Clinical manifestations

Presentation and course

Recognition of classic and atypical variants of chronic inflammatory polyradiculopathy is important as the response to the immunotherapy differ in some variants.

Classic chronic inflammatory demyelinating polyradiculoneuropathy. The clinical picture of this most common subtype (50% to 60%) of chronic inflammatory demyelinating polyradiculoneuropathy consists of a symmetrical proximal and distal weakness with variable sensory symptoms that exhibits either a relapsing, stepwise progressive or steadily progressive course. Symptoms develop slowly and the nadir of maximal neurologic deficit is reached after 8 weeks or later from the onset. Aside from limb weakness, patients often have fatigue, numbness, tingling, or tight sensation in their extremities. Painful symptoms occur less often and include burning, aching, tenderness, or jabbing feelings. Ataxia and limb incoordination may result from the lack of proprioceptive inputs. Hyporeflexia or areflexia is the rule. In a large clinical study of 92 patients, motor deficits were the most frequent clinical feature (94%), followed by paresthesia (64%) (27). Cranial nerve involvement occurs in 10% to 20% of patients. Autonomic symptoms, if present, are usually mild. Postural and kinetic tremors are common and can be debilitating (12). Peripheral nerve hypertrophy may occur and, when strategically located, result in nerve root compression syndromes. Papilledema has been reported in up to 7% of patients (27), often associated with high CSF protein values.

Age of onset may influence clinical and prognostic features. Juvenile patients (under 20 years of age) more often exhibit a motor dominant neuropathy with subacute progression, relapsing-remitting course, and good functional recovery, whereas elderly patients (over 64 years of age) commonly show a sensorimotor neuropathy with chronic insidious progression and a less favorable recovery (85; 37).

Variants of chronic inflammatory demyelinating polyradiculoneuropathy. Clinical variants of chronic inflammatory demyelinating polyradiculoneuropathy have been described, and their phenotypes are summarized below (61).

Sensory chronic inflammatory demyelinating polyradiculoneuropathy is characterized by a predominantly sensory syndrome or ataxic neuropathy. If there is a concomitant or subsequent involvement of motor fibers electrophysiologically in two motor nerves, the diagnosis becomes sensory predominant chronic inflammatory demyelinating polyradiculoneuropathy (73).

Pure motor chronic inflammatory demyelinating polyradiculoneuropathy is characterized by weakness of proximal and distal muscles without sensory findings, a relapsing-remitting course, and good response to intravenous immunoglobulins but not to steroids (80). If there are sensory conduction abnormalities in two nerves, the diagnosis becomes the motor-predominant subtype.

Multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) or Lewis-Sumner syndrome is an asymmetric neuropathy initially affecting upper extremities (predominantly sensory or sensorimotor) and characterized by multifocal conduction block and a favorable response to intravenous immunoglobulin (56; 82).

Distal acquired demyelinating symmetric (DADS) neuropathy is a chronic symmetric distal sensory or sensorimotor neuropathy that is subclassified into DADS-M (those with an IgM monoclonal gammopathy and anti-myelin-associated glycoprotein antibodies), and DAD-I (idiopathic DADS neuropathy). Patients with DADS-M have poor response to prednisone and incomplete response to intravenous immunoglobulin G whereas those with DAD-I neuropathy respond well to the usual therapies for chronic inflammatory demyelinating polyradiculopathy (46; 55; 43).

Focal chronic inflammatory demyelinating polyneuropathy affecting only brachial plexus, lumbosacral plexus, or individual nerves is rare (89).

Chronic inflammatory axonal polyneuropathy is an acquired chronic progressive or relapsing sensorimotor neuropathy that is axonal on electrophysiological studies, but with either elevated CSF protein or evidence of inflammatory axonal neuropathy in the nerve biopsy plus responsiveness to steroids or intravenous gamma globulin (90; 74). There is no consensus regarding whether this condition should be considered as a variant of chronic inflammatory demyelinating polyradiculoneuropathy.

In the revised guideline from the Joint Task Force of the European Federation of Neurological Societies and the Peripheral Nerve Society, chronic immune sensory polyradiculopathy and autoimmune nodopathies are not included as variants of chronic inflammatory demyelinating polyradiculoneuropathy (93). These disorders are now listed under the Differential diagnosis section of this article.

Table 1. Autoimmune Nodopathies, Previously Classified as Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Antibodies to Nodal or Paranodal Glycoproteins

Prognosis and complications

The course of chronic inflammatory demyelinating polyradiculoneuropathy is variable and depends on the treatments and the degree of axonal involvement. Approximately two thirds of patients will respond to single therapy such as intravenous immunoglobulin, plasma exchange, or steroids, whereas 10% to 15% of patients are resistant to these treatments. One study reports that complete cure (5 or more years off treatment) occurs in 11%, remission (less than 5 years off treatment) in 20%, stable /improving in 51%, and unstable active disease in 18% of patients (33). However, the need for continuous and, sometimes, combined treatments to sustain remissions often leads to potentially serious side effects. Patients who respond to intravenous immunoglobulin may carry a better prognosis. One study reports that single nucleotide polymorphisms of TAG-1, an adhesion molecule expressed in the juxtaparanode, influence the responsiveness to intravenous immunoglobulin in Japanese patients with chronic inflammatory polyradiculoneuropathy (42). Another study found that the responsiveness to immunoglobulin may be influenced by promoter variants of genes encoding perforin1 and FcγRIIb (54).

Clinical vignette

A 65-year-old man presented with 5 months of ascending limb numbness, and paresthesias of the lower limbs, and mild leg weakness. Three months after onset, his strength was considerably reduced, he had difficulties with climbing stairs, his gait was unsteady and required the help of a cane, and his hands were clumsy. On admission, a neurologic exam showed an ataxic gait with Romberg sign, weakness of both distal and proximal muscles in lower extremities and distal muscles only in upper extremities, diffuse areflexia, and moderate to severe distal loss of all sensory modalities. Cerebrospinal fluid protein was elevated (134 mg/dl), without an increase in the number of cells. Conduction velocity of motor and sensory nerves in the lower extremities ranged from 25 to 28 m/s, with increased distal and F wave latencies, and relatively preserved amplitudes. Other diseases, such as neoplasm, paraproteinemia, systemic lupus erythematosus, systemic vasculitis, and HIV-1 infection, were ruled out. The patient received intravenous immunoglobulin (0.4 g/kg per day for 5 consecutive days). Within 4 weeks after this treatment began, he experienced marked improvement of strength and balance, with restoration of the ability to walk unaided and climb stairs. Eight weeks after therapy, his clinical condition began to deteriorate, and he was given monthly infusions of intravenous immunoglobulin (0.2 g/kg for 1 day) with further improvement. On this treatment schedule, the patient’s motor function was maintained to near normal level for up to 20 months.

Biological basis

Etiology and pathogenesis

Genetic susceptibility. Although chronic inflammatory demyelinating polyradiculoneuropathy is not inherited, genetic factors may render individuals more susceptible to develop the disease. A significant association with selected histocompatibility antigens such as HLA-A30, A31, B8, DR3, and Cw7 was reported by some authors but not confirmed by others (95). There is increased frequency of DRB1*15 alleles in the anti-neurofascin155 antibody+ subset (60; 72). The susceptibility to develop chronic inflammatory demyelinating polyradiculoneuropathy has also been linked to polymorphic GA repeats in the SH2D2A gene, which encodes a T cell-specific adaptor protein involved in the negative control of T cell activation (71). Patients with loss of function mutations in AIRE, a gene crucial for central tolerance, develop a multiorgan autoimmunity that includes chronic inflammatory demyelinating polyradiculoneuropathy-like illness as one of the phenotypic manifestations (92; 99).

Immunologic mechanisms. The specific trigger resulting in the disruption of immune tolerance is unclear in the majority of patients with chronic inflammatory demyelinating polyradiculoneuropathy. Both cellular and humoral immunity are involved in the immunopathogenesis, although the relative contribution of each component may differ depending on the subtype. Animal models have provided some insights into central and peripheral tolerance mechanisms such as regulatory T and B lymphocytes that are important in preventing or alleviating PNS autoimmunity (77; 99).

Cellular immunity. Complete activation of T cells requires signaling via costimulatory molecules such as B7-1 (CD80) and B7-2 (CD86), in addition to antigen-specific signaling via T cell receptors. The significance of costimulatory molecules is demonstrated by the development of a spontaneous autoimmune polyneuropathy in B7.2-deficient nonobese diabetic mice (81; 50). B7-1 (CD80) is expressed on the surface of endoneurial macrophages, and BB-1 and LFA-3 (CD58) on that of Schwann cells coexpressing MHC class II antigens (48; 68). Therefore, antigen presentation and T cell activation may be amplified by Schwann cells. Once lymphocytes and macrophages migrate across the blood nerve barrier, peripheral nerve injury and demyelination can occur by multiple mechanisms, including T cell mediated cytotoxicity, damage from cytokines and oxygen free radicals, and antibody-mediated attack (75; 52). The role of proinflammatory cytokines is supported by findings of elevated serum levels of TNF-alpha in patients with severe disease, increased production of IL-17 and IFN-gamma by T cells in those with active disease, and by in vitro studies demonstrating a synergistic detrimental action of TNF-alpha and IFN-gamma on Schwann cell viability (64; 69; 58).

Humoral immunity. Data supporting the role of humoral immunity include the demonstration of immunoglobulin and complement deposition on myelinated nerve fibers, passive transfer experiments using sera or purified immunoglobulins from patients, and therapeutic benefits of plasma exchange (53; 38; 101). Antibodies to components of peripheral nerve myelin, such as P0 or sulfated glucuronyl paragloboside, or to neuronal antigens such as anti-beta tubulin and GM1, have been detected in a subset of patients, but their importance remains unclear (15; 86; 88; 100). Studies indicate that adhesion molecules in the nodal and paranodal regions, such as gliomedin, contactin1, and neurofascins, are target antigens in this condition and in Guillain-Barré syndrome (21; 70; 78; 79), though these conditions are now separately classified as autoimmune nodopathies (Table 1).

Neuropathologic findings. Pathologic hallmarks of demyelination in classic chronic inflammatory demyelinating polyradiculopathy include segmental demyelination and remyelination, thinned myelin sheaths, and onion bulb formation, which may or may not be seen in the sural nerve biopsy as the disease is often multifocal and motor predominant. In addition, demyelination at proximal sites will not be detected by sural nerve biopsy. Segmental demyelination is best detected by teased fiber studies. Other common findings are endoneurial and subepineurial edema and axonal changes, such as axonal loss and regenerating axons (07). Myelinated fibers are mostly affected, especially those of large diameter, and their density frequently appears reduced.

The presence of inflammatory infiltrates in peripheral nerves is supportive of an autoimmune etiology. Epineurial and endoneurial infiltrates consist mainly of T lymphocytes and macrophages expressing MHC class II molecules and chemokine receptors (83; 49). In 26% to 40% of nerves studied, macrophage-induced demyelination characterized by active stripping of myelin lamellae and debris-laden macrophages were seen (07; 98).

The pathology is different in autoimmune nodopathies associated with Ig4 antibodies against contactin-1 or neurofascin155. In these conditions, there is subperineurial edema and paranodal dissection characterized by detachment of terminal loops from the axolemma without inflammatory infiltrates, or typical macrophage-induced demyelination (51; 91). Complement deposition was not detected at the paranodes where there was deposition of IgG4 (51). These findings suggest that the pathophysiology of these IgG4 autoantibodies involve blocking protein-protein interaction at the paranodal /axoglial junctions.

Epidemiology

Chronic inflammatory demyelinating polyradiculoneuropathy is believed to be a rare disorder, but its prevalence and incidence may vary depending on the diagnostic criteria adopted. A meta-analysis found that the pooled prevalence rate of chronic inflammatory demyelinating polyradiculoneuropathy was 2.81 per 100,000, and the pooled incidence rate was 0.33 per 100,000. However, the incidence rate was reported to be higher (0.68 per 100,000 person-years) in the Netherlands (09; 10). Male predominance is noted. Although the disease can occur at any age, the incidence is higher in those aged 50 years or older (10). Twenty percent of cases had diabetes, and 9% had concomitant autoimmune diseases. Preceding infectious illness or vaccination were reported in 12% and 1.5% of patients with chronic inflammatory demyelinating polyradiculoneuropathy, respectively (22). There are anecdotal reports of the disorder occurring after COVID-19 infection or vaccination (45). In 2007, a cluster of patients experiencing a polyradiculoneuropathy mimicking chronic inflammatory demyelinating polyradiculoneuropathy was identified at swine abattoirs (40). A few patients also had aseptic meningitis, meningoencephalitis, or myelitis. Further investigation revealed that this novel polyradiculoneuropathy is linked to exposure to aerosolized brain tissue and is associated with higher levels of interferon-gamma, supporting the concept of immune-mediated disease following respiratory or mucosal exposure to antigens. Chronic inflammatory demyelinating polyradiculoneuropathy can occasionally be triggered by use of immune checkpoint inhibitors, which usually respond to steroids with or without intravenous immunoglobulin (76).

Prevention

There is no known prevention for chronic inflammatory demyelinating polyradiculoneuropathy.

Differential diagnosis

Chronic inflammatory demyelinating polyradiculoneuropathy is distinguished from acute inflammatory demyelinating polyradiculoneuropathy mainly by its slower time course (over many weeks, months, or years), its response to steroids, and less complete recovery. The diagnosis is made after excluding polyradiculoneuropathy due to an infiltrative process such as lymphomas, carcinomatosis or sarcoidosis. A demyelinating neuropathy may occur as a complication of some medications such as amiodarone, tacrolimus, or TNF-alpha blockers; the neuropathy generally improves after the cessation of treatment. The polyradiculopathy associated with HIV infection often has a greater degree of pleocytosis than that of chronic inflammatory demyelinating polyradiculoneuropathy. Classical paraneoplastic neuropathies are sensory neuronopathies (ganglionopathies) usually associated with Hu (ANNA1) antibodies and lung cancer. On the other hand, patients with CRMP5 (CV2) antibodies may present with paraneoplastic sensorimotor, more frequently asymmetric, polyneuropathies that may be confused with chronic inflammatory demyelinating polyradiculoneuropathy. Neurophysiological studies, however, show axonal involvement and do not meet the established EMG criteria for demyelination (23). Vasculitic neuropathy has to be considered in patients with marked asymmetry. Diabetic polyneuropathy may present with a clinical picture of chronic distal symmetric sensorimotor polyneuropathy, exhibiting features of axonal greater than myelin damage. However, diabetic patients may also develop chronic inflammatory demyelinating polyradiculoneuropathy, which responds to immunomodulating treatment (84; 44).

Other chronic autoimmune/dysimmune neuropathies

Multifocal motor neuropathy (MMN). MMN presents with asymmetric limb weakness more frequently involving the upper than lower extremities and is associated with IgM anti-GM1 antibody and persistent conduction block involving motor fibers. In general, these patients respond well to treatment with intravenous immunoglobulin G but not to steroids or plasma exchange (04; 94).

Distal acquired demyelinating symmetric (DADS) neuropathy that is associated with IgM antibodies against myelin-associated glycoprotein shows predominantly sensory symptoms and signs, although demyelination of motor nerves can be demonstrated by electrodiagnostic studies. This group of patients rarely progresses to severe motor disability, and their response to intravenous immunoglobulin or other immunomodulating therapies is usually poor. Those patients with DADS but without anti-MAG antibodies appear more sensitive to immunomodulating drugs (46; 55).

Chronic ataxic neuropathy with ophthalmoplegia, IgM paraprotein, cold agglutinins and disialosyl antibodies (CANOMAD) manifests clinically like a chronic form of Miller Fisher syndrome.

Chronic immune sensory polyradiculopathy is characterized by symmetric sensory ataxia with marked vibration and position sense deficits due to an inflammatory process affecting the dorsal roots. Nerve conduction studies are usually normal, but somatosensory evoked potentials may be absent or enhancing nerve roots may be seen on MRI. If ventral roots are also involved, it is called chronic immune sensorimotor polyradiculopathy.

Autoimmune nodopathies. Although initially considered variants of chronic inflammatory demyelinating polyneuropathy, autoimmune nodopathies are now considered a separate entity due to their distinct clinical features, absence of overt inflammation, and poor response to intravenous immunoglobulin. Patients with antibodies against neurofascin155 or contactin-1, which are mostly of the IgG4 subclass, have a severe phenotype with aggressive symptom onset and poor response to IVIg (78; 79). The anti-neurofascin155 antibody is associated with younger onset, ataxia, tremors, higher frequency of foot drop, and CNS demyelination (20). The anti-contactin-1 antibody is predominantly associated with motor neuropathy or sensory ataxia and is sometimes associated with membranous glomerulonephritis (78; 65; 43; 19).

Polyneuropathy associated with IgG gammopathies are heterogenous, which include neuropathy associated with osteolytic or osteosclerotic myeloma and neuropathy associated with an IgG monoclonal gammopathy of unclear significance (MGUS). In addition, a subgroup of 10% to 20% of patients with typical chronic inflammatory demyelinating polyradiculoneuropathy may have IgG or IgA monoclonal gammopathy of undetermined significance, but their clinical features and response to therapy are similar to those of patients without paraprotein (34).

Polyneuropathy associated with POEMS should also be considered because this syndrome responds to other treatments, such as lenalidomide, bortezomib, or melphalan. As proposed by Suichi and colleagues, the core features of this syndrome consist of polyneuropathy, monoclonal gammopathy, and elevation of vascular endothelial growth factor whereas minor criteria include extravascular volume overload, skin changes, organomegaly, and sclerotic bone lesions (87).

Confusing conditions

Hereditary motor and sensory neuropathies (Charcot Marie Tooth disease, demyelinating type) can be easily identified when there is early onset, positive family history, and uniform slowing of conduction velocity in electrodiagnostic tests. However, a multifocal, nonuniform slowing and conduction blocks can be seen in some subtypes such as hereditary neuropathy with liability to pressure palsies.

Transthyretin (TTR) familial amyloid polyneuropathy is typically axonal but can occasionally present with features that mimic chronic inflammatory demyelinating polyradiculopathy. There is usually prominent pain and dysautonomia in these patients.

Associated or underlying disorders

Diagnostic workup

Laboratory studies. Evaluations for concomitant diseases or mimics include complete blood count, complete metabolic panel, thyroid function tests, Vitamin B12 levels, serum protein electrophoresis with immunofixation, serum free light chains, Lyme serology, and anti-ganglioside antibody panel. Other labs to consider are hepatitis B and C serology, HIV antibody, C-reactive protein, angiotensin-converting enzyme, antinuclear antibodies, SSA/SSB, and vascular endothelial growth factor. In selected cases, tests for antibodies against myelin-associated glycoprotein, neurofascin and contactin-1 are requested.

Lumbar puncture. CSF analysis in chronic inflammatory demyelinating polyradiculoneuropathy usually reveals elevated protein values with minimal pleocytosis. CSF cell values higher than 10/mm3 are incompatible with the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy, except for those forms associated with HIV-1 infection and with EB virus infection (in this case a CSF pleocytosis up to 50/mm3 may be tolerated). CSF protein levels are often above 60 mg/dl, although normal CSF protein values are found in a small minority of cases. The presence of CSF oligoclonal bands has been sporadically reported in patients with chronic inflammatory demyelinating polyradiculoneuropathy who also show clinical and MRI evidence of central white matter lesions.

Electrophysiological studies. Nerve conduction studies usually show features of demyelination, which include prolonged distal latencies, slowed conduction velocity, abnormal temporal dispersion, and conduction block (93) (Table 2). F-waves may be delayed or absent, suggesting demyelination of proximal nerve segments. Overinterpretation of electrophysiologic findings resulting in misdiagnosis is common and is further complicated by subjective perception of treatment benefit. A study showed that 47% of patients referred with a diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy failed to meet the minimal diagnostic requirements according to 2010 EFNS/PNS criteria (01).

Table 2. Electrodiagnostic Criteria for Definitive and Probable Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Additional tests. Sural nerve biopsy was initially considered mandatory for a definite diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (02). The current consensus is that nerve biopsy should be considered only in specific circumstances, such as the need to exclude an alternative diagnosis (eg, sarcoidosis, amyloidosis) or when the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy is suspected but cannot be confirmed with laboratory, electrodiagnostic, or imaging studies (93). Multifocal demyelination, inflammatory infiltrates, various degrees of axonal loss, and onion bulbs are the main features of chronic inflammatory demyelinating polyradiculoneuropathy. MRI in patients may reveal gadolinium-enhancement of the cauda equina or peripheral nerve trunks, or hypertrophic nerve roots (17; 24). Nerve sonography shows that nerve size in this disorder varies with disease activity and therapeutic response in some studies; although reports regarding poor correlation with functional disability also exist (102; 47; 36).

Management

Oral prednisone is efficacious in the majority of patients with chronic inflammatory demyelinating polyradiculoneuropathy, regardless of a relapsing or progressive course (29). The conventional approach is to start with high doses (up to 100 mg/day) with gradual tapering over 3 months. However, indefinite treatment with maintenance doses may be required, eventually leading to deleterious side effects. Pulsed intravenous dexamethasone (6 monthly cycles at 40 mg/day for 4 consecutive days) or methylprednisolone (1 g/d for 3 days followed by 1 g/d once a week) has been reported to be effective in two uncontrolled studies (66; 57). In a double-blind, randomized, controlled trial, pulsed high-dose dexamethasone showed a similar efficacy than oral prednisolone treatment (97).

Aside from steroids, intravenous immunoglobulin should be considered for induction of treatment for chronic inflammatory demyelinating polyradiculoneuropathy (28; 63; 93). In the study by Dyck and colleagues, intravenous immunoglobulin was given at dosages of 0.4 g/kg once a week for the first 3 weeks, followed by 0.2 g/kg once a week for the next 3 weeks (28). The long-term efficacy and safety of intravenous immunoglobulin were demonstrated in a randomized placebo-controlled trial of 117 patients who were randomized to placebo or intravenous immunoglobulin with a loading dose of 2 g/kg in 2 to 4 days followed by maintenance dose of 1 g/kg every 3 weeks (41). In a randomized trial of 142 patients (ProCID), the response rates were 65%, 80%, and 92% in the 0.5, 1.0, and 2.0 g/kg maintenance dose groups, respectively (16). An alternative approach, subcutaneous administration of immunoglobulin, has been reported to be effective at weekly doses of 0.2 g/kg or 0.4 g/kg in a double-blind, placebo-controlled phase 3 PATH trial of 172 patients (96). The primary outcome was the proportion of patients with a relapse or who withdrew for any reason during 24 weeks of treatment. The mechanisms of action of intravenous or subcutaneous immunoglobulin may involve anti-idiotypic interactions, complement inactivation, cytokine inhibition, and saturation of Fc receptors on endoneurial macrophages (18).

Two double-blind randomized controlled trials showed that plasma exchange produces significant improvements in about two thirds of patients (26; 35). Anemia, high cost, and hospitalization are the main disadvantages of plasma exchange. In general, plasmapheresis should be considered only if intravenous immunoglobulin and steroids are ineffective. A more selective technique of immunoglobulin removal from plasma is the immunoadsorption system, which has been shown to have an 80% clinical response rate in a small pilot study (103).

Other immunosuppressive or immunomodulating agents such as azathioprine, methotrexate, and interferon beta-1a have not been proven to be of added benefit in randomized trials (30; 59). Intravenous cyclophosphamide, either by monthly pulses (1 g/m2 every month) or by a single high-dose course (200 mg/kg over 4 days) may produce persistent functional improvement (32; 08). Thus far, only anecdotal reports or uncontrolled studies on the use of cyclosporine, mycophenolate mofetil, etanercept, and alemtuzumab are available (05; 14; 06; 39). Of note, there is some evidence that patients with refractory chronic inflammatory demyelinating polyradiculoneuropathy may respond well to rituximab (67). In a systematic literature review, rituximab was found to be effective in 63% of patients (13). Other potential therapeutic agents include, but are not limited to, eculizumab, which blocks complement C5 cleavage, and antibodies targeting the neonatal Fc receptor, which is involved in intracellular recycling of immunoglobulin. Two neonatal Fc receptor biologics, efgartigimod and rozanolixizumab. are currently being assessed in phase 2 trials for chronic inflammatory demyelinating polyradiculoneuropathy. Lastly, autologous hematopoietic stem cell transplantation, which has risks of infections and other complications, can be considered in refractory cases. An open-label study of 66 patients that underwent autologous stem cell transplantation showed immune medication-free remission of 83% at 5 years and overall survival of 97% (11).

Special considerations

Pregnancy

Pregnancy was associated with a significant increase of relapse rate in nine women with chronic inflammatory demyelinating polyradiculoneuropathy of relapsing type (62). Relapses occurred more frequently during the third trimester of pregnancy or 3 months postpartum. There are also reports of isolated patients who experienced relapses while taking oral contraceptives.