Electrodiagnostic subtyping in Guillain-Barré syndrome patients in the International Guillain-Barré Outcome Study.

BACKGROUND AND PURPOSE: Various electrodiagnostic criteria have been developed in Guillain-Barré syndrome (GBS). Their performance in a broad representation of GBS patients has not been evaluated. Motor conduction data from the International GBS Outcome Study (IGOS) cohort were used to compare two widely used criterion sets and relate these to diagnostic amyotrophic lateral sclerosis criteria. METHODS: From the first 1500 patients in IGOS, nerve conduction studies from 1137 (75.8%) were available for the current study. These patients were classified according to nerve conduction studies criteria proposed by Hadden and Rajabally. RESULTS: Of the 1137 studies, 68.3% (N = 777) were classified identically according to criteria by Hadden and Rajabally: 111 (9.8%) axonal, 366 (32.2%) demyelinating, 195 (17.2%) equivocal, 35 (3.1%) inexcitable and 70 (6.2%) normal. Thus, 360 studies (31.7%) were classified differently. The areas of differences were as follows: 155 studies (13.6%) classified as demyelinating by Hadden and axonal by Rajabally; 122 studies (10.7%) classified as demyelinating by Hadden and equivocal by Rajabally; and 75 studies (6.6%) classified as equivocal by Hadden and axonal by Rajabally. Due to more strictly defined cutoffs fewer patients fulfilled demyelinating criteria by Rajabally than by Hadden, making more patients eligible for axonal or equivocal classification by Rajabally. In 234 (68.6%) axonal studies by Rajabally the revised El Escorial (amyotrophic lateral sclerosis) criteria were fulfilled; in axonal cases by Hadden this was 1.8%. CONCLUSIONS AND DISCUSSION: This study shows that electrodiagnosis in GBS is dependent on the criterion set utilized, both of which are based on expert opinion. Reappraisal of electrodiagnostic subtyping in GBS is warranted.

Advances in diagnosis and management of distal sensory polyneuropathies.

Distal sensory polyneuropathy (DSP) is characterised by length-dependent, sensory-predominant symptoms and signs, including potentially disabling symmetric chronic pain, tingling and poor balance. Some patients also have or develop dysautonomia or motor involvement depending on whether large myelinated or small fibres are predominantly affected. Although highly prevalent, diagnosis and management can be challenging. While classic diabetes and toxic causes are well-recognised, there are increasingly diverse associations, including with dysimmune, rheumatological and neurodegenerative conditions. Approximately half of cases are initially considered idiopathic despite thorough evaluation, but often, the causes emerge later as new symptoms develop or testing advances, for instance with genetic approaches. Improving and standardising DSP metrics, as already accomplished for motor neuropathies, would permit in-clinic longitudinal tracking of natural history and treatment responses. Standardising phenotyping could advance research and facilitate trials of potential therapies, which lag so far. This review updates on recent advances and summarises current evidence for specific treatments.

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy. Symptoms may vary greatly in presentation and severity. Besides weakness and sensory disturbances, patients may have cranial nerve involvement, respiratory insufficiency, autonomic dysfunction and pain. To develop an evidence-based guideline for the diagnosis and treatment of GBS, using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology, a Task Force (TF) of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) constructed 14 Population/Intervention/Comparison/Outcome questions (PICOs) covering diagnosis, treatment and prognosis of GBS, which guided the literature search. Data were extracted and summarised in GRADE Summaries of Findings (for treatment PICOs) or Evidence Tables (for diagnostic and prognostic PICOs). Statements were prepared according to GRADE Evidence-to-Decision (EtD) frameworks. For the six intervention PICOs, evidence-based recommendations are made. For other PICOs, good practice points (GPPs) are formulated. For diagnosis, the principal GPPs are: GBS is more likely if there is a history of recent diarrhoea or respiratory infection; CSF examination is valuable, particularly when the diagnosis is less certain; electrodiagnostic testing is advised to support the diagnosis; testing for anti-ganglioside antibodies is of limited clinical value in most patients with typical motor-sensory GBS, but anti-GQ1b antibody testing should be considered when Miller Fisher syndrome (MFS) is suspected; nodal-paranodal antibodies should be tested when autoimmune nodopathy is suspected; MRI or ultrasound imaging should be considered in atypical cases; and changing the diagnosis to acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (A-CIDP) should be considered if progression continues after 8 weeks from onset, which occurs in around 5% of patients initially diagnosed with GBS. For treatment, the TF recommends intravenous immunoglobulin (IVIg) 0.4 g/kg for 5 days, in patients within 2 weeks (GPP also within 2-4 weeks) after onset of weakness if unable to walk unaided, or a course of plasma exchange (PE) 12-15 L in four to five exchanges over 1-2 weeks, in patients within 4 weeks after onset of weakness if unable to walk unaided. The TF recommends against a second IVIg course in GBS patients with a poor prognosis; recommends against using oral corticosteroids, and weakly recommends against using IV corticosteroids; does not recommend PE followed immediately by IVIg; weakly recommends gabapentinoids, tricyclic antidepressants or carbamazepine for treatment of pain; does not recommend a specific treatment for fatigue. To estimate the prognosis of individual patients, the TF advises using the modified Erasmus GBS outcome score (mEGOS) to assess outcome, and the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess the risk of requiring artificial ventilation. Based on the PICOs, available literature and additional discussions, we provide flow charts to assist making clinical decisions on diagnosis, treatment and the need for intensive care unit admission.

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.

Causes and consequences of diagnostic delay in Guillain-Barré syndrome in a UK tertiary center.

INTRODUCTION/AIMS: Understanding the potential causes and consequences of diagnostic delay in Guillain-Barré syndrome (GBS) could improve quality of care and outcomes. We aimed to determine these causes and consequences in our cohort of patients with GBS. METHODS: We retrospectively reviewed records of subjects with GBS, admitted to our center at University Hospitals Birmingham, UK, between January 2005 and December 2020. We evaluated time to diagnosis from presentation, factors associated with diagnostic delay, and its potential consequences. RESULTS: We included 119 consecutive subjects. Diagnostic delay at least 5 days from first presentation occurred in 27 of 119 (22.7%) of patients. Diagnostic delay was associated with age >60 years (odds ratio [OR], 3.58; 95% confidence interval [CI], 1.44-8.85), pre-existing cardiac/respiratory disease (OR, 4.10; 95% CI, 1.46-11.54), pre-existing diabetes (OR, 10.38; 95% CI, 2.47-43.69), documented normal initial neurological examination (OR, 2.49; 95% CI, 1.03-6.02), initial assessment by primary care (OR, 3.33; 95% CI, 1.22-9.10) and at least one visit for medical attention (OR, 10.29; 95% CI, 3.81-27.77). Diagnostic delay was not associated with length of inpatient stay, intensive care unit admission, ventilation, ability to walk at discharge, or inpatient mortality. Independent associations with diagnostic delay were observed for at least one visit for medical attention (OR, 10.15; 95% CI, 3.64-28.32) and pre-existing cardiac/respiratory disease (OR, 3.98; 95% CI, 1.19-13.28). An association of diagnostic delay with inpatient mortality was ascertained specifically in subjects with classic GBS (OR, 5.33; 95% CI, 1.1-25.87). DISCUSSION: Diagnostic delay in GBS results from patient-specific factors and patient pathways. A high index of suspicion is appropriate for certain patient groups. Prospective studies are needed to further investigate this topic.

Assessment timing and choice of outcome measure in determining treatment response in chronic inflammatory demyelinating polyneuropathy: A post hoc analysis of the PRISM trial.

INTRODUCTION/AIMS: Treatment response and its timing are variable in chronic inflammatory demyelinating polyneuropathy (CIDP). In this study we assessed the variability using multiple outcome measures. METHODS: We performed a post hoc analysis of the PRISM trial, a 24-week prospective, multicenter, single-arm, open-label, phase III study of a 10% intravenous immunoglobulin preparation for CIDP. We ascertained timing of response with primary/secondary outcome measures. RESULTS: At 6 weeks after treatment initiation, 13 of 40 subjects (32.5%) were defined as responders on the primary outcome measure, the adjusted Inflammatory Neuropathy Cause And Treatment (INCAT) scale. This increased to 20 of 41 (48.8%) at 12 weeks and to 32 of 42 (76.2%) at 24 weeks. Use of minimal important difference (MID)-determined amelioration of the inflammatory Rasch-built Overall Disability Scale (I-RODS), or of the Medical Research Council sum score (MRCSS), or of dominant hand-grip strength, in addition to the adjusted INCAT, indicated a sensitivity of 41.7% in identifying adjusted INCAT nonresponders at week 12 who subsequently responded at week 24. Specificity was 60% vs INCAT nonresponders at week 24. Consideration of amelioration of any amplitude on any secondary outcome measure indicated a 75% sensitivity, but only 30% specificity vs adjusted INCAT nonresponders at week 24. DISCUSSION: Immunoglobulin treatment continuation may be justified for up to 24 weeks in CIDP. Additional outcome measures may help in the early treatment stages to predict delayed response on the adjusted INCAT. However, their use is limited by high false-positive rates. More robust, reliable, and relevant outcome measures are needed to detect early improvement in immunoglobulin-treated CIDP.

The value of MUNIX as an objective electrophysiological biomarker of disease progression in chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION/AIMS: Objective outcome measures to monitor treatment response and guide treatment are lacking in chronic inflammatory demyelinating polyneuropathy (CIDP). In this study we aimed to evaluate the motor unit number index (MUNIX) as an outcome measurement in patients with CIDP and determine the correlation of MUNIX with functional and standard electrodiagnostic tests in a single follow-up study. METHODS: We evaluated MUNIX of the abductor pollicis brevis, abductor digiti minimi, and tibialis anterior (TA) muscles bilaterally. Muscle force was assessed by Medical Research Council Sum Score (MRCSS). Functional measures used were the Overall Neuropathy Limitation Score (ONLS) and the Rasch-built Overall Disability Scale (R-ODS) score at baseline and after 6 months of treatment. Standard electrophysiology was evaluated by the Nerve Conduction Study Score (NCSS). RESULTS: Twenty patients were included at baseline, and 16 completed the follow-up study. Significant correlations were found between the MUNIX sum score and both MRCSS and NCSS at baseline, between both the pinch strength and grip and upper limb MUNIX at baseline and follow-up, and between MUNIX of TA and both lower limb MRCSSs with lower limb ONLS at baseline and follow-up. Significant correlations also were found between MUNIX sum score change and MRCSS change, R-ODS change, and ONLS change. DISCUSSION: MUNIX changes correlated with strength and electrophysiological improvements in CIDP patients. This suggests that MUNIX may represent a useful objective biomarker for patient follow-up.

Acute-onset polyradiculoneuropathy after SARS-CoV2 vaccine in the West and North Midlands, United Kingdom.

INTRODUCTION/AIMS: We aimed to determine whether specific severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) vaccines may be associated with acute-onset polyradiculoneuropathy and if they may result in particular clinical presentations. METHODS: We retrospectively reviewed records of all persons presenting with acute-onset polyradiculoneuropathy from January 1, 2021, to June 30, 2021, admitted to two Neuroscience centers, of the West and North Midlands, United Kingdom. We compared subjects with previous SARS-CoV2 vaccine exposure with a local cohort of persons with acute-onset polyradiculoneuropathy admitted between 2005 and 2019 and compared admission numbers for the studied time frame with that of the previous 3 years. RESULTS: Of 24 persons with acute-onset polyradiculoneuropathy, 16 (66.7%) presented within 4 weeks after first SARS-CoV2 vaccine. Fourteen had received the AstraZeneca vaccine and one each, the Pfizer and Moderna vaccines. The final diagnosis was Guillain-Barré syndrome (GBS) in 12 and acute-onset chronic inflammatory demyelinating polyneuropathy in 4. Among AstraZeneca vaccine recipients, facial weakness in nine persons (64.3%), bulbar weakness in seven (50%), and the bifacial weakness and distal paresthesias GBS variant in three (21.4%), were more common than in historical controls (P = .01; P = .004, and P = .002, respectively). A 2.6-fold (95% confidence interval: 1.98-3.51) increase in admissions for acute-onset polyradiculoneuropathy was noted during the studied time frame, compared to the same period in the previous 3 years. DISCUSSION: Despite a low risk, smaller than that of SARS-CoV2 infection and its complications, exposure to the first dose of AstraZeneca SARS-CoV2 vaccine may be a risk factor for acute-onset polyradiculoneuropathy, characterized by more common cranial nerve involvement.

Iatrogenic immune-mediated neuropathies: diagnostic, epidemiological and mechanistic uncertainties for causality and implications for clinical practice.

Acute and chronic immune-mediated neuropathies have been widely reported with medical intervention. Although causal relationship may be uncertain in many cases, a variety of drugs, several vaccination types, surgical procedures and bone marrow transplants have been reported as possible cause or trigger of a putative immune-mediated response resulting in acute and chronic neuropathies. We conducted a systematic review of the literature from 1966 to 2020 on reported cases of possible iatrogenic immune-mediated neuropathies. We determined in each case the likelihood of causality based on frequency of the association, focusing primarily on clinical presentation and disease course as well as available ancillary investigations (electrophysiology, blood and cerebrospinal fluid and neuropathology). The response to immunotherapy and issue of re-exposure were also evaluated. We also considered hypothesised mechanisms of onset of immune-mediated neuropathy in the specific iatrogenic context. We believe that a likely causal relationship exists for only few drugs, mainly antitumour necrosis factor alpha agents and immune checkpoint inhibitors, but remains largely unsubstantiated for most other suggested iatrogenic causes. Unfortunately, given the lack of an accurate diagnostic biomarker for most immune-mediated neuropathies, clinical assessment will often override ancillary investigations, resulting in lower levels of certainty that may continue to cast serious doubts on reliability of their diagnosis. Consequently, future reports of suspected cases should collect and exhaustively assess all relevant data. At the current time, besides lack of evidence for causality, the practical implications on management of suspected cases is extremely limited and therapeutic decisions appear likely no different to those made in non-iatrogenic cases.

Minimal important differences and self-identifying treatment response in chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION/AIM: The use of outcome measures is recommended for chronic inflammatory demyelinating polyneuropathy (CIDP). Implications of minimal important differences (MID) to ascertain responder status are unknown. The reliability of patient-reported treatment-response in relation to clinically relevant change is also unknown. METHODS: We retrospectively studied 72 subjects with "definite" or "probable" CIDP evaluated at pre-specified time-intervals pre- and post-treatment. We derived MID and the minimum detectable change with 95% confidence intervals (MDC95 ) for four scales. Scale sensitivities were determined with applicable MID-defined cutoffs (aMIDc), to detect subjects with self-identifying treatment response through a single question. RESULTS: The use of MID was not valid for the Medical Research Council Sum Score, as MDC95 > MID. The aMIDc for the Overall Neuropathy Limitation Score (ONLS) was 1 (sensitivity: 84.7%). The aMIDc for the centile Inflammatory Rasch-built Overall Disability Scale (cI-RODS) was 8 (sensitivity: 62.3%). The aMIDc for grip strength was 4 kg (sensitivity: 79.1%). MID-defined amelioration of any one scale among ONLS, cI-RODS, or grip strength, significantly improved sensitivity to detect treatment-responders compared with the ONLS alone (McNemar test: P = .008, odds ratio: 3.36 [95% confidence interval: 1.44-7.86]). Patient-reported improvement was highly reliable in relation to MID-defined amelioration on any one scale. DISCUSSION: In subjects with CIDP, MID-defined amelioration of any one of three commonly used outcome measures offers optimum relevance and sensitivity to detect self-identifying treatment-responders. Patient reliability to single-question ascertainment of response is high in relation to MID-defined clinical relevance. These findings support use of multiple outcome measures in CIDP monitoring and justify enhanced patient involvement in the process.

Antecedent infections and vaccinations in chronic inflammatory demyelinating polyneuropathy: A European collaborative study.

INTRODUCTION/AIMS: Chronic inflammatory demyelinating polyneuropathy (CIDP) may be rarely preceded by infection. A causative link remains unproven, in contrast to Guillain-Barré syndrome (GBS), which is commonly postinfectious with well-demonstrated pathophysiological mechanisms of molecular mimicry following Campylobacter jejuni enteritis. Uncommonly, infections are reported before the onset of CIDP. In this study we aimed to determine the frequency and characteristics of CIDP occurring after antecedent infections or vaccinations in two large European cohorts. METHODS: We reviewed the records of 268 subjects with "definite" or "probable" CIDP from the Inflammatory Neuropathy Clinic, Birmingham, UK (129 subjects), and from the Serbian national CIDP database (139 subjects). RESULTS: Twenty-five of 268 (9.3%) subjects had a respiratory or gastrointestinal infection in the 6 weeks preceding CIDP onset, and 3 of 268 (1.1%) had received an influenza vaccination. CIDP disease onset occurred at a younger age (mean [standard deviation], 44.25 [17.36] years vs 54.05 [15.19] years; P < .005) and acute-onset CIDP was more common (42.9% vs 12.1%; odds ratio, 5.46; 95% confidence interval, 2.35-12.68; P < .001) in subjects with preceding infections or vaccinations. No differences in CIDP subtype, rates of cerebrospinal fluid protein level elevation, disability, or likelihood of treatment response, were observed. DISCUSSION: Antecedent infections or vaccinations may precede about 10% of cases of CIDP and are more common in younger subjects. Acute-onset CIDP is more frequent after antecedent events. These findings may suggest specific pathophysiological mechanisms in such cases.

Patient perceptions of outcome measures in chronic inflammatory demyelinating polyneuropathy: A study of the Inflammatory Rasch-built Overall Disability Scale.

BACKGROUND: Patients' perceptions of outcome measures used in chronic inflammatory demyelinating polyneuropathy (CIDP) are unknown. METHODS: We performed a cross-sectional evaluation of patient perceptions of the Inflammatory Rasch-built Overall Disability Scale (I-RODS) from 41 subjects with CIDP through a structured questionnaire. We assessed perceived hesitation to provide a response, item importance and relevance, understanding of specific items and factors affecting responses. RESULTS: Hesitation to provide a categorical answer was reported by 20% of subjects or more, for 5/24 (20.8%) items. Uncertainty was most frequent for "travel by public transport" (22.4%) and "catch an object (e.g., ball)" (24%). Six of 24 (25%) items were perceived as unimportant to their disease by at least a third of participants. Items most commonly perceived as unimportant were "travel by public transport" in 53.7%, "catch an object (e.g., ball)" in 61% and "dance" in 65.9%. Several items were frequently perceived as irrelevant. These included "move a chair" (39%), "do the dishes" (46.3%), "catch an object (e.g., ball)" (61%), "travel by public transport" (68.3%) and "stand for hours" (82.9%). The understanding of multiple items such as "read a book", "sit on a toilet" and "take a shower" was found to be highly variable. Fatigue was perceived more commonly than mood (53.7% vs. 17.1%, p = 0.001), and more commonly in younger subjects (p = 0.037), as influencing responses to the I-RODS. CONCLUSIONS: Patient-perceived uncertainty, unimportance, irrelevance and poor understanding of items, as well as fatigue and mood, impact on the value of the I-RODS. Greater emphasis on individualized disability assessments requires consideration in future.

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.

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

Retrospective analysis of response to rituximab in chronic inflammatory demyelinating polyneuropathy refractory to first-line therapy.

Few case reports/series describe the efficacy of rituximab in refractory chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), which is preferred in the presence of anti-nodal/paranodal antibodies. We aimed at evaluating the clinical response to rituximab in a subset of patients with refractory CIDP for whom the anti-nodal/paranodal antibodies status was unknown, as not available in Iran. We retrospectively analyzed the response to rituximab in 14 Iranian patients with refractory CIDP (3 children, 11 adults), in whom the anti-nodal/paranodal antibodies status was unknown. The subjects were evaluated with the Medical Research Council (MRC) sum score (MRCSS), Inflammatory Neuropathy Cause and Treatment (INCAT) disability scores, and electrophysiology, before and after treatment. Mean age was 34.4 ± 20.7 years, disease duration pre-rituximab treatment was 27.8 ± 18.8 (range: 6-60) months, and mean follow-up duration was 18.5 ± 11.0 (range: 4-36) months. Considering the INCAT sum score, one worsened during post-rituximab treatment, and three patients did not change. Considering MRCSS, notably, four patients achieved normalization of their MRCSS. Regarding the corticosteroid dose, two patients could discontinue prednisolone. As rated by a pre-defined scoring system, nerve conduction parameters improved significantly post-rituximab in the treated cohort (P = .006). All patients tolerated rituximab infusions without adverse effects. Rituximab may be effective in refractory CIDP, even though worsening may occur in some patients. Anti-nodal/paranodal antibodies assay, when available, and other criteria may help drive therapeutic decision-making on rituximab as second-line treatment.

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

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

Diagnostic challenges in chronic inflammatory demyelinating polyradiculoneuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) consists of a spectrum of autoimmune diseases of the peripheral nerves, causing weakness and sensory symptoms. Diagnosis often is challenging, because of the heterogeneous presentation and both mis- and underdiagnosis are common. Nerve conduction study (NCS) abnormalities suggestive of demyelination are mandatory to fulfil the diagnostic criteria. On the one hand, performance and interpretation of NCS can be difficult and none of these demyelinating findings are specific for CIDP. On the other hand, not all patients will be detected despite the relatively high sensitivity of NCS abnormalities. The electrodiagnostic criteria can be supplemented with additional diagnostic tests such as CSF examination, MRI, nerve biopsy, and somatosensory evoked potentials. However, the evidence for each of these additional diagnostic tests is limited. Studies are often small without the use of a clinically relevant control group. None of the findings are specific for CIDP, meaning that the results of the diagnostic tests should be carefully interpreted. In this update we will discuss the pitfalls in diagnosing CIDP and the value of newly introduced diagnostic tests such as nerve ultrasound and testing for autoantibodies, which are not yet part of the guidelines.

Chronic inflammatory demyelinating polyneuropathy associated with diabetes: a European multicentre comparative reappraisal.

INTRODUCTION: The association between chronic inflammatory demyelinating polyneuropathy (CIDP) and diabetes is uncertain despite important diagnostic and management implications. METHODS: We retrospectively analysed two European cohorts, totaling 257 patients with 'definite' or 'probable' CIDP, from Serbia and Birmingham, UK. RESULTS: Diabetes was present at CIDP diagnosis in 25/139 (18%) subjects in the Serbian cohort and in 23/118 (19.5%) in the UK cohort. In both cohorts, diabetes prevalence was higher than local general population prevalence rates (RR: 2.09; 95% CI 1.39 to 2.95 and RR: 2.22; 95% CI 1.46 to 3.17, respectively). Considering typical CIDP only, diabetes prevalence was greater than expected in both cohorts (RR: 2.58; 95% CI 1.60 to 3.82 and RR: 2.68; 95% CI 1.71 to 3.87, respectively). CIDP with diabetes occurred later in life than CIDP without diabetes (58.96 years, SD: 11.09 vs 51.71 years, SD: 16.02; p=0.003) and presented more frequently in the typical form than in patients without diabetes (79.2% vs 61.2%; p=0.02). Baseline Inflammatory Neuropathy Cause and Treatment disability scores were similar in patients with and without diabetes (p=0.90). Proportions of treatment responders were similar in both groups (70% vs 74.9%; p=0.65), as were response amplitudes (p=0.87). DISCUSSION: Our results, both for all CIDP and typical CIDP presentations, support a twofold increased relative risk of diabetes compared with the general population. CIDP with diabetes appears to present older and more frequently in the typical form, as compared with CIDP without diabetes. CIDP with diabetes appears similar to CIDP without diabetes in disability levels at diagnosis and probability, as well as amplitude of treatment response.

Small fiber neuropathy in unexpected clinical settings: a review.

Small fiber neuropathy (SFN) is being recognized with increasing frequency in neuromuscular practice due to improved diagnostic techniques. Although there are some common etiologies, up to one-third of cases are considered idiopathic. In recent years, several disorders have unexpectedly been reported in association with SFN, on clinical grounds and complementary investigations, including quantitative sensory testing, intraepidermal nerve fiber density and confocal corneal microscopy. Knowledge of these disorders is important in clinical practice as increased awareness enables prompt diagnosis of SFN in these settings and early optimal therapeutic management of affected patients. Furthermore, these new developments may lead to a better understanding of the pathophysiologic mechanisms underlying SFN in these different disorders as well as, in some cases, an expanded spectrum of affected organs and systems. This article reviews these reported associations, their possible pathophysiologic bases, and the potential resulting management implications.

Comparative value and determinants of suitability of outcome measures in treated chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION: The comparative value and suitability of outcome measures are uncertain in chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: We studied 35 patients with CIDP using the Overall Neuropathy Limitation Scale (ONLS), the inflammatory Rasch-built Overall Disability Scale (I-RODS), and the Medical Research Council Sum Score (MRCSS). RESULTS: Significant associations were determined between initial deficit and ONLS score (P = .002) and MRCSS improvement (P = .001) but not I-RODS score. A strong inverse correlation was observed between disease duration and I-RODS score(P = .002) but not ONLS/MRCSS improvement. A strong association was observed between age ≤ 40 years and I-RODS score (P = .001) but not ONLS/MRCSS improvement. When minimum important differences were used, ONLS and I-RODS sensitivities were comparable (P = .19). DISCUSSION: Overall Neuropathy Limitation Scale and I-RODS are equally sensitive in identifying change. Ease of administration, better ability to detect improvement in severe disease, and greater amplitude responses throughout the disease and in older patients favor the ONLS. The I-RODS appears more useful in early disease/younger patients.