Clinical and electrophysiological parameters distinguishing acute-onset chronic inflammatory demyelinating polyneuropathy from acute inflammatory demyelinating polyneuropathy

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.

A study on the role of serum uric acid in differentiating acute inflammatory demyelinating polyneuropathy from acute-onset chronic inflammatory demyelinating polyneuropathy

BACKGROUND AND PURPOSE

Clinical symptoms and laboratory indices for acute inflammatory demyelinating polyneuropathy (AIDP), a variant of Guillain-Barré syndrome, and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) were analyzed to identify factors that could contribute to early differential diagnosis.

METHODS

A retrospective chart review was performed on 44 AIDP and 44 A-CIDP patients looking for any demographic characteristics, clinical manifestations or laboratory parameters that might differentiate AIDP from acutely presenting CIDP.

RESULTS

In Guillain-Barré syndrome patients (N = 63), 69.84% (N = 44) were classified as having AIDP, 19.05% (N = 12) were found to have acute motor axonal neuropathy, 6.35% (N = 4) were found to have acute motor and sensory axonal neuropathy, and 4.76% (N = 3) were found to have Miller Fisher syndrome. Serum uric acid (UA) was higher in A-CIDP patients (329.55 ± 72.23 μmol/L) than in AIDP patients (221.08 ± 71.32 μmol/L) (p = 0.000). Receiver operating characteristic analyses indicated that the optimal UA cutoff was 283.50 μmol/L. Above this level, patients were more likely to present A-CIDP than AIDP (specificity 81.80%, sensitivity 81.80%). During the follow-up process, serum samples were effectively collected from 19 AIDP patients during the rehabilitation phase and 28 A-CIDP patients during the remission stage, and it was found that UA levels were significantly increased in A-CIDP (remission) (298.9 ± 90.39 μmol/L) compared with AIDP (rehabilitation) (220.1 ± 108.2 μmol/L, p = 0.009).

CONCLUSION

These results suggest that serum UA level can help to differentiate AIDP from A-CIDP with high specificity and sensitivity, which is helpful for early diagnosis and guidance of treatment.

Repeated Acute Exacerbations of Chronic Inflammatory Demyelinating Polyradiculoneuropathy Accompanied by Pain and Swelling in Distal Extremities

An 81-year-old man experienced acute progression of weakness in the extremities accompanied by a fever, tenderness, and swelling in distal parts of the extremities. He had flaccid tetraparesis with fasciculations and general hyporeflexia. Nerve conduction studies indicated demyelinating sensorimotor neuropathy. A cerebrospinal fluid examination revealed elevated proteins without pleocytosis. Immunological treatments were effective, but his symptoms exhibited repeated relapse and remission phases. He was diagnosed with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with an acute onset. The highlight of this case is pain with inflammatory reaction recognized as red flags of CIDP, with the clinical course and electrophysiological findings compatible with CIDP.

[Modern aspects of diagnosis and treatment of chronic inflammatory demyelinating polyneuropathy in children]

OBJECTIVE

Analysis of demographic, clinical, laboratory, electrophysiological and neuroimaging data and pathogenetic therapy of pediatric patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

MATERIAL AND METHODS

Patients (n=30) were observed in a separate structural unit of the Russian Children's Clinical Hospital of the Russian National Research Medical University named after. N.I. Pirogova Ministry of Health of the Russian Federation in the period from 2006 to 2023. The examination was carried out in accordance with the recommendations of the Joint Task Force of the European Federation of Neurological Societies and the Peripheral Nerve Society on the Management of CIDP (2021). All patients received immunotherapy, including intravenous immunoglobulin (IVIG) (n=1), IVIG and glucocorticosteroids (GCS) (n=17, 56.7%), IVIG+GCS+plasmapheresis (n=12, 40.0%). Alternative therapy included cyclophosphamide (n=1), cyclophosphamide followed by mycophenolate mofetil (n=1), rituximab (n=2, 6.6%), azathioprine (n=3), mycophenolate mofetil (n=2, 6.6%).

RESULTS

In all patients, there was a significant difference between scores on the MRCss and INCAT functional scales before and after treatment. At the moment, 11/30 (36.6%) patients are in clinical remission and are not receiving pathogenetic therapy. The median duration of remission is 48 months (30-84). The longest remission (84 months) was observed in a patient with the onset of CIDP at the age of 1 year 7 months.

CONCLUSION

Early diagnosis of CIDP is important, since the disease is potentially curable; early administration of pathogenetic therapy provides a long-term favorable prognosis.

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.

Guillain-Barré Syndrome

OBJECTIVE

This article summarizes the clinical features, diagnostic criteria, differential diagnosis, pathogenesis, and prognosis of Guillain-Barré syndrome (GBS), with insights into the current and future diagnostic and therapeutic interventions for this neuromuscular syndrome.

LATEST DEVELOPMENTS

GBS is an acute, inflammatory, immune-mediated polyradiculoneuropathy that encompasses many clinical variants and divergent pathogenic mechanisms that lead to axonal, demyelinating, or mixed findings on electrodiagnostic studies. The type of antecedent infection, the development of pathogenic cross-reactive antibodies via molecular mimicry, and the location of the target gangliosides affect the subtype and severity of the illness. The data from the International GBS Outcome Study have highlighted regional variances, provided new and internationally validated prognosis tools that are beneficial for counseling, and introduced a platform for discussion of GBS-related open questions. New research has been undertaken, including research on novel diagnostic and therapeutic biomarkers, which may lead to new therapies.

ESSENTIAL POINTS

GBS is among the most frequent life-threatening neuromuscular emergencies in the world. At least 20% of patients with GBS have a poor prognosis and significant residual deficits despite receiving available treatments. Research is ongoing to further understand the pathogenesis of the disorder, find new biomarkers, and develop more effective and specific treatments.

Nerve ultrasound for the diagnosis and follow-up of peripheral neuropathies

PURPOSE OF REVIEW

The purpose if this review is to provide an overview of the available data on the use of nerve ultrasound for the diagnosis and follow-up of peripheral neuropathies.

RECENT FINDINGS

During the last decade, nerve ultrasound has been established as a complementary tool for the evaluation of morphological changes mostly for immune-mediated polyneuropathies. Through the development of ultrasound protocols for evaluation of disease-specific sites, nerve ultrasound has proven to be a practical, widely available, reproducible diagnostic tool with no relevant contraindications.

SUMMARY

Cross-sectional area, echogenicity, morphology of the individual nerve fascicles, thickness of the epineurium, vascularization and mobility of the nerve are the main parameters evaluated with nerve ultrasound in polyneuropathies. Patients with typical chronic inflammatory demyelinating polyneuropathy show multifocal nerve enlargements easily visible on the upper extremities and the brachial plexus, whereas its variants show focal nerve enlargements. On the other hand, axonal neuropathies including diabetic neuropathy present with isolated nerve enlargement mostly in compression sites.

Chronic Immune-Mediated Demyelinating Neuropathies

OBJECTIVE

This article is an overview of chronic demyelinating neuropathies and highlights the phenotypic categorization, diagnosis, and treatment of chronic immune-mediated neuropathies. The clinical and diagnostic characteristics of other chronic demyelinating neuropathies that are common mimics of immune-mediated neuropathies are also discussed.

LATEST DEVELOPMENTS

The underlying pathophysiology of chronic demyelinating neuropathies is heterogeneous, and components of both humoral and cellular immune responses are thought to play a role in the immune-mediated types of chronic demyelinating neuropathy. The role of the humoral response is highlighted with a specific focus on the relatively recent discovery of antibody-mediated antinodal and paranodal demyelinating neuropathies. Additionally, new diagnostic criteria for some of the chronic demyelinating neuropathies, as well as ways to differentiate chronic inflammatory demyelinating polyradiculoneuropathy from other chronic demyelinating polyneuropathies, are discussed.

ESSENTIAL POINTS

Chronic demyelinating neuropathies can present with overlapping clinical characteristics with seemingly subtle variations. It is clinically important to differentiate these types of neuropathies because the treatment and management can vary and affect prognosis.

Autonomic nervous system involvement in chronic inflammatory demyelinating polyradiculoneuropathy: a literature review

BACKGROUND AND AIMS

Although dysautonomia is a well-recognized complication of acute demyelinating polyradiculoneuropathy, it is rarely reported and evaluated in chronic demyelinating neuropathies. The purpose of this review is to search and synthesize the current literature on the prevalence and type of autonomic dysfunction (AD) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

PubMed and Web of Science were searched for studies reporting AD in CIDP.

RESULTS

Twelve studies, including 346 patients with CIDP, were found eligible for the review. Seven studies used autonomic tests only as an additional component of the comprehensive clinical evaluation, and found that dysautonomia in CIDP may indicate the presence of a comorbid disease (e.g., diabetes) and facilitate the differentiation of CIDP from other neuropathies (e.g., amyloid neuropathy). Five studies performed quantitative assessment of autonomic function in CIDP as a primary goal. Two studies have used the Composite Autonomic Severity Score (CASS) to assess severity and distribution of dysautonomia. The reported prevalence of dysautonomia in CIDP during quantitative assessment of autonomic function ranged from 25 to 89%, depending on the battery of tests used, with CASS not exceeding 4 points. The abnormalities in autonomic tests indicated both sympathetic and parasympathetic dysfunction and did not correlate with the duration, severity and variant of CIDP.

CONCLUSIONS

Clinical or subclinical involvement of the ANS has been shown to be common and relatively mild in CIDP. The impact of autonomic impairment on disability and of its possible response to therapy in CIDP needs to be further investigated.

Immune-mediated polyneuropathy in cats: Clinical description, electrodiagnostic assessment, and treatment

BACKGROUND

Suspected immune-mediated polyneuropathy has been increasingly reported in cats, especially in the last decade, but the condition remains poorly understood.

OBJECTIVES

Refine the clinical description and review the classification of this condition based on electrodiagnostic investigation and evaluate the benefit of corticosteroid treatment and L-carnitine supplementation.

ANIMALS

Fifty-five cats presented with signs of muscular weakness and electrodiagnostic findings consistent with polyneuropathy of unknown origin.

METHODS

Retrospective, multicenter study. Data from the medical records were reviewed. The owners were contacted by phone for follow-up at the time of the study.

RESULTS

The male-to-female ratio was 2.2. The median age of onset was 10 months, with 91% of affected cats being <3 years of age. Fourteen breeds were represented in the study. The electrodiagnostic findings supported purely motor axonal polyneuropathy. Histological findings from nerve biopsies were consistent with immune-mediated neuropathy in 87% of the tested cats. The overall prognosis for recovery was good to excellent, as all but 1 cat achieved clinical recovery, with 12% having mild sequelae and 28% having multiple episodes during their lifetime. The outcome was similar in cats with no treatment when compared with cats receiving corticosteroids or L-carnitine supplementation.

CONCLUSIONS AND CLINICAL IMPORTANCE

Immune-mediated motor axonal polyneuropathy should be considered in young cats with muscle weakness. This condition may be similar to acute motor axonal neuropathy in Guillain-Barré syndrome patients. Based on our results, diagnostic criteria have been proposed.

French recommendations for the management of adult & pediatric chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare autoimmune disorder of the peripheral nervous system, primarily affecting the myelin sheath. The pathophysiology of CIDP is complex, involving both humoral and cellular immunity. The diagnosis of CIDP should be suspected in patients with symmetrical proximal and distal motor weakness and distal sensory symptoms of progressive onset, associated with decreased/abolished tendon reflexes. Treatments include intraveinous immunoglobulins, steroids and plasma exchange, with usually an induction phase followed by a maintenance therapy with progressive weaning. Treatment should be rapidly initiated to prevent axonal degeneration, which may compromise recovery. CIDP outcome is variable, ranging from mild distal paresthesiae to complete loss of ambulation. There have been several breakthroughs in the diagnosis and management of CIDP the past ten years, e.g. discovery of antibodies against the node of Ranvier, contribution of nerve ultrasound and magnetic resonance imaging to diagnosis, and demonstration of subcutaneous immunoglobulins efficiency. This led us to elaborate French recommendations for the management of adult & pediatric CIDP patients. These recommendations include diagnosis assessment, treatment, and follow-up.

Controversies in neuroimmunology: multiple sclerosis, vaccination, SARS-CoV-2 and other dilemas

Neuroimmunology is a discipline that increasingly broadens its horizons in the understanding of neurological diseases. At the same time, and in front of the pathophysiological links of neurological diseases and immunology, specific diagnostic and therapeutic approaches have been proposed. Despite the important advances in this discipline, there are multiple dilemmas that concern and filter into clinical practice. This article presents 15 controversies and a discussion about them, which are built with the most up-to-date evidence available. The topics included in this review are: steroid decline in relapses of multiple sclerosis; therapeutic recommendations in MS in light of the SARS-CoV-2 pandemic; evidence of vaccination in multiple sclerosis and other demyelinating diseases; overview current situation of isolated clinical and radiological syndrome; therapeutic failure in multiple sclerosis, as well as criteria for suspension of disease-modifying therapies; evidence of the management of mild relapses in multiple sclerosis; recommendations for prophylaxis against Strongyloides stercolaris; usefulness of a second course of immunoglobulin in the Guillain-Barré syndrome; criteria to differentiate an acute-onset inflammatory demyelinating chronic polyneuropathy versus Guillain-Barré syndrome; and, the utility of angiotensin-converting enzyme in neurosarcoidosis. In each of the controversies, the general problem is presented, and specific recommendations are offered that can be adopted in daily clinical practice.

Chronic inflammatory demyelinating polyneuropathy with an acute onset. Clinical case

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a heterogeneous treatable dysimmune neuropathy. The variety of clinical forms and course of the disease can be challenging for proper diagnosis and early treatment. In a quarter of cases CIDP starts acutely, mimicking GuillainBarr syndrome. The early diagnosis is especially important regarding differences in treatment and prognosis of these conditions. In this article, we present a clinical case of acute onset CIDP with a detailed analysis of the differential diagnosis between acute and chronic immune-mediated neuropathies.

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).

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.

Pediatric CIDP: Diagnosis and Management. A Single-Center Experience

Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare acquired polyneuropathy that especially among youngest children should be differentiated with hereditary neuropathies. Even though upon diagnosis treatment options are similar in children and adults, diagnostic challenges are faced in the pediatric population. Methods: We conducted a retrospective analysis of clinical symptoms, nerve conduction study results, modes of treatment, and final outcome in 37 children aged 3.5-17 years with a final diagnosis of CIDP (18 girls, 19 boys). We established three groups of patients based on age at onset of CIDP: 0-4, 4-13, and 13-18 years. Follow-up ranged from 10 to 222 months. Results: In our analysis, 19/37 patients (51.4%) had an atypical presentation: distal variant of CIDP in 12/37 patients (32.4%) and pure motor variant of CIDP in 5/37 patients (13.5%), and one patient had a pure sensory variant (1/37, 2.7%). Furthermore, 3/37 patients (8.1%) had additional concurring symptoms, including involuntary movements of face muscles (1/37, 2.7%) or hand tremor (2/37, 5.4%). During the follow-up, 23/37 patients (62.2%) received intravenous immunoglobulin (IVIg); 22/37 patients (59.5%) received steroids, 6/37 patients (16.2%) received IVIg and steroids, and 12/37 patients (32.4%) received immunosuppressive drugs, mostly azathioprine, but also methotrexate and rituximab. One patient was treated with plasmapheresis. Complete remission was achieved in 19/37 patients (51.4%) with CIDP in its typical form. Remission with residual symptoms or minimal deficit was observed in 4/37 patients (10.8%), whereas 14/37 patients (37.8%) remain on treatment with gradual improvement. Conclusion: Childhood CIDP may occur in its typical form, but even ~50% of children can present as an atypical variant including distal, pure motor, or pure sensory. Most children have a good prognosis; however, many of them may require long-term treatment. This highlights the importance of an early diagnosis and treatment for childhood CIDP.

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).

Acute-onset chronic inflammatory demyelinating polyneuropathy with cranial nerves and respiratory tract involvement: A case report

Sixteen percent of chronic inflammatory demyelinating polyneuropathy (CIDP) patients may present acutely like acute idiopathic demyelinating polyneuropathy (AIDP) the demyelinating form of GBS, developing in <8 weeks 2. This entity is classified as acute-onset CIDP (A-CIDP) which presents overlapping clinical and electrophysiological findings with GBS during early stages of disease, but followed with a chronic course beyond 2 months. Also, those who have three or more treatment-related fluctuations (TRF) are included under this term. Distinguishing between acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) and acute idiopathic demyelinating polyneuropathy (AIDP) may be difficult during early stages but is crucial in order to guide treatment strategies without delay. These two forms share some overlapping clinical and electrophysiological findings, including some severe clinical features such as cranial nerve and respiratory tract involvement making the diagnosis of A-CIDP more difficult.

Evolving Immunologic Perspectives in Chronic Inflammatory Demyelinating Polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is the commonest chronic idiopathic dysimmune neuropathy. Pathophysiologic processes involve both cellular and humoral immunity. There are various known forms of CIDP, likely caused by varying mechanisms. CIDP in its different forms is a treatable disorder in the majority of patients. The diagnosis of CIDP is clinical, supported routinely by electrophysiology. Cerebrospinal fluid analysis may be helpful. Routine immunology currently rarely adds to the diagnostic process but may contribute to the identification of an associated monoclonal gammopathy with or without hematologic malignancy and the consideration of alternative diagnoses, such as POEMS syndrome, anti-myelin associated glycoprotein (MAG) neuropathy or chronic ataxic neuropathy, with ophthalmoplegia, M-protein, cold aglutinins and disialosyl antibodies (CANOMAD). The search for antibodies specific to CIDP has been unsuccessful for many years. Recently, antibodies to paranodal proteins have been identified in a minority of patients with severe CIDP phenotypes, often unresponsive to first-line therapies. In conjunction with reports of high rates of antibody responses to neural structures in CIDP, this entertains the hope that more discoveries are to come. Although still arguably for only a small minority of patients, in view of current knowledge, such progress will enable earlier accurate diagnosis with direct management implications but only if the important, unfortunately and infrequently discussed issues of immunologic technique, test reliability and reproducibility are adequately tackled.

A case of Recurrent Guillain-Barre Syndrome observed by the same clinician 12 years apart

Recurrent GBS is a rare neurological condition in which patients develop similar symptoms of motor weakness after different preceding infections and suffer shorter intervals in between subsequent episodes of GBS. However, the majority of RGBS patients undergo full recovery.

Longitudinal study on nerve ultrasound and corneal confocal microscopy in NF155 paranodopathy

We report the case of a 27‐year‐old patient with subacute anti‐neurofascin‐155 neuropathy with bifacial palsy, who showed excellent response to rituximab. We provide longitudinal data of established clinical scores, nerve conduction studies, antibody titers, and novel imaging methods (nerve ultrasonography and corneal confocal microscopy). Clinical and electrophysiological improvement followed the reduction of serum antibody titer and correlated with a reduction of corneal inflammatory cellular infiltrates whereas the increase in the cross‐sectional area of the peripheral nerves remained 12 months after first manifestation. Our findings suggest that novel techniques provide useful follow‐up parameters in paranodopathies.

Cerebrospinal fluid total protein in Guillain-Barré syndrome variants: correlations with clinical category, severity, and electrophysiology

The discriminative value of CSF total protein (CSF-TP) in subtypes of Guillain-Barré syndrome has not been well documented in North-American patients. We reviewed 173 cases from a single institution, comprising the following clinical categories of neuropathy: 134 Sensorimotor (SM) GBS, 13 Motor (M) GBS, 8 Localized (L) GBS, and 18 Miller Fisher syndrome (MFS). We grouped the electrophysiological interpretation in primarily demyelinating, primarily axonal and normal / equivocal categories. Mean CSF-TP were substantially higher for SM and L-GBS, as well as cases classified as Acute-onset chronic inflammatory demyelinating polyneuropathy. They were lower for M-GBS and L-GBS. The most statistically significant correlation was found for elevated CSF-TP in GBS cases showing an electrophysiologic pattern classified as demyelinating (1.56 g/L) compared with axonal (0.68 g/L) or normal/ equivocal patterns (0.65 g/L). There was a correlation between CSF-TP and time interval between symptom onset and lumbar puncture. There was a weak correlation between CSF-TP and maximal overall-clinical severity grade, which was likely mostly determined by the electorphysiological pattern. Though CSF-TP is a sensitive test for GBS in the second week after onset, it may not be a reliable predictor of clinical severity. There is a robust association of CSF-TP elevation and a demyelinative electrophysiologic pattern and a suggestion that lower mean CSF-TP values can be expected in GBS-spectrum disorders thought to represent nodo-paranodopathies.

Acute-onset chronic inflammatory demyelinating polyneuropathy with anti-neurofascin-155 antibodies and bilateral facial nerve enhancement

A 26-year-old female presented with acute onset distal paraparesis, upper limb tremor and bilateral facial palsy. Neurophysiology revealed a sensorimotor demyelinating polyneuropathy and lumbar puncture revealed an albuminocytologic dissociation. Neuroaxis MRI revealed bilateral facial nerve and cauda equina enhancement. Initially diagnosed as Guillain-Barré Syndrome, poor response to intravenous immunoglobulin, persistent deterioration, anti-neurofascin-155 antibodies and clinical response to steroid therapy led to diagnosis of acute-onset chronic inflammatory demyelinating polyneuropathy (CIDP). CIDP patients with anti-neurofascin-155 antibodies are younger, with distal predominant weakness, tremor, and poor response to intravenous immunoglobulin. Up to 16% can present acutely, however bilateral facial weakness is rare.

Neuroimaging markers of clinical progression in chronic inflammatory demyelinating polyradiculoneuropathy

Background:

One of the main goals of novel, noninvasive imaging techniques like high-resolution nerve ultrasound (HRUS) and corneal confocal microscopy (CCM) is the prediction of treatment response for patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

Methods:

A total of 17 patients with CIDP were examined prospectively at baseline and every 9 months over a period of 18 months using CCM to quantify corneal nerve degeneration markers and immune cell infiltration as well as HRUS to detect changes of the cross-sectional area (CSA) of the peripheral nerves. Additionally, skin biopsy of the distal and proximal leg as well as quantitative sensory testing were performed at the first follow-up visit.

Results:

A value of more than 30 total corneal cells/mm² in CCM at baseline identified patients with clinical progression with a sensitivity/specificity of 100% in our cohort. Corneal nerve fiber density and length remained low and stable over the study period and intra-epidermal fiber density was markedly reduced in the majority of the patients. Furthermore, an increase in Bochum ultrasound score (BUS), which summarizes the CSA of the ulnar nerve in Guyons’ canal, the ulnar nerve in the upper arm, the radial nerve in the spiral groove and the sural nerve between the gastrocnemius muscle, and a maximum BUS of 4 at study initiation identified patients with disease progression (sensitivity 80%, specificity 88%).

Conclusions:

BUS and corneal total cell infiltration seem to represent early markers for clinical progression in CIDP, thus having the potential to identify at-risk patients and impact treatment decisions.

A Rare case of recurrent Guillain-Barré syndrome without albuminocytological dissociation

Guillain-Barré syndrome (GBS) is an immune-mediated polyneuropathy, often preceded by an illness. It is a self-limiting illness in most of the cases, but recurrence is rare and can be seen in about 1%–6% of patients. GBS is characterised by progressive, symmetrical, proximal and distal weakness. Areflexia and sensory disturbances are also common. Patients with GBS usually have albuminocytological dissociation on cerebrospinal fluid (CSF) analysis. This is a case of a 69-year-old woman with recurrent GBS and normal CSF findings.

Chronic Demyelinating Polyneuropathies

PURPOSE OF REVIEW

This article reviews the chronic demyelinating neuropathies, with a focus on the diagnosis and treatment of immune-mediated neuropathies and the features that can help differentiate immune-mediated neuropathies from other chronic demyelinating peripheral nerve conditions.

RECENT FINDINGS

Advances in clinical phenotyping and outcomes assessment have enabled neurologists to improve disease recognition, treatment, and disease monitoring. Our understanding of the immunopathogenesis of demyelinating neuropathies is evolving. Identification of new antibodies and recognition that node of Ranvier dysfunction may be an early pathogenic feature may herald further diagnostic and treatment advancements.

SUMMARY

The chronic demyelinating polyneuropathies are heterogeneous. The clinical and diagnostic features are sometimes overlapping, and the specific disorders are variable in pathogenesis, treatment, and prognosis. This heterogeneity underscores the importance of achieving diagnostic accuracy and implementing disease-specific treatment approaches.

Differences between acute-onset chronic inflammatory demyelinating polyneuropathy and acute inflammatory demyelinating polyneuropathy in adult patients

Acute inflammatory demyelinating polyneuropathy (AIDP) and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) are conditions presenting overlapping clinical features during early stages (first 4 weeks), although the latter may progress after 8 weeks. The aim of this study was to identify predictive factors contributing to their differential diagnosis. Clinical records of adult patients with AIDP or A-CIDP diagnosed at our institution between January 2006 and July 2017 were retrospectively reviewed. Demographic characteristics, clinical manifestations, cerebrospinal-fluid (CSF) findings, treatment and clinical evolution were analyzed. Nerve conduction studies were performed in all patients with at least 12 months follow-up. A total of 91 patients were included (AIDP, n = 77; A-CIDP, n = 14). The median age was 55.5 years in patients with A-CIDP vs 43 years in AIDP (P = .07). The history of diabetes mellitus was more frequent in A-CIDP (29% vs 8%, P = .04). No significant differences between groups were observed with respect to: human immunodeficiency virus (HIV) status, presence of auto-immune disorder or oncologic disease. Cranial, motor and autonomic nerve involvement rates were similar in both groups. Patients in the A-CIDP group showed higher frequency of proprioceptive disturbances (83% vs 28%; P < .001), sensory ataxia (46% vs 16%; P = .01), and the use of combined immunotherapy with corticoids (29% vs 3%; P = .005). There were no significant differences in CSF findings, intensive care unit (ICU) admission, or mortality rates. During the first 8 weeks both entities are practically indistinguishable. Alterations in proprioception could suggest A-CIDP. Searching for markers that allow early differentiation could favor the onset of corticotherapy without delay.

Guillain-Barré syndrome

Guillain-Barré syndrome is the most common and most severe acute paralytic neuropathy, with about 100,000 people developing the disorder every year worldwide. Under the umbrella term of Guillain-Barré syndrome are several recognisable variants with distinct clinical and pathological features. The severe, generalised manifestation of Guillain-Barré syndrome with respiratory failure affects 20-30% of cases. Treatment with intravenous immunoglobulin or plasma exchange is the optimal management approach, alongside supportive care. Understanding of the infectious triggers and immunological and pathological mechanisms has advanced substantially in the past 10 years, and is guiding clinical trials investigating new treatments. Investigators of large, worldwide, collaborative studies of the spectrum of Guillain-Barré syndrome are accruing data for clinical and biological databases to inform the development of outcome predictors and disease biomarkers. Such studies are transforming the clinical and scientific landscape of acute autoimmune neuropathies.

Acute-onset chronic inflammatory demyelinating polyneuropathy: An electrodiagnostic study

INTRODUCTION

Acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) is an increasingly recognized CIDP subtype. Differentiating A-CIDP from Guillain-Barré syndrome (GBS) is challenging but important, because there are different treatment outcomes.

METHODS

We report 3 patients with A-CIDP who were initially diagnosed with severe GBS but were later confirmed to have CIDP based on their clinical course and electrodiagnostic (EDx) studies. We also report on the long-term treatment of these patients and review the literature on EDx studies in this syndrome.

RESULTS

Three patients were initially diagnosed with GBS and responded to treatment. However, all 3 had arrest in improvement or deterioration during their rehabilitation phases. EDx studies showed prominent demyelinating changes many months after the initial presentation. All responded very well to immunotherapy.

CONCLUSION

Although several features may suggest the diagnosis of A-CIDP at initial presentation, close follow-up of GBS patients during the recovery phase is also needed for accurate diagnosis. EDx studies may distinguish patients with A-CIDP from GBS patients.

The frequencies of Killer immunoglobulin-like receptors and their HLA ligands in chronic inflammatory demyelinating polyradiculoneuropathy are similar to those in Guillian Barre syndrome but differ from those of controls, suggesting a role for NK cells in pathogenesis

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired inflammatory neuropathy, which has similar clinical and pathological features to Guillain-Barré Syndrome (GBS), but differs in time course. We investigated the frequency of genes encoding Killer immunoglobulin-like receptors and their HLA ligands in subjects with CIDP, in subjects with GBS and in healthy controls. There were no differences in KIR gene frequency among the 3 groups. The gene frequencies for HLA-B Bw4-I were significantly greater in CIDP than HC, but did not differ from GBS. The frequency of the combination of 3DL1/HLA-B Bw4I was greater in CIDP than HC, but did not differ from that of GBS. These data raise the possibility of NK cell function being an important factor in the pathogenesis of CIDP.

Chronic inflammatory demyelinating polyneuropathy in children: a report of four patients with variable relapsing courses

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronically progressive or relapsing symmetric sensorimotor disorder presumed to occur because of immunologic antibody-mediated reactions. To understand the clinical courses of CIDP, we report variable CIDP courses in children with respect to initial presentation, responsiveness to medical treatment, and recurrence interval. Four patients who were diagnosed with acute-onset and relapsing CIDP courses at Severance Children's Hospital, Seoul, Korea, were enrolled in this retrospective study. We diagnosed each patient on the basis of the CIDP diagnostic criteria developed in 2010 by the European Federation of Neurological Societies/Peripheral Nerve Society Guidelines. We present the cases of four pediatric patients diagnosed with CIDP to understand the variable clinical course of the disease in children. Our four patients were all between 8 and 12 years of age. Patients 1 and 2 were diagnosed with acute cerebellar ataxia or Guillain-Barré syndrome as initial symptoms. While patients 1 and 4 were given only intravenous dexamethasone (0.3 mg/kg/day) for 5 days at the first episode, Patients 2 and 3 were given a combination of intravenous immunoglobulin (2 g/kg) and dexamethasone (0.3 mg/kg/day). All patients were maintained with oral prednisolone at 30 mg/day, but their clinical courses were variable in both relapse intervals and severity. We experienced variable clinical courses of CIDP in children with respect to initial presentation, responsiveness to medical treatment, and recurrence interval.

Bochum ultrasound score versus clinical and electrophysiological parameters in distinguishing acute-onset chronic from acute inflammatory demyelinating polyneuropathy

INTRODUCTION

The aim of this study was to evaluate whether a nerve ultrasound score (Bochum ultrasound score, BUS), clinical, and electrophysiological parameters could distinguish subacute chronic (CIDP) from acute inflammatory demyelinating polyneuropathy (AIDP).

METHODS

Phase 1: The charts of 35 patients with polyradiculoneuropathy were evaluated retrospectively regarding BUS, clinical, and electrophysiological parameters (A-waves, sural nerve sparing pattern, sensory ratio>1). Phase 2: All parameters were evaluated prospectively in 10 patients with subacute polyradiculoneuropathy.

RESULTS

Phase 1: A sum score of ≥2 points in BUS and the presence of sensory symptoms were significantly more frequent in the subacute CIDP group than in the AIDP group (P<0.001).The electrophysiological parameters showed no significant changes between the 2 groups. Phase 2: BUS (83.3%; 100%;), sensory symptoms (100%; 75%), absence of autonomic nervous system dysfunction (83.3%; 75%), or bulbar palsy (83.3%; 50%) showed the best sensitivity and specificity in distinguishing subacute CIDP from AIDP.

CONCLUSIONS

BUS is a useful diagnostic tool for distinguishing subacute CIDP from AIDP.

Chronic inflammatory demyelinating polyradiculoneuropathy and variants: where we are and where we should go

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic and often disabling sensory motor neuropathy postulated as caused by an immune attack against peripheral nerve myelin. In addition to a classic sensory–motor polyneuropathy, other phenotypes of CIDP have been described including the Lewis- Sumner syndrome, distal acquired demyelinating symmetric (DADS) neuropathy, pure motor CIDP, pure sensory CIDP including chronic immune sensory polyradiculopathy (CISP), and focal CIDP. These phenotypes are currently considered to be variants of CIDP, even if the possibility that they represent different demyelinating neuropathies cannot be fully excluded considering differences in their response to therapy. Several data support the role of the immune system in the pathogenesis of CIDP even if the precise targets and actors (antibodies and lymphocytes) of this immune response remain uncertain. Recent studies have shown that the therapeutic response may differ in patients with peculiar clinical presentations supporting the hypothesis that different pathogenetic mechanisms may underlie the heterogeneity of CIDP. The majority of patients with CIDP show improvement after immune therapies including corticosteroids, plasma exchange, and high-dose intravenous immunoglobulin (IVIg). It remains unclear why none of the other immune therapies that were reported to be variably effective in other immune disorders proved to be effective also in CIDP.

Acute demyelinating polyneuropathy after lung transplantation: guillain-barré syndrome or tacrolimus toxicity?

Guillain-Barré syndrome (GBS) has been described after solid organ and bone marrow transplantation mostly due to viral infections and possibly calcineurin inhibitors. Incidence after bone marrow transplant is 0.3–0.7%, though incidence in other transplants is not well known. We present the first description of tacrolimus associated GBS in lung transplant recipients in the English language literature. The pathophysiology of tacrolimus-induced polyneuropathy is not known, but some have hypothesized that tacrolimus induces an inflammatory phenomenon by differential effects on T cell subsets. Diagnosis of association may be challenging and requires high index of suspicion. The optimal treatment of GBS-associated with tacrolimus after lung transplantation is unknown, although drug discontinuation may result in improvement in some patients, while some reports suggest that the use of IVIG and/or plasmapheresis may be helpful and safe in organ transplant recipients with severe symptoms.

Early identification of 'acute-onset' chronic inflammatory demyelinating polyneuropathy

Distinguishing patients with acute-onset chronic inflammatory demyelinating polyneuropathy from acute inflammatory demyelinating polyneuropathy prior to relapse is often challenging at the onset of their clinical presentation. In the present study, nerve excitability tests were used in conjunction with the clinical phenotype and disease staging, to differentiate between patients with acute-onset chronic inflammatory demyelinating polyneuropathy and patients with acute inflammatory demyelinating polyneuropathy at an early stage, with the aim to better guide treatment. Clinical assessment, staging and nerve excitability tests were undertaken on patients initially fulfilling the diagnostic criteria of acute inflammatory demyelinating polyneuropathy soon after symptom onset and their initial presentation. Patients were subsequently followed up for minimum of 12 months to determine if their clinical presentations were more consistent with acute-onset chronic inflammatory demyelinating polyneuropathy. Clinical severity as evaluated by Medical Research Council sum score and Hughes functional grading scale were not significantly different between the two cohorts. There was no difference between the time of onset of initial symptoms and nerve excitability test assessment between the two cohorts nor were there significant differences in conventional nerve conduction study parameters. However, nerve excitability test profiles obtained from patients with acute inflammatory demyelinating polyneuropathy demonstrated abnormalities in the recovery cycle of excitability, including significantly reduced superexcitability (P < 0.001) and prolonged relative refractory period (P < 0.01), without changes in threshold electrotonus. In contrast, in patients with acute-onset chronic inflammatory demyelinating polyneuropathy, a different pattern occurred with the recovery cycle shifted downward (increased superexcitability, P < 0.05; decreased subexcitability, P < 0.05) and increased threshold change in threshold electrotonus in both hyperpolarizing and depolarizing directions [depolarizing threshold electrotonus (90-100 ms) P < 0.005, hyperpolarizing threshold electrotonus (10-20 ms), P < 0.01, hyperpolarizing threshold electrotonus (90-100 ms), P < 0.05], perhaps suggesting early hyperpolarization. In addition, using excitability parameters superexcitability, subexcitability and hyperpolarizing threshold electrotonus (10-20 ms), the patients with acute inflammatory demyelinating polyneuropathy and acute-onset chronic inflammatory demyelinating polyneuropathy could be clearly separated into two non-overlapping groups. Studies of nerve excitability may be able to differentiate acute from acute-onset chronic inflammatory demyelinating polyneuropathy at an early stage. Characteristic nerve excitability parameter changes occur in early acute-onset chronic inflammatory demyelinating polyneuropathy, to match the clinical phenotype. Importantly, this pattern of change was strikingly different to that shown by patients with acute inflammatory demyelinating polyneuropathy, suggesting that nerve excitability techniques may be useful in distinguishing acute-onset chronic inflammatory demyelinating polyneuropathy from acute inflammatory demyelinating polyneuropathy at the initial stage.

Chronic inflammatory demyelinating polyradiculoneuropathy: update on clinical features, phenotypes and treatment options

PURPOSE OF REVIEW

In this review, we focus on less recognised signs and symptoms in typical chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and on the clinical presentation, course of disease and response to treatment of the atypical CIDP phenotypes.

RECENT FINDINGS

Frequently occurring and often disabling symptoms in CIDP such as fatigue, pain and tremor have recently been emphasised, whereas autonomic dysfunction, if present, is usually mild. Sensory CIDP is probably the most frequent atypical CIDP phenotype and diagnosis can be difficult in the absence of clear demyelinating features on nerve conduction studies. The most important study comparing intravenous immunoglobulin treatment with intravenous methylprednisolone showed a lower rate of discontinuation due to inefficacy, adverse events or intolerance with intravenous immunoglobulin treatment. However, improvement after corticosteroids seems to be more long-lasting than after intravenous immunoglobulin suggesting superior long-term immunosuppressive and immunomodulating effect of corticosteroids in CIDP.

SUMMARY

Symptoms other than the classical motor and sensory symptoms can lead to significant disability in CIDP patients. Based on limited evidence from largely small retrospective case series, we conclude that atypical CIDP phenotypes often have a different course of disease and sometimes response to treatment when compared with typical CIDP. Prospective multicentre cohort studies using standardised clinical description, electrophysiological parameters and outcome measures are needed to study the natural disease course of these phenotypes including response to different treatments.

Acute-onset chronic inflammatory demyelinating polyneuropathy with focal segmental glomerulosclerosis

Inflammatory neuropathies have been reported to occur in association with nephrotic syndrome. Their underlying immuno-pathogenic mechanisms remain unknown. A 50-year-old woman concurrently presented with acute-onset chronic inflammatory demyelinating polyneuropathy and nephrotic syndrome secondary to focal segmental glomerulosclerosis. Both neuropathy and proteinuria improved after plasma exchange and steroids. Literature review of cases of concurrent inflammatory neuropathies and nephrotic syndrome revealed similar neuro-renal presentations. This neuro-renal condition may be mediated by autoantibodies targeting myelin and podocytes.