients received a transthyretin stabiliser, gene silencer or liver transplant. Overall assessment of the cohort showed clinical, biological and electrophysiological stability. However, on an individual basis, NIS worsened in 45% of patients (14/31), ONLS in 46% (13/28), PND in 28% (9/32) and RODS in 39% (11/28) at the last follow-up. Motor amplitude sum score decreased in 33% (11/33), amplitude recorded on tibialis anterior muscle in 44% (12/27), sensory amplitude sum score in 39% (11/28) and MUNIX sum score in 27% (7/26).

CONCLUSIONS

Overall effectiveness of ATTRv-PN treatments in routine care is good. However, individual assessments show up to 40% deterioration over time. Electrophysiological measures are valuable monitoring tools but are not more sensitive to change than clinical scores. Results must be confirmed in larger cohorts.

Serum glycobiomarkers for chronic inflammatory demyelinating polyneuropathy

BACKGROUND

This study conducted a comprehensive glycan analysis of serum to determine how glycan biomarkers are associated with the pathophysiology of chronic inflammatory demyelinating polyneuropathy (CIDP) and the effects of its treatment.

METHODS

We comparatively analyzed N- and O-glycans in the pretreatment serum of 27 treatment-naïve patients with typical CIDP and 20 age- and sex-matched healthy controls (HC) using mass spectrometry. We determined the association between clinical parameters and glycans. The serum glycan and neurofilament light-chain (NfL) levels were assessed at the baseline, and treatment response was defined according to the degree of improvement in the modified Rankin scale 12 weeks after the first dose of intravenous immunoglobulin (IVIg).

RESULTS

Compared with the HC, the CIDP group demonstrated significantly lower levels of serum total N-glycans (CIDP, median 973.3 [IQR 836.2-1131.3] pmol/μL; HC, 1125.0 [1005.0-1236.2] pmol/μL; p < 0.05), especially sialylated N-glycans (CIDP, 898.0 [752.2-1037.2] pmol/μL; HC, 1064.4 [942.7-1189.8] pmol/μL; p < 0.01). In contrast, the O-glycan levels did not differ significantly between the two groups. The treatment response was associated with low N-glycan levels, but not with the serum NfL levels. Low levels of sialylated N-glycans were associated with resistance to treatment over 12 weeks, with an area under the curve of 0.822 (p < 0.01).

CONCLUSIONS

Low levels of sialylated N-glycans could potentially serve as a novel biomarker, reflecting pathophysiology and therapeutic resistance in typical CIDP.

Regulatory T cells in CIDP and the inhibitory effect of rapamycin on them

We aim to investigate the proportion and function of regulatory T (Treg) cells, as well as mTORC activity in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients. Peripheral blood mononuclear cells (PBMCs) from 15 CIDP and healthy controls (HC) were collected. Treg and responsive T (Tresp) cells were isolated. The inhibition rate of Treg cells was analyzed with and without rapamycin. The percentage of CD4 + CD25highFoxP3+ Tregs was higher in CIDP than in HCs (median 3.06 % vs 1.98 %, P = 0.014). The suppressive function of CIDP Tregs was normal compared with that of HCs. The activity of mTORC1 and mTORC2 revealed by pAKT and p4EBP1 in Treg cells was not significantly different between CIDP and HC. The percentage of Treg cells showed no difference in the presence or absence of rapamycin, while the suppressive function of CIDP and HC Tregs was dramatically diminished in the presence of rapamycin. The percentage of P-akt in Tregs was also reduced in the presence of rapamycin. In conclusion, the percentage and suppressive function of Tregs were not impaired in CIDP patients. The presence of rapamycin had no effect on the percentage of Treg cells but could reduce the suppressive function of CIDP and HC Tregs, possibly by reducing P-Akt.

A Retrospective Analysis of Morbidity and Risk Factors of Multiple Myeloma with Peripheral Neuropathy

Aims/Background Peripheral nerve injury affects some people with multiple myeloma; this condition can be brought on by the disease itself or by the treatments they receive. Such a complication increases patients' financial burden, causes treatment to be interrupted or delayed, and reduces treatment efficacy. However, opinions regarding the risk factors for peripheral neuropathy are currently divided. Consequently, the primary goals of this study were to determine the prevalence of peripheral neuropathy and related risk factors in newly diagnosed and untreated patients of multiple myeloma. Methods Sixty-one patients with newly diagnosed and untreated multiple myeloma were retrospectively analyzed. Peripheral neuropathy (PN) in all patients was assessed via electromyography. The patients were divided into two groups according to the presence of PN. The differences in body mass index, haemoglobin, monoclonal M protein (M protein) and other related indicators between the two groups were analyzed using independent sample t-tests and Mann-Whitney U tests. Results Of the 61 patients, 72% had PN. Neuroelectrophysiological studies revealed that PN patients have abnormalities in both their motor and sensory fibres. We discovered that PN was strongly correlated with age, haemoglobin, and levels of creatinine (p = 0.039, p = 0.045, and p = 0.030, respectively). Conclusion Age, haemoglobin and creatinine levels are associated with the occurrence of PN. Investigation of the incidence and risk factors of multiple myeloma-associated PN can provide a better theoretical basis for the selection of treatment options and the enhancement of patient well-being and satisfaction.

Pattern, causes and functional outcome of peripheral neuropathies in the Amazon region

BACKGROUND

Peripheral neuropathies have a wide variety of causes and pathophysiologies. Assuming that there are local particularities in the Amazon region, the aim of this study was to describe the characteristics of patients by determining the factors associated with functional severity.

METHODS

This was a retrospective observational study at Cayenne Hospital between January 2015 and May 2023. We included patients from the French hospital activity monitoring database "Programme de médicalisation des systèmes d'information" by searching for the keywords "neuropathy" "Guillain-Barre syndrome"(GBS) "multineuritis" "polyneuritis". The Peripheral Neuropathy Disability (PND) score was determined to quantify the functional severity of patients.

RESULTS

A total of 754 patients were included, with a mean age of 60 years (SD = 14.6) and a predominance of women (53.6%). Gait disorders were present in 16.3% of patients (PND between 2 and 4). Mortality was 14.3% at 3 years. The most common causes of neuropathy were diabetes (58.2%), chemotherapy induced polyneuropathy toxicity (21.5%), Guillain-Barre syndrome (6.0%), unlabeled (3.2%), and infectious causes (2.0%). Infectious causes mainly included HIV in 13 patients (43.3%) and leprosy in 8 patients (26.7%). Only GBS was significantly associated with functional severity but all patients with a deficiency had a severe score. But, after excluding GBS, infectious causes were significantly associated with a severe PND score (aOR = 3.69 [1.18-11.58]).

DISCUSSION

The characteristics of French Guiana combine those found in developed and developing countries, with an over-representation of infections (notably HIV and leprosy), and diabetes. The causes often result from social inequalities in health.

CONCLUSION

This is the first comprehensive study of the diverse causes of neuropathy in a territory undergoing epidemiologic transition in the Amazon region.

Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is a rare immune-mediated polyradiculoneuropathy. Patients typically develop rapidly progressive weakness and sensory deficits that can result in complete paralysis requiring mechanical ventilation. GBS is usually a monophasic disease in which an aberrant immune response to an infection or other trigger damages the peripheral nerves. For example, in patients with preceding Campylobacter jejuni infection, molecular mimicry causes a cross-reactive antibody response to nerve gangliosides. Diagnosis is based on clinical features, supported by cerebrospinal fluid analysis and nerve conduction studies. Effective treatments include plasma exchange and intravenous immunoglobulins. However, ~20% of patients who received treatment are unable to walk after 6 months and ~5% die as a consequence of GBS. Important knowledge gaps in GBS include its pathogenesis, especially after viral infections. In addition, there is a lack of specific biomarkers to improve the diagnosis, monitor the disease activity, and predict the clinical course and outcome of GBS. Major challenges for the future include finding more effective and personalized treatments, which are affordable in low-income and middle-income countries, and preparation for outbreaks of infections as potential triggers for GBS.

Assessing axonal pathology and disease progression in chronic inflammatory demyelinating polyneuropathy using corneal confocal microscopy

OBJECTIVE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune neuropathy characterized by progressive or relapsing-remitting weakness and sensory deficits. This study aims to evaluate the utility of corneal confocal microscopy (CCM) in diagnosing and monitoring CIDP.

METHODS

We analysed 100 CIDP patients and 31 healthy controls using CCM to measure corneal nerve fiber density (CNFD), length (CNFL), and branch density (CNBD). Standardized clinical and electroneurographic evaluation were conducted, and statistical analyses were performed to compare CCM parameters between groups and across disease stages.

RESULTS

CIDP patients and subgroups exhibited significant reduction in CNFD, CNFL, and CNBD compared to controls. This reduction was observed in late disease stages and severe overall disability sum score (ODSS), and Inflammatory Neuropathy Cause and Treatment Sensory Sum Score (ISS). CCM parameters correlated with axonal pathology in electroneurography of sensory, but not motor nerves. Despite the significant differences, the diagnostic sensitivity (41%) and specificity (77%) of CCM parameters were limited.

CONCLUSION

While CCM effectively differentiates CIDP patients from healthy controls and was associated with disease severity, its diagnostic accuracy for routine clinical use is a posteriori. However, CCM shows promise as a non-invasive tool for monitoring sensory axonal pathology in CIDP.

Favorable long-term outcomes of autoimmune nodopathy with mycophenolate mofetil

Autoimmune nodopathy (AN) is a rare immune-mediated neuropathy characterized by autoantibodies against nodal or paranodal proteins. Patients with AN generally respond poorly to immunoglobulin therapy, and as a newly defined condition, there are currently no established treatment guidelines. Although rituximab shows potential as a therapeutic option, its high cost, limited availability, and the need for infusion monitoring hinder its use as a first-line treatment in many countries. In this report, we identified AN antibodies in five of 106 serum samples (4.7%) prospectively collected from patients initially diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): anti-neurofascin 155 (NF155) in 2 patients, anti-contactin-1 (CNTN1) in 1, anti-contactin associated protein 1 (CASPR1), and anti-NF186/140 in 1. Notably, we observed favorable long-term outcomes in these patients following treatment with mycophenolate mofetil (MMF) and corticosteroids. Given that these patients had not responded to immunoglobulin therapy and/or experienced relapses with corticosteroid monotherapy in their prior episodes, we propose MMF as a cost-effective treatment strategy for AN.

Co-Existent Central and Peripheral Demyelination: Related or Coincidental?

BACKGROUND

Hereditary Sensory Motor Neuropathy (HSMN) 1A and Multiple Sclerosis (MS) are distinct demyelinating disorders affecting the peripheral and central nervous systems, respectively. We present a case of simultaneous occurrence of both conditions, exploring the clinical presentation, diagnostic workup, and potential interplay between these diseases. Case presentation and clinical approach: A 49-year-old male with a history of optic neuritis presented with progressive numbness, weakness, and sensory loss in all extremities over four years. Neurological examination revealed distal weakness, sensory deficits in a stocking-glove distribution, pes cavus, and hammer toes. Nerve conduction studies and electromyography confirmed sensory motor demyelinating polyneuropathy. The patient's lack of response to intravenous immunoglobulin therapy suggested hereditary neuropathy as an etiology. Genetic testing identified a PMP22 gene duplication, confirming HSMN 1A. Elevated cerebrospinal fluid protein level and oligoclonal bands, combined with magnetic resonance of the brain showing multiple T2 hyperintense lesions in the brain and spinal cord, fulfilled the diagnostic criteria for MS.

DISCUSSION

This case of co-existing HSMN 1A and MS highlights a rare overlap of peripheral and central demyelination. While HSMN 1A results from PMP22 gene duplication, primarily affecting peripheral myelin, MS is driven by immune-mediated central myelin attacks. The co-existence of these disorders suggests potential shared mechanisms, such as immune dysregulation. Some evidence suggests that overexpression of PMP22 in HSMN 1A may disturb immune tolerance, possibly triggering autoimmune responses linked to MS. Further research is needed to explore the genetic and autoimmune interplay between these two diseases, expanding our understanding of demyelinating disorders.

Therapeutic potentials of adoptive cell therapy in immune-mediated neuropathy

Immune-mediated neuropathy (IMN) is a group of heterogenous neuropathies caused by intricate autoimmune responses. For now, known mechanisms of different IMN subtypes involve the production of autoantibodies, complement activation, enhanced inflammation and subsequent axonal/demyelinating nerve damages. Recent therapeutic studies mainly focus on specific antibodies and small molecule inhibitors previously approved in rheumatoid diseases. Initial strategies based on the pathophysiologic features of IMN should be explored. Adoptive cell therapy (ACT) refers to the emerging immunotherapies in which circulating immunocytes are collected from peripheral blood and modified with killing and immunomodulatory capacities. It consists of chimeric antigen receptor-T cell therapy, T cell receptor-engineered T cell, CAR-Natural killer cell therapy, and others. In the last decade, ACT has demonstrated extraordinary potentials in treating cancers, infectious diseases and autoimmune diseases. Versatile combinations of targets, chimeric domains and effector cells greatly empower ACT to treat complicated immune disorders. In this review, we summarized the advances of ACT and envisioned suitable strategies for different IMN subtypes.

Diagnostic criteria and therapeutic implications of rapid-onset demyelinating polyneuropathies

Guillain-Barré syndrome (GBS) and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) are the most common autoimmune polyneuropathies. Their aetiology is unclear. The pathomechanism includes damage mainly to the myelin sheath and, in the long-term process, secondary axonal loss. Both inflammatory polyneuropathies involve different combinations of motor, sensory and autonomic fibres in the peripheral nerves. The differential diagnosis should be based on clinical and neurophysiological features, and laboratory tests. Numerous studies aim to demonstrate the most common errors in the diagnosis of Guillain-Barré syndrome and acute-onset CIDP. Misdiagnosis can result in the wrong treatment. We still do not have reliable markers to help diagnose the disease or to monitor the effectiveness of the therapy.

Neurofilament light chain as a biomarker for hereditary ATTR amyloidosis - correlation between neurofilament light chain and nerve conduction study

BACKGROUND

Neurofilament light chain (NfL) is a biomarker of neuronal injury in hereditary ATTR (ATTRv) amyloidosis. However, the correlation between NfL and nerve conduction study (NCS), the standard test for ATTRv neuropathy, has not been investigated.

OBJECTIVE

Elucidate the correlation between NfL and NCS parameters.

METHODS

227 serum NfL measurements were performed in 45 ATTRv patients, 5 asymptomatic carriers, and 12 controls. Among them, 177 simultaneous analyses of NCS and NfL were conducted in 45 ATTRv patients.

RESULTS

NfL levels of symptomatic patients were significantly higher than those of asymptomatic carriers and controls. Serum NfL levels were correlated with NCS parameters, especially compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes, indicators of axonal damage. CMAP and/or SNAP amplitudes were undetectable in 9 patients (no-amplitude group) due to advanced neuropathy. NfL levels in the no-amplitude group were significantly higher than those in patients with detectable CMAP/SNAP. NfL levels significantly decreased with patisiran, although no significant changes were observed in CMAP and SNAP.

CONCLUSIONS

NfL levels are found to be correlated with CMAP/SNAP amplitudes. Compared with NCS, NfL can be a more sensitive biomarker for detecting treatment response and active nerve damage even in patients with advanced neuropathy.

Phenotyping peripheral neuropathies with and without pruritus: a cross-sectional multicenter study

ABSTRACT

Pruritus often escapes physicians' attention in patients with peripheral neuropathy (PNP). Here we aimed to characterize neuropathic pruritus in a cohort of 191 patients with PNP (large, mixed, or small fiber) and 57 control subjects with deep phenotyping in a multicenter cross-sectional observational study at 3 German sites. All participants underwent thorough neurological examination, nerve conduction studies, quantitative sensory testing, and skin biopsies to assess intraepidermal nerve fiber density. Patients filled in a set of questionnaires assessing the characteristics of pruritus and pain, the presence of depression and anxiety, and quality of life. Based on the severity of pruritus and pain, patients were grouped into 4 groups: "pruritus," "pain," "pruritus and pain," and "no pruritus/no pain." Although 11% (21/191) of patients reported pruritus as their only symptom, further 34.6% (66/191) reported pruritus and pain. Patients with pain (with or without pruritus) were more affected by anxiety, depression, and reduced quality of life than control subjects. Patients with pruritus (with and without pain) had increases in cold detection threshold, showing Aδ-fiber dysfunction. The pruritus group had lower intraepidermal nerve fiber density at the thigh, concomitant with a more proximal distribution of symptoms compared with the other PNP groups. Stratification of patients with PNP by using cross-sectional datasets and multinominal logistic regression analysis revealed distinct patterns for the patient groups. Together, our study sheds light on the presence of neuropathic pruritus in patients with PNP and its relationship with neuropathic pain, outlines the sensory and structural abnormalities associated with neuropathic pruritus, and highlights its impact on anxiety levels.

Comparison of the diagnostic accuracy of the 2010 European Federation of Neurological Societies/Peripheral Nerve Society and American Association of Electrodiagnostic Medicine diagnostic criteria for multifocal motor neuropathy

BACKGROUND AND PURPOSE

This study was undertaken to compare the sensitivity and specificity of the 2010 European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria for multifocal motor neuropathy (MMN) with those of the American Association of Electrodiagnostic Medicine (AAEM).

METHODS

Sensitivity and specificity of the two sets of criteria were retrospectively evaluated in 53 patients with MMN and 280 controls with axonal peripheral neuropathy, inflammatory demyelinating polyneuropathy, or amyotrophic lateral sclerosis. Comparison of the utility of nerve conduction studies with different numbers of nerves examined was also assessed.

RESULTS

The 2010 EFNS/PNS criteria had a sensitivity of 47% for definite MMN and 57% for probable/definite MMN, whereas the AAEM criteria had a sensitivity of 28% for definite MMN and 53% for probable/definite MMN. The sensitivity of the AAEM criteria was higher when utilizing area compared to amplitude reduction to define conduction block. Using supportive criteria, the sensitivity of the 2010 EFNS/PNS criteria for probable/definite MMN increased to 64%, and an additional 36% patients fulfilled the criteria (possible MMN). Specificity values for definite and probable/definite MMN were slightly higher with the AAEM criteria (100%) compared to the EFNS/PNS criteria (98.5% and 97%). Extended nerve conduction studies yielded slightly increased diagnostic sensitivity for both sets of criteria without significantly affecting specificity.

CONCLUSIONS

In our patient populations, the 2010 EFNS/PNS criteria demonstrated higher sensitivity but slightly lower specificity compared to the AAEM criteria. Extended nerve conduction studies are advised to achieve slightly higher sensitivity while maintaining very high specificity.

Characteristics of anti-contactin1 antibody positive autoimmune nodopathies combined with membranous nephropathy

BACKGROUND

Autoimmune nodopathy (AN) is a very rare new disease entity, especially when combined with membranous nephropathy (MN).

METHODS

Antibodies against nodal-paranodal cell adhesion molecules in the serum were detected using cell-based assays. Antibody subtypes against contactin-1 (CNTN1) were confirmed. Cases of anti-CNTN1 antibody-positive AN with and without MN were retrieved through a literature search to compare clinical and electrophysiological characteristics.

RESULTS

A 65-year-old male patient with MN developed limb numbness and weakness, along with walking instability. Serum CNTN1 antibodies were positive, primarily those of the IgG4 subtype. Electromyography showed prominent demyelination patterns in both the proximal and distal segments of the nerves compared to the middle nerve trunk. Magnetic resonance imaging revealed enlargement of the bilateral brachial and lumbosacral plexuses and local hyperintensity of the right C5-C6 nerve roots. Thirty-five cases with anti-CNTN1 antibody-positive AN with MN and 51 cases with anti-CNTN1 antibody-positive AN without MN were compared. Furthermore, the proportion of patients with MN combined with AN presenting with acute or subacute onset was higher than that observed in the MN without AN group. Nevertheless, no substantial differences were noted between the two groups concerning the clinical and electrophysiological characteristics, which were mainly elderly men, manifested as sensory ataxia, IgG4 antibody subtype, electrophysiological demyelination, and a certain effect on immunotherapy.

CONCLUSION

In cases of electrophysiological manifestation of demyelinating peripheral neuropathy, especially in distal and poximal segments of nerves, AN should be considered, and further screening for renal function should be performed. Concomitant MN does not aggravate or alleviate peripheral nerve symptoms.

European Academy of Neurology: First 10 years

The European Academy of Neurology (EAN) was founded in May 2014 as the scientific society of all neurologists and all national neurological societies in Europe. The creation of EAN was based on the conscious decision of two predecessor societies (the European Federation of Neurological Societies and the European Neurological Society) to have a unique society for this continent with its 53 countries according to the World Health Organization and with the EU as the most important continental political decision level. In this report, the important milestones and the motivations of the decision-makers during the first 10 years are described. The development of the annual congress, the broad educational agenda, and the scientific groundwork including the European guidelines for the practise of neurology are described. Collaboration with and work for the national neurological societies is an important task for EAN. The political representation of neurology in Brussels and collaboration with the scientific societies of neighbouring medical disciplines and patient organizations are other major tasks on the agenda of the organization. EAN's goal is to reduce the burden of neurological diseases and to be the "home of neurology" in Europe for physicians, patients, and society. EAN communicates and interacts with its members, patients, partners, politicians, and the public through different channels. EAN is the owner of the scientifically independent European Journal of Neurology. EAN is based in Vienna, where its head office is located, but is also strongly represented in Brussels.

Usefulness of somatosensory evoked potentials for monitoring the clinical course of patients with chronic inflammatory demyelinating polyradiculoneuropathy

INTRODUCTION/AIMS

Somatosensory evoked potentials (SSEPs) are described as a supportive tool to diagnose chronic inflammatory demyelinating polyradiculoneuropathy (CIDP); however, there is a lack of studies determining the effectiveness of SSEPs in monitoring the clinical course of individuals with this condition. The aims of this study are to evaluate the utility of SSEPs in monitoring patients with CIDP and to assess their association with clinical outcomes following immunomodulatory therapy.

METHODS

This was a single-center retrospective observational study that included patients who met European Federation of Neurological Societies and Peripheral Nerve Society criteria for CIDP between 2018 and 2023. SSEPs were performed at diagnosis and during follow-up after the start of immunomodulatory treatment. Fisher's exact test was employed to assess the association between clinical improvement and SSEP improvement.

RESULTS

Eighteen patients were included in the study. Ten patients had a typical CIDP pattern and 11 were male. In 17, SSEPs were abnormal prior to the start of immunomodulatory treatment. In patients who showed clinical improvement with immunomodulatory therapy, we observed that 15/17 had partial or complete improvement in SSEPs. Patients who showed no clinical improvement with first-line treatment exhibited worsening SSEPs. There was a significant association between clinical and SSEPs improvement (p = 0.009).

DISCUSSION

We observed a positive association between improvement in SSEPs and clinical improvement in patients with CIDP. Our data suggest that SSEPs may be useful for monitoring the clinical course of patients with CIDP, but additional, larger studies are needed.

Pediatric Chronic Inflammatory Demyelinating Polyneuropathy: Challenges in Diagnosis and Therapeutic Strategies

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare autoimmune neurological disorder seen in both pediatric and adult populations. CIDP typically presents with progressive and persistent weakness over at least 4 weeks in addition to sensory symptoms in the extremities. Although CIDP shares common clinical features between children and adults, it sometimes presents as a distinct clinical entity in children that requires close attention and recognition. A major caveat when diagnosing a child with CIDP is the clinical and diagnostic overlap with inherited neuropathies, most commonly Charcot-Marie-Tooth disease (CMT). Demyelinating CMT (dCMT) and CIDP might share similar clinical presentations, and sometimes it might be difficult to differentiate them on the basis of the electrodiagnostic findings or cerebrospinal fluid (CSF) albumino-cytological dissociation. This indeed merits early consideration for genetic testing in patients who do not respond to conventional CIDP therapies. Current treatment options for CIDP include intravenous immunoglobulins (IVIG), corticosteroids (CS), and plasmapheresis (PLEX). The need for novel therapies is essential in instances where patients continue to have symptoms despite the standard therapies or due to adverse effects of long-term use of standard therapies such as CS. This paper reviews the challenges in the diagnosis of CIDP in children and the current as well as novel therapies for CIDP.

Early differential diagnosis between acute inflammatory demyelinating polyneuropathy and acute-onset chronic inflammatory demyelinating polyneuropathy in children: Clinical factors and routine biomarkers

BACKGROUND

To identify clinical factors and biomarkers that could contribute to early differential diagnosis of acute inflammatory demyelinating polyneuropathy (AIDP) and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) in the pediatric population, with limited evidence.

METHODS

We conducted an observational retrospective study of children diagnosed with AIDP and A-CIDP between January 2014 and December 2022. Demographic data, clinical features, and routine biomarkers were also analyzed. Statistical analysis was used to identify significant features with high sensitivity and specificity.

RESULTS

We included 91 AIDP and 17 A-CIDP patients. The A-CIDP group had an older median age (6.33 vs. 4.33 years, p = 0.017), required more complex immunotherapies (p < 0.001), and showed a longer time to nadir over 2 weeks (76.5 % vs. 7.7 %, p < 0.001). Gastrointestinal dysfunction (29.4 % vs. 6.59 %, p = 0.014) and numbness (35.3 % vs. 12.1 %, p = 0.027) were more prevalent in A-CIDP. The AIDP patients had a longer median hospitalization stays (13 vs. 11 days, p < 0.05), more prodromal events (90.1 % vs. 64.7 %, p = 0.013), and more frequent cranial nerve palsy (61.5 % vs. 5.88 %, p < 0.001). The disability scores on admission, discharge, and peak were worse in the AIDP group (p < 0.001). AIDP patients showed higher cerebrospinal fluid protein (p = 0.039), albumin quotient (p = 0.048), leukocytes (p = 0.03), neutrophils (p = 0.010), platelet count (p = 0.005), systemic inflammatory index (SII) (p = 0.009), and gamma-glutamyl transferase (p = 0.039). Multivariable regression identified two independent predictors of early A-CIDP detection: time from onset to peak beyond 2 weeks (OR = 37.927, 95%CI = 7.081-203.15) and lower modified Rankin Scale score on admission (OR = 0.308, 95%CI = 0.121-0.788).

CONCLUSION

Our study found that when the condition continued to deteriorate beyond two weeks with a lower mRS on admission and possibly less cranial nerve involvement, we may favor the diagnosis of pediatric A-CIDP rather than AIDP.

Antibodies in immune-mediated peripheral neuropathies. Where are we in 2024?

Over the past 30 years, about 20 antibodies have been identified in immune-mediated neuropathies, recognizing membrane or intracellular proteins or glycolipids of neuron and Schwann cells. This article reviews the different methods used for their detection, what we know about their pathogenic role, how they have helped identify several disorders, and how they are essential for diagnosis. Despite sustained efforts, some immune-mediated disorders still lack identified autoantibodies, notably the classical form of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy. The reasons for this are discussed. The article also tries to determine potential future developments in antibody research, particularly the use of omic approaches and the search for other types of biomarkers beyond diagnostic ones, such as those that can identify patients who will respond to a given treatment.

Autoantibodies in neuromuscular disorders: a review of their utility in clinical practice

A great proportion of neuromuscular diseases are immune-mediated, included myasthenia gravis, Lambert-Eaton myasthenic syndrome, acute- and chronic-onset autoimmune neuropathies (anti-MAG neuropathy, multifocal motor neuropathy, Guillain-Barré syndromes, chronic inflammatory demyelinating polyradiculoneuropathy, CANDA and autoimmune nodopathies), autoimmune neuronopathies, peripheral nerve hyperexcitability syndromes and idiopathic inflammatory myopathies. The detection of autoantibodies against neuromuscular structures has many diagnostic and therapeutic implications and, over time, allowed a better understanding of the physiopathology of those disorders. In this paper, we will review the main autoantibodies described in neuromuscular diseases and focus on their use in clinical practice.

Utilizing nerve conduction studies to identify very early Guillain-Barré syndrome and distinguish it from mimics in emergency settings

INTRODUCTION/AIMS

Accurately diagnosing Guillain-Barré syndrome (GBS) in its early stages and distinguishing it from mimics poses challenges. This study aimed to evaluate the utility of an existing electrodiagnostic criterion in very early GBS (VEGBS) for discerning mimics. Additionally, we explored specific electrophysiological abnormalities in VEGBS to design a new diagnostic criterion for more accurate VEGBS diagnosis.

METHODS

We retrospectively identified all patients with flaccid quadriparesis initially suspected of GBS who underwent nerve conduction studies (NCS) ≤4 days from symptom onset. We then retrieved their NCS data and applied an existing electrodiagnostic criterion for sensitivity and specificity analyses based on the final discharge diagnosis. Furthermore, we designed a new criterion based on the observed electrophysiological abnormalities that have maximum specificity and at least 50% sensitivity.

RESULTS

Among 70 patients suspected of VEGBS, 44 (63%) received a final diagnosis of GBS, while in 26 (37%), the GBS diagnosis was later refuted. Umapathi's definite criterion exhibited a sensitivity of 61.36% and a specificity of 92.31%. The probable and possible groups showed very high sensitivity (90.91% and 100%, respectively); however, specificity was low (57.69% and 30.77%, respectively) in the very early stage. Our proposed criterion demonstrated a sensitivity of 88.64% (CI: 75.44%-96.21%) and a specificity of 96.15% (CI: 80.36%-99.90%).

DISCUSSION

The criterion based on presumed electrophysiological correlates of specific early GBS pathophysiology proved more effective than the existing electrodiagnostic criterion in differentiating VEGBS from mimics.