Chronic inflammatory demyelinating polyneuropathy

Exogenous Antioxidants in Remyelination and Skeletal Muscle Recovery

Inflammatory, oxidative, and autoimmune responses cause severe damage to the nervous system inducing loss of myelin layers or demyelination. Even though demyelination is not considered a direct cause of skeletal muscle disease there is extensive damage in skeletal muscles following demyelination and impaired innervation. In vitro and in vivo evidence using exogenous antioxidants in models of demyelination is showing improvements in myelin formation alongside skeletal muscle recovery. For instance, exogenous antioxidants such as EGCG stimulate nerve structure maintenance, activation of glial cells, and reduction of oxidative stress. Consequently, this evidence is also showing structural and functional recovery of impaired skeletal muscles due to demyelination. Exogenous antioxidants mostly target inflammatory pathways and stimulate remyelinating mechanisms that seem to induce skeletal muscle regeneration. Therefore, the aim of this review is to describe recent evidence related to the molecular mechanisms in nerve and skeletal muscle regeneration induced by exogenous antioxidants. This will be relevant to identifying further targets to improve treatments of neuromuscular demyelinating diseases.

A case of cauda equina syndrome in early-onset chronic inflammatory demyelinating polyneuropathy clinically similar to charcot-marie-tooth disease type 1

To present a case of cauda equina syndrome (CES) caused by chronic inflammatory demyelinating polyneuropathy (CIDP) which seemed clinically similar to Charcot-Marie-Tooth disease type1 (CMT1). CIDP is an immune-mediated polyneuropathy, either progressive or relapsing-remitting. It is a non-hereditary disorder characterized by symmetrical motor and sensory deficits. Rarely, spinal nerve roots can be involved, leading to CES by hypertrophic cauda equina. A 34-year-old man presented with low back pain, radicular pain, bilateral lower-extremity weakness, urinary incontinence, and constipation. He had had musculoskeletal deformities, such as hammertoes and pes cavus, since age 10. Lumbar spine magnetic resonance imaging showed diffuse thickening of the cauda equina. Electrophysiological testing showed increased distal latency, conduction blocks, temporal dispersion, and severe nerve conduction velocity slowing (3 m/s). We were not able to find genetic mutations at the PMP 22, MPZ, PRX, and EGR2 genes. The pathologic findings of the sural nerve biopsy revealed thinly myelinated nerve fibers with Schwann cells proliferation. We performed a decompressive laminectomy, intravenous IgG (IV-IgG) and oral steroid. At 1 week after surgery, most of his symptoms showed marked improvements except foot deformities. There was no relapse or aggravation of disease for 3 years. We diagnosed the case as an early-onset CIDP with cauda equine syndrome, whose initial clinical findings were similar to those of CMT1, and successfully managed with decompressive laminectomy, IV-IgG and oral steroid.

Impairment of circulating CD4+CD25+ regulatory T cells in patients with chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated peripheral nervous system disease. CD4+CD25+ T regulatory cells (Tregs) have been unequivocally shown to be critical in maintaining immune tolerance and preventing auto-immune diseases by suppressing self-reactive T cells. Thus, we hypothesized that the numbers and/or the function of Tregs would be deranged during the progressive or relapse phases of CIDP. The number of Tregs was determined by flow cytometry according to their characteristic CD4+CD25(high) membrane phenotype. Functional characterization of Tregs was analyzed by suppression of proliferation and secretion of cytokines by co-cultured effector CD4+CD25- T cells. FOXP3 message expression level was assessed by quantitative real-time polymerase chain reaction. The results showed significant reduction in both the number and the suppressive function of Tregs in the patients with CIDP compared with healthy controls. Also, Tregs isolated from CIDP patients expressed lower levels of FoxP3 mRNA. During the progressive or the relapsing phases of CIDP, the number of Tregs was reduced, and the suppressive function of them decreased. These findings may be helpful to our understanding of the possible role of Tregs in the pathogenesis of CIDP.

Anti-MAG/SGPG associated neuropathy does not commonly cause distal nerve temporal dispersion

Patients with anti-myelin associated glycoprotein (anti-MAG) neuropathy have uniform slowing without temporal dispersion, but do usually have disproportionately distal slowing. We evaluated distal compound muscle action potential (CMAP) dispersion in 29 patients with anti-MAG/sulphated glucuronyl paragloboside (SGPG) neuropathy (titres > or = 12,800). Among 138 motor responses, 15% (tibial), 7.3% (peroneal), 10.7% (median) and 13.8% (ulnar) had distal CMAP duration > 9 ms. Disproportionate distal slowing with normal distal CMAP duration in the arms may be useful to differentiate chronic inflammatory demyelinating polyneuropathy from anti-MAG/SGPG associated neuropathy.

Chronic inflammatory demyelinating polyneuropathies: Current treatment strategies

Chronic inflammatory demyelinating polyradiculopathy (CIDP), considered an immune-mediated disease, is likely under-recognized and under-treated due to its heterogeneous presentation and the limitations of clinical, serologic, and electrophysiologic diagnostic criteria. Despite these limitations, early diagnosis and treatment is important in preventing irreversible axonal loss and improving functional recovery. Primary treatment modalities include intravenous immunoglobulin and plasmapheresis, for which there is randomized, double-blind, placebo-controlled evidence. In addition, despite less definitive published evidence of efficacy, corticosteroids are considered standard therapies because of their long history of use. Studies have failed to demonstrate a difference in efficacy among these three treatments; consequently, the choice is usually based on availability and side-effect profile. A number of chemotherapeutic and immunosuppressive agents have also shown to be effective in treating CIDP but significant evidence is lacking; therefore, these agents are primarily used in conjunction with other modalities. Regardless of the treatment choice, long-term therapy is required to maintain a response and prevent relapse.

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.

A review of the medical management of chronic inflammatory demyelinating polyradiculoneuropathy

Chronic idiopathic demyelinating polyradiculoneuropathy (CIDP) is a rare condition, but merits consideration due to its disabling consequences for patients and the growing existence of efficacious therapies during the last few decades. The first step is to characterise this neuropathy among the chronic dysimmune polyneuropathies, according to clinical, electrophysiologicalal and sometimes pathologicalal and immunochemical criteria. Typical CIDP is currently defined by criteria which have progressively improved since the first attempt made by an Ad Hoc Subcommittee of the American Academy of Neurology in 1991. However, CIDP may be associated with several concurrent diseases, and other chronic demyelinating polyneuropathies may be considered as either subtypes of CIDP, such as sensory CIDP and multifocal acquired sensory and motor neuropathy, or frontiers of CIDP, such as multi-focal motor neuropathy and polyneuropathy associated with monoclonal gammopathy. These considerations are helpful in the choice of treatments, as the response to immunomodulatory agents is different according to the type of the dysimmune neuropathy. CIDP is considered to be an immune-mediated disorder and may respond dramatically to numerous short-term therapies, such as corticosteroids, plasma exchanges, or intravenous immunoglobulin. The aim of this review is both to summarise the main results of the published open and randomised controlled trials for CIDP, and to provide some information about randomised controlled trials currently in progress. The objectives of the current and future trials are firstly, to choose the best regimen for short-term treatments, and secondly, to test new immunosuppressants in long-term therapy, if the neurological condition requires it.

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.

Etanercept (Enbrel) therapy for chronic inflammatory demyelinating polyneuropathy

Patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and/or variants who were refractory or intolerant of standard therapies were treated with etanercept, 25 mg twice per week. Ten patients underwent treatment, and manual muscle strength, sensory thresholds and functional abilities were tested prior to and 4-6 months after initiating therapy. Three patients had significant improvement and three others had possible improvement. Based on these preliminary observations, treatment with etanercept may be considered in patients with CIDP, who cannot undergo standard therapies, although its efficacy in CIDP needs to be examined in a double-blinded, controlled clinical trial.

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.

Demyelinating focal motor neuropathy of the ulnar nerve masquerading as compression in Guyon's canal: a case report

Ulnar nerve-innervated intrinsic muscle weakness, in the absence of sensory complaints or deficits, usually is the result of compression at the ulnar nerve in zone II of Guyon's canal. In rare instances the problem is not caused by a compressive neuropathy but by a demyelinating focal motor neuropathy. Demyelinating neuropathies have been well documented in the neurologic literature but they have received little attention in the hand surgery literature. We report on one such case and the importance of differentiating the 2 neuropathies. Although surgery often is necessary for a compressive neuropathy it is contraindicated for a demyelinating neuropathy.

High-dose cyclophosphamide without stem-cell rescue for refractory CIDP

Four patients with chronic inflammatory demyelinating polyneuropathy (CIDP) who were refractory to conventional treatment were treated with high-dose cyclophosphamide (200 mg/kg over 4 days). All improved in functional status and muscle strength. Nerve conduction studies improved in three of four. Other immunomodulatory medications have been discontinued. High-dose cyclophosphamide can be given safely to patients with CIDP and patients with disease persistence after standard therapy may have a response that lasts for over 3 years and results in long-term disease remission.

Proposed revised electrophysiological criteria for chronic inflammatory demyelinating polyradiculoneuropathy

Electrophysiological criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) were proposed by an Ad Hoc Subcommittee of the American Academy of Neurology (AAN) in 1991. Only 60% of CIDP patients fulfilled these criteria, which therefore appear poorly sensitive. We therefore sought to revise the electrophysiological criteria. We selected 40 CIDP patients and compared them with 35 patients with axonal polyneuropathy, 116 patients with Charcot-Marie-Tooth type 1A (CMT1A) disease, and 66 patients with immunoglobulin M (IgM) monoclonal gammopathy. The proposed electrophysiological criteria identified 90% of the CIDP patients, although 3% of patients with axonal polyneuropathy were falsely identified. For the CIDP patients, sensitivity and specificity were 90% and 97%, respectively. Of the patients with IgM monoclonal gammaglobulin of undetermined significance (MGUS) and CMT1A, 100% fulfilled these new criteria, whereas 90% and 97%, respectively, fulfilled the AAN criteria. These results suggest that the AAN criteria are more appropriate for IgM MGUS and CMT1A patients than for CIDP patients. We therefore propose new electrophysiological criteria for CIDP that appear to have better sensitivity.

A surface plasmon resonance biosensor assay for measurement of anti-GM(1) antibodies in neuropathy

OBJECTIVE

To develop a rapid assay for the detection and measurement of anti-GM(1) ganglioside antibodies in patients with neuropathy, using a surface plasmon resonance-based biosensor.

BACKGROUND

Elevated levels of anti-GM(1) ganglioside antibodies are observed in patients with acute and chronic motor neuropathies. Assays for detecting anti-GM(1) antibodies in serum are increasingly being used to help the physician in the evaluation of these patients.

METHODS

Antigens were immobilized by adsorption of GM(1) (active) and GM(2) (control) gangliosides onto a dextran-based sensor chip which is in contact with a flow cell carrying the sample. Interaction of specific antibodies directed against GM(1) with the ganglioside-coated sensor chip caused a change in refractive index at the surface of the chip, which was detected by an optical sensor, using the phenomenon of surface plasmon resonance. Sera from patients and healthy individuals were analyzed by the new assay and results were compared with those from ELISA. Anti-GM(1) antibody isotype was identified by using a secondary antibody.

RESULTS

The binding of anti-GM(1) antibodies to the immobilized GM(1) was observed in real time after reference subtraction of the response from GM(2) control. The response was proportional to antibody concentration. The assay exhibited high specificity for sera from patients with multifocal motor neuropathy and Guillain-Barré syndrome with antibodies against GM(1).

CONCLUSIONS

The surface plasmon resonance biosensor assay offers a rapid system for directly measuring antibody levels in serum without the use of any labels, while comparing favorably with the ELISA system in sensitivity and specificity.

Clinical spectrum of chronic acquired demyelinating polyneuropathies

A number of presentations of chronic demyelinating polyneuropathy have been identified, each distinguished by its phenotypic pattern. In addition to classic chronic inflammatory demyelinating polyneuropathy (CIDP), which is characterized clinically by symmetric proximal and distal weakness and sensory loss, several regional variants can be recognized: multifocal motor neuropathy (MMN: asymmetric and pure motor), multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy (asymmetric, sensory, and motor), and distal acquired demyelinating symmetric (DADS) neuropathy (symmetric, distal, sensory, and motor). There are also temporal, pathological, and disease-associated variants. This review describes a clinical scheme for approaching the chronic acquired demyelinating polyneuropathies that leads to a rational use of supportive laboratory studies and treatment options. In addition, we propose new diagnostic criteria for CIDP that more accurately reflect current clinical practice.

Ganglioside agglutination immunoassay for rapid detection of autoantibodies in immune-mediated neuropathy

Elevated levels of serum autoantibodies directed against gangliosides are closely associated with acute and chronic autoimmune neuropathies. An agglutination immunoassay using polystyrene microparticles coated with a total extract of brain gangliosides was used to test patient sera for the presence of anti-ganglioside antibodies. Results were compared with those obtained by ELISA for anti-GM1 and anti-GQ1b ganglioside antibodies. Eight of the twelve sera from patients with multifocal motor neuropathy and seven of the thirteen sera from patients with Guillain-Barré syndrome were positive for the presence of anti-ganglioside antibodies by the ganglioside agglutination immunoassay. The assay compared favorably with the ELISA system in sensitivity and specificity, while requiring a fraction of the time and cost to perform. The new assay can serve as a rapid and effective method for detecting or screening for anti-ganglioside antibodies in patients with acute or chronic immune-mediated neuropathies. It would be particularly useful for detecting antibodies that react with multiple gangliosides, or with minor or as yet uncharacterized gangliosides.

Chronic Inflammatory Demyelinating Polyneuropathy

Treatment of chronic inflammatory demyelinating polyneuropathy (CIDP) requires long-term immunomodulatory therapy, which has potential side effects. Before such therapy is instituted, a firm diagnosis of CIDP must be established. Prednisone, plasma exchange (PE), and intravenous immunoglobulin (IVIG) are all proven first-line therapies for CIDP that are of similar efficacy. The choice of treatment should be individualized based on costs, availability, and potential adverse effects. Except in the elderly and in those with complicating medical illnesses, IVIG is well tolerated and easy to administer; hence, it should be the initial therapy for most patients with CIDP. Because of its prohibitive costs and limited availability, however, it is not ideal for long-term administration. In the elderly and in those with complicating medical illnesses (eg, diabetes, obesity, or hypertension), PE may be used as the first-line therapy. Because the effects of PE are transient and because it is expensive, requires vascular access, and can only be performed in specialized centers, long-term therapy with PE alone is problematic. Prednisone is inexpensive, easily available, and of proven efficacy. It is the preferred treatment in young, otherwise healthy persons either as a first-line therapy or in association with IVIG or PE. Patients who require repeated treatment with IVIG or PE and cannot tolerate prednisone or those who require high-dose prednisone should be administered azathioprine, cyclosporin A, or cyclophosphamide, usually in combination with one of the first-line therapies.

Recurrent multifocal demyelinating neuropathy with febrile illness and IgG subset deficiency

We describe a unique syndrome of recurrent multifocal demyelinating motor greater than sensory deficits in cranial and peripheral nerve distributions with rapid, spontaneous improvement. Three patients presented with episodes over a period of 7 to 24 years, largely accompanied by febrile illness. Variably decreased IgG1 and IgG3 subclass levels were found. We postulate an immune-mediated process based upon the clinical presentation and presence of decreased IgG subclass levels.

Acute and chronic neuropathies: new aspects of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, an overview and an update

During the last 15 years new information about clinical, electrophysiological, immunological and histopathological features of acute and chronic inflammatory neuropathies have emerged. Thus, the Guillain-Barré syndrome (GBS) is no longer considered a simple entity. Subtypes of the disorder besides the typical predominant motor manifestation, are recognized, i.e. a cranial nerve variant with ophthalmoplegia, ataxia and areflexia, an immune-mediated primary motor axonal neuropathy (AMAN), and a motor-sensory syndrome (AMSAN). Also, the clinical pattern of GBS is related to preceding viral or bacterial infections. Two types of acute motor paralysis have been described, one with slow and incomplete recovery, another with recovery times identical with acute inflammatory demyelinating polyneuropathy (AIDP). Histologically, the first is characterized by Wallerian degeneration of motor roots and peripheral motor nerve fibres. In the latter anti-GM antibodies bind to the nodes of Ranvier producing a failure of impulse transmission. Motor-point biopsies have shown denervated neuromuscular junctions and a reduced number of intramuscular nerve fibres. Molecular mimicry has been postulated as a possible mechanism triggering GBS. Thus, in the cranial variant antibodies to ganglioside GQ1b recognizes similar epitopes on Campylobacter jejuni strains and similar observations apply to anti-GM1 antibodies. Chronic inflammatory demyelinating polyneuropathy (CIDP) also has several different clinical presentations such as a pure motor syndrome, a sensory ataxic variant, a mononeuritis multiplex pattern, relapsing GBS, and a paraparetic subtype. Each of the acute and the subtypes have different, more or less distinct, electrophysiologic and pathological findings. Instructive patient stories are presented together with there electrophysiologic and biopsy findings.

Childhood chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic disorder of the peripheral nervous system with sensory and motor involvement, and insidious onset over a period of months. In children and adults, both proximal and distal muscles are affected. Muscle stretch reflexes are absent or depressed. Laboratory findings include elevated cerebrospinal fluid protein with no increase of mononuclear cells. Electrophysiological and pathological studies show evidence of demyelination. No control studies of the efficacy of immunomodulating therapy in childhood CIDP are available. However, several studies have indicated clinical improvement after treatment with prednisolone, plasmapheresis and intravenous immunoglobulin, but disappointing results with other immunosuppressive agents. While some children have a monophasic course, with complete recovery, others have a protracted course, with either a slowly progressive or a relapsing-remitting course, resulting in prolonged morbidity and disability.