Proposed revised electrophysiological criteria for chronic inflammatory demyelinating polyradiculoneuropathy

[Management and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Results of a French national opinion survey]

AIM

To assess the clinical and epidemiological characteristics of chronic inflammatory demyelinating polyneuropathy (CIDP) in a French population opinion survey.

METHODS

A national and multicentric metropolitan French opinion survey was conducted by TNS Healthcare Sofres from October to December 2006. Five thousand and thirty three hospital or private practice physicians were contacted by mail. A specific questionnaire (38 questions) was designed for the survey to evaluate epidemiology, diagnosis and treatment of CIDP.

RESULTS

Four hundred and forty one responses were obtained, 430 were analyzed, 11 being excluded. Only 172 physicians were caring for patients with CIDP, the others feeling that they were not competent for this management (only 34% of the physicians cared for at least one patient during the study). Treatment was managed by only 28% of the physicians and mainly by neurologists working in public hospitals. The percentage of treated patients was 84%, the others were not treated because the impairment was too mild. IVIg were the first intention treatment for 63.2% of the patients and steroids for 30.8% of them. The choice was mainly based on the good tolerance profile of IVIg, both treatments being considered as efficacious.

CONCLUSION

This survey has shown a higher incidence and prevalence of CIDP than expected but a methodological bias may have led to an overestimation (a same patient being included twice). Treatment complied with recommendations and guidelines while the diagnosis may be improved.

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.

Long-term effects of intravenous immunoglobulin in CIDP

OBJECTIVE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired demyelinating disease of the peripheral nervous system characterized by muscle weakness, areflexia or hyporeflexia, and sensory disturbances. Although short-term efficacy of intravenous immunoglobulin (IVIg) has been demonstrated in randomized-controlled trials, the data pertaining to long-term outcome in CIDP are limited. Consequently, the aim of the present study was to assess the long-term effects of IVIg on neurophysiological parameters in CIDP.

METHODS

Neurophysiological records from 11 CIDP patients, treated with IVIg for 12 months, were reviewed. Nerve conduction studies were assessed at baseline, 1-year, and last follow-up.

RESULTS

There was a significant reduction in the frequency of conduction blocks (pre-treatment nerve segments affected 61%; last follow-up 39%, P<0.01) and a reduction in ongoing axonal loss (pre-treatment regions with spontaneous activity, 47%; post-treatment 29%, P<0.01) with IVIg treatment. Further, there was significant improvement in sensory nerve conduction studies with IVIg treatment (sensory amplitudes reduced pre-treatment, 90% nerves tested; post-treatment, 62%, P<0.01).

CONCLUSIONS

The present study suggests that long-term IVIg maintenance therapy improves neurophysiological parameters in CIDP. However, CIDP patients remain IVIg dependent and new conduction blocks may develop.

SIGNIFICANCE

The present study suggests that long-term IVIg maintenance therapy improves neurophysiological parameters in CIDP, possibly by reducing the immune response and thereby fostering nerve healing.

The value of sensory electrophysiology in chronic inflammatory demyelinating polyneuropathy

OBJECTIVE

The purpose of this study was to evaluate the usefulness of sensory nerve conduction studies in comparison and in combination with motor conductions in diagnosing chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

We retrospectively compared the electrophysiology of 20 patients with CIDP to that of 20 controls with axonal polyneuropathy, and 20 controls with myopathy. Five sensory abnormality patterns were evaluated.

RESULTS

The "abnormal radial normal sural" ("ARNS") pattern showed a sensitivity of 25% for CIDP and specificity of 100% versus axonal neuropathies (p=0.047). The "abnormal sural normal radial" ("ASNR") pattern had a sensitivity of 75% for axonal neuropathy with a specificity of 80% versus CIDP (p=0.0012). Presence of ARNS or absence of ASNR patterns showed equivalent or superior sensitivity and specificity to most individual motor demyelinating defects for CIDP. Presence of ARNS or absence of ASNR patterns, integrated within three different sets of electrodiagnostic criteria for CIDP, increased sensitivity in all without significantly altering specificity. Effects were most remarkable with the American Academy of Neurology criteria (1991), which showed significantly improved sensitivity (50-85%; p=0.041), with preserved specificity of 100%.

CONCLUSIONS

The use of sensory abnormality patterns appears justified in comparison and combination with motor defects in diagnosing CIDP.

SIGNIFICANCE

Sensory studies may be useful in contributing to the electrodiagnosis of CIDP and their inclusion in existing electrodiagnostic criteria deserves consideration.

A comparative study of chronic inflammatory demyelinating polyradiculoneuropathy with and without diabetes mellitus

Diabetes mellitus (DM) is occasionally associated with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) raising the question of coexistence or etiological link. The study compares, neurophysiological and outcome of CIDP patients with and without DM. Consecutive CIDP patients were subjected to detailed clinical evaluation, haematology, serum chemistry, vasculitis profile, paraproteins, myeloma screening and cerebrospinal fluid (CSF) examination. Electrodiagnostic (EDx) tests included motor and sensory conduction and F-wave studies. The patients were treated with oral prednisolone 1 mg/kg/day with or without azathioprine 1-2 mg/kg and followed up for 6 months. The clinical and EDx finding in CIDP with and without DM were compared. Thirty-five CIDP patients were included and nine had DM. CIDP with diabetes (CIDP-D) had higher frequency of autonomic dysfunction. In CIDP-D, motor (38.9% vs. 16.7%) and sensory (40.7% vs. 14.1%) nerve conductions were more frequently unrecordable or had reduced compound muscle action potential (CMAP) amplitude. F-waves were also more frequently unrecordable in CIDP-D (28.8% vs. 12.8%) compared with idiopathic CIDP (I-CIDP). The degree of conduction block was more in I-CIDP. At 6-month follow up, I-CIDP patients improved better than CIDP-D. CIDP-D patients present with higher frequency of autonomic dysfunction, electrophysiological evidences of associated axonal loss and had a poorer outcome at 6 months compared with I-CIDP.

A prospective study of physiotherapist prescribed community based exercise in inflammatory peripheral neuropathy

There is insufficient evidence to support the use of exercise in the management of chronic disablement in people with inflammatory peripheral neuropathy. Therefore, our study aimed to determine the feasibility and effectiveness of a physiotherapist prescribed community based exercise programme for reducing chronic disablement in patients with stable motor neuropathy. We assessed the effects of a 12 week unsupervised, community based strengthening, aerobic and functional exercise programme on activity limitation and other measures of functioning in 16 people with stable motor neuropathy and 10 healthy control subjects. Fourteen of 16 patients and 8 out of 10 healthy control subjects completed the study and exercised safely in the community with no adverse events. Significant improvements were seen in all measures of activity limitation and in wider measures of health including anxiety, depression and fatigue in the patient group. Improvements were sustained at six months after completion of the exercise programme, except for depression. Ten patients continued to exercise regularly at six months. These findings demonstrate that individually prescribed community based exercise is feasible and acceptable for people with stable motor neuropathy and participation in exercise may be successful in reducing chronic disablement. Future randomised controlled trials are needed to examine the efficacy of this complex community based intervention.

Chronic inflammatory demyelinating polyneuropathy: A 6-year retrospective clinical study of a hospital-based population

We reviewed the clinical, electrophysiological, laboratory and neuroimaging features of 25 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) admitted to Aeginition Hospital from 1996 to 2001. We also investigated the response to several treatment modalities. The aim was to reveal the clinical spectrum of the disease; the diagnostic criteria developed by the Ad Hoc Subcommittee of the American Academy of Neurology (AAN) in 1991 were used. The subjects consisted of 17 men (68%) and eight women (32%) aged 18-81 years (mean age: 48.5 years) with CIDP. Eighteen patients (72%) had a symmetric neuropathy, whereas seven (28%) had an asymmetric neuropathy. Two patients (8%) had a pure sensory neuropathy. Nine (36%) presented with cranial nerve involvement and only one (4%) had central nervous system demyelination. Most patients had a satisfactory response after treatment with corticosteroids, intravenous immunoglobulins, plasma exchange and azathioprine. In conclusion, CIDP is a clinically heterogeneous disorder. It is one of the few serious chronic neuropathies that has a good (although not permanent) treatment response.

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.

Dixièmes Journées des Maladies du Système Nerveux Périphérique Quoi de neuf depuis 10 ans dans l’évaluation des neuropathies périphériques?

In the past ten years, clinical evaluation of peripheral neuropathy has greatly improved, thanks to the development and validation of new evaluation tools. Notably, new functional scales that may be used in clinical trials as well as in daily practice have emerged. This evolution is remarkable, but will necessitate considerable efforts from Neurologists in their clinical practice. In the field of electrophysiological examination, techniques have not evolved as much in the past ten years. However, interpretation of abnormal results leading to the diagnosis of immune mediated peripheral neuropathies has improved, allowing the development of new rationales for diagnostic strategies.

Dixièmes Journées des Maladies du Système Nerveux Périphérique Diagnostic des polyneuropathies axonales chroniques : les polyradiculonévrites chroniques méconnues

Chronic inflammatory demyelinating polyradiculoneuropathy is an autoimmune disease that target myelin sheats of peripheral nerves. Its diagnosis is often difficult to make, and a number of cases are probably not identified because of the clinical and electrophysiological heterogeneity. Typical cases associate progressive or relapsing-remitting motor and sensory deficit with increased CSF protein content and electrophysiological features of demyelination. In some cases electrophysiological studies fail to show evidence of demyelination, conventional electrophysiological diagnostic criteria are not filled yet the patient may respond to immunomodulatory treatments. In such cases, presence of clinical characteristics suggestive of CIDP (that means not compatible with a length-dependent axonal process) are critical justifying fully investigations including sural nerve biopsy. The main clinical characteristic are: a symmetric proximal and distal motor weakness predominantly affecting the lower limbs, a diffuse areflexia, a sensory deficit characterized by a preferential involvement of large fibers, an evolution which may be either chronic progressive or recurrent. Usual therapeutic agents (corticosteroids, intravenous immunoglobulins, plasma exchanges) seem to have the same efficacy whatever the electrophysiologic profile.

Clinical heterogeneity in mild chronic inflammatory demyelinating polyneuropathy

We describe the clinical presentation, progression and electrodiagnostic features of three patients with a mild form of chronic inflammatory demyelinating polyneuropathy (CIDP). The unusually mild but also variable clinical picture was a cause of diagnostic uncertainty in all, but CIDP was eventually confirmed by extensive electrophysiological studies in each case, as well as by histology in one. Cerebrospinal fluid protein was raised in only one patient. Two patients were treated by intravenous immunoglobulins and both improved. Awareness of the existence of this relatively benign form of CIDP in its various presentations is essential as it can be functionally disabling, progress to more severe symptomatology, and as patients may benefit from immunomodulatory therapy.

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.

Proximal nerve conduction studies in chronic inflammatory demyelinating polyneuropathy

OBJECTIVE

The purpose of this study was to evaluate the sensitivity and specificity of proximal upper limb motor nerve conduction study abnormalities in chronic inflammatory demyelinating polyneuropathy (CIDP), using standard percutaneous stimulations up to Erb's point.

METHODS

Electrophysiologic data relating to proximal conductions of median and ulnar nerves of 22 patients with CIDP were retrospectively analyzed and compared to those of 22 controls with sensory neuropathy. Distal conduction results were also reviewed.

RESULTS

The findings demonstrate independent high sensitivity of abnormal upper limb proximal nerve conduction studies in CIDP. Demonstration of conduction block of >20% and temporal dispersion of >15% had low specificity. However, conduction block was highly specific with cut-off values of >30% at axilla and >50% at Erb's point. Specificity was considerably improved using a cut-off value of >30% at proximal levels for temporal dispersion. Diagnostic sensitivity improved significantly with proximal studies with the criteria used in this population. No adverse effects had occurred as result of proximal stimulations.

CONCLUSIONS

Proximal studies are safe, sensitive and reliable procedures in cases of suspected CIDP. Their use appears justified although adequate cut-off values are desirable to optimize their specificity.

SIGNIFICANCE

This study indicates that proximal upper limb nerve conductions are appropriate in investigating suspected CIDP, as detailed in recently established electrophysiologic criteria. However, specificity is largely dependent on cut-off values for conduction block and temporal dispersion.

Chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinative polyneuropathy (CIDP) is an acquired neuropathy, presumably of immunological origin. Its clinical presentation and course are extremely variable. CIDP is one of the few peripheral neuropathies amenable to treatment. Typical cases associate progressive or relapsing-remitting motor and sensory deficit with increased CSF protein content and electrophysiological features of demyelination. In other instances the neuropathy is predominantly or exclusively motor or sensory, CSF normal and electrophysiological studies fail to show evidence of demyelination. In such cases conventional diagnostic criteria are not filled yet the patient may respond to immunomodulatory treatments. In this paper we review the diagnostic pitfalls and clinical variants of CIDP to illustrate the problems that may arise. The different therapeutic options are reviewed. Axon loss associated with demyelination is the most important factor of disability and resistance to treatment.

Immunotherapy for IgM anti-myelin-associated glycoprotein paraprotein-associated peripheral neuropathies

BACKGROUND

Serum monoclonal anti-myelin associated glycoprotein antibodies may be pathogenic in some people with IgM paraprotein and demyelinating neuropathy. Immunotherapies aimed at reducing the level of these antibodies might be expected to be beneficial.

OBJECTIVES

To examine the efficacy of any form of immunotherapy in reducing disability and impairment resulting from IgM anti-myelin associated glycoprotein paraprotein-associated demyelinating peripheral neuropathy.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register (March 2005), MEDLINE (January 1966 to March 2005) and EMBASE (January 1980 to March 2005) for controlled trials. We also checked bibliographies and contacted authors and experts in the field.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials of participants of any age treated with any type of immunotherapy for anti-myelin-associated glycoprotein antibody associated demyelinating peripheral neuropathy with monoclonal gammopathy of undetermined significance of any severity. Our primary outcome measure was change in the Neuropathy Impairment Scale or Modified Rankin Scale at six months after randomisationSecondary outcome measures were: Neuropathy Impairment Scale or the Modified Rankin Score at 12 months after randomisation; ten-metre walk time, subjective clinical scores and electrophysiological parameters at six and 12 months after randomisation; IgM paraprotein levels and anti-myelin associated glycoprotein antibody titres at six months after randomisation and adverse effects of treatments.

DATA COLLECTION AND ANALYSIS

We identified eight possible trials. Of these, five randomised controlled trials were included after discussion between the authors. One author extracted and the other checked the data. No missing data could be obtained from trial authors.

MAIN RESULTS

The five eligible trials (97 participants) tested intravenous immunoglobulin, interferon-alpha or plasma exchange. Only two, of intravenous immunoglobulin, had comparable interventions and outcomes but both were short-term. There were no significant benefits of the treatments used in the outcomes predefined for this review, but not all the predefined outcomes were used in every included trial. Intravenous immunoglobulin showed benefits in terms of improvement in Modified Rankin Scale at two weeks and 10-metre walk time at four weeks. Serious adverse effects of intravenous immunoglobulin are known to occur from observational studies but none were encountered in these trials.

AUTHORS' CONCLUSIONS

There is inadequate reliable evidence from trials of immunotherapies in anti-myelin associated glycoprotein paraproteinaemic neuropathy to recommend any particular immunotherapy treatment. Intravenous immunoglobulin is relatively safe and may produce some short-term benefit. Large well-designed randomised trials of at least six to 12 months duration are required to assess existing or novel therapies.

[Electrophysiological manifestations of chronic inflammatory demyelinating polyradiculoneuropathy]

There are four basic electrophysiological parameters of demyelination: reduced motor conduction velocity, prolonged distal motor latency and F waves, and motor conduction blocks. These parameters are combined to determine an electrophysiological set of criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). Whereas their specificity is good, their sensitivity level does not exceed 75 percent. However, these sets of criteria are not commonly used especially in benign forms, at the beginning of the disease, in associated forms or in case of secondary axonal degeneration. We can push the limits using others criteria such as the terminal latency index, sensory criteria, or by the contribution of others electrophysiological procedures such as the radicular stimulation or sensory evoked potentials. Due to the therapeutic implications, any axonal neuropathy without aetiologia, with at least one demyelinating electrophysiological criteria, could be considered as a putative CIDP.

Les neuropathies périphériques : orientations et moyens diagnostiques

PURPOSES

Neuropathies are defined as dysfunction of peripheral nerves, which may show motor, sensory and autonomic symptoms. Although most neuropathies are symmetric, it is important to distinguish a polyneuropathy from a mononeuropathy, a multiple mononeuropathy or a polyradiculoneuropathy. Electrophysiological procedures are helpful in determining the pathological process which may be either an axonopathy, a myelinopathy or a neuronopathy.

MAIN POINTS

Major progresses have been made in the ten past years in the management and diagnostic approaches of peripheral neuropathy. The history and the physical examination are the first steps to the evaluation of patients with peripheral neuropathy. Electrodiagnostic studies and then laboratory tests are the next step in the diagnostic procedures of peripheral neuropathies. These will lead to a proper identification of the cause of neuropathy, allowing to develop a specific treatment for the patient. However, even after a careful work-up of a patient with neuropathy, 25 to 40% of patients with polyneuropathies remain undiagnosed.

PERSPECTIVES

Further development are focused in better understanding the pathogenesis and molecular mechanisms of peripheral nerve diseases in order to provide a specific and adequate treatment for each neuropathy.

Chronic inflammatory demyelinating polyneuropathy in patients with systemic lupus erythematosus: prognosis and outcome

OBJECTIVES

To identify clinical characteristics, laboratory features, approaches to management, and predictors of outcome of chronic inflammatory demyelinating polyneuropathy (CIDP) in patients with systemic lupus erythematosus (SLE).

METHODS

An analysis of 6 adults with the concurrent diagnosis of CIDP and SLE seen at a SLE Clinic from 1994 to 2004 with a review of 13 patients with SLE and CIDP reported in the medical literature from 1950 through 2004.

RESULTS

Among our 6 patients with SLE and CIDP, 3 (50%) achieved a substantial clinical response to intravenous immunoglobulin (IVIg) and the remainder had a minimal response. The improved patients were more likely to have received treatment earlier (within 1 year of CIDP onset) and to respond faster (<1 to 3 months) than minimally improved patients. They tended to have CIDP features of weakness of all extremities, hyporeflexia of the upper extremities, and slowed nerve conduction velocity of the motor median nerve. Compared with minimal responders, responders had more serious internal organ manifestations and multiple autoantibodies associated with SLE. Review of the literature identified 13 previously reported CIDP patients with SLE. Many had neurological involvement of all extremities, nerve biopsies showing demyelination, and serious SLE internal organ manifestations. Most were treated with steroids, but the 1 treated with IVIg had similar characteristics to our subset of patients who improved with IVIg.

CONCLUSIONS

CIDP is an uncommon, but not rare, manifestation of SLE. Certain characteristics including early CIDP diagnosis, involvement of all 4 extremities, hyporeflexia of the upper extremities, and slowed motor nerve conduction velocity of the median nerve in addition to SLE involvement of critical internal organs and the presence of multiple antibodies associated with SLE all appear to predict a good response to IVIg.

Pathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy

The acute lesions of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) consist of endoneurial foci of chemokine and chemokine receptor expression and T cell and macrophage activation. The myelin protein antigens, P2, P0, and PMP22, each induce experimental autoimmune neuritis in rodent models and might be autoantigens in CIDP. The strongest evidence incriminates P0, to which antibodies have been found in 20% of cases. Failure of regulatory T-cell mechanism is thought to underlie persistent or recurrent disease, differentiating CIDP from the acute inflammatory demyelinating polyradiculoneuropathy form of Guillain-Barré syndrome. Corticosteroids, intravenous immunoglobulin and plasma exchange each provide short term benefit but the possible long-term benefits of immunosuppressive drugs have yet to be confirmed in randomised, controlled trials.

Diagnosis and treatment of chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated acquired polyneuropathy that may lead to disability. CIDP is characterized by an autoimmune attack against peripheral nervous system myelin, by cellular and humoral mechanisms. Early diagnosis and treatment may yield better functional recovery, probably by minimizing secondary axonal loss from a primary demyelinating insult. Intravenous immunoglobulin and plasmapheresis are considered standard-of-care therapy in CIDP, based on randomized, double-blinded, placebo-controlled evidence. Corticosteroids, despite less robust evidence, are also considered standard therapy for CIDP. Other nonstandard therapies may work in refractory patients. These include azathioprine, cyclophosphamide, cyclosporine A, etanercept, interferon-alpha 2a, mycophenolate mofetil, and tacrolimus. Emerging therapies include interferon-beta 1a, rituximab, and high-dose cyclophosphamide without stem-cell rescue. Because most patients will require prolonged therapy, long-term side effects are important considerations.

Cervical nerve root stimulation. Part II: Findings in primary demyelinating neuropathies and motor neuron disease

OBJECTIVE

Cervical nerve root stimulation (CRS) allows the assessment of conduction in the proximal segments of motor fibers destined to the upper extremities, which are not evaluated by routine nerve conduction studies (NCS). Since many primary demyelinating polyneuropathies (PDP) are multifocal lesions may be confined to the proximal nerve segments. CRS may therefore increase the yield of neurophysiologic studies in diagnosing PDP.

METHODS

We reviewed clinical and neurophysiologic data from 38 PDP patients and compared them to 35 patients with motor neuron disease (MND), and 21 healthy controls (HC).

RESULTS

Mean onset-latency was significantly prolonged in PDP patients. The optimal onset-latency cutoff necessary to distinguish PDP from MND and controls was 17.5 ms for the abductor pollicis brevis (APB) and abductor digiti minimi (ADM), and 7 ms for Biceps and Triceps. Mean reduction in proximal to distal CMAP amplitude to APB and ADM was significantly greater in PDP patients, with an optimal cutoff in proximal to distal CMAP amplitude reduction necessary to distinguish PDP from MND and HC being 45%.

CONCLUSIONS

CRS is effective in distinguishing PDP from MND and HC based on prolonged onset latency and conduction block criteria.

SIGNIFICANCE

CRS may increase the diagnostic yield in cases where demyelinating lesions are confined to the proximal peripheral neuraxis.

Acute inflammatory demyelinating polyneuropathy: Contribution of a dispersed distal compound muscle action potential to electrodiagnosis

Prolonged duration of the distal compound muscle action potential (DCMAP) ("DCMAP dispersion") is useful in the electrodiagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) with good specificity in distinguishing CIDP from amyotrophic lateral sclerosis (ALS) and diabetic polyneuropathy, but its role in the electrodiagnosis of acute inflammatory demyelinating polyneuropathy (AIDP) is unclear. This study addresses this issue by determining the optimal cutoff for DCMAP duration using receiver operating characteristic (ROC) analysis in 207 motor nerves from 53 clinically defined AIDP patients compared to 148 motor nerves from 55 ALS patients. We also determined whether the presence of DCMAP dispersion improves the sensitivity of four of the most sensitive published sets of electrodiagnostic criteria for AIDP. Using the ROC-derived optimal DCMAP duration cutoff of 8.5 ms, DCMAP dispersion was found in at least one motor nerve in 66% of subjects with AIDP compared to 9% of subjects with ALS. DCMAP dispersion improved the sensitivity of the four tested criteria sets to 76%-87% from 43%-77%. Moreover, of 13 AIDP patients who met none of the four published criteria sets, 5 (38%) had at least one dispersed DCMAP. These findings indicate that the presence of DCMAP dispersion adds electrodiagnostic sensitivity to the currently published criteria sets, while maintaining reasonably high specificity against a prototypical disorder of the primary motor neuron with axon loss.

Polyradiculonévrites inflammatoires démyélinisantes chroniques : stratégie diagnostique

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.

Different types of chronic inflammatory demyelinating polyneuropathy have a different clinical course and response to treatment

Chronic inflammatory demyelinating polyneuropathy (CIDP) can occur in association with other systemic diseases such as diabetes mellitus (DM) and IgG or IgA monoclonal gammopathy of undetermined significance (MGUS). Whether CIDP that is idiopathic (I-CIDP) or associated with diabetes (CIDP-DM) or MGUS (CIDP-MGUS) differ in clinical presentation, laboratory features, response to treatment, and long-term outcome is unclear, as is the relationship between these coexisting diseases and CIDP. In order to clarify this issue, we began a prospective follow-up study. Thirty-one consecutive patients with untreated CIDP, fulfilling the most restrictive diagnostic criteria, were enrolled over 18 months. Among the patients, 16 were diabetic, 7 had a MGUS, and 8 had an idiopathic CIDP. All patients were treated with IVIg, and the responders were treated again if they relapsed. In all three groups, improvement occurred after treatment. At the end of the follow-up, there was no difference in clinical conditions between groups, but a significant difference existed in the number of relapses and of IVIg administrations. CIDP-DM is a more severe disease, but with a significantly better response to IVIg and fewer relapses, than the other types that we studied.

Optimizing the use of electrophysiology in the diagnosis of chronic inflammatory demyelinating polyneuropathy: a study of 20 cases

Current electrophysiologic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP) are highly specific but poorly sensitive. The required extensiveness and best practical way of performing nerve conduction studies to achieve optimal sensitivity remain unknown. We here initially retrospectively analyzed the motor nerve conduction study results of 20 consecutive patients with a clinical diagnosis of CIDP (four performed prior to, and 16 after, treatment initiation) to assess the sensitivity of six published sets of criteria (Nicolas et al., 2002; Thaisetthawatkul et al., 2002; Ad Hoc Subcommittee of the American Academy of Neurology AIDS Taskforce, 1991; Magda et al., 2003; Hughes et al., 2001; Saperstein et al., 2001), as well as four combinations (Nicolas et al., 2002; Ad Hoc Subcommittee of the American Academy of Neurology AIDS Taskforce, 1991; Hughes et al., 2001; Saperstein et al., 2001, each individually combined with Thaisetthawatkul et al., 2002). Sensitivity was highest for the combination of Nicolas et al. (2002) and Thaisetthawatkul et al. (2002) (100%). We then determined the sensitivity of this combined criteria, using five different, hypothetical, nerve conduction study protocols, applied retrospectively to the neurophysiologic data of our 20 patients (exclusive upper limb studies with proximal stimulations; exclusive lower limb studies; full forearm and foreleg studies without proximal stimulations; right-sided studies with proximal stimulations; and left-sided studies with proximal stimulations). The findings showed that exhaustive upper limb or, alternatively, four-limb forearm and foreleg testing would have proved considerably more sensitive than unilateral or lower limb studies to achieve an electrophysiologic diagnosis of CIDP.

Fatigue as the main presenting symptom of chronic inflammatory demyelinating polyradiculoneuropathy: a study of 11 cases

Fatigue has been shown to be more frequent than previously thought in immune-mediated polyneuropathies. However, fatigue has not been reported as the main cause of referral in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients. Between January 2001 and December 2003, we investigated 11 patients referred for fatigue, for which we established a final diagnosis of CIDP. All patients had at least two clinical examinations including assessment of the fatigue severity scale (FSS) and one electrophysiological and laboratory work up. Additionally, 10 of the 11 patients had a nerve biopsy. There were 11 male patients. Mean age at onset was 53 +/- 11 years. Main cause of referral was fatigue in all patients. Additional symptoms included cramps (one case), distal paresthesias (six cases), limb pain (seven cases) and vasomotor disturbances (one case). Cerebrospinal fluid (CSF) analysis displayed a moderate increase in protein content in four patients. Electrophysiological analysis showed abnormalities in all patients. Among 11 patients, one fulfilled the American Academy of Neurology electrodiagnostic criteria for CIDP and three fulfilled the inflammatory neuropathy cause and treatment group or the Nicolas et al. criteria. In the eight remaining patients, a nerve biopsy confirmed the diagnosis of CIDP. Ten patients were treated, among which seven showed a significant improvement based on the FSS scale. This study shows that fatigue is a possible cause of referral for patients with CIDP and, like previous reports, emphasizes the lack of sensitivity of widely accepted electrophysiological criteria of CIDP. Long-term follow up of these patients is warranted to determine the prognosis of these minimal forms of CIDP and establish the best therapeutic strategy in such cases.

Treatment of immune-mediated, dysimmune neuropathies

This review focuses on the actual status and recent advances in the treatment of immune-mediated neuropathies, including: Guillain-Barre syndrome (GBS) with its subtypes acute inflammatory demyelinating polyradiculoneuropathy, acute motor axonal neuropathy, acute motor and sensory axonal neuropathy, Miller Fisher syndrome, and acute pandysautonomia; chronic inflammatory demyelinating polyneuropathy (CIDP) with its subtypes classical CIDP, CIDP with diabetes, CIDP/monoclonal gammopathy of undetermined significance (MGUS), sensory CIDP, multifocal motor neuropathy (MMN), multifocal acquired demyelinating sensory and motor neuropathy or Lewis-Sumner syndrome, multifocal acquired sensory and motor neuropathy, and distal acquired demyelinating sensory neuropathy; IgM monoclonal gammopathies with its subtypes Waldenstrom's macroglobulinemia, myelin-associated glycoprotein-associated gammopathy, polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes syndrome, mixed cryoglobulinemia, gait ataxia, late-onset polyneuropathy syndrome, and MGUS. Concerning the treatment of GBS, there is no significant difference between intravenous immunoglobulins (IVIG), plasma exchange or plasma exchange followed by IVIG. Because of convenience and absent invasiveness, IVIG are usually preferred. In treating CIDP corticosteroids, IVIG, or plasma exchange are equally effective. Despite the high costs and relative lack of availability, IVIG are preferentially used. For the one-third of patients, who does not respond, other immunosuppressive options are available. In MMN IVIG are the treatment of choice. Inadequate response in 20% of the patients requires adjunctive immunosuppressive therapies. Neuropathies with IgM monoclonal gammopathy may respond to various chemotherapeutic agents, although the long-term effects are unknown. In addition, such treatment may be associated with serious side effects. Recent data support the use of rituximab, a monoclonal antibody against the B-cell surface-membrane-marker CD20.

Pathophysiology inferred from electrodiagnostic nerve tests and classification of polyneuropathies. Suggested guidelines

OBJECTIVE

To present criteria for pathophysiological interpretation of motor and sensory nerve conduction studies and for pathophysiological classification of polyneuropathies suggested by a group of European neurophysiologists.

METHODS

Since 1992 seven neurophysiologists from six European countries have collected random samples of their electrodiagnostic examinations for peer review medical audit in the ESTEEM (European Standardized Telematic tool to Evaluate Electrodiagnostic Methods) project. Based on existing criteria in the literature, the experience with a patient material of 572 peer reviewed electrodiagnostic examinations, and productive discussions between the physicians at workshops, the collaboration has produced a set of criteria now routinely used at the centres involved in the project.

RESULTS

The first part of the paper considers pathophysiology of individual nerve segments. For interpretation of motor and sensory nerve conduction studies, figures showing change in amplitude versus change in conduction velocity/distal latency and change in F-wave frequency versus change in F-wave latency are presented. The suggested boundaries delimit areas corresponding to normal, axonal, demyelinated, or neuropathic nerve segments. Criteria for motor conduction block in upper and lower extremities are schematically depicted using the parameters CMAP amplitude and CMAP duration. The second part of the paper suggests criteria for classification of polyneuropathies into axonal, demyelinating, or mixed using the above-mentioned criteria.

CONCLUSIONS

The suggested criteria are developed during many years of collaboration of different centres and may be useful for standardization in clinical neurophysiology.

SIGNIFICANCE

Consistent interpretation of nerve conduction studies is an important step in optimising diagnosis and treatment of nerve disorders.

Characterization of neuropathies associated with elevated IgM serum levels

BACKGROUND

In contrast to the IgM monoclonal gammopathies the neuropathy associated with polyclonal IgM gammopathy has not been well characterized.

OBJECTIVE

To characterize the neuropathy in patients with elevated serum IgM.

DESIGN

Retrospective review.

SETTING

Academically based neuropathy center.

PATIENTS

45 patients with elevated quantitative immunoglobulin M were identified.

MAIN OUTCOME MEASURES

Patients are described with regard to clinical phenotype, electrodiagnostic features of demyelination or focality, presence of IgM monoclonal gammopathy, and presence of autoantibody activity.

RESULTS

Elevated IgM levels occurred in 45 (11.5%) of 391 patients. Of these, 24 (53%) had polyclonal gammopathy and 21 (47%) had an IgM monoclonal gammopathy. Anti-nerve antibodies occurred in 14/21 (67%) of patients with monoclonal gammopathy, as compared to 1/24 (4%) with polyclonal gammopathy. Clinically, most patients in all groups had a predominantly large fiber sensory neuropathy. Thirty patients underwent electrodiagnostic testing. Of these, 22/30 (73%) fulfilled at least one published criteria for CIDP, including 92% of the monoclonal gammopathy patients and 59% of the polyclonal gammopathy patients. Fifteen of the 30 patients had evidence of focality or multifocality, with 14 of these 15 showing evidence of demyelination.

CONCLUSIONS

Monoclonal and polyclonal IgM patients have similar distributions of neuropathy phenotypes. Neuropathy in association with elevated serum IgM, with or without monoclonal gammopathy or autoantibody activity, is more likely to be demyelinating or multifocal. Serum quantitative IgM level and immunofixation in neuropathy patients may aid in identification of an immune mediated or a demyelinating component.

[The diagnosis of acquired sensory neuropathies]

INTRODUCTION

Peripheral neuropathies usually include a sensory component of various causes. The diagnosis approach requires careful a clinical assessment and a precise electrophysiological exploration.

STATE OF ART

Axonal sensory polyneuropathies are classified according to the type of fibers involved (large or small fibers). While there is a large number of causes, current emphasis is placed on glucose intolerance as a source of small-fiber sensory neuropathies. Demyelinating polyneuropathies are often associated with a monoclonal IgM gammapathy with anti-MAG activity. Multiple sensory mononeuropathies are exceptional and suggest possible early-phase vasculities, sensorymotor neuropathy with conduction blocks or leprosy. Sensory neuronopathies can also suggest Sjögren's syndrome or a paraneoplastic syndrome. Finally chronic sensory polyradiculoneuritis constitute a rare subgroup clearly defined as demyelinating inflammatory neuropathy.

CONCLUSION

The diagnostic approach to sensory neuropathies requires careful nosological electroclinical classification to reduce the number of explorations performed for etiological diagnosis.

Unusual neurophysiological and immunological findings in myasthenia gravis: a case report

We describe the case of a male patient with ocular myasthenia gravis who developed a diabetic neuropathy similar to chronic inflammatory demyelinating polyradiculoneuropathy associated with transient generalized 'myokymic' discharges and distal weakness. He had antibodies against acetylcholine receptor and GQ1b ganglioside, but not anti-voltage-gated K(+) channel antibodies. Serial electrophysiological and immunological findings showed that diabetes was involved in the immune-mediated mechanism of peripheral neuropathy. We hypothesize that the concomitant appearance of distal motor weakness and decreased compound muscle action potentials upon repetitive nerve stimulation, together with increased distal motor latency and generalized peripheral nerve hyperexcitability, were all related to transient serum positivity to anti-GQ1b antibodies.

Electrodiagnostic criteria for acute and chronic inflammatory demyelinating polyradiculoneuropathy

Electrodiagnosis plays an important role in the early detection and characterization of inflammatory demyelinating polyradiculoneuropathies, because timely treatment reduces morbidity and disability. The challenge consists of defining electrodiagnostic criteria that are highly specific for primary demyelination but sufficiently sensitive to be useful in clinical practice. We compared 10 published sets of criteria in 53 patients with demyelinating Guillain-Barré syndrome (GBS) and 28 with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Specificity of criteria sets was tested in 40 patients with amyotrophic lateral sclerosis (ALS) and 32 with diabetic polyneuropathy (DPN). Sensitivity ranged from 24 to 83% (mean, 54.3%) in GBS and 39 to 89% (mean, 64.9%) in CIDP. With regard to ALS, specificity was 100% for nine sets but was 97% in one. In contrast, 3-66% of DPN patients fulfilled criteria in eight of ten sets. We propose a set of criteria with 72% and 75% sensitivity in our GBS and CIDP patient series, respectively, and 100% specificity with regard to ALS and DPN. Our data illustrate that most, but not all, patients can be electrodiagnostically ascertained.

Atypical electrophysiologic findings in chronic inflammatory demyelinating polyneuropathy (CIDP) – diagnosis confirmed by nerve biopsy

OBJECTIVES

Numerous sets of electrophysiological criteria of chronic inflammatory demyelinating polyneuropathy (CIDP) have been proposed, among which the criteria established by an ad hoc subcommittee of the American Academy of Neurology (AAN) in 1991 (Neurology 41 (1991) 617) are the most widely used. As they seemed rather restrictive, the Inflammatory Neuropathy Cause and Treatment (INCAT) group (Ann. Neurol. 50 (2001) 195) proposed modifications of these electrophysiological criteria. However, even using these criteria, some cases of CIDP may not be recognized. In such cases, nerve biopsy has proven useful for confirmation of the diagnosis by demonstrating specific abnormalities. The objective of the study was to determine the profile of electrophysiological abnormalities in patients with atypical electrophysiologic criteria of CIDP and the diagnostic value of multiple A waves and a low median to sural amplitude ratio.

PATIENTS AND METHODS

Over a period of 3 years, we classified 44 patients into two categories: those presenting the strict AAN and/or INCAT criteria and those who we regarded as cases of CIDP not meeting these criteria. All patients benefited from one or more clinical and electrophysiological examination. Extensive biological workup and genetic study when appropriate excluded other causes of neuropathy. Nerve biopsies were taken from all patients and samples were included in paraffin and epon for systematic light, teasing and electron microscopic examination.

RESULTS AND CONCLUSION

Out of 44 patients, 36 fulfilled the INCAT or AAN criteria. In eight other patients, the diagnosis of CIDP was suspected on clinical and EMG examinations and confirmed by nerve biopsy. In these cases, the electrophysiological exploration showed some abnormalities such as multiple A waves in four out of eight patients or an abnormal pattern of the sensory responses of the median and sural nerves in four out of eight patients that were more indicative of an initial demyelinating process. Six of our patients received immunomodulatory treatment, and five responded favorably.

Acquisitions récentes dans le traitement des polyneuropathies dysimmunitaires chroniques

Chronic immune-mediated polyneuropathies encompass chronic inflammatory demyelinating polyneuropathies, polyneuropathies associated with monoclonal gammopathy and multifocal motor neuropathy with persistent conduction blocks. Their diagnosis is made on clinical, electrophysiological and sometimes immunochemical and pathological criteria. The efficacy of intravenous immunoglobulins has been reported in the short-term treatment of these neuropathies in the same way than corticosteroids and plasma exchanges, depending on the type of the polyneuropathy. The efficacy of long-term treatments needs further evaluation.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP): A Review of Clinical Syndromes and Treatment Approaches in Clinical Practice

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic, acquired immune and inflammatory disorder of the peripheral nervous system. The classic form of the disorder is manifested by progressive or relapsing proximal or generalized limb weakness and areflexia, and usually easily recognized; it is the large number of regional and functional variants and variety of associated illnesses that pose a challenge to the clinician in practice. Similarly, laboratory and electromyography criteria have been developed to confirm the diagnosis; however, these various schemes are contrived because only 50% to 60% of patients with typical clinical features of CIDP fulfill these strict electrodiagnostic research criteria. Several studies have established the efficacy of immune therapies such as corticosteroids, plasma exchange, and intravenous immune globulin as the mainstay of treatment of CIDP, but these treatments might provide only short-term benefit. This review offers an approach to the evaluation and management of patients with CIDP and highlights the difficult clinical problems in those who do not respond or frequently relapse after treatment with standard therapies such as patients with CIDP and concomitant axonal loss, and the assessment of those with CIDP and concurrent diseases such as diabetes mellitus.

Electrodiagnostic evaluation of hereditary motor and sensory neuropathies

Electrodiagnosis can classify hereditary motor and sensory neuropathies (HMSN) into two basic types: primarily demyelinating with secondary axonal loss and primarily axonal. For the most part, the various forms of HMSN show uniform symmetric nerve conduction slowing, in contrast to acquired neuropathies, which may be multifocal with nonuniform conduction velocity slowing and temporal dispersion. Nevertheless, there are exceptions. This article reviews the available literature and describes the electrodiagnostic approach to HMSN, detailing potential sources of error that can lead to misinterpretation of data.

Management of chronic inflammatory demyelinating polyradiculoneuropathy

This review briefly describes current concepts concerning the nosological status, pathogenesis and management of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). CIDP is an uncommon variable disorder of unknown but probably autoimmune aetiology. The commonest form of CIDP causes more or less symmetrical progressive or relapsing weakness affecting proximal and distal muscles. Against this background the review describes the short-term responses to corticosteroids, intravenous immunoglobulin (IVIg) and plasma exchange that have been confirmed in randomised trials. In the absence of better evidence about long-term efficacy, corticosteroids or IVIg are usually favoured because of convenience. Benefit following introduction of azathioprine, cyclophosphamide, cyclosporin, other immunosuppressive agents, and interferon-beta and -alpha has been reported but randomised trials are needed to confirm these benefits. In patients with pure motor CIDP and multifocal motor neuropathy, corticosteroids may cause worsening and IVIg is more likely to be effective. General measures to rehabilitate patients and manage symptoms, including foot drop, weak hands, fatigue and pain, are important.

Diagnostic value of nerve biopsy for atypical chronic inflammatory demyelinating polyneuropathy: evaluation of eight cases

The diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) relies primarily on clinical and electrophysiologic examination, but the nerve biopsy findings may be supportive, especially in atypical cases. In order to define the usefulness of nerve biopsy in this disease, we retrospectively studied 44 consecutive patients whom we classified as having CIDP on pathological grounds. We found that 8 of these 44 patients had pathological findings indicative of CIDP but did not meet any of the usually accepted electrophysiological criteria for its diagnosis. Among these eight patients, five responded favorably to conventional therapy. All of these eight patients had an electrophysiological pattern of generalized axonopathy with additional subtle findings suggestive of demyelination that prompted us to perform a nerve biopsy. Our data suggest that a significant number of patients with unrecognized CIDP are erroneously classified as having chronic idiopathic axonal polyneuropathy. CIDP should be suspected if the electrophysiological examination displays subtle abnormalities suggestive of demyelination, even in the presence of a prominent axonal pattern. Nerve biopsy in these patients may reveal abnormalities suggestive of CIDP and guide therapeutic options.

Variation in the classification of polyneuropathies among European physicians

OBJECTIVE

Considerable debate still exists regarding the classification of polyneuropathies (PNPs) into predominantly demyelinating, predominantly axonal loss, mixed or unclassified. This study was designed to determine the variation among physicians in the classification of PNPs by using the European Standardized Telematic tool to Evaluate Electromyography knowledge-based systems and Methods (ESTEEM) multicenter database.

METHODS

Seven physicians from 6 laboratories in Europe sent a total of 156 prospectively collected cases of PNP with electromyography (EMG) data including diagnosis (examination diagnosis) to the database. Each physician interpreted the electrophysiological data from all cases (interpretation diagnosis) and a final diagnosis was given at the consensus meetings of the group (consensus diagnosis).

RESULTS

Comparison of each physician's examination diagnosis with his/her interpretation diagnosis, i.e. intra-physician variation, showed a change towards less classified PNPs (P < 0.05). Interpretation diagnoses showed large inter-physician variation in the classification of PNPs. The consensus group was more cautious than individual physicians in classifying PNPs as mixed and axonal. The probability of the consensus diagnosis increased with increasing number of abnormal motor and sensory segments tested.

CONCLUSIONS

Recognition of variation in classification of PNP as shown in this study and suggesting standards of good clinical practice developed by a consensus group may increase the quality of EMG practice.

Current concepts and controversy in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired, immune-mediated demyelinating neuropathy. It is the most common treatable acquired polyneuropathy and represents a significant number of initially undiagnosed neuropathy patients. This article reviews the common clinical, laboratory, and electrodiagnostic features of CIDP. In addition, current areas of uncertainty are discussed.