Dans le domaine des neuropathies dysimmunitaires, l’année 2010 a vu paraître des articles recouvrant des domaines aussi divers que les critères diagnostiques et les formes cliniques, la prévalence de ...la douleur et les facteurs l’influençant, l’évaluation de l’incapacité et du handicap, et les nouveaux marqueurs immunologiques. La neuropathologie gardant un intérêt dans le diagnostic de ces neuropathies, des guidelines françaises et internationales ont par ailleurs été publiées. Le présent article résume dans les grandes lignes cette actualité des neuropathies dysimmunitaires.
Many papers have been published in the field of immune-mediated neuropathies in 2010. Various topics have been covered: diagnostic criteria and clinical forms, pain and its risk factors, clinical evaluation and new immunological markers. Additionally, as nerve biopsy is still useful for evaluating patients with peripheral neuropathy, French and international guidelines have been published. This paper aims to summarize recent discoveries in the field of immune-mediated neuropathies.
Le diagnostic de polyradiculonévrite inflammatoire démyélinisante chronique (PIDC) repose principalement sur l’analyse clinique et électrophysiologique, complétée par la ponction lombaire. Dans de ...nombreux cas, ce diagnostic est relativement facile et conduit rapidement à la mise en route d’un traitement immunomodulateur. Cependant, certains patients ne sont pas diagnostiqués en raison d’atypies cliniques et/ou électrophysiologiques et ne peuvent donc pas bénéficier de traitements potentiellement efficaces. C’est pourquoi il a paru indispensable à un groupe de travail de publier des recommandations sur les stratégies diagnostiques à mettre en œuvre dans les principales situations cliniques où un diagnostic de PIDC peut être envisagé. Ces recommandations sont rappelées et mises en perspective sous forme d’un arbre décisionnel.
The diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) requires a careful clinical and neurophysiological evaluation, often completed by CSF analysis. In numerous cases, this diagnosis is straightforward and leads to rapid initiation of an immunomodulatory treatment. However, some patients are not diagnosed because of atypical clinical and/or neurophysiological features, and do not benefit from a potentially effective treatment. In this context, a working group was composed with the task of establishing recommendations on diagnostic strategies for CIDP in the main clinical situations where this diagnosis may be suspected. We have summarized these recommendations and tried to present them in the form of a decision-making algorithm.
Diagnostiquer une neuropathie périphérique est parfois difficile tant les tableaux cliniques sont variés et les étiologies multiples. De façon générale, l’abord d’un patient souffrant d’une ...neuropathie peut réclamer des connaissances dans quasiment tous les domaines de la médecine. C’est pourquoi il est nécessaire dans la plupart des cas d’adopter une démarche diagnostique rationnelle fondée sur les données cliniques et électrophysiologiques. Le présent article décrit cette démarche diagnostique en trois étapes : (1) délimiter une entité clinico-pathologique à partir des données de l’examen clinique et de l’électroneuromyogramme ; (2) proposer en fonction de l’anamnèse, du contexte clinique général et des données de la première étape une liste d’étiologies plausibles ; (3) mettre en œuvre les examens complémentaires nécessaires et suffisants pour déterminer l’étiologie ou éventuellement le mécanisme de la neuropathie. Les trois étapes de cette démarche nécessitent un niveau d’expertise important et bien souvent des interactions sont nécessaires entre spécialistes. Finalement, c’est l’évolutivité de la neuropathie et sa sévérité, qui devront le plus souvent conduire à rechercher avec acharnement la cause éventuellement curable d’une neuropathie.
Diagnosing a peripheral neuropathy is sometimes challenging, as the causes are diverse and the clinical pictures heterogeneous. Overall, diagnosing a patient with peripheral neuropathy will require some knowledge in almost every field of medicine. Therefore, it appears crucial to adopt a diagnostic strategy that is based on solid clinical and neurophysiological grounds. The present paper describes a three-step diagnostic strategy: (1) to delineate a clinico-pathologic entity from clinical and electrodiagnostic findings; (2) to propose a list of plausible causes based on step one, history and clinical context; (3) to use appropriate workup in order to determine the cause or mechanism of the neuropathy. The three steps of this diagnostic strategy necessitate a high level of expertise and interaction between physicians is highly desirable. Finally, an aggressive course and a severe impairment should lead to relentlessly look for a curable cause.
Diagnosing a peripheral neuropathy is sometimes challenging, as the causes are diverse and the clinical pictures heterogeneous. Overall, diagnosing a patient with peripheral neuropathy will require ...some knowledge in almost every field of medicine. Therefore, it appears crucial to adopt a diagnostic strategy that is based on solid clinical and neurophysiological grounds. The present paper describes a three-step diagnostic strategy: (1) to delineate a clinico-pathologic entity from clinical and electrodiagnostic findings; (2) to propose a list of plausible causes based on step one, history and clinical context; (3) to use appropriate workup in order to determine the cause or mechanism of the neuropathy. The three steps of this diagnostic strategy necessitate a high level of expertise and interaction between physicians is highly desirable. Finally, an aggressive course and a severe impairment should lead to relentlessly look for a curable cause.
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.
