Chronic inflammatory demyelinating polyradiculoneuropathy: from bench to bedside

Rehabilitation of Rare Neurological Complications of COVID-19 Infection in Health Resort Settings

There is increasing evidence of neurological involvement in patients with coronavirus disease. Reports of neurological manifestations include altered mental status, Guillain-Barré syndrome (GBS) and its forms, encephalopathy, psychosis, neurocognitive (dementia) syndrome, ischemic strokes, intracerebral hemorrhage, and acute transverse myelitis. We present three patients with rare neurological manifestations of the COVID-19 disease, with a special focus on rehabilitation in a health resort setting. Outcomes were evaluated based on neurological examination and the modified Barthel index. We highlight the importance of an interdisciplinary approach to reduce disability and improve functionality and quality of life.

Central nervous system involvement in chronic inflammatory demyelinating polyradiculoneuropathy-MRS and DTI study

Objective

The current research aimed to analyze the alterations within the motor cortex and pyramidal pathways and their association with the degree of damage within the peripheral nerve fibers in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). To achieve that goal, we investigated the microstructural changes within the pyramidal white matter tracts using diffusion tensor imaging (DTI) parameters, evaluated metabolic alterations in both precentral gyri using magnetic resonance spectroscopy (MRS) ratios, and correlated them with the neurographic findings in patients with CIDP.

Methods

The spectroscopic ratios of NAA/Cr, Cho/Cr, and mI/Cr from both precentral gyri and the values of fractional anisotropy (FA), axial diffusivity (AD), and mean diffusivity (MD) from both of the corticospinal tracts were correlated with the results of neurological and neurographic findings. The comparison of DTI parameters between the patients and controls was performed using Student's t-test or the Mann-Whitney U test. Due to the lack of normal distribution of most variables, Spearman's Rho rank coefficient was used to test all correlations. All analyses were performed at a significant level of alpha = 0.05 using STATISTICA 13.3.

Results

Compared to the control group (CG), the patient group showed significantly lower ratios of NAA/Cr (1.66 ± 0.11 vs. 1.61 ± 0.15; p = 0.022), higher ratios of ml/Cr in the right precentral gyrus (0.57 ± 0.15 vs. 0.61 ± 0.08; p = 0.005), and higher levels of Cho/Cr within the left precentral gyrus (0.83 ± 0.09 vs. 0.88 ± 0.14, p = 0.012). The DTI parameters of MD from the right CST and AD from the right and left CSTs showed a strong positive correlation (0.52-0.53) with the sural sensory nerve action potential (SNAP) latency of the right sural nerve. There were no other significant correlations between other DTI and MRS parameters and neurographic results.

Significance

In our study, significant metabolic alterations were found in the precentral gyri in patients with CIDP without clinical symptoms of central nervous system involvement. The revealed changes reflected neuronal loss or dysfunction, myelin degradation, and increased gliosis. Our results suggest coexisting CNS damage in these patients and may provide a new insight into the still unknown pathomechanism of CIDP.

Choroid plexus mis-splicing and altered cerebrospinal fluid composition in myotonic dystrophy type 1

Myotonic dystrophy type 1 is a dominantly inherited multisystemic disease caused by CTG tandem repeat expansions in the DMPK 3' untranslated region. These expanded repeats are transcribed and produce toxic CUG RNAs that sequester and inhibit activities of the MBNL family of developmental RNA processing factors. Although myotonic dystrophy is classified as a muscular dystrophy, the brain is also severely affected by an unusual cohort of symptoms, including hypersomnia, executive dysfunction, as well as early onsets of tau/MAPT pathology and cerebral atrophy. To address the molecular and cellular events that lead to these pathological outcomes, we recently generated a mouse Dmpk CTG expansion knock-in model and identified choroid plexus epithelial cells as particularly affected by the expression of toxic CUG expansion RNAs. To determine if toxic CUG RNAs perturb choroid plexus functions, alternative splicing analysis was performed on lateral and hindbrain choroid plexi from Dmpk CTG knock-in mice. Choroid plexus transcriptome-wide changes were evaluated in Mbnl2 knockout mice, a developmental-onset model of myotonic dystrophy brain dysfunction. To determine if transcriptome changes also occurred in the human disease, we obtained post-mortem choroid plexus for RNA-seq from neurologically unaffected (two females, three males; ages 50-70 years) and myotonic dystrophy type 1 (one female, three males; ages 50-70 years) donors. To test that choroid plexus transcriptome alterations resulted in altered CSF composition, we obtained CSF via lumbar puncture from patients with myotonic dystrophy type 1 (five females, five males; ages 35-55 years) and non-myotonic dystrophy patients (three females, four males; ages 26-51 years), and western blot and osmolarity analyses were used to test CSF alterations predicted by choroid plexus transcriptome analysis. We determined that CUG RNA induced toxicity was more robust in the lateral choroid plexus of Dmpk CTG knock-in mice due to comparatively higher Dmpk and lower Mbnl RNA levels. Impaired transitions to adult splicing patterns during choroid plexus development were identified in Mbnl2 knockout mice, including mis-splicing previously found in Dmpk CTG knock-in mice. Whole transcriptome analysis of myotonic dystrophy type 1 choroid plexus revealed disease-associated RNA expression and mis-splicing events. Based on these RNA changes, predicted alterations in ion homeostasis, secretory output and CSF composition were confirmed by analysis of myotonic dystrophy type 1 CSF. Our results implicate choroid plexus spliceopathy and concomitant alterations in CSF homeostasis as an unappreciated contributor to myotonic dystrophy type 1 CNS pathogenesis.

Recurrent acute-onset of chronic inflammatory demyelinating polyneuropathy after COVID-19 vaccination

This is the case of 54-year-old male with a past medical history of Chronic Inflammatory Demyelinating Polyneuropathy (CIPD) who was found to have an acute exacerbation of CIPD shortly after receiving his 1st COVID 19 booster (3rd dose of vaccination series) and was successfully treated with intravenous immunoglobulin (IVIG) and then was found to have another acute exacerbation of CIDP 6 months later after receiving his 2nd COVID 19 booster (4th dose of vaccination series) that required intubation and long term tracheostomy. CIPD is an acquired immune-mediated polyneuropathy that mainly affects the peripheral nerve roots nerves. It typically presents with relapsing/remitting, or progressive symmetrical muscle weakness and sensory involvement and can cause decreased respiratory effort. COVID-19 is mainly a respiratory disease, but it has been associated with a wide variety of neurological conditions. Although there have been several findings of acute inflammatory demyelinating polyneuropathy in association with COVID-19, CIDP exacerbation as a result of COVID-19 has rarely been seen in the literature. Furthermore, CIDP exacerbation as a result of COVID-19 vaccination is even less frequently seen.

Emerging Role of Neuron-Glia in Neurological Disorders: At a Glance

Based on the diverse physiological influence, the impact of glial cells has become much more evident on neurological illnesses, resulting in the origins of many diseases appearing to be more convoluted than previously happened. Since neurological disorders are often random and unknown, hence the construction of animal models is difficult to build, representing a small fraction of people with a gene mutation. As a result, an immediate necessity is grown to work within in vitro techniques for examining these illnesses. As the scientific community recognizes cell-autonomous contributions to a variety of central nervous system illnesses, therapeutic techniques involving stem cells for treating neurological diseases are gaining traction. The use of stem cells derived from a variety of sources is increasingly being used to replace both neuronal and glial tissue. The brain's energy demands necessitate the reliance of neurons on glial cells in order for it to function properly. Furthermore, glial cells have diverse functions in terms of regulating their own metabolic activities, as well as collaborating with neurons via secreted signaling or guidance molecules, forming a complex network of neuron-glial connections in health and sickness. Emerging data reveals that metabolic changes in glial cells can cause morphological and functional changes in conjunction with neuronal dysfunction under disease situations, highlighting the importance of neuron-glia interactions in the pathophysiology of neurological illnesses. In this context, it is required to improve our understanding of disease mechanisms and create potential novel therapeutics. According to research, synaptic malfunction is one of the features of various mental diseases, and glial cells are acting as key ingredients not only in synapse formation, growth, and plasticity but also in neuroinflammation and synaptic homeostasis which creates critical physiological capacity in the focused sensory system. The goal of this review article is to elaborate state-of-the-art information on a few glial cell types situated in the central nervous system (CNS) and highlight their role in the onset and progression of neurological disorders.

Relevance of Nerve Biopsy in the Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy—A Systematic Review

Chronic Inflammatory Demyelinating Polyneuropathy is an immune-mediated pathology of the peripheral nerves and nerve roots that leads to weakness and sensory symptoms. Given its clinical heterogeneity, often times diagnosis is challenging. Even though nerve conduction studies and clinical features are the main criteria used for diagnosis, supplementary investigations, such as nerve biopsies, cerebral spinal fluid examination and magnetic resonance studies, may be used in order to confirm the diagnosis. Given the fact that the hallmark in CIDP physiopathology is the demyelination process, nerve biopsies are used to demonstrate and assess the magnitude of the phenomenon. The question and the main interest of this review is whether histopathological findings are relevant for the diagnosis and can be useful in disease assessment.

A Rare Case of COVID-19-Induced Chronic Demyelinating Polyneuropathy

Chronic autoimmune demyelinating polyneuropathy (CIDP) is a rare autoimmune disorder in which the body's immune system attacks the myelin sheaths. Myelin sheaths are the fatty insulation covering and protecting the nerves, and damage to these can lead to neurological symptoms like numbness, tingling, and weakness. CIDP is a chronic disease in the Guillain-Barré syndrome spectrum. Numerous case reports of autoimmune diseases linked to coronavirus disease 2019 (COVID-19) have been seen since the onset of COVID-19 pandemic. We present one such challenging case of COVID-19-induced CIDP.

Chronic Inflammatory Demyelinating Polyneuropathy Post-mRNA-1273 Vaccination

Massive efforts are being made to develop coronavirus disease 2019 (COVID-19) vaccines at an unprecedented rate. The vaccinations' adverse impact profile, on the other hand, has not been well established. Neurological complications are increasingly reported as a result of these vaccines. One such complication identified is immune-mediated inflammatory polyneuropathy, which affects peripheral nerves and neurons. We report a case of chronic inflammatory demyelinating polyneuropathy (CIDP) post-mRNA-1273 (Moderna) COVID-19 vaccine. Recognizing this complication and distinguishing it from Guillain-Barré syndrome enables timely initiation of treatment. Additionally, our report highlights a possible link between vaccination and subsequent development of CIDP, but conclusive evidence of a causal relationship requires more extensive studies.

Expression Analysis of Protein Inhibitor of Activated STAT in Inflammatory Demyelinating Polyradiculoneuropathy

Protein inhibitors of activated STAT (PIAS) are involved in the regulation of the JAK/STAT signaling pathway and have interactions with NF-κB, p73 and p53. These proteins regulate immune responses; therefore dysregulation in their expression leads to several immune-mediated disorders. In the present study, we examined expression of PIAS1-4 in peripheral blood of patients with acute/chronic inflammatory demyelinating polyradiculoneuropathy (AIDP/CIDP) compared with healthy subjects. We demonstrated down-regulation of all PIAS genes in both AIDP and CIDP cases compared with controls. Similarly, comparisons in gender-based groups revealed down-regulation of these gene0s in patients of each gender compared with gender-matched controls. There was no significant difference in expression of PIAS genes between AIDP and CIDP cases. Based on the area under the receiver operating characteristic curves, PIAS1-4 genes could distinguish between inflammatory demyelinating polyradiculoneuropathy and healthy status with accuracy values of 0.87, 0.87, 0.79 and 0.80, respectively. In differentiation between AIDP cases and healthy controls, these values were 0.92, 0.92, 0.83 and 0.86, respectively. Finally, PIAS1-4 genes could discriminate CIDP from healthy status with accuracy values of 0.82, 0.83, 0.75 and 0.75, respectively. The current study underscores the role of PIAS genes in the pathogenesis of inflammatory demyelinating polyradiculoneuropathy and their potential usage as biomarkers.

The Cost Effectiveness of Immunoglobulin vs. Hematopoietic Stem Cell Transplantation for CIDP

Background: Intravenous immunoglobulin (IVIG) is effective as standard first line therapy for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), but some patients remain dependent on its long-term use. Recently, we have reported that autologous non-myeloablative hematopoietic stem cell transplantation (HSCT) is an effective second line therapy for CIDP. Objectives: To compare the cost of chronic IVIG vs. autologous HSCT (a one-time therapy), we collected data on patients with CIDP undergoing HSCT between 2017 and 2019. This was compared with published literature on the costs and efficacy defined by the Inflammatory Neuropathy Cause And Treatment (INCAT) disability score, Medical Research Council (MRC) sum score, hand grip strength, and SF-36 quality of life (QOL) for CIDP. Methods: Between 2017 and 2019, nineteen patients with chronic CIDP (mean disease treatment duration prior to HSCT of 6 years) underwent autologous HSCT with mean cost of $108,577 per patient (range $56,327-277,119, standard deviation $53,092). After HSCT, 80% of patients remain IVIG and immune treatment free for up to 5 years. In comparison, published cost of IVIG treatment in the USA for an average CIDP patient exceeds $136,000 per year. Despite remaining treatment free, HSCT demonstrated greater improvement in efficacy compared to immunoglobulins. Recommendations: Given the long-term treatment-free remission and better outcome measurements, autologous HSCT is more cost effective than long-term IVIG treatment in patients with chronic CIDP. However, costs will depend on patient selection, the HSCT regimen, and regional variations. Further analysis of the health economics, i.e., cost/outcome ratio, of HSCT as therapy for chronically IVIG dependent CIDP is warranted.

Changes of clinical, neurophysiological and nerve ultrasound characteristics in CIDP over time: a 3-year follow-up

OBJECTIVES

To evaluate, in a prospective study, high-resolution ultrasound (HRUS) changes of nerve segments in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and their relationships with clinical and electrodiagnostic (EDX) characteristics.

METHODS

Twenty-three consecutive patients with CIDP were included in a 3-year follow-up (FU) study. Each patient underwent neurologic examination, EDX and HRUS study. HRUS was performed on median, ulnar and peroneal nerves, yielding a total of 319 scanned nerve segments. INCAT and MRC-sum scores, motor nerve conduction velocity (NCV), compound muscle action potential (cMAP) amplitude, and nerve cross-sectional area (NCSA) were collected at baseline and at FU end, and were used for statistical analysis. Twenty-two healthy individuals, matched to patients for age and BMI, served as controls.

RESULTS

NCSA was higher in patients than in controls (p < 0.0001) and showed significant direct correlation with disease severity, and inverse correlation with NCV and cMAP amplitude, both at baseline and at FU end. Disease duration, clinical scores and EDX were predictors of NCSA enlargement at both time points. During FU, NCSA increased in 51% of nerve segments (p = 0.006), in correlation with INCAT increase and with NCV and cMAP reduction. Considering EDX changes in subgroups that reflect the different types of nerve damage, NCSA significantly increased in those nerve segments that from normal EDX switched to prevalent myelinopathic EDX characteristics.

CONCLUSIONS

Peripheral nerve size tends to increase over time in patients with CIDP, in correlation with clinical and EDX changes, in particular in those nerve segments that undergo a predominantly demyelinating damage.

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) and Vaccinations: Examining the Current Literature on Vaccinations and the Onset or Worsening of CIDP Symptoms

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Chronic inflammatory demyelinating polyradiculoneuropathy associated with systemic lupus erythematosus

BACKGROUND

Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) is an uncommon subtype of peripheral neuropathy (PN) and especially when associated with systemic lupus erythematosus (SLE). There are few reports characterizing PN-associated to SLE, in particular CIDP. This study reviewed the frequency and profile of SLE-related CIDP in our cohort and in the literature and propose a treatment scheme for CIDP associated with SLE.

METHOD

We reviewed our database to identify patients with CIDP and SLE. The literature was also reviewed following the guidelines of PRISMA and using the terms "Polyradiculoneuropathy", "Chronic inflammatory demyelinating polyradiculoneuropathy", "CIDP", "Systemic lupus erythematosus", "SLE", "Autoimmune diseases of the nervous system" until December 2019. Selected articles were published in English.

RESULTS

We identified 3 patients with SLE and CIDP in our cohort of 1,349 patients with SLE (0.2%). All patients were female, aged between 30 and 44 years and 2 (66.7%) had active disease in other organs. In the literature, we identified additional 16 patients. A predominance of women with disease activity, specially nephritis and hematological involvement, was observed. Treatment schemes are diverse, including corticosteroids and immunosuppressive drugs.

CONCLUSION

Although rare, CIDP has increased frequency in SLE. Women and younger age should rise suspicion of an underlying autoimmune disease. We suggest that CIDP should be included as a possible neuropsychiatric manifestation in SLE.

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.

Expression analysis of BDNF, BACE1 and their antisense transcripts in inflammatory demyelinating polyradiculoneuropathy

Acute and chronic inflammatory demyelinating polyradiculoneuropathies (AIDP and CIDP) are two immune-related conditions in the peripheral nervous system. In the current study, we assessed expression levels of Beta-secretase (BACE1), brain-derived neurotrophic factor (BDNF) and their antisense transcripts in the peripheral blood of AIDP and CIDP patients compared with age- and sex-matched controls to assess their potential as biomarkers for these conditions. Expressions of BACE1 and BACE1-AS were down-regulated in CIDP cases compared with controls (Ratios of mean expressions=0.01 and 0.03; P values= 1.07E-08, respectively). On the other hand, expressions of BDNF and BDNF-AS were up-regulated in CIDP cases compared with controls (Ratios of mean expressions=4.78 and 25.71; P values= 7.84E-03 and 2.66E-07, respectively). Expressions of BACE1 and BACE1-AS were lower in AIDP cases compared with controls (Ratios of mean expressions=0.00; P values= 6.92E-10 and 8.04E-10, respectively). While expression of BDNF was not different between AIDP cases and controls, expression of its antisense transcript was higher in total AIDP cases compared with total controls (Ratio of mean expression= 8.61, P value=3.69E-04). Expressions of BACE1-AS, BDNF and BDNF-AS were significantly higher in CIDP cases compared with AIDP cases (Ratios of mean expression=1.98, 3.49 and 2.99; P values=4.67E-02, 4.67E-04 and 8.94E-03 respectively). Expression levels of BACE1, BACE1-AS and BDNF-AS could distinguish AIDP and CIDP cases from healthy subjects. BACE1 had the best diagnostic values in differentiation of CIDP and AIDP cases from controls (AUC values=0.88 and 0.91, respectively). Combination of all genes enhanced the diagnostic power to 0.96, 0.97 and 0.97 for differentiation between CIDP/controls, AIDP/controls and all patients/controls, respectively. Taken together, these genes might be implicated in the pathogenesis of AIDP and CIDP and can be suggested as putative markers for these conditions.

Chronic inflammatory demyelinating polyradiculoneuropathy relapse after mexiletine withdrawal in a patient with concomitant myotonia congenita: A case report on a potential treatment option

INTRODUCTION

we report on the first case of a woman affected by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and recessive myotonia congenita (MC), treated with mexiletine. We aimed at describing the possible role of mexiletine in CIDP management.

PATIENT CONCERNS

A 44-year-old female affected by CIDP and MC, gained beneficial effects for CIDP symptoms (muscle weakness, cramps, and fatigue) and relapses, after mexiletine intake (200 mg twice a day). The patient presented with detrimental effects after mexiletine drop out, with a worsening of CIDP symptoms.

INTERVENTIONS

The patient reported a nearly complete remission of muscle stiffness and weakness up to 3 years since mexiletine intake. Then, she developed an allergic reaction with glottis edema, maybe related to mexiletine intake, as per emergency room doctors' evaluation, who suggested withdrawing the drug.

OUTCOMES

The patient significantly worsened after the medication drop out concerning both CIDP and MC symptoms.

CONCLUSION

This is the first report on the association of CIDP and MC in the same patient. Such diseases may share some clinical symptoms related to a persistent sodium currents increase, which maybe due either to the over-expression of sodium channels following axonal damage due to demyelination or to the chloride channel genes mutations. This is the possible reason why mexiletine maybe promising to treat CIDP symptoms.

Demyelinating polyneuropathy and lymphoplasmacytic lymphoma coexisting in 36-year-old man: A case report

BACKGROUND

Lymphoplasmacytic lymphoma is a rare non-Hodgkin’s lymphoma, occurring mostly in the elderly. It develops slowly and leads to malignant proliferation of lymphoid line cells in the bone marrow, lymph nodes and spleen. It may also affect nerve roots and meninges; some patients develop sensorimotor polyneuropathy which may precede general symptoms of lymphoma.

CASE SUMMARY

We present a case of a 36-year-old man diagnosed in 2012 with chronic inflammatory demyelinating polyneuropathy (CIDP), then he was hospitalized in 2019 due to progressive symptoms of heart failure and significant weight loss over the previous four months. Based on clinical and laboratory findings a diagnosis of lymphoplasmacytic lymphoma was suspected and confirmed by bone marrow flow cytometry. There was no improvement in the results of laboratory tests and the patient's condition after immediate implementation of chemotherapy. Patient died on the fifth day of treatment.

CONCLUSION

While CIDP and malignant disease co-occurrence is rare, it should be suspected and investigated in patients with atypical neuropathy symptoms.

Neuraxial Anesthesia and Lower Extremity Peripheral Nerve Blocks for Ankle Surgery in a Patient With Chronic Inflammatory Demyelinating Polyneuropathy: A Case Report

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare autoimmune disease that targets the peripheral nervous system. The literature on the use of regional anesthesia in CIDP is limited. We report a patient with CIDP who received a combined spinal-epidural (CSE) and saphenous and popliteal peripheral nerve blocks (PNBs) for ankle surgery. The CSE and PNBs resolved without incident. On approximately the fourth postoperative day, the patient reported a worsening of baseline CIDP symptoms in all extremities. Given the diffuse presentation, the CIDP exacerbation was attributed to the perioperative stress response. The exacerbation improved by 4 months postoperatively.

Therapeutic Plasma Exchange in Guillain-Barre Syndrome and chronic inflammatory demyelinating polyradiculoneuropathy

Therapeutic plasma exchange (TPE) has been used as a treatment modality in many autoimmune disorders, including neurological conditions, such as Guillain-Barre syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The American Society for Apheresis (ASFA) publishes its guidelines on the use of therapeutic apheresis every 3 years based on published evidence to assist physicians with both the medical and technical aspects of apheresis consults. The ASFA Guidelines included the use of TPE in both GBS and CIDP as an acceptable first-line therapy, either alone and/or in conjunction with other therapeutic modalities. In this article, we briefly reviewed GBS and CIDP, discussed the role of apheresis in these conditions as well as various technical aspects of the TPE procedure, such as apheresis calculation, number of volume exchange, replacement fluid, and management of potential complications.

Intravenous immunoglobulin therapy: a snapshot for the internist

Intravenous immunoglobulins are the cornerstone for the treatment of primary humoral immunodeficiencies and may be used for a great number of other autoimmune, neurological and hematological conditions as well. Given their wide application, the possibility of running across a patient who needs this kind of therapy is becoming increasingly common. Generally, intravenous immunoglobulins are well tolerated. However, numerous adverse reactions ranging from mild to severe have been reported and linked to patient- and product-related factors. For all these reasons, we present herein a comprehensive review of the on- and off-label applications of intravenous immunoglobulins and provide a guide for the internist how to minimize the risk of adverse reactions and manage them.

Peripheral nervous system alterations in infant and adult neurofibromatosis type 2

OBJECTIVE

To examine the involvement of dorsal root ganglia and peripheral nerves in children with neurofibromatosis type 2 compared to healthy controls and symptomatic adults by in vivo high-resolution magnetic resonance neurography.

METHODS

In this prospective multicenter study, the lumbosacral dorsal root ganglia and sciatic, tibial, and peroneal nerves were examined in 9 polyneuropathy-negative children diagnosed with neurofibromatosis type 2 by a standardized magnetic resonance neurography protocol at 3T. Volumes of dorsal root ganglia L3 to S2 and peripheral nerve lesions were assessed and compared to those of 29 healthy children. Moreover, dorsal root ganglia volumes and peripheral nerve lesions were compared to those of 14 adults with neurofibromatosis type 2.

RESULTS

Compared to healthy controls, dorsal root ganglia hypertrophy was a consistent finding in children with neurofibromatosis type 2 (L3 +255%, L4 +289%, L5 +250%, S1 +257%, and S2 +218%, p < 0.001) with an excellent diagnostic accuracy. Moreover, peripheral nerve lesions occurred with a high frequency in those children compared to healthy controls (18.89 ± 11.11 vs 0.90 ± 1.08, p < 0.001). Children and adults with neurofibromatosis type 2 showed nonsignificant differences in relative dorsal root ganglia hypertrophy rates (p = 0.85) and peripheral nerve lesions (p = 0.28).

CONCLUSIONS

Alterations of peripheral nerve segments occur early in the course of neurofibromatosis type 2 and are evident even in children not clinically affected by peripheral polyneuropathy. While those early alterations show similar characteristics compared to adults with neurofibromatosis type 2, the findings of this study suggest that secondary processes might be responsible for the development and severity of associated polyneuropathy.

Peripheral Demyelinating Diseases: From Biology to Translational Medicine

Demyelinating diseases represent a spectrum of disorders that impose significant burden on global economy and society. Generally, the prognosis of these diseases is poor and there is no available cure. In recent decades, research has shed some light on the biology and physiology of Schwann cells and its neuroprotective effects in the peripheral nervous system (PNS). Insults to the PNS by various infectious agents, genetic predisposition and immune-related mechanisms jeopardize Schwann cell functions and cause demyelination. To date, there are no effective and reliable biomarkers for PNS-related diseases. Here, we aim to review the following: pathogenesis of various types of peripheral demyelinating diseases such as Guillain-Barre syndrome, Chronic Inflammatory Demyelinating Polyradiculoneuropathy, Anti-Myelin Associated Glycoprotein Neuropathy, POEMS syndrome, and Charcot-Marie-Tooth disease; emerging novel biomarkers for peripheral demyelinating diseases, and Schwann cell associated markers for demyelination.

Conductive hearing loss in chronic inflammatory demyelinating polyneuropathy (CIDP): A case report

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a progressive autoimmune disorder that targets peripheral nerves. It commonly presents with motor-predominant dysfunction and enlargement of cranial nerves. With regards to hearing loss, a few cases of sensorineural loss have been described. We present a novel case of conductive hearing loss caused by a mass on the tympanic segment of the facial nerve in the setting of CIDP.

Neuromuscular complications of immune checkpoint inhibitor therapy

Immune checkpoint inhibitor (ICPI) therapy unleashes the body's natural immune system to fight cancer. ICPIs improve overall cancer survival, however, the unbridling of the immune system may induce a variety of immune-related adverse events. Neuromuscular immune complications are rare but they can be severe. Myasthenia gravis and inflammatory neuropathy are the most common neuromuscular adverse events but a variety of others including inflammatory myopathy are reported. The pathophysiologic mechanism of these autoimmune disorders may differ from that of non-ICPI-related immune diseases. Accordingly, while the optimal treatment for ICPI-related neuromuscular disorders generally follows a traditional paradigm, there are important novel considerations in selecting appropriate immunosuppressive therapy. This review presents 2 new cases, a summary of neuromuscular ICPI complications, and an approach to the diagnosis and treatment of these disorders. Muscle Nerve, 2018.

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): An Uncommon Manifestation of Systemic Lupus Erythematosus (SLE)

BACKGROUND Chronic inflammatory demyelinating polyneuropathy (CIDP) is an uncommon manifestation of systemic lupus erythematosus (SLE). We report a case of SLE presenting as CIDP and discuss the diagnosis, management, and prognosis of CIDP. CASE REPORT A 40-year-old woman with a past medical history of SLE treated with hydroxychloroquine presented with bilateral, progressive, ascending, sensory and motor neuropathy. Physical examination showed weakness and reduced temperature of all extremities, reduced pinprick and vibration sense of the distal extremities, loss of reflexes, and walking with a wide-based unsteady gait. Laboratory investigations showed positive antinuclear antibodies (ANA), anti-(smooth muscle (SM) antibody, anti-RNP antibody, anti-SSA antibody, anti-ds-DNA antibody, and an erythrocyte sedimentation rate (ESR) of 75 mm/hr, low C4, leukopenia, and anemia. Electromyography (EMG) confirmed the diagnosis of CIDP. The patient's neuropathy and muscle weakness improved on treatment with intravenous immunoglobulin (IVIG) and high-dose steroids. CONCLUSIONS The early clinical diagnosis of CIDP, supported by serological autoantibody profiles associated with SLE, can predict a good response to steroids. Most patients with CIDP are treated successfully with steroids if the diagnosis is made early. IVIG, plasmapheresis, or immunosuppressive therapy should be considered if there is no response to steroids.

Inflammatory demyelinating neuropathy heralding accelerated chediak-higashi syndrome

INTRODUCTION

Chediak-Higashi syndrome (CHS) is a very rare autosomal recessive disorder (gene CHS1/LYST) characterized by partial albinism, recurrent infections, and easy bruising. Survivors develop a constellation of slowly progressive neurological manifestations.

METHODS

We describe clinical, laboratory, electrophysiological, and genetic findings of a patient who developed an immune-mediated demyelinating neuropathy as the main clinical feature of CHS.

RESULTS

The patient presented with subacute flaccid paraparesis, absent reflexes, and reduced vibration sense. Protein and immunoglobulins (Igs) were elevated in the cerebrospinal fluid. Electrodiagnostic tests indicated an acquired chronic demyelinating polyneuropathy. Intravenous Ig and immunosuppressant treatment resulted in neurological improvement. The patient later developed organomegaly and pancytopenia. Bone-marrow smear revealed giant azurophilic granules pathognomonic for CHS. Two novel mutations in the LYST gene were identified through whole exome sequencing [c.7786C>T and c.9106 + 1G>T].

CONCLUSIONS

This case expands the clinical phenotype of CHS and highlights inflammatory demyelinating neuropathy as a manifestation of the disease. Muscle Nerve 55: 756-760, 2017.

Subcutaneous immunoglobulins in the treatment of chronic immune-mediated neuropathies

Intravenous immunoglobulins represent an established therapy for the treatment of chronic immune-mediated neuropathies, specifically chronic inflammatory demyelinating polyradiculoneuropathies (CIDPs) as well as multifocal motor neuropathies (MMNs). For the treatment of antibody deficiency syndromes, subcutaneous immunoglobulins (SCIgs) have represented a mainstay for decades. An emerging body of evidence suggests that SCIg might also exhibit clinical efficacy in CIDP and MMN. This article reviews the current evidence for clinical effectiveness, as well as safety of SCIg for the treatment of immune-mediated neuropathies, and addresses remaining open questions in this context. We conclude that despite the need for controlled long-term studies to demonstrate long-term efficacy of SCIg in immune-mediated neuropathies, SCIg may already represent a potential therapeutic alternative for selected patients.

Optimizing IgG therapy in chronic autoimmune neuropathies: a hypothesis driven approach

Prolonged intravenous immunoglobulin (IVIG) therapy is used for the chronic autoimmune neuropathies chronic idiopathic demyelinating polyneuropathy and multifocal motor neuropathy, but the doses and treatment intervals are usually chosen empirically due to a paucity of data from dose-response studies. Recent studies of the electrophysiology and immunology of these diseases suggest that antibody-induced reversible dysfunction of nodes of Ranvier may play a role in conduction block and disability which responds to immunotherapy more rapidly than would be expected for demyelination or axonal damage per se. Clinical reports suggest that in some cases, the effects of each dose of IVIG may be transient, wearing-off before the next dose is due. These observations lead us to hypothesize that that therapeutic IgG acts by competing with pathologic autoantibodies and that individual patients may require different IgG levels for optimal therapeutic effects. Frequent IVIG dosing and weekly subcutaneous IgG have been tried as ways of continuously maintaining high serum IgG levels, resulting in stabilization of neuromuscular function in small case series. Frequent grip strength and disability measurements, performed by the patient at home and reported electronically, can be used to assess the extent and duration of responses to IgG doses. Individualization of IgG treatment regimens may optimize efficacy, minimize disability, and identify nonresponders.

Rapid and reversible responses to IVIG in autoimmune neuromuscular diseases suggest mechanisms of action involving competition with functionally important autoantibodies

Intravenous immunoglobulin (IVIG) is widely used in autoimmune neuromuscular diseases whose pathogenesis is undefined. Many different effects of IVIG have been demonstrated in vitro, but few studies actually identify the mechanism(s) most important in vivo. Doses and treatment intervals are generally chosen empirically. Recent studies in Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy show that some effects of IVIG are readily reversible and highly dependent on the serum IgG level. This suggests that in some autoantibody-mediated neuromuscular diseases, IVIG directly competes with autoantibodies that reversibly interfere with nerve conduction. Mechanisms of action of IVIG which most likely involve direct competition with autoantibodies include: neutralization of autoantibodies by anti-idiotypes, inhibition of complement deposition, and increasing catabolism of pathologic antibodies by saturating FcRn. Indirect immunomodulatory effects are not as likely to involve competition and may not have the same reversibility and dose-dependency. Pharmacodynamic analyses should be informative regarding most relevant mechanism(s) of action of IVIG as well as the role of autoantibodies in the immunopathogenesis of each disease. Better understanding of the role of autoantibodies and of the target(s) of IVIG could lead to more efficient use of this therapy and better patient outcomes.

Subcutaneous IgG in neurologic diseases

Subcutaneous administration of IgG (SCIG) has become widely used in primary immune deficiency diseases but it has only recently been studied for maintenance therapy in autoimmune peripheral neuropathies, such as chronic idiopathic demyelinating polyneuropathy and multifocal motor neuropathy. Weekly self-administration of SCIG is safe and well-tolerated, and results in steady-state serum IgG levels, as contrasted with the peaks and troughs of monthly immune globulin (human) for intravenous use. Freedom from the need for venous access or medical personnel for infusions, flexibility in scheduling, convenience of home therapy, and improved clinical stability due to the steady-state IgG levels, lead many patients to prefer SCIG to immune globulin (human) for intravenous use. Long-term studies are needed to determine if the constant IgG levels and clinical stability translate into better long-term outcomes.