Peripheral neuropathy in osteosclerotic myeloma: clinical and electrodiagnostic improvement with chemotherapy

Pain as a First Manifestation of Paraneoplastic Neuropathies: A Systematic Review and Meta-Analysis

INTRODUCTION

Paraneoplastic neurological syndromes (PNS) consist of a heterogeneous group of neurological disorders triggered by cancer. The aim of this systematic review is to estimate the reported prevalence of pain in patients with paraneoplastic peripheral neuropathy (PPN).

METHODS

A systematic computer-based literature search was conducted on PubMed database.

RESULTS

Our search strategy resulted in the identification of 126 articles. After the eligibility assessment, 45 papers met the inclusion criteria. Full clinical and neurophysiological data were further extracted and involved 92 patients with PPN (54.5% males, mean age 60.0 ± 12.2 years). The commonest first manifestation of PPN is sensory loss (67.4%), followed by pain (41.3%), weakness (22.8%), and sensory ataxia (20.7%). In 13.0% of the cases, pain was the sole first manifestation of the PPN. During the course of the PPN, 57.6% of the patients may experience pain secondary to the neuropathy.

CONCLUSIONS

Pain is very prevalent within PPN. Pain specialists should be aware of this. Detailed history-taking, full clinical examination, and requesting nerve conduction studies might lead to an earlier diagnosis of an underlying malignancy.

Plasma exchange for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon progressive or relapsing paralysing disease caused by inflammation of the peripheral nerves. If the hypothesis that it is due to autoimmunity is correct, removal of autoantibodies in the blood by plasma exchange should be beneficial.

OBJECTIVES

To assess the effects of plasma exchange for treating CIDP.

SEARCH METHODS

On 30 June 2015, we searched the Cochrane Neuromuscular Disease Group Specialized Register, the Cochrane Central Register for Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL Plus, and LILACS. We also scrutinised the bibliographies of the trials, contacted the trial authors and other disease experts, and searched trials registries for ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs in participants of any age comparing plasma exchange with sham treatment or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the trials, extracted the data, and assessed risk of bias. Where possible the review authors combined data according to the methods of the Cochrane Neuromuscular Disease Review Group.

PRIMARY OUTCOME MEASURE

one cross-over trial including 18 participants showed after four weeks, 2 (95% confidence interval (CI) 0.8 to 3.0) points more improvement on an 11-point disability scale with plasma exchange (10 exchanges over four weeks) than with sham exchange. Rapid deterioration after plasma exchange occurred in eight of 12 who had improved.

SECONDARY OUTCOME MEASURES

when we combined the results of this cross-over trial and a trial with 29 participants treated in a parallel-group design, there were 31 points (95% CI 16 to 45) more improvement on an impairment scale (maximum score 280) after plasma exchange (six exchanges over three weeks) than after sham exchange. There were significant improvements in both trials in an electrophysiological measure, the proximally evoked compound muscle action potential, after three or four weeks. Nonrandomised evidence indicates that plasma exchange induces adverse events in 3% to 17% of procedures. These events are sometimes serious. Both trials had a low risk of bias. A trial that showed no significant difference in the benefit between plasma exchange and intravenous immunoglobulin is included in the Cochrane review of intravenous immunoglobulin for this condition.

AUTHORS' CONCLUSIONS

Moderate- to high-quality evidence from two small trials shows that plasma exchange provides significant short-term improvement in disability, clinical impairment, and motor nerve conduction velocity in CIDP but rapid deterioration may occur afterwards. Adverse events related to difficulty with venous access, use of citrate, and haemodynamic changes are not uncommon. We need more research to identify agents that will prolong the beneficial action of plasma exchange.

Plasma exchange for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon progressive or relapsing paralysing disease caused by inflammation of the peripheral nerves. If the hypothesis that it is due to autoimmunity is correct, removal of autoantibodies in the blood by plasma exchange should be beneficial.

OBJECTIVES

To evaluate the efficacy of plasma exchange in CIDP.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (14 May 2012), CENTRAL (2012, Issue 4), MEDLINE (January 1966 to May 2012), EMBASE (January 1980 to May 2012), CINAHL Plus (January 1937 to May 2012) and LILACS (January 1982 to May 2012). We also scrutinised the bibliographies of the trials, and contacted the trial authors and other disease experts.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs in participants of any age comparing plasma exchange with sham treatment or no treatment.

DATA COLLECTION AND ANALYSIS

Two authors selected the trials, extracted the data and assessed risk of bias independently. Where possible data were combined according to the methods of the Cochrane Neuromuscular Disease Review Group.

PRIMARY OUTCOME MEASURE

one cross-over trial including 18 participants showed two (95% confidence interval (CI) 0.8 to 3.0) points more improvement after four weeks on an 11-point disability scale with plasma exchange (10 exchanges over four weeks) than with sham exchange. Rapid deterioration after plasma exchange occurred in eight of 12 who had improved.

SECONDARY OUTCOME MEASURES

when the results of this trial and another with 29 participants treated in a parallel group design trial were combined, there were 31 points (95% CI 16 to 45, maximum score 280) more improvement in an impairment scale after plasma exchange (six exchanges over three weeks) than after sham exchange. There were significant improvements in both trials in an electrophysiological measure, the proximally evoked compound muscle action potential, after three or four weeks. Non-randomised evidence indicates that plasma exchange induces adverse events in 3% to 17% of procedures. These are sometimes serious. A trial showing no significant difference in the benefit between plasma exchange and intravenous immunoglobulin has been included in the Cochrane review of intravenous immunoglobulin for this condition.

AUTHORS' CONCLUSIONS

Moderate to high quality evidence from two small trials showed that plasma exchange provides significant short-term improvement in disability, clinical impairment and motor nerve conduction velocity in CIDP but rapid deterioration may occur afterwards. Adverse events related to difficulty with venous access, use of citrate and haemodynamic changes are not uncommon. More research is needed to identify agents which will prolong the beneficial action of plasma exchange.

Plasma exchange for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy is an uncommon progressive or relapsing paralysing disease caused by inflammation of the peripheral nerves. If the hypothesis that it is due to autoimmunity is correct, removal of autoantibodies in the blood by plasma exchange should be beneficial.

OBJECTIVES

To evaluate the efficacy of plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy.

SEARCH STRATEGY

We searched the Neuromuscular Disease Group Register (December 2003), and MEDLINE (January 1966 to January 2003), EMBASE (January 1980 to January 2003), CINAHL (January 1982 to December 2002) and LILACS (January 1982 to January 2003). We also scrutinised the bibliographies of the trials, and contacted the trial authors and other disease experts.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials in participants of any age comparing plasma exchange with sham treatment or no treatment. A trial showing no significant difference in the benefit from plasma exchange with intravenous immunoglobulin has been included in a separate Cochrane review.

DATA COLLECTION AND ANALYSIS

Two authors selected the trials, extracted the data and assessed methodological quality independently. Where possible data were combined according to the methods of the Cochrane Neuromuscular Disease Review Group.

PRIMARY OUTCOME MEASURE

one crossover trial including 18 participants showed 2 (95% confidence interval (CI) 0.8 to 3.0) points more improvement after four weeks in an 11-point disability scale with plasma exchange (10 exchanges over four weeks) than with sham exchange. Rapid deterioration after plasma exchange occurred in eight of 12 who had improved.

SECONDARY OUTCOME MEASURES

when the results of this trial and another with 29 participants treated in a parallel group design trial were combined, there were 31 points (95% CI 16 to 45) more improvement in an impairment scale after plasma exchange (six exchanges over three weeks) than after sham exchange. There were significant improvements in both trials in an electrophysiological measure, the proximally evoked compound muscle action potential, after three or four weeks. Non-randomised evidence indicates that plasma exchange induces adverse events in 3% to 17% of procedures. These are sometimes serious.

REVIEWERS' CONCLUSIONS

Evidence from two small trials showed that plasma exchange provides significant short-term benefit in about two-thirds of patients with chronic inflammatory demyelinating polyradiculoneuropathy but rapid deterioration may occur afterwards. Adverse events related to difficulty with venous access, use of citrate and haemodynamic changes are not uncommon. More research is needed to identify agents which will prolong the beneficial action of plasma exchange.

Immunotherapy of idiopathic inflammatory neuropathies

Evaluation of peripheral neuropathy is a common reason for referral to a neurologist. Recent advances in immunology have identified an inflammatory component in many neuropathies and have led to treatment trials using agents that attenuate this response. This article reviews the clinical presentation and treatment of the most common subacute inflammatory neuropathies, Guillain-Barré syndrome (GBS) and Fisher syndrome, and describes the lack of response to corticosteroids and the efficacy of treatment with plasma exchange and intravenous immunoglobulin (IVIG). Chronic inflammatory demyelinating polyneuropathy, although sharing some clinical, electrodiagnostic, and pathologic similarities to GBS, improves after treatment with plasma exchange and IVIG and numerous immunomodulatory agents. Controlled trials in multifocal motor neuropathy have shown benefit after treatment with IVIG and cyclophosphamide. Also discussed is the treatment of less common inflammatory neuropathies whose pathophysiology involves monoclonal proteins or antibodies directed against myelin-associated glycoprotein or sulfatide. Little treatment data exist to direct the clinician to proper management of rare inflammatory neuropathies resulting from osteosclerotic myeloma; POEMS syndrome; vasculitis; Sjögren's syndrome; and neoplasia (paraneoplastic neuropathy).

POEMS syndrome: definitions and long-term outcome

The POEMS syndrome (coined to refer to polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) remains poorly understood. Ambiguity exists over the features necessary to establish the diagnosis, treatment efficacy, and prognosis. We identified 99 patients with POEMS syndrome. Minimal criteria were a sensorimotor peripheral neuropathy and evidence of a monoclonal plasmaproliferative disorder. To distinguish POEMS from neuropathy associated with monoclonal gammopathy of undetermined significance, additional criteria were included: a bone lesion, Castleman disease, organomegaly (or lymphadenopathy), endocrinopathy, edema (peripheral edema, ascites, or effusions), and skin changes. The median age at presentation was 51 years; 63% were men. Median survival was 165 months. With the exception of fingernail clubbing (P =.03) and extravascular volume overload (P =.04), no presenting feature, including the number of presenting features, was predictive of survival. Response to therapy (P <.001) was predictive of survival. Pulmonary hypertension, renal failure, thrombotic events, and congestive heart failure were observed and appear to be part of the syndrome. In 18 patients (18%), new disease manifestations developed over time. More than 50% of patients had a response to radiation, and 22% to 50% had responses to prednisone and a combination of melphalan and prednisone, respectively. We conclude that the median survival of patients with POEMS syndrome is 165 months, independent of the number of syndrome features, bone lesions, or plasma cells at diagnosis. Additional features of the syndrome often develop, but the complications of classic multiple myeloma rarely develop.

Crow-Fukase syndrome

Crow-Fukase syndrome is a unique multisystem disorder that is also known as POEMS syndrome (an acronym for polyneuropathy, organomegaly, endocrinopathy, the presence of M-protein and skin change). This syndrome is strongly associated with plasma cell dyscrasia. Circulating light chains of M component, almost invariably IgG lambda or IgA lambda, are found in 75% of patients. Neuropathologically, segmental demyelination, particularly in the proximal segment of the peripheral nerve trunk, is the primary process. Axonal degeneration and marked endoneurial edema are also characteristic. Focal excessive myelin outfolds with globular features corresponding to periodicity and paranodal enlargement of myelin are also highly characteristic of this syndrome. Vascular endothelial growth factor (VEGF) was found to be specifically and highly elevated in the serum of patients with this syndrome, suggesting a pathogenic role. M-protein, interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha are also considered to be involved in the pathogenesis. Treatment consists of radiation and surgical resection of the myeloma, chemotherapy, and a high dose of intravenous immunoglobulin (IVIg).

Rapidly deteriorating polyneuropathy associated with osteosclerotic myeloma responsive to intravenous immunoglobulin and radiotherapy

Osteosclerotic myeloma is a plasma-cell dyscrasia characterized by osteosclerotic bone lesions, which may be associated with progressive demyelinating polyneuropathy. We describe a 49-year-old patient with rapidly deteriorating polyneuropathy associated with osteosclerotic myeloma, who responded favorably to a combination of intravenous immunoglobulin and radiotherapy.

Marked improvement of severe polyneuropathy associated with multifocal osteosclerotic myeloma following surgery, radiation, and chemotherapy

We describe a patient with a 3 year history of progressive polyneuropathy that rendered him severely quadriparetic and bedridden. Work up revealed an IgG lambda monoclonal spike and multifocal osteosclerotic myeloma. Remarkable improvement followed combined treatment with surgical excision, radiation therapy, and chemotherapy using chlorambucil, danazol, and hydrocortisone. Hence, we believe that aggressive local therapy associated with systemic chemotherapy should be considered in severely affected patients with multifocal osteosclerotic myeloma and peripheral neuropathy.

Pathogenesis and therapy of neuropathies associated with monoclonal gammopathies

Approximately 10% of patients with peripheral neuropathy of otherwise unknown etiology have an associated monoclonal gammopathy. Both the neuropathies and the monoclonal gammopathies in these patients are heterogeneous, but several distinct clinical syndromes that may respond to specific therapies can be recognized. It is important to recognize these syndromes because monoclonal gammopathies also occur in 1% of the normal adult population, and in some cases, monoclonal gammopathies are coincidental and unrelated to the neuropathy. In patients with IgM monoclonal gammopathies, IgM M proteins frequently have autoantibody activity and are implicated in the pathogenesis of the neuropathy. IgM M proteins that bind to myelin-associated glycoprotein (MAG) have been shown to cause demyelinating peripheral neuropathy; anti-GM1 antibody activity is associated with predominantly motor neuropathy, and anti-sulfatide or chondroitin sulfate antibodies are associated with sensory neuropathy. The IgM monoclonal gammopathies may be malignant or nonmalignant, and polyclonal antibodies with the same specificities are associated with similar clinical presentations in the absence of monoclonal gammopathy. IgG or IgA monoclonal gammopathies are associated with neuropathy in patients with osteosclerotic myeloma or the POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy myeloma, and skin changes). Amyloidosis or cryoglobulinemic neuropathies can occur with either IgM or IgG and IgA monoclonal gammopathies. Therapeutic intervention depends on the specific clinical syndrome but is generally directed at removing the autoantibodies, reducing the number of monoclonal B cells, and interfering with the effector mechanisms.

POEMS syndrome: a study of 25 cases and a review of the literature. French Study Group on POEMS Syndrome

OBJECTIVE

To determine whether there are peculiarities of the POEMS syndrome (a multisystemic disorder associated with polyneuropathy, organomegaly, endocrinopathy of various forms, production of a monoclonal [M] component, and skin changes) in Caucasian patients, especially signs and symptoms absent in other series; and to attempt a reappraisal of the neuropathy and endocrinopathy to find a unifying mechanism.

DESIGN

A retrospective, cooperative study compared 25 cases, observed over a 15-year period, with two published series of patients, one of Japanese patients and one of American patients, and with a review of the literature on non-Asian cases. Details were obtained of patients' medical history, physical examination, immunochemical and hormonal testing, roentgenographic examination, computed tomography imaging, and electromyography.

RESULTS

The main features of the syndrome found in these patients were those first described in Japan: polyneuropathy, enlargement of the lymph nodes, liver, and spleen, endocrine disturbances, low concentration of the monoclonal component, hyperpigmentation, and hypertrichosis. Three other symptoms were found more frequently than previously reported: skin angiomas, scleroderma changes of the hands, and thrombocytosis. Electromyography and nerve biopsy showed a variety of abnormalities ranging from demyelination to axonal degeneration. Nerve deposits of immunoglobulin were absent. Organomegaly seemed to be heterogeneous. Pathologic findings in the enlarged lymph nodes and spleen were compatible with Castleman's disease. Liver biopsies were usually normal. The endocrine changes were surprisingly diverse, with some observations combining unrelated primary and secondary insufficiencies. No single hypothesis emerged regarding their mechanism. All M components had a lambda-light chain. An IgG M component was found more frequently in solitary lesions. An IgA M component was found more frequently in patients without bone lesions. Sedimentation rate was usually normal. Radiotherapy of solitary plasma-cytomas was followed by dramatic improvement of extramedullary signs and symptoms in all cases.

CONCLUSIONS

The symptoms, clinical course, and management of the patients reported here were similar to those observed in the literature. This study confirms the existence of a close link between symptoms and lambda-light-chain production. There are indications that a plasma cell growth factor that does not cross-react with interleukin-6 (IL-6) may be involved.

The natural history of a "benign" rib lesion in a patient with a demyelinating polyneuropathy and an unusual variant of POEMS syndrome

Patients with POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes) syndrome exhibit great clinical variability and often have osteosclerotic myeloma. We present a patient with an acquired demyelinating polyneuropathy who was eventually diagnosed as having POEMS syndrome. Her long period of observation permitted documentation of the natural history of a plasmacytoma, including its remarkably slow rate of growth and its transformation from a nonsclerotic to a sclerotic bone lesion. Her clinical and laboratory features emphasize the variability of this syndrome. Biopsy of benign-appearing bone lesions should be considered in patients with acquired demyelinating polyneuropathies who do not respond to standard treatment modalities. Serial x-rays may not distinguish benign lesions from plasmacytomas in this treatable condition.

Peripheral neuropathies associated with monoclonal proteins

Peripheral neuropathies associated with monoclonal proteins have received considerable attention as a clinically important group of chronic late-onset neuropathies. When a monoclonal protein is found in patients with peripheral neuropathy of unknown cause, as occurs in 10% of such cases, usually no associated disease is discovered; hence MGUS. Less often, disorders such as multiple myeloma, AL amyloidosis, Waldenström's macroglobulinemia, osteosclerotic myeloma, and lymphoma are found. Demyelinating neuropathies associated with MGUS of all classes, but particularly IgM, Waldenström's macroglobulinemia, and osteosclerotic myeloma typically follow an indolently progressive course, and frequently respond to treatments aimed at interfering with putative underlying immune mechanisms. By contrast, axonal neuropathies associated with MGUS, multiple myeloma, and AL amyloidosis have generally shown no response to therapy. Recently, IgM monoclonal and polyclonal antibodies directed against human peripheral nerve antigens including MAG and various glycolipids such as GM1 ganglioside have been found in patients with specific neuropathy syndromes. Anti-MAG antibodies occur in predominantly sensory demyelinating neuropathies, whereas elevated titers of anti-GM1 ganglioside antibodies are associated with lower motor neuron syndromes with multifocal motor conduction block. Although the evidence for autoimmune mechanisms in some monoclonal protein-associated neuropathies is mounting, a causal connection between monoclonal proteins and these neurologic syndromes has yet to be established.

Polyneuropathy associated with IgA monoclonal gammopathy of undetermined significance

Although polyneuropathies associated with IgM and IgG monoclonal gammopathies have been well described, polyneuropathy with IgA monoclonal gammopathy of undetermined significance (MGUS) is less commonly seen and has not been well studied. We reviewed the clinical and electrodiagnostic features of 5 such patients, and the sural nerve biopsy findings in 4 of them. One patient was diabetic, while 4 were free of other diagnoses commonly associated with neuropathy. Clinical presentations were varied. Electrodiagnostic and histological studies ranged from primary demyelination to primary axon loss to a mixed axonal/demyelinating picture. Three patients who were treated appeared to respond to prednisone or intravenous gamma globulin, despite clear clinical, electrodiagnostic, and histological differences. We conclude that the polyneuropathy associated with IgA MGUS is heterogeneous, similar to that in IgM and IgG MGUS. A trial of immunomodulating therapy appears to be warranted in such patients if the neuropathy is sufficiently severe.

POEMS syndrome with myocardial infarction: observations concerning pathogenesis and review of the literature

A 27-year-old white man with no significant risk factors for coronary artery disease presented with a 9-month history of progressive impotence, gynecomastia, lower extremity paresthesias, and extensive myocardial infarction and subsequently developed ulcerative proctitis. A diagnosis of POEMS syndrome was made based on the clinical presentation; additional physical findings of papilledema, clubbing, and hyperpigmentation; and laboratory findings of an immunoglobulin G M component of the lambda subtype, elevated cerebrospinal fluid protein, and typical sclerotic bone lesions. Abnormal in vitro binding of the patient's serum immunoglobulin to testicular tissue was also seen. Cardiac catheterization showed evidence of diffuse coronary artery narrowing and left ventricular wall motion abnormalities. Diffuse coronary involvement and ulcerative proctitis have not been previously described in POEMS syndrome. It is hypothesized that an abnormal immunoglobin (or fragment) is responsible for both findings. Furthermore, the detection of antitesticular autoantibodies suggests the possibility of an interaction between the antibody and Leydig cells, leading to an alteration in the synthesis and release of sex steroids and thereby explaining the gonadal failure seen in this syndrome. Long-term glucocorticoid therapy for the past 5 years has resulted in marked subjective and objective improvement.

Peripheral neuropathy and multiple myeloma in aging: a case report

A 67-year-old man affected by moderate weight loss, acral paresthesia and plantar burning sensation was admitted to our department. Electromyographic (EMG) and electroneurographic (ENG) studies confirmed a peripheral, asymmetrical, motor-sensorial polyneuropathy (PPN). Hematological data and bone marrow biopsy discovered a non-secerning multiple myeloma (MM). All other probable causes of peripheral neuropathy could be excluded, and the possible relationship between nerve damage and neoplasia was confirmed. Furthermore, all possibilities of association of MM with PPn, namely the osteosclerotic variant, the Crow-Fukase syndrome, and the amyloid one have been evaluated. The only finding of osteolytic bone areas by radiology, the absence of organomegaly, diabetes mellitus, skin alterations, and of amyloid deposition in muscles and nerves, exclude the possible connection of the case to any of the listed possibilities. On the other hand, some clinical aspects differ, in part, to others described in the literature. In conclusion, the association between PPN and MM as the result of multiform clinical variants could be considered.

Prognosis in long-term immunosuppressive treatment of refractory chronic inflammatory demyelinating polyradiculoneuropathy

Treatment of chronic inflammatory demyelinating polyneuropathy (CIDP) frequently includes use of immunosuppressive agents. Controlled treatment trials demonstrating efficacy are available only for prednisone and therapeutic plasma exchange (TPE). When these fail to achieve lasting chemical improvement after reduction or cessation of therapy, subsequent regimens are empiric, often leading to prolonged immunosuppression. It is not possible to predict who will respond to which agent and when. Administered individually, immunosuppressive agents may pose an acceptable risk, but cumulative effects of multiple agents in refractory patients may suppress the immune system and contribute to increased morbidity and mortality. Treatment difficulties with refractory CIDP patients have not been emphasized, and long-term effects of immunosuppression have focused on the risk of malignancy. In reviewing our clinical experience treating over 100 CIDP patients we identified approximately 20 patients who could be considered refractory to multiple immunosuppressive therapies and dependent upon long-term intermittent TPE. Two of these patients exemplify the morbidity associated with CIDP and its associated treatment. Our review of the clinical course of these patients raised issues about the use of multiple immunosuppressive agents, long-term goals, and long-term prognosis in CIDP.

AAEM minimonograph #34: polyneuropathy: classification by nerve conduction studies and electromyography

Electrodiagnostic evaluation of patients with suspected polyneuropathy is useful for detecting and documenting peripheral abnormalities, identifying the predominant pathophysiology, and determining the prognosis for certain disorders. The electrodiagnostic classification of polyneuropathy is associated with morphologic correlates and is based upon determining involvement of sensory and motor fibers and distinguishing between predominantly axon loss and demyelinating lesions. Accurate electrodiagnostic classification leads to a more focused and expedient identification of the etiology of polyneuropathy in clinical situations.

Acquired inflammatory demyelinating polyneuropathies: clinical and electrodiagnostic features

The acquired demyelinating polyneuropathies include acute (AIDP, Guillain-Barré syndrome, GBS) and chronic (CIDP, dysproteinemic) forms which differ primarily in their temporal profile. They are inflammatory-demyelinating diseases of the peripheral nervous system and likely have an immunologic pathogenesis. Although these neuropathies usually have a characteristic presentation, the electromyographer plays a central role in their recognition, since the demyelinating component of the neuropathy, which greatly reduces the differential diagnosis, is often first identified in the electromyography laboratory. In AIDP, the electromyographer, in addition to establishing the diagnosis, can sometimes predict the prognosis. Recognition of the chronic and dysproteinemic forms of acquired demyelinating polyneuropathy is important since they are treatable. The dysproteinemic forms also may be associated with occult systemic disorders that also may require treatment, independent of the neuropathy.

AAEE case report #17: Peripheral neuropathy in monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is the most common paraproteinemia associated with polyneuropathy. Although the clinical and electrodiagnostic manifestations most resemble those of chronic inflammatory demyelinating polyneuropathy, some patients manifest a pure sensory neuropathy or neuronopathy. The M protein is usually IgM, and its concentration in serum is low. Nerve pathology from patients with demyelinating disease shows a reduction of large myelinated fibers and segmental demyelination with remyelination. In some cases, the M protein possesses antibody activity against components of the myelin sheath or axon. These neuropathies may respond to treatment with steroids, immunosuppressant agents, and plasma exchange.

Successful treatment of peripheral neuropathy with chemotherapy in osteosclerotic myeloma

A patient with a severe polyneuropathy in association with osteosclerotic myeloma improved after melphalan and prednisone treatment. Aggressive treatment with chemotherapy is appropriate in this type of patient.

Peripheral neuropathies associated with monoclonal proteins: a clinical review

Over the last decade, the increasing use of serum and urine protein electrophoretic screening of patients with idiopathic peripheral neuropathy has led to greater recognition of peripheral neuropathy syndromes that are associated with monoclonal proteins and plasma cell dycrasias. After careful evaluation, most of these patients have benign monoclonal gammopathy, followed in frequency by primary systemic amyloidosis and osteosclerotic myeloma, with occasional cases associated with osteolytic multiple myeloma, Waldenstrom's macroglobulinemia, gamma heavy chain disease, and other rare disorders. Several of these syndromes have distinctive presentations and are recognizable clinically, whereas others (especially multiple myeloma neuropathy) are diverse clinically and are not clearly distinguishable from other chronic neuropathies. The discovery of IgM-kappa monoclonal proteins directed at myelin antigens in some patients with benign monoclonal gammopathy and the delineation of the syndrome of neuropathy and multiorgan involvement in osteosclerotic myeloma are important developments which may shed light on the mechanism of the remote effects of malignancies on the nervous system.