IVIg increases interleukin-11 levels, which in turn contribute to increased platelets, VWF and FVIII in mice and humans.

The mechanisms of action of intravenous immunoglobulins (IVIg) in autoimmune diseases are not fully understood. The fixed duration of efficacy and noncumulative effects of IVIg in immune thrombocytopenia (ITP) and acquired von Willebrand disease (AVWD) suggest other mechanisms besides immunological ones. Additionally to the peripheral destruction of platelets in ITP, their medullary hypoproduction emerged as a new paradigm with rescue of thrombopoietin receptor agonists (TPO-RA). In an ITP mouse model, interleukin (IL)-11 blood levels increase following IVIg. IL-11 stimulates the production of platelets and other haemostasis factors; recombinant IL-11 (rIL-11) is thus used as a growth factor in post-chemotherapy thrombocytopenia. We therefore hypothesized that IVIg induces IL-11 over-production, which increases platelets, VWF and factor VIII (FVIII) levels in humans and mice. First, in an ITP mouse model, we show that IVIg or rIL-11 induces a rapid increase (72 h) in platelets, FVIII and VWF levels, whereas anti-IL-11 antibody greatly decreased this effect. Secondly, we quantify for the first time in patients with ITP, AVWD, inflammatory myopathies or Guillain-Barré syndrome the dramatic IL-11 increase following IVIg, regardless of the disease. As observed in mice, platelets, VWF and FVIII levels increased following IVIg. The late evolution (4 weeks) of post-IVIg IL-11 levels overlapped with those of VWF and platelets. These data may explain thrombotic events following IVIg and open perspectives to monitor post-IVIg IL-11/thrombopoietin ratios, and to assess rIL-11 use with or without TPO-RA as megakaryopoiesis co-stimulating factors to overcome the relative hypoproduction of platelets or VWF in corresponding autoimmune diseases, besides immunosuppressant.

Antibody- and macrophage-mediated segmental demyelination in chronic inflammatory demyelinating polyneuropathy: clinical, electrophysiological, immunological and pathological correlates.

BACKGROUND AND PURPOSE: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous autoimmune disorder critically lacking diagnostic biomarkers. Autoantibodies to nodal and paranodal components have recently been described in a small subset of patients. Here, the diagnostic value of immune reactivity toward the myelin compartment was investigated. METHODS: Ninety-four French CIDP patients were retrospectively studied. The reactivity toward the peripheral nerve was investigated. Sural nerve biopsies were examined by electron microscopy and immunofluorescence. RESULTS: Twenty-one patients (22%) and three patients (3%) presented with a strong immunoglobulin G or immunoglobulin M reactivity respectively against the myelin compartment. The clinical, electrophysiological and morphological features were examined in nine of these patients for whom sural nerve biopsies were available. Seven patients were electrodiagnosed with definite CIDP, one with possible CIDP and one was unclassifiable but sural nerve biopsy argued for CIDP diagnosis. Electron microscopy of sural nerve biopsies demonstrated the presence of macrophage-mediated demyelination restricted to the internode in all nine patients. Immunolabelling for voltage-gated sodium channels, myelin and axonal markers confirmed the presence of segmental demyelination and of remyelination. The nodal and paranodal regions, however, were unaffected in these patients. Nerve conduction studies corroborated the multifocal and segmental profile, and seven patients showed increased duration of proximal (1.5-5.1 times) and/or distal (1.2-3.4 times) compound muscle action potential in at least two nerves. CONCLUSION: Antibody- and macrophage-mediated demyelination appears responsible for conduction alterations in CIDP patients and nerve immunostaining assays may serve as a supportive diagnostic biomarker.

Classifications of neurogenetic diseases: An increasingly complex problem.

Neurodegenerative disorders represent a wide group of diseases affecting the central and/or peripheral nervous system. Many of these disorders were described in the 19th century, but our genetic knowledge of them is recent (over the past 25 years). However, the continual discovery of disease-causing gene mutations has led to difficulties in the classification of these diseases. For this reason, our present proposals for updating and simplifying the classification of some of these conditions (Charcot-Marie-Tooth diseases, distal hereditary motor neuropathies, hereditary sensory and autonomic neuropathies, hereditary spastic ataxias, hereditary spastic paraplegias and hereditary spastic ataxias) are expounded here.

Peripheral nervous system neuroimmunology seen by a neuro-pathologist.

In most dysimmune neuropathies, historically the microscopical lesions were described prior to immunological studies. The latter along with neuropathological studies have found some immune, albeit incomplete, explanations of the mechanisms of these lesions which we will describe in two main syndromes: the primitive auto-immune inflammatory peripheral polyneuropathies (GBS and CIDP) and polyneuropathies induced by a monoclonal dysglobulinemia. In some patients who have to be discussed case by case pathology (nerve biopsy) will confirm the diagnosis, may help to delineate the molecular anomalies and identify lesional mechanisms. We will review the high variability of nerve lesions which is characteristic of dysimmune neuropathies. Pathological studies confirm that both humoral and cellular immune reactions against Schwann cell and/or axonal antigens are implicated in primitive dysimmune neuropathies due to a dysfunction or failure of immune tolerance mechanisms. In case of a polyneuropathy associated to a monoclonal dysglobulinemia, pathological and immunological studies have shown that in many patients, the dysglobulinemia did harm the peripheral nerve; knowledge of the pathological lesions and their mechanisms is of major interest for orienting specific treatments.

Krox20 inactivation in the PNS leads to CNS/PNS boundary transgression by central glia.

CNS/PNS interfaces constitute cell boundaries, since they delimit territories with different neuronal and glial contents. Despite their potential interest in regenerative medicine, the mechanisms restricting oligodendrocytes and astrocytes to the CNS, and Schwann cells to the PNS in mammals are not known. To investigate the involvement of peripheral glia and myelin in the maintenance of the CNS/PNS boundary, we have first made use of different mouse mutants. We show that inactivation of Krox20/Egr2, a master regulatory gene for myelination in Schwann cells, results in transgression of the CNS/PNS boundary by astrocytes and oligodendrocytes and in myelination of nerve root axons by oligodendrocytes. In contrast, such migration does not occur with the Trembler(J) mutation, which prevents PNS myelination without affecting Krox20 expression. Altogether these data suggest that maintenance of the CNS/PNS boundary requires a new Krox20 function separable from myelination control. Finally, we have analyzed a human patient affected by a congenital amyelinating neuropathy, associated with the absence of the KROX20 protein in Schwann cells. In this case, the nerve roots were also invaded by oligodendrocytes and astrocytes. This indicates that transgression of the CNS/PNS boundary by central glia can occur in pathological situations in humans and suggests that the underlying mechanisms are common with the mouse.

Microglia-neuron interaction at nodes of Ranvier depends on neuronal activity through potassium release and contributes to remyelination.

Microglia, the resident immune cells of the central nervous system, are key players in healthy brain homeostasis and plasticity. In neurological diseases, such as Multiple Sclerosis, activated microglia either promote tissue damage or favor neuroprotection and myelin regeneration. The mechanisms for microglia-neuron communication remain largely unkown. Here, we identify nodes of Ranvier as a direct site of interaction between microglia and axons, in both mouse and human tissues. Using dynamic imaging, we highlight the preferential interaction of microglial processes with nodes of Ranvier along myelinated fibers. We show that microglia-node interaction is modulated by neuronal activity and associated potassium release, with THIK-1 ensuring their microglial read-out. Altered axonal K+ flux following demyelination impairs the switch towards a pro-regenerative microglia phenotype and decreases remyelination rate. Taken together, these findings identify the node of Ranvier as a major site for microglia-neuron interaction, that may participate in microglia-neuron communication mediating pro-remyelinating effect of microglia after myelin injury.

[Management of stroke in sub-Saharan Africa: current issues]. / Prise en charge des accidents vasculaires cérébraux en Afrique subsaharienne.

In sub-Saharan Africa, stroke is likely to present an increasingly important public health problem with a larger relative share of overall morbidity and mortality. Overall, sub-Saharan Health Care is characterized by a lack of human resources, lack of facilities for special investigations, and especially an absence of specific programs addressing the prevention of cardiovascular conditions. Current data on the epidemiology of stroke in sub-Saharan Africa, although sparse and fragmentary, indicate a comparatively high incidence of cerebral hemorrhage associated with high blood pressure, while ischemic stroke in black Africans still appears to be related primarily to small artery disease, HIV infection, and sickle cell disease. With urbanization, the role of large-vessel atherosclerosis is increasing. It is thus essential to coordinate government funding, health care professionals and development agencies to address this rising health problem. Access to health care needs to be better structured, and screening programs should be developed in order to identify and treat vascular risk factors. Improved training of health care professionals is also required in the areas of prevention, diagnosis and management of stroke. Implementation of best-practice recommendations for the management of stroke adapted to the specificities and resources of African countries would help rationalize the scarce resources currently available.

Ataxia with oculomotor apraxia type 2: a clinical and genetic study of 19 patients.

Ataxia with oculo-motor apraxia type 2 (AOA2) is a recently described autosomal recessive cerebellar ataxia (ARCA) caused by mutations in the senataxin gene (SETX). We analysed the phenotypic spectrum of 19 AOA2 patients with mutations in SETX, which seems to be the third most frequent form of ARCA in Algeria after Freidreich ataxia and Ataxia with vitamin E deficiency. In AOA2 patients, the mean age at onset for all families was in the second decade. Cerebellar ataxia was progressive, slowly leading to disability which was aggravated by axonal polyneuropathy present in almost all the patients. Mean disease duration until wheelchair was around 20 years. Oculo-motor apraxia (OMA) was present in 32% of the patients while convergent strabismus was present in 37%. Strabismus is therefore also very suggestive of AOA2 when associated with ataxia and polyneuropathy even in the absence of OMA. Cerebellar atrophy was more severe in the eldest patients; however it may also be an early sign since it was present in the youngest and paucisymptomatic patients. The initial sign was gait ataxia in all but two patients who presented with head tremor and writer cramp, respectively. Serum alpha-fetoprotein, which was elevated in all tested patients, was a good marker to suggest molecular studies of the SETX gene.

[Polyneuropathies in vitamin B1 deficiency in Reunion and Mayotte islands in 70 patients of Maori and Comorian descent]. / Polyneuropathies par hypovitaminose B1 aux îles de la Réunion et de Mayotte: à propos de 70 cas d'origine mahoraise et comorienne.

Beriberi is an uncommon disorder related to thiamine deficiency. It is mainly found in underdeveloped countries among populations with poorly diversified diet, consisting largely of milled white cereals, a poor source of thiamine. In industrialized countries, thiamine deficiency with cardiac failure is more frequently found than the dry beriberi in high risk groups like chronic alcoholics. Nevertheless our attention was drawn to an outbreak of 70 cases of dry beriberi which occurred from 1997 to 2005 in the French territories of Reunion and Mayotte islands. It was characterized by an acute or sub-acute sensorimotor polyneuropathy with axonal lesions, affecting the lower limbs and occasionally the upper limbs, sometimes associated with cardiac beriberi. It affected young, non alcoholic individuals from the Mahoran and Comorian community who were in apparent good health when the illness occurred. Our study highlighted the feeding habits which are partly responsible for the development of the disease due to a chronic lack of thiamine and which probably contributed together with multiple cofactors to trigger off the illness. But many elements and mainly biological ones, also lead us to think that there is a genetic predisposition to develop this neuropathy.

Proteolipid protein is necessary in peripheral as well as central myelin.

Alternative products of the proteolipid protein gene (PLP), proteolipid protein (PLP) and DM20, are major components of compact myelin in the central nervous system, but quantitatively minor constituents of Schwann cells. A family with a null allele of PLP has a less severe CNS phenotype than those with other types of PLP mutations. Moreover, individuals with PLP null mutations have a demyelinating peripheral neuropathy, not seen with other PLP mutations of humans or animals. Direct analysis of normal peripheral nerve demonstrates that PLP is localized to compact myelin. This and the clinical and pathologic observations of the PLP null phenotype indicate that PLP/DM20 is necessary for proper myelin function both in the central and peripheral nervous systems.

Contribution of electron microscopy to the study of neuropathies associated with an IgG monoclonal paraproteinemia.

A typical monoclonal IgG dysglobulinemia whether benign (monoclonal gammopathy of undetermined significance, MGUS) or malignant can give rise to peripheral neuropathy by damaging nerves. At first, neurotoxicity of the chemotherapy if the patient is treated must be ruled out in such cases. Indeed, a variety of other mechanisms have been described: endoneurial deposits of immunoglobulin, infiltration of the immunoglobulin within myelin sheaths, POEMS syndrome, deposits of amyloid, chronic inflammatory demyelinating polyradiculoneuropathy and infiltration of malignant cells. Ultrastructural examination of a nerve biopsy can be decisive in combination with routine histological and immunopathological examinations. Characterization of the mechanism of the neuropathy in a dysglobulinemic context is important as it governs therapeutic options, which in certain cases are particularly beneficial.

Recommendations on diagnostic strategies for chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune mediated treatable peripheral neuropathy, the diagnosis of which is straightforward in more than half of cases. Numerous sets of electrophysiological criteria have been published. However, in some cases, electrophysiological data are not sufficient and patients that may benefit from treatment escape accurate diagnosis. OBJECTIVE: To describe a step by step diagnostic procedure for neurologists facing a peripheral neuropathy of undetermined cause, to help make an accurate diagnosis of CIDP. METHODS: A group of French experts was established, neurologists and neurophysiologists being recruited on the basis of personal experience with patients suffering from CIDP and also on publications in the field. A full literature review was conducted on the topic of diagnostic criteria and procedures for the diagnosis of CIDP, and meetings were scheduled to reach a consensus on the best diagnostic workup in different clinical situations. RESULTS: Six meetings were conducted and a consensus was reached, based on the available literature and experience in the management of such patients. Discussions resulted in defining five clinical situations in which a diagnosis of CIDP may be considered, and procedures were detailed in each case, including the location of nerve biopsy and use of non-conventional electrophysiological testing and imaging procedures. CONCLUSION: The guidelines in the diagnostic procedure reported here result from a consensus of French experts in the field of peripheral neuropathy and allow a diagnosis of CIDP to be made in the most frequently encountered situations. These recommendations may be of value for physicians as they rely on the rational use of available techniques in typical clinical situations.

[Sensory-motor neuropathy: a slow and misleading case of leprosy]. / Neuropathie périphérique sensitivomotrice : une forme lente et trompeuse de maladie de Hansen.

The diagnostic process of sensory-motor neuropathies is difficult. Atypical variants and rare etiologies also contribute to delay the diagnosis. We report the case of a 70-year-old woman with slowly progressive asymmetric axonal sensory-motor neuropathy. Leprosy was identified after an eight-year delay. Nerve biopsy was required to establish the diagnosis: electron microscopy revealed debris of Hansen's bacillus in the nerve. Treatment was fully curative after several months. Leprosy is a rare cause of neuropathy in Europeans. Systematic inquiry about travel to endemic areas would be helpful in establishing the diagnosis. In such cases, nerve biopsy is crucial.

Pain as the presenting symptom of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

Numerous clinical forms of CIDP have been described, but pain is generally considered a rare or secondary sign. We describe here the clinical, electrophysiological and neuropathological characteristics of five patients with CIDP and pain as the main presenting symptom, and their course with treatment. Between January 2003 and December 2004, we selected five patients with prominent or isolated pain among 27 patients diagnosed with CIDP. All patients were subjected to clinical and electrophysiological examinations, and had a complete laboratory work up to exclude other causes of neuropathy. In view of the atypical clinical presentation, all five patients underwent nerve biopsy. There were two men and three women. The mean age at onset of neuropathy was 70+/-7.39 years. All patients initially presented with pain in the lower limbs associated with modest motor impairment (1 case), distal paresthesia (4 cases), cramps (1 case) and fatigue (2 cases). CSF was normal in three cases. On electrophysiological examination, three patients had nerve conduction abnormalities with subtle or clear signs of demyelination: three (case 1, 2 and 4) fulfilled the criteria of Rotta et al. and two (case 2 and 4) the criteria of both Nicolas et al and the INCAT group. Patients were all given symptomatic treatment and four patients received an immunomodulatory treatment, which was constantly effective. Pain may be a major and disabling symptom in patients with CIDP, so this diagnosis has to be considered in patients referred for a painful polyneuropathy. Moreover, immunomodulatory treatment has to be considered in such patients as symptomatic therapy may be ineffective.

[Axonal involvement in dysimmune neuropathies]. / Mécanismes et prévention de la dégénérescence axonale dans les neuropathies dysimmunitaires.

Dysimmune neuropathies, in common with other neuropathies, comprise an axonal impairment that it is primary or secondary to a demyelinating process. We consider here axonal impairment in the course of certain dysimmune neuropathies, such as the Guillain Barré syndrome, chronic inflammatory demyelinating polyradiculoneuritis and multiple conduction block neuropathy. We mention the fact that it is not always easy to evidence the axonal impairment, its severity and its potential for regeneration. The mechanisms of the axonal lesions stem essentially from the special and tight bonds between the axon and the Schwann cell, which in the central central nervous system are mirrored by the bonds between axons and oligodendrocytes. Indeed, myelinating Schwann cells modify the properties of the axon in the normal peripheral nervous system, and abnormal Schwann cells induce pathological modifications. The periods of appearance of the axonal impairment are nevertheless quite variable depending on the type of the dysimmune neuropathy: acute or chronic. Some Guillain-Barré syndromes may be distinguished by a severe axonal impairment, now well documented and referred to as AMSAN and AMAN. Various mechanisms of axonal impairment are discussed. The bond between axon and myelin means that any pathological process in Schwann cells leads to axonal impairment, with inflammatory processes having a direct impact on the axon: mechanism of typical 'by-stander effect', repressive role of endoneurial edema, direct dysimmune attack on axonal epitopes on the corresponding axolemma, especially on the GM1 gangliosides, intra-axonal accumulation of sodium and calcium due to disruption the voltage-dependent sodium/potassium ion channels, slow retrograde progression to anterior horn neurons and possibly also to posterior spinal cords. The treatment of the axonal impairment is not straightforward; it is based, in a first instance, on the direct relation between the severity of the demyelinating lesions and the axonal impairment. For the acute forms of typical Guillain-Barré syndrome, the value of plasma exchanges and intravenous immunoglobulins has demonstrated in double blind, randomized trials. For the chronic demyelinating inflammatory polyradiculoneuritis, corticotherapy, along with plasma exchange and the immunoglobulins, have also been shown to be effective. Immunosuppressor treatment has benefits, but it is hard to prove objectively. It is generally recognized that it is only useful if applied for a period of weeks, although this is currently a matter of debate. Other therapeutic options have been discussed and proposed, although to date there is a lack of proven efficiency: such treatments include neuroprotective agents and drugs which block sodium/potassium ion channels. It is increasingly difficult to propose new treatments with validated efficiency, due to the small number of patients presenting dysimmune neuropathies of the type discussed here that are both typical and suitable for inclusion in medium to long term studies.

Polyneuropathy with demyelinating features in mixed cryoglobulinemia with hepatitis C virus infection.

Peripheral neuropathy can arise from various mechanisms during hepatitis C virus (HCV) infection, mainly involving associated mixed cryoglobulinemia. The frequency of demyelinating polyneuropathy is probably underestimated in these patients. We report two cases of demyelinating polyneuropathy in HCV-infected patients. The first case concerned a 76-year-old woman followed for hepatitis C associated with a mixed cryoglobulinemia (type II), who developed a chronic progressive distal motor weakness and sensory disturbances concomitant with a raise in serum aspartate aminotransferase (GOT/AST) and alanine aminotransferase (GPT/ALT) levels. Other laboratory studies were normal except for a decrease in the hemolytic fraction of complement to 75 IU (n = 400-520). The second case was a 68-year-old woman followed for hepatitis C associated with a mixed cryoglobulinemia (type II), who had sensory disturbances in the lower limbs. Laboratory studies were otherwise unremarkable. Cerebrospinal fluid studies showed a normal protein content without pleocytosis in both patients. In both cases nerve conduction studies were suggestive of a mixed axonal and demyelinating sensorimotor neuropathy. Sural nerve biopsy showed segmental demyelination and severe loss of large myelinated fibers as well as some onion bulb formation in both cases. The two patients subsequently improved, the first with an antiviral treatment and the second with oral steroids.

[Inflammation and demyelinization: IgIV mode of action]. / Inflammation et démyélinisation: mode d'action des IgIV.

Immunoglobulins have a variety of actions in dysimmune disorders. In neurological conditions such as the dysimmune neuropathies and multiple sclerosis, immunoglobulins are thought to exert a twofold effect: an immunomodulating action and a positive action on remyelination. We outline well recognized immunomodulator actions including the suppression of antibody production and neutralization of pathogenic antibodies, action on T lymphocytes and endothelial cells, modulation of complement proteins, and modulation of the expression of Fc gamma receptors on the surface of macrophages. Along with these actions in dysimmune disorders of the central and peripheral nervous systems, recent studies have provided evidence for an action on remyelination. In cultures of oligodendrocytes or myelinating cocultures of rat embryo brains, we have noted a direct action of immunoglobulins (tégéline) on myelination of the central nervous system. Our investigations have also indicated that immunoglobulins have an action on myelination of the peripheral nervous system. We employed the experimental acute neuritis model as well as in vitro models such as cultures of embryonic dorsal root ganglia and isolated Schwann cells. Interestingly the typical IgM immunoglobulins seemed more active than typical IgG ones. This observation may prompt new therapeutic options.

[Polyneuropathy involving cranial nerves associated with monoclonal IgM antibodies with anti-MAG/SGPG/SGPLG/sulfatides activity]. / Une polyneuropathie avec atteinte des nerfs crâniens associée à une IgM monoclonale à activité anti-MAG/SGPG/SGPLG/sulfatides.

INTRODUCTION: A typically distal and symmetrical, slowly progressive sensorimotor demyelinating neuropathy is caused by monoclonal IgM against myelin-associated glycoprotein (MAG) and SGPG, SGLPG glycolipids in the context of a benign IgM paraproteinemia. We studied a patient with a neuropathy that fulfilled the diagnostic criteria for CIDP in whom IgM kappa anti-MAG/SGPG/SGLPG were detected. OBSERVATION: The patient was a 57-year-old man who had developed a slowly progressive distal sensorimotor neuropathy, involving the lower then upper limbs, with cranial nerves palsies (oro-pharyngo-laryngo territory). ENMG showed a demyelinating neuropathy with a disproportionate slowing of conduction in distal segments of motor and axonal features in the lower limbs. The first routine laboratory analysis revealed negative or normal findings. Several serum protein electrophoreses were normal. The third cerebrospinal fluid examination demonstrated a moderate and late rise in CSF protein level with no cells. Monoclonal IgM-kappa against MAG/SGPG/SGLPG, was detected; anti-MAG antibody titre in the serum was 20 059 BTU (N<1000). A small IgM-kappa paraprotein was identified by immunofixation. Electron microscopy failed to show nerve fibers with widening of outer lamellae of the myelin. There is no clinical improvement after different treatments, immunoglobulins IV, cortisteroids, plasma exchange, rituximab. CONCLUSION: It is not known whether this neuropathy is an atypical form of PNMAG or an CIDP associated with anti-MAG. When ENMG show a disproportionate slowing of conduction in distal segments of motor nerves, one should screen the serum with immunofixation to identify small monoclonal components. If IgM-MGUS is present, search should be undertaken for anti-MAG/SGPG/SGLPG antibodies. Diagnosis enables optimal treatment using, in severe cases, expensive current strategies with immunoglobulins IV, plasma exchange, and corticosteroids, or, in the event of no response, rituximab before resorting to more toxic drugs like cyclophosphamide.

[Autonomic nervous system involvement in chronic inflammatory demyelinating polyneuropathy]. / Polyradiculonévrite inflammatoire démyélinisante chronique et atteinte du système nerveux autonome.

INTRODUCTION: Involvement of the autonomic nervous system during Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is rare. Localised hyperhydrosis and Claude Bernard Horner (CBH) syndrome have never been reported in patients with CIDP. CASE REPORT: We report the case of a 65-year-old right handed man who presented with hyperhydrosis localised to the right hemithorax and hemiface and a left CBH syndrome. After an extensive workup, the patient was found to have CIDP as the only cause of autonomic nervous system involvement. The symptoms resolved slowly after three courses of intravenous immunoglobulins. CONCLUSION: Signs of autonomic nervous system involvement can be observed in CIDP as in Guillain-Barré syndrome. This case report shows that immunomodulatory treatment can be effective against dysautonomia in CIDP.

[Chronic inflammatory demyelinating polyradiculoneuropathy: diagnostic strategy. Guidelines of the French CIDP study group]. / Polyradiculonévrites inflammatoires démyélinisantes chroniques: stratégie diagnostique. Recommandations du groupe d'Etude français des PIDC.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) comprises a group of dysimmune neuropathies easily diagnosed in more than half of the patients. Diagnosis is based on clinical, electrophysiological and biological clues. In some patients, diagnosis is unclear because of the debated value of the available clues. In such circumstances, dysimmune neuropathies may not be diagnosed, leading to insufficient treatment. This is an important category of patients because immunomodulatory drugs have proven efficacy. The CIDP spectrum includes a relatively wide range of diseases. Besides the easily recognized classic forms, there are many clinical variants, sometimes with a paucisymptomatic presentation leading to uncertain diagnosis. The French CIDP study group has established guidelines for diagnostic strategy in CIDP patients. The first part of this paper is devoted to the clinical aspects of the disease, classical forms and variants. In the second part, the results of electrophysiological studies are reported. In a third chapter, complementary examinations useful for diagnosis are discussed. The fourth chapter deals with the diagnostic strategy, discussed in relation to the different situations which may be encountered in clinical practice. details the technical modalities of appropriate electrophysiological studies and presents normal results together with those indicating demyelinating neuropathy. Nerve biopsy technique and results are given in appendix II.