Background:Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable immune-mediated neuropathy, yet real-world evidence on therapeutic strategies and their evolution over time remains limited. This study aimed to characterise prescription patterns across Italian centres, assess adherence to international guidelines, and identify clinical, structural, and temporal determinants of therapeutic decision-making. Methods:This multicentre, combined prospective and retrospective observational study used data from the Italian CIDP registry, including 653 patients from 24 tertiary centres from 2015 to 2025. Detailed treatment histories were collected for induction and maintenance regimens, including intravenous immunoglobulin (IVIg), corticosteroids, plasma exchange (PE), subcutaneous immunoglobulin (SCIg), and immunosuppressants. A structured questionnaire assessed centre-level factors influencing treatment choices. Findings:Marked inter-centre heterogeneity across all treatment options was observed (p < 0.001). Over time, IVIg and SCIg use increased, while corticosteroids, PE, and traditional immunosuppressants declined. Independent determinants of induction therapy included patient characteristics, treatment period, and treating centre. Lower IVIg induction doses and oral corticosteroids were associated with worse long-term outcomes. Over time, induction response rates, residual disability, and therapy suspension rates improved. Questionnaire data revealed that although guideline recommendations strongly influenced decisions, organisational constraints, local prescribing culture, and patient preferences independently shaped treatment allocation. Interpretation:CIDP management in routine clinical practice is highly heterogeneous and influenced by both clinical and structural factors. These findings underscore the need for standardised, evidence-based, and sustainable treatment pathways to reduce unwarranted variability and ensure equitable access to optimal care as therapeutic options continue to expand. Funding:Grant from Regione Lombardia, Italy; Grant from Ministero della Salute, Ricerca Finalizzata; Kedrion Biopharma (Italy); CSL Behring (Italy); Humanitas Research Institute (Milan, Italy); GBS-CIDP Foundation International (USA).

Background: Demyelination and remyelination are major issues for scientists dealing with myelin disorders in both clinical and research fields. Despite that, rapid, reliable and convenient tools to monitor myelin changes still lack both in central and peripheral nervous system. Given that myelin is enriched in specific lipids and proteins, it is reasonable they could represent eligible candidates as structural damage biomarkers for this characteristic membrane. Among them, we focused on sphingomyelin (SM) due to the enrichment in myelin and because it is easily measurable in different biological matrices. Objective: Depicting the roadmap to identify and validate SM dosage as a myelin biomarker useful for pre-clinical and clinical practice. Design: This study adheres to STROBE guidelines for observational cross-sectional studies on human patients and to ARRIVE guidelines for animal models. Method: Following the recommendations of the Society for CSF Analysis and Clinical Neurochemistry, we describe the stepwise process to validate SM as a myelin biomarker, starting from the optimization of the fluorescence-based assay and analytical validation in experimental models until clinical and pathological validation in biological fluids of neurological patients. Results: SM dosage monitors myelination, demyelination, remyelination and even small myelin changes associated to myelin pathology and pharmacological treatments in experimental models. SM is detectable in human biological fluids and informative of myelin damage in the CSF of neurological patients. SM dosage identifies myelin breakdown in the CSF of patients affected by Guillain-Barrè Syndrome (GBS) and Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP), identifying disease activity, axonal from demyelinating variants, and avoiding misdiagnosis. Conclusion: SM dosage displayed extremely promising real-word performances being able to identify, monitor and stage myelin pathology. Given that it is simple, inexpensive and easily adaptable to routine use in any hospital setting, it might rapidly progress to the implementation and impact on clinical outcomes.

Hereditary transthyretin amyloidosis (ATTRv) is a rare, multisystemic disorder often presenting with peripheral neuropathy and can be misdiagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), especially in non-endemic areas. While clinical red flags have been proposed to aid diagnosis, their predictive value remains uncertain. This study prospectively assessed the prevalence of TTR variants in CIDP patients with red flags for ATTRv and retrospectively analyzed features of genetically confirmed ATTRv cases initially misdiagnosed as CIDP. Thirteen Italian tertiary neuromuscular centers consecutively screened CIDP patients with at least one red flag for TTR gene variants. A retrospective analysis was also conducted on ATTRv patients initially misdiagnosed as CIDP, comparing clinical, electrophysiological, and treatment response features to confirmed CIDP cases. No TTR variants were identified among 124 screened CIDP patients despite 65

Background and purposeThis study aimed to assess the diagnostic criteria, ancillary investigations and treatment response using real-life data in multifocal motor neuropathy (MMN) patients.MethodsClinical and laboratory data were collected from 110 patients enrolled in the Italian MMN database through a structured questionnaire. Twenty-six patients were excluded due to the unavailability of nerve conduction studies or the presence of clinical signs and symptoms and electrodiagnostic abnormalities inconsistent with the MMN diagnosis. Analyses were conducted on 73 patients with a confirmed MMN diagnosis and 11 patients who did not meet the diagnostic criteria.ResultsThe European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria were variably applied. AUTHOR:When applying the American Association of Electrodiagnostic Medicine criteria, an additional 17% of patients fulfilled the criteria for probable/definite diagnosis whilst a further 9.5% missed the diagnosis. In 17% of the patients only compound muscle action potential amplitude, but not area, was measured and subsequently recorded in the database by the treating physician. Additional investigations, including anti-GM1 immunoglobulin M antibodies, cerebrospinal fluid analysis, nerve ultrasound and magnetic resonance imaging, supported the diagnosis in 46%-83% of the patients. Anti-GM1 immunoglobulin M antibodies and nerve ultrasound demonstrated the highest sensitivity. Additional tests were frequently performed outside the EFNS/PNS guideline recommendations.ConclusionsThis study provides insights into the real-world diagnostic and management strategies for MMN, highlighting the challenges in applying diagnostic criteria.

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

The aim was to evaluate the risk of relapse after severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccination, and its safety and tolerability, in patients with chronic inflammatory neuropathies.

Background To assess the ability of the 2021 European Academy of Neurology/Peripheral Nerve Society (EAN/PNS) clinical criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) to include within their classification the whole spectrum of clinical heterogeneity of the disease and to define the clinical characteristics of the unclassifiable clinical forms. Methods The 2021 EAN/PNS clinical criteria for CIDP were applied to 329 patients fulfilling the electrodiagnostic (and in some cases also the supportive) criteria for the diagnosis of CIDP. Clinical characteristics were reviewed for each patient not strictly fulfilling the clinical criteria (‘unclassifiable’). Results At study inclusion, 124 (37.5%) patients had an unclassifiable clinical presentation, including 110 (89%) with a typical CIDP-like clinical phenotype in whom some segments of the four limbs were unaffected by weakness (‘incomplete typical CIDP’), 10 (8%) with a mild distal, symmetric, sensory or sensorimotor polyneuropathy confined to the lower limbs with cranial nerve involvement (‘cranial nerve predominant CIDP’) and 4 (1%) with a symmetric sensorimotor polyneuropathy limited to the proximal and distal areas of the lower limbs (‘paraparetic CIDP’). Eighty-one (65%) patients maintained an unclassifiable presentation during the entire disease follow-up while 13 patients progressed to typical CIDP. Patients with the unclassifiable clinical forms compared with patients with typical CIDP had a milder form of CIDP, while there was no difference in the distribution patterns of demyelination. Conclusions A proportion of patients with CIDP do not strictly fulfil the 2021 EAN/PNS clinical criteria for diagnosis. These unclassifiable clinical phenotypes may pose diagnostic challenges and thus deserve more attention in clinical practice and research.

BACKGROUND AND PURPOSE:Many single cases and small series of Guillain-Barré syndrome (GBS) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were reported during the coronavirus disease 19 (COVID-19) outbreak worldwide. However, the debate regarding the possible role of infection in causing GBS is still ongoing. This multicenter study aimed to evaluate epidemiological and clinical findings of GBS diagnosed during the COVID-19 pandemic in northeastern Italy in order to further investigate the possible association between GBS and COVID-19.METHODS:Guillain-Barré syndrome cases diagnosed in 14 referral hospitals from northern Italy between March 2020 and March 2021 were collected and divided into COVID-19-positive and COVID-19-negative. As a control population, GBS patients diagnosed in the same hospitals from January 2019 to February 2020 were considered.RESULTS:The estimated incidence of GBS in 2020 was 1.41 cases per 100,000 persons/year (95% confidence interval 1.18-1.68) versus 0.89 cases per 100,000 persons/year (95% confidence interval 0.71-1.11) in 2019. The cumulative incidence of GBS increased by 59% in the period March 2020-March 2021 and, most importantly, COVID-19-positive GBS patients represented about 50% of the total GBS cases with most of them occurring during the two first pandemic waves in spring and autumn 2020. COVID-19-negative GBS cases from March 2020 to March 2021 declined by 22% compared to February 2019-February 2020.CONCLUSIONS:Other than showing an increase of GBS in northern Italy in the "COVID-19 era" compared to the previous year, this study emphasizes how GBS cases related to COVID-19 represent a significant part of the total, thus suggesting a relation between COVID-19 and GBS.

Compression of the median nerve at the carpal tunnel can give demyelinating features and result in distal motor latency (DML) prolongation fulfilling the EFNS/PNS demyelinating criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). Accordingly, being carpal tunnel syndrome (CTS) common in the general population, the EFNS/PNS guidelines recommend excluding the DML of the median nerve when DML prolongation may be consistent with median neuropathy at the wrist from CTS. The main aims of this study were to verify whether the inclusion of DML of the median nerve (when consistent with CTS) could improve electrophysiological diagnostic accuracy for CIDP and if the median nerve at the carpal tunnel was more prone to demyelination. We analyzed electrophysiological data from 499 patients included consecutively into the Italian CIDP Database. According to the EFNS/PNS criteria, 352 patients had a definite, 10 a probable, and 57 a possible diagnosis of CIDP, while 80 were not fulfilling the diagnostic criteria. The inclusion of DML prolongation of median nerve did not improve significantly the diagnostic accuracy for CIDP; overall diagnostic class changed in 6 out of 499 patients (1.2%) and electrodiagnostic class of CIDP changed from not fulfilling to possible in only 2 patients (2.5% of not-fulfilling patients). In conclusion, we can infer that excluding DML prolongation of median nerve does not increase the risk of missing a diagnosis of CIDP thus corroborating the current EFNS/PNS criteria.