Progress in diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy

Ultrasound scanning in the diagnosis of peripheral neuropathies

Nerve ultrasound scanning has become a valuable diagnostic tool in the routine workup of peripheral nerve disorders, effectively complementing conventional electrodiagnostic studies. The most relevant sonographic features are nerve size and structural integrity. Several peripheral neuropathies show characteristic and distinct patterns of nerve enlargement, allowing their early and accurate identification, and reducing test-burden and diagnostic delay for patients. In mononeuropathies such as carpal tunnel syndrome and ulnar neuropathy at the elbow, nerve enlargement develops only at specific sites of entrapment, while in polyneuropathy the nerve enlargement may be multifocal, regional or even diffuse. Nerve ultrasound scanning can reliably identify chronic inflammatory neuropathies, even when extensive electrodiagnostic studies fail, and it should therefore be embedded in routine diagnostic workup of peripheral neuropathies. In this paper we describe a potential diagnostic strategy to achieve this.

Association between chronic inflammatory demyelinating polyneuropathy and gastrointestinal malignancies

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an uncommon and under-recognized immune-mediated disorder of the peripheral nervous system. It is associated with both infectious and non-infectious etiologies and presents in several variant forms. In rare instances, CIDP has been reported in association with gastrointestinal (esophageal, hepatic, colorectal, and pancreatic) malignancies. The diagnosis of malignancy is typically preceded by weeks to months by that of CIDP, though the inverse may also be seen. As with other etiologies of CIDP, cases associated with gastrointestinal malignancies are often treated with corticosteroids, intravenous immunoglobulins, and/or plasma exchange, with improvement or resolution of neurological symptoms in the majority of cases. In this review, we provide a practical overview of CIDP, with an emphasis on recognizing the clinical association between CIDP and gastrointestinal malignancies.

Magnetic resonance neurography in diagnosing childhood chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Peripheral nerve imaging is increasingly recognized as a powerful tool to evaluate nerve hypertrophy in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and Charcot-Marie-Tooth diseases (CMT), whereas data in pediatric patients are limited.

CASE DESCRIPTION

We describe the case of a 15-year-old Japanese girl with asymmetric demyelinating polyneuropathy, who, at the age of 10 years, was initially diagnosed with a demyelinating form of CMT. Fluorescence in situ hybridization for peripheral myelin 22 was negative, and already-known pathogenic variants were not detected by whole-genome sequencing, and nerve conduction studies revealed multifocal conduction blocks. Over the next 5 years, the patient showed gradual improvement in muscle weakness and sensory disturbance without immunological treatment and was referred to our hospital.

RESULTS

At the age of 15 years, magnetic resonance (MR) neurography showed asymmetric multifocal fusiform enlargement of nerve roots, brachial and lumbosacral plexuses, and intermediated nerve trunks, as well as cranial nerves. Based on the MR neurography findings and multifocal nerve conduction blocks, she was diagnosed as having multifocal CIDP (multifocal demyelinating sensory and motor neuropathy [MADSAM]) according to the European Federation of Neurological Societies/Peripheral Nerve Society diagnostic criteria.

DISCUSSION

Clinical diagnosis of childhood CIDP is challenging because its neurological manifestations and nerve conduction study findings occasionally resemble those of inherited demyelinating neuropathies. MR neurography is helpful for the assessment of patterns of nerve hypertrophy; MADSAM-CIDP is characterized by multiple fusiform nerve enlargement, whereas CMT shows symmetric and diffuse nerve hypertrophy.

CONCLUSION

The MR neurography patterns would help in diagnosing pediatric demyelinating neuropathies.

Elevated levels of NLRP3 inflammasome in serum of patients with chronic inflammatory demyelinating polyradiculoneuropathy are associated with disease severity

This study aims to compare the levels of NLRP3 inflammasome and its related cytokines (IL-1β, IL-6, and IL-17), in serum and cerebrospinal fluid (CSF) of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), non-inflammatory chronic polyneuropathy, and functional neurological disorders. The results showed elevated NLRP3 inflammasome, IL-1β, IL-6, and IL-17 levels in serum but not in CSF of CIDP, compared to the other groups. Moreover, there was a positive correlation between NLRP3 inflammasome level and each cytokine. We also found a positive correlation between serum NLRP3 inflammasome level and disease severity in CIDP patients. Taken together, these results suggested that NLRP3 inflammasome could act as a potential biomarker to diagnose CIDP and assess the severity of the disease.

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.

Pathophysiology of Chronic Inflammatory Demyelinating Polyneuropathy: Insights into Classification and Therapeutic Strategy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is classically defined as polyneuropathy with symmetric involvement of the proximal and distal portions of the limbs. In addition to this "typical CIDP", the currently prevailing diagnostic criteria proposed by the European Federation of Neurological Societies and Peripheral Nerve Society (EFNS/PNS) define "atypical CIDP" as encompassing the multifocal acquired demyelinating sensory and motor (MADSAM), distal acquired demyelinating symmetric (DADS), pure sensory, pure motor, and focal subtypes. Although macrophage-induced demyelination is considered pivotal to the pathogenesis of CIDP, recent studies have indicated the presence of distinctive mechanisms initiated by autoantibodies against paranodal junction proteins, such as neurofascin 155 and contactin 1. These findings led to the emergence of the concept of nodopathy or paranodopathy. Patients with these antibodies tend to show clinical features compatible with typical CIDP or DADS, particularly the latter. In contrast, classical macrophage-induced demyelination is commonly found in some patients in each major subtype, including the typical CIDP, DADS, MADSAM, and pure sensory subtypes. Differences in the distribution of lesions and the repair processes underlying demyelination by Schwann cells may determine the differences among subtypes. In particular, the preferential involvement of proximal and distal nerve segments has been suggested to occur in typical CIDP, whereas the involvement of the middle nerve segments is conspicuous in MADSAM. These findings suggest that humoral rather than cellular immunity predominates in the former because nerve roots and neuromuscular junctions lack blood-nerve barriers. Treatment for CIDP consists of intravenous immunoglobulin (IVIg) therapy, steroids, and plasma exchange, either alone or in combination. However, patients with anti-neurofascin 155 and contactin 1 antibodies are refractory to IVIg. It has been suggested that rituximab, a monoclonal antibody to CD20, could have efficacy in these patients. Further studies are needed to validate the CIDP subtypes defined by the EFNS/PNS from the viewpoint of pathogenesis and establish therapeutic strategies based on the pathophysiologies specific to each subtype.

[Pronounced proximally accentuated changes in high-voltage stimulation and nerve ultrasound in long-standing therapy-naive CIDP variants]

The differential diagnosis of chronic demyelinating polyneuropathy particularly includes inflammatory (CIDP) and hereditary causes. Using the example of a 63-year-old patient, we show the diagnostic procedure with conventional electrophysiological diagnostics and additionally by the use of proximal nerve conduction studies with high-voltage stimulation (HVS) and the direct morphological examination by high-resolution nerve ultrasound. In the present case, the focal accentuation of the changes in HVS and the equally pronounced focal thickening of the most affected ulnar nerve in ultrasound confirmed the diagnosis of CIDP instead of hereditary neuropathy.

Electrophysiological testing in chronic inflammatory demyelinating polyneuropathy patients treated with subcutaneous immunoglobulin: The Polyneuropathy And Treatment with Hizentra (PATH) study

OBJECTIVE

To assess electrophysiology parameters that can reflect patients' clinical status and show changes in nerve function with treatment, in a study of subcutaneous immunoglobulin in chronic inflammatory demyelinating polyneuropathy.

METHODS

Nerve conduction studies (latency, conduction velocity, conduction block and compound muscle action potential [CMAP] on upper limb median, ulnar, and lower limb peroneal motor nerves) were conducted in the placebo-controlled PATH (Polyneuropathy And Treatment with Hizentra) study of two doses of maintenance subcutaneous immunoglobulin (SCIG) IgPro20 in CIDP.

RESULTS

Averaged proximal latency substantially increased with placebo (+1.1 ms) indicating electrophysiologic deterioration but remained stable with IgPro20 (0.2 g/kg bodyweight [bw]: +0.1 ms; 0.4 g/kg bw: -0.1 ms). Distal latencies were also more prolonged with placebo versus IgPro20. Averaged motor nerve conduction velocity substantially decreased with placebo (-1.6 m/s) versus increasing in both IgPro20 groups (+0.2 m/s and +1.0 m/s, respectively). Conduction block and CMAP amplitudes did not change substantially.

CONCLUSION

These findings support the effectiveness of maintenance IgPro20, as nerve function changed in the direction of increasing nerve dysfunction with placebo but remained stable with ongoing IgPro20 therapy.

SIGNIFICANCE

Electrophysiology testing can support assessment of clinical status in CIDP to determine treatment efficacy.

The comparison of MRN, electrophysiology and progression among typical CIDP and atypical CIDP subtypes

We aimed to compare the electrophysiology and magnetic resonance neurography (MRN) results of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) subtypes and to explore the progression from atypical CIDP to typical CIDP. We collected the medical records of 45 CIDP patients to analyse the rate of progression from atypical CIDP to typical CIDP subtypes. The cerebrospinal fluid (CSF) protein (p = 0.024) and overall disability sum score (ODSS) (p = 0.000) differed among patients with typical CIDP, distal acquired demyelinating symmetric neuropathy (DADS) and Lewis-Sumner syndrome (LSS). The compound motor action potential (CMAP) of typical CIDP was lower than that of the other subtypes (p = 0.016, p = 0.022 and p = 0.012). The cross-sectional area (CSA) of nerve roots in typical CIDP was significantly thicker than that of nerve roots in DADS and LSS. There were fewer DADS and LSS patients who progressed to typical CIDP than those who progressed to pure motor and pure sensory CIDP (p = 0.000), and the progression from pure motor to typical CIDP required a significantly longer time than the progression from pure sensory to typical CIDP (p = 0.007). Typical CIDP was more severe than the other subtypes not only in terms of clinical and electrophysiology factors but also in terms of MRN factors.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Its Variants

PURPOSE OF REVIEW

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and its variants comprise a group of immune-mediated neuropathies with distinctive clinical presentations and electrodiagnostic features. Prompt recognition of these treatable disorders is mandatory as delays result in significant disability and morbidity. This article highlights the clinical presentation, pathophysiology, diagnostic evaluation, and treatment approach of these polyneuropathies.

RECENT FINDINGS

The spectrum of CIDP is expanding with the recent characterization of neuropathies associated with nodal and paranodal antibodies. These neuropathies are distinguished by their unique presentations and are often refractory to IV immunoglobulin (IVIg) therapy. Subcutaneous immunoglobulins have recently been approved as a treatment option for CIDP and join corticosteroids, IVIg, and plasma exchange as first-line treatment.

SUMMARY

CIDP is characterized by progressive symmetric proximal and distal weakness, large fiber sensory loss, and areflexia, with clinical nadir reached more than 8 weeks after symptom onset. Autoimmune demyelinating neuropathies fall on a continuum, with differences in the type of nerve fibers affected and pattern of deficits. Distinguishing between typical CIDP and its variants allows for selection of the most appropriate treatment.

NK cell markers predict the efficacy of IV immunoglobulins in CIDP

Objective

To assess whether IV immunoglobulins (IVIgs) as a first-line treatment for chronic inflammatory demyelinating polyneuropathy (CIDP) have a regulative effect on natural killer (NK) cells that is related to clinical responsiveness to IVIg.

Methods

In a prospective longitudinal study, we collected blood samples of 29 patients with CIDP before and after initiation of IVIg treatment for up to 6 months. We used semiquantitative PCR and flow cytometry in the peripheral blood to analyze the effects of IVIg on the NK cells. The results were correlated with clinical aspects encompassing responsiveness.

Results

We found a reduction in the expression of several typical NK cell genes 1 day after IVIg administration. Flow cytometry furthermore revealed a reduced cytotoxic CD56^dim NK cell population, whereas regulatory CD56^bright NK cells remained mostly unaffected or were even increased after IVIg treatment. Surprisingly, the observed effects on NK cells almost exclusively occurred in IVIg-responsive patients with CIDP.

Conclusions

The correlation between the altered NK cell population and treatment efficiency suggests a crucial role for NK cells in the still speculative mode of action of IVIg treatment. Analyzing NK cell subsets after 24 hours of treatment initiation appeared as a predictive marker for IVIg responsiveness. Further studies are warranted investigating the potential of NK cell status as a routine parameter in patients with CIDP before IVIg therapy.

Classification of evidence

This study provides Class I evidence that NK cell markers predict clinical response to IVIg in patients with CIDP.

Cranial nerve involvement in typical and atypical chronic inflammatory demyelinating polyneuropathies

BACKGROUND AND PURPOSE

Cranial nerve palsy is occasionally present in patients with chronic inflammatory demyelinating polyneuropathy (CIDP), but its prevalence, characteristics and relations with the CIDP subtypes have rarely been investigated. The aim of this study was to systematically assess cranial nerve involvement in typical and atypical CIDP.

METHODS

Clinical data were reviewed in 132 consecutive patients with CIDP, including typical CIDP (n = 89), multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) (n = 31), distal acquired demyelinating symmetric (DADS) (n = 9) and others (n = 3).

RESULTS

The frequency of cranial nerve palsy was 11% in typical CIDP, 48% in MADSAM and 11% in DADS. Facial and bulbar palsy was most frequently present (9%), followed by ocular motor nerve palsy (5%). Bilateral involvement was seen in all typical CIDP and DADS patients, whereas 80% of MADSAM patients had unilateral palsy. The presence of cranial nerve involvement was associated with more severe limb muscle weakness in typical CIDP, but not in MADSAM. Cranial nerve palsy fully recovered in 90% of typical CIDP and in 67% of MADSAM patients.

CONCLUSION

Amongst the CIDP subtypes, cranial palsy is frequent and unilateral in MADSAM, and less frequent and bilateral in typical CIDP and DADS. In typical CIDP, facial and bulbar palsy reflects more severe and extensive inflammation.

Chronic inflammatory demyelinating polyradiculoneuropathy-Diagnostic pitfalls and treatment approach

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is characterized by progressive weakness and sensory loss, often affecting patients' ability to walk and perform activities of daily living independently. With the lack of a diagnostic biomarker, the diagnosis relies on clinical suspicion, clinical findings, and the demonstration of demyelinating changes on electrodiagnostic (EDx) testing and nerve pathology. As a result, patients can often be misdiagnosed with CIDP and unnecessarily treated with immunotherapy. Interpreting the EDx testing and cerebrospinal fluid findings in light of the clinical phenotype, recognizing atypical forms of CIDP, and screening for CIDP mimickers are the mainstays of the approach to patients suspected of having CIDP, and are detailed in this review. We also review the currently available treatment options, including intravenous immunoglobulin (IVIg), corticosteroids (CCS), and plasma exchange (PE), and discuss how to approach treatment-refractory cases. Finally, we emphasize the need to adopt objective outcome measures to monitor treatment response.

Acute Guillain-Barré polyradiculoneuritis indicative of COVID-19 infection: a case report

The new coronavirus 2019 epidemic declared in China on December 31, 2019 soon spread to the rest of the world, becoming the subject of an unprecedented health pandemic according to the World Health Organization's declaration of March 11, 2020. It is a disease that has the potential to cause multiple systemic infections. We report here the case of an acute polyradiculoneuritis of the Guillain-Barré type (GBS) indicative of a COVID-19 infection. This is a 41 year old patient seen for ascending, symmetrical and bilateral, progressive and acute tetraparesis with in a context of influenza syndrome and digestive infections treated 2 weeks earlier. During a COVID-19 infection, certain inflammatory cells stimulated by the virus produce inflammatory cytokines creating immune-mediated processes. The same mechanism is observed in GBS being also an immune-mediated disorder. The management of this disease in COVID-19 positive patients does not differ from that of patients who do not carry the virus. The risk of respiratory distress in COVID-19 positive patients becomes twice as great in patients with GBS who test positive for COVID-19 at the same time. Monitoring for hemodynamic disorders and respiratory distress in a neuro-intensive care unit may be fruitful.

Chronic immune sensory polyradiculopathy (CISP): First juvenile case description

In its typical presentation, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) occurs more often in old males as a progressive/recurrent motor and sensory nerve dysfunction with tendon areflexia. However, CIDP has also atypical clinical presentations, including pure sensory neuropathies, among which chronic immune sensory polyradiculopathy (CISP) accounts for only 0.5% of all CIDP, with no juvenile cases reported as yet. A 17-year-old girl presented for a progressive sensory ataxia and hands clumsiness. Diffuse tendon areflexia and hypokinaesthesia were observed. Motor and sensory nerve conduction studies were normal. F-waves were normal in median nerves and elongated in tibial nerves. H-reflex and somatosensory evoked potentials (SSEP) were absent. CSF normal cellularity with hyperproteinorrachia was found. Paraneoplastic, metabolic, and paraproteinemic neuropathies were excluded. A diagnosis of CISP has been made based on the presence of pure sensory symptoms in a polyneuropathic distribution, normal peripheral nerve conduction studies, and two supportive criteria (SSEP and CSF). Our paper describes the first CISP case in the pediatric age. We confirm SSEP and CSF as useful complementary tests for this diagnosis also at this age and suggest that clinicians should consider CISP in the spectrum of sporadic sensory ataxias of the pediatric age. We also suggest that in the presence of normal F-wave and peripheral motor nerve conduction, an absent H-reflex can further substantiate SSEPs in the diagnosis of CISP. Intravenous immunoglobulins were rapidly effective and safe.

Diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy in clinical practice: A survey among Dutch neurologists

The diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is often a challenge. The clinical presentation is diverse, accurate biomarkers are lacking, and the best strategy to initiate and maintain treatment is unclear. The aim of this study was to determine how neurologists diagnose and treat CIDP. We conducted a cross‐sectional survey on diagnostic and treatment practices among Dutch neurologists involved in the clinical care of CIDP patients. Forty‐four neurologists completed the survey (44/71; 62%). The respondents indicated to use the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) 2010 CIDP guideline for the diagnosis in 77% and for treatment in 50%. Only 57% of respondents indicated that the presence of demyelinating electrophysiological findings was mandatory to confirm the diagnosis of CIDP. Most neurologists used intravenous immunoglobulins (IVIg) as first choice treatment, but the indications to start, optimize, or withdraw IVIg, and the use of other immune‐modulatory therapies varied. University‐affiliated respondents used the EFNS/PNS 2010 diagnostic criteria, nerve imaging tools, and immunosuppressive drugs more often. Despite the existence of an international guideline, there is considerable variation among neurologists in the strategies employed to diagnose and treat CIDP. More specific recommendations regarding: (a) the minimal set of electrophysiological requirements to diagnose CIDP, (b) the possible added value of nerve imaging, especially in patients not meeting the electrodiagnostic criteria, (c) the most relevant serological examinations, and (d) the clear treatment advice, in the new EFNS/PNS guideline, would likely support its implementation in clinical practice.

MRI quantifies lumbosacral nerve root and sciatic nerve hypertrophy in chronic inflammatory demyelinating polyradiculoneuropathy

PURPOSE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable, immune-mediated condition characterised by progressive or relapsing motor and sensory neurological deficits. The diagnosis is based on a combination of clinical, neurophysiological and supportive criteria, but can be challenging. In this study, we quantified the diameter and cross-sectional area of the lumbosacral nerve roots, and explored the imaging characteristics of the sciatic nerves, in patients with CIDP versus healthy controls using MRI.

METHODS

MRI of the lumbosacral plexus and both thighs was performed at 3 T. Orthogonal diameter and cross-sectional area of the lumbosacral nerve roots were measured, along with sciatic nerve cross-sectional area at the mid-thigh level. The MRI appearance of the sciatic nerves was also evaluated qualitatively. All measurements were performed by an observer blinded to the diagnosis.

RESULTS

10 patients with CIDP and 10 healthy controls (age and sex-matched) were studied. Lumbosacral nerve root diameter and cross-sectional area were significantly increased in patients with CIDP compared to controls (mean diameter 6.0 ± 1.1 mm vs 4.8 ± 0.3 mm; p = 0.006), with a high sensitivity (89 %) and specificity (90 %) on ROC analysis. Sciatic nerve cross sectional area was also significantly increased in the CIDP group, and was accompanied by qualitative MRI changes.

CONCLUSIONS

Quantitative MRI reveals significant hypertrophy of the lumbosacral nerve roots and sciatic nerves in patients with CIDP compared to controls. This study provides further evidence for the inclusion of lumbosacral nerve root and sciatic nerve hypertrophy on MRI as a supportive feature in the diagnostic criteria for CIDP.

Guillain-Barré syndrome in a patient infected with SARS-CoV-2, a case report

BACKGROUND

The COVID-19 is a novel condition affecting all the world, so every manifestation of disease should be reported. Neurologic manifestations of the disease are increasingly identified and this will help clinician to improve their diagnostic and therapeutic skills in dealing with COVID-19 patients.

CASE

In this article we report a 41-year-old male that developed ascending paresthesia and paralysis following infection with SARS-CoV-2 virus. Electrodiagnostic evaluation in patient revealed demyelinating type polyneuropathy and patient diagnosed as Guillain-Barré syndrome (AIDP type) and treated with IVIG which resulted in favorable response.

CONCLUSIONS

Considering this report and other reports that are mentioned in our short review, there is probably causal relationship between COVID-19 and development of Guillain-Barré syndrome.

Immune-Mediated Neuropathies

The immune-mediated neuropathies are a broad category of diseases differentiated by time course, affected nerve fibers, and disease associations. This article spans the common, well-defined inflammatory demyelinating polyradiculoneuropathies (Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy) to the rarer, acquired demyelinating neuropathy variants (Miller-Fisher syndrome and multifocal motor neuropathy), vasculitic neuropathies, and sensory neuronopathies (dorsal root ganglionopathies). These case studies illustrate the characteristic clinical patterns of the immune-mediated neuropathies encountered in neurologic practice. Recommendations for diagnostic evaluation and treatment approach accompany each case. Prompt recognition of these disorders is imperative; delays in treatment may result in prolonged morbidity and permanent disability.

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.

Long-term treatment with subcutaneous immunoglobulin in patients with chronic inflammatory demyelinating polyradiculoneuropathy: a follow-up period up to 7 years

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a rare and heterogeneous acquired sensory-motor polyneuropathy with autoimmune pathogenesis. Intravenous immunoglobulins (IVIG) are a well-established therapy for CIDP: it is well known that at least two-thirds of these patients need these infusions for several years. More recently, Subcutaneous Immunoglobulins (SCIg) have been proved to be effective: this finding has been confirmed either in isolated cases or in few randomized trials. However, it appeared that the longest SCIg treatment follow up lasted no longer than 48 months. We report herein the results of a long-term SCIg treatment with a follow up period up to 7 years (84 months), considering safety, tolerability and patients’ perception of SCIg treatment in a CIDP population. We studied 17 patients (10 M; 7 F) with a diagnosis of CIDP, defined according to the EFNS/PNS criteria, successfully treated with IVIG every 4/6 weeks before being switched to SCIg treatment. Clinical follow-up included, apart from a routinely clinical assessment, the administration of Medical Research Council (MRC) sum-score, the Overall Neuropathy Limitation Scale (ONLS) and the Life Quality Index questionnaire (LQI). The results showed that, in the majority of this pre-selected group of CIDP patients (16/17), SCIg were well tolerated and were preferred over IVIG. Strength and motor functions remained stable or even improved during the long term follow-up (up to 84 months) with benefits on walking capability and resistance, manual activity performances and fatigue reduction.

Distinguish CIDP with autoantibody from that without autoantibody: pathogenesis, histopathology, and clinical features

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is considered to be an immune-mediated heterogeneous disease involving cellular and humoral immunity. In recent years, autoantibodies against nodal/paranodal protein neurofascin155 (NF155), neurofascin186 (NF186), contactin-1 (CNTN1), and contactin-associated protein 1 (CASPR1) have been identified in a small subset of patients with CIDP, which disrupt axo-glial interactions at nodes/paranodes. Although CIDP electrodiagnosis was made in patients with anti-nodal/paranodal component autoantibodies, macrophage-induced demyelination, the characteristic of typical CIDP, was not observed. Apart from specific histopathology, the pathogenic mechanisms and clinical manifestations of CIDP with autoantibody are also distinct. We herein compared pathogenesis, histopathology, clinical manifestations, and therapeutic response in CIDP with autoantibody vs. CIDP without autoantibody. CIDP with autoantibodies should be considered as an independent disease entity, not a subtype of CIDP due to many differences. They possibly should be classified as CIDP-like chronic nodo-paranodopathy, which can better characterize these disorders, help diagnose and make the most effective therapeutic decisions.

What Can Mimic Multiple Sclerosis?

This article discusses mimics of multiple sclerosis (MS). Excluded in this discussion are neuromyelitis optica and vasculitis, discussed in other articles in this journal. Covered entities include posterior reversible encephalopathy syndrome, reversible vasoconstriction syndrome, acute disseminated encephalomyelitis, Sussac's Syndrome, and chronic idiopathic demyelinating polyneuropathy. There are also multiple infectious entities that mimic MS including; progressive multi-focal leukoencephalopathy (PML), Toxoplasmosis, Tuberculosis, Herpes Simplex Virus, Cytomegalovirus, Varicella zoster virus, Epstein Barr virus, Cryptococcus and Human immunodeficiency virus. In addition, there are leukoencephalopathies that can present in adulthood including Adrenoleukodystrophy, Metachromatic leukodystrophy, Cerebral autosomal dominant idiopathic leukoencephalopathy, Leigh's and Alexanders disease that could be mistaken for MS.

Pitfalls in the diagnosis of myositis

The idiopathic inflammatory myopathies are a group of heterogeneous autoimmune connective tissue diseases. Despite increase in the understanding of these conditions, securing a timely diagnosis and accurate subtype classification remains difficult in some cases. This has important implications for patients, where delayed or inappropriate treatments can have a negative effect on outcomes. Several conditions can mimic myositis, including metabolic myopathies, genetic myopathies and neurological disease. In addition, the heterogeneity within the idiopathic inflammatory myopathy spectrum can also create diagnostic confusion, referred to here as 'myositis chameleons'. This includes inclusion body myositis, immune-mediated necrotizing myopathy, hypomyopathic variants of anti-synthetase syndrome and overlap disease. We highlight the importance of a thorough diagnostic workup, refer to updated classification criteria and emphasize the importance of myositis autoantibody testing. Where diagnostic doubt exists, the involvement of a specialist centre and a multidisciplinary team is vital.

Nerve ultrasound improves detection of treatment-responsive chronic inflammatory neuropathies

OBJECTIVE

To examine the diagnostic accuracy of nerve ultrasound in a prospective cohort of consecutive patients with a clinical suspicion of chronic inflammatory neuropathies, including chronic inflammatory demyelinating polyneuropathy, Lewis-Sumner syndrome, and multifocal motor neuropathy, and to determine the added value in the detection of treatment-responsive patients.

METHODS

Between February 2015 and July 2018, we included 100 consecutive incident patients with a clinical suspicion of chronic inflammatory neuropathy. All patients underwent nerve ultrasound, extensive standardized nerve conduction studies (NCS), and other relevant diagnostic investigations. We evaluated treatment response using predefined criteria. A diagnosis of chronic inflammatory neuropathy was established when NCS were abnormal (fulfilling criteria of demyelination of the European Federation of Neurological Societies/Peripheral Nerve Society) or when the degree of nerve enlargement detected by sonography was compatible with chronic inflammatory neuropathy and there was response to treatment.

RESULTS

A diagnosis of chronic inflammatory neuropathy was established in 38 patients. Sensitivity and specificity of nerve ultrasound and NCS were 97.4% and 69.4% and 78.9% and 93.5%, respectively. The added value of nerve ultrasound in detection of treatment-responsive chronic inflammatory neuropathy was 21.1% compared to NCS alone.

CONCLUSIONS

Nerve ultrasound and NCS are complementary techniques with superior sensitivity in the former and specificity in the latter. Addition of nerve ultrasound significantly improves the detection of chronic inflammatory neuropathies. Therefore, it deserves a prominent place in the diagnostic workup of chronic inflammatory neuropathies.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that nerve ultrasound is an accurate diagnostic tool to detect chronic inflammatory neuropathies.

MR neurography of lumbosacral nerve roots: Diagnostic value in chronic inflammatory demyelinating polyradiculoneuropathy and correlation with electrophysiological parameters

PURPOSE

MR neurography(MRN) is an advanced imaging technique to visualize peripheral nerves. Our aim was to determine the value of morphological features of lumbosacral nerve roots on MRN in diagnosing chronic inflammatory demyelinating polyradiculoneuropathy(CIDP) and analyze their correlations with electrophysiological parameters.

METHODS

MRN of lumbosacral plexus was performed in 21 CIDP patients and 21 healthy volunteers. The cross-sectional areas(CSAs) and signal intensities(SI) of L3 to S1 nerve roots were measured and compared between two groups. Receiver operating characteristic(ROC) curves were plotted to assess the diagnostic accuracy. All patients also underwent nerve conduction studies. Correlations between CSAs and SI of lumbosacral nerve roots and electrophysiological parameters were analyzed.

RESULTS

Compared with control group, CIDP patients showed significantly increased CSAs and SI from L3 to S1 nerve root (P < 0.001 and P < 0.05 respectively for all nerve roots). The CSA_mean and SI_mean were 28.04 ± 8.55mm², 1.314 ± 0.199 for patient group and 14.91 ± 2.36mm²,1.155 ± 0.094 for control group. ROC analysis revealed the best diagnostic accuracy for the CSA_mean with an area under the curve of 0.968 and optimal cut-off value of 19.20 mm². CSAs of L5 or S1 nerve root correlated positively with central latency and negatively with conduction velocity of tibial nerve. SI of L5 also had a positive correlation with latency of sural nerve.

CONCLUSIONS

Evaluation of lumbosacral nerve roots on MRN in a quantitative manner may serve as an important tool to support the diagnosis of CIDP.

Bilateral phrenic neuropathy responsive to intravenous immunoglobulin treatment

The aetiology of phrenic neuropathy is often unknown, but immune mechanisms may play a role. In a typical case of bilateral phrenic neuropathy with paradoxical breathing (video), an inflammatory pathogenesis was suggested by prolonged distal latency of phrenic nerve compound muscle action potentials in nerve conduction studies and a clear-cut albumin-cytologic dissociation. This encouraged us to treat the patient with a standard dose of intravenous immunoglobulin. After obtaining a strong improvement at spirometry, we repeated the second cycle of intravenous immunoglobulin and observed normalization of symptoms within few weeks and no relapse after 3 years. This case suggests that lumbar puncture should be performed in the acute phase of phrenic neuropathies to detect potential responders to immunomodulatory treatment.

Immunoglobulin administration for the treatment of CIDP: IVIG or SCIG?

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired neurological disorder characterized clinically by weakness and impaired sensory function evolving over 2 months or more, loss or significant decrease in deep tendon reflexes, and by electrophysiological evidence of peripheral nerve demyelination. Expeditious diagnosis and treatment of CIDP early in the disease course is critical such that irreversible disability can be avoided. Intravenous immunoglobulin (IVIG) is one first-line and maintenance therapy option for CIDP. The US Food & Drug Administration's (FDA's) approval of subcutaneous immunoglobulin (SCIG) in 2018 provides patients with CIDP more treatment options for maintenance therapy. The different options for administration of IG treatment create the need for information to assist clinicians and patients in choosing the optimal therapeutic approach. Considerations for pharmacokinetics, administration procedures, adverse events, patient variables, and cost will all be discussed in this article.