Neuromuscular complications of connective tissue diseases

Peripheral Neuropathy in Systemic Autoimmune Rheumatic Diseases-Diagnosis and Treatment

Peripheral neuropathy (PN) is frequently observed in systemic rheumatic diseases and is a challenge in clinical practice. We aimed to review the evidence on the subject and proposed a comprehensive approach to these patients, facilitating diagnosis and management. We searched the MEDLINE database for the terms (and its respective Medical Subject Headings (MeSH) terms): "peripheral neuropathy" AND "rheumatic diseases" OR "systemic lupus erythematosus", "rheumatoid arthritis", "Sjogren syndrome", and "vasculitis" from 2000 to 2023. This literature review focuses on the diagnostic workup of PNs related to systemic lupus erythematosus, Sjögren's syndrome, rheumatoid arthritis, and systemic vasculitis. For every type of PN, we provide a pragmatic flowchart for diagnosis and also describe evidence-based strategies of treatment.

Peripheral nervous system manifestations of rheumatological diseases

Rheumatological diseases result in immune-mediated injury to not only connective tissue, but often components of the peripheral nervous system. These overlap conditions can be broadly categorized as peripheral neuropathies and overlap myositis. The peripheral neuropathies are distinctive as many have unusual presentations such as non-length-dependent, small fiber neuropathies and sensory neuronopathies (both due to dorsal root ganglia dysfunction), multiple mononeuropathies (e.g. vasculitic neuropathies), and even cranial neuropathies. Overlap myositis is increasingly recognized and is often associated with specific autoantibodies. Sarcoidosis also has widespread neurological manifestations and impacts both the peripheral nerves and muscle. Much work is needed to fully characterize the vast presentations of these overlap diseases. Given the rarity of these disorders, they are understudied, resulting in significant knowledge gaps with regards to their underlying pathophysiology and the best treatment approach. A basic knowledge of these disorders is mandatory for both practicing rheumatologists and neurologists as prompt recognition and early initiation of immunotherapy may prevent significant morbidity and permanent disability.

Peripheral neuropathies in rheumatic diseases: More diverse and frequent than expected. A cross-sectional study

BACKGROUND/OBJECTIVE

Peripheral neuropathies (PN) are heterogeneous nerve disorders; frequently rheumatic patients have neuropathic symptoms. In some rheumatic diseases (RD) PN are secondary to nerve compression while others are related to metabolic abnormalities, inflammation or vasculitis. Our aim was to explore the frequency of neuropathic symptoms with three neuropathy questionnaires (NQ) and nerve conduction studies (NCS) in RD.

METHODS

This is a cross-sectional study in patients with any RD attending for the first time to a rheumatology outpatient clinic. We included all patients who accepted to participate and who answered three NQ and received a physical evaluation. Twenty patients were randomly selected to perform NCS and 10 healthy subjects were included as controls. The topographic diagnoses were: mononeuropathy, multiplex mononeuropathy, and/or polyneuropathy.

STATISTICAL ANALYSIS

descriptive statistics (mean, median, standard deviation, interquartile range and frequency, odds ratios and Pearson correlation test).

RESULTS

One hundred patients and 10 healthy subjects were included. Sixty-nine were female, mean age 40.6 ± 15.7 years. Rheumatic diagnoses were: systemic lupus erythematosus (26%), rheumatoid arthritis (16%), gout (14%), and osteoarthritis (11%). Fifty-two patients had neuropathic signs during physical examination and 67% had positive questionnaires with variable scores among several RD. Abnormal NCS was reported in 14 patients (70%): 6 (42.8%) median nerve mononeuropathies, 4 (28.5%) multiplex mononeuropathies and 4 (28.5%) polyneuropathies. None of the healthy subjects had neuropathy (NQ, physical evaluation, or NCS). Risk of being NCS positive is higher when the patients were NQ positive.

CONCLUSION

PN has variable distribution and high frequency in patients with RD; NQ+ increases the risk of presenting NCS+ for PN.

Vasculitis in the Central Nervous System

Central nervous system (CNS) vasculitides are a heterogeneous group of disorders characterized by an inflammatory cell infiltration and necrosis of blood vessel walls in the brain, spinal cord, and the meninges. The CNS complications are likely to be fatal without judicious use of immunosuppression; thus, early diagnosis may prevent from damage and disability. This chapter updates our knowledge on CNS vasculitis-related immunological mechanisms, neurological complications, diagnosis, and management.

Peripheral nervous system involvement in systemic lupus erythematosus: Prevalence, clinical and immunological characteristics, treatment and outcome of a large cohort from a single centre

Disorders of peripheral nervous system in patients with systemic lupus erythematosus (PNS-SLE) are a major cause of morbidity. The aims of the present study were to determine the prevalence of PNS-SLE involvement in a large cohort of SLE patients from a single centre, to characterize such involvement, treatment modalities and outcome, and to identify the possible variables that may be associated with its presence. We performed an observational cross-sectional study that included all SLE patients being followed in our department between March and December 2015 who met at least one of the PNS-SLE case definitions proposed in 1999 by the American College of Rheumatology. Overall, 93 out of 524 (17,7%) patients presented with PNS-SLE syndrome; 90 (96.8%) of them were women with a mean age at PNS-SLE syndrome diagnosis was 44.8±14.1years and the average time from diagnosis of SLE to PNS-SLE diagnosis was 88 (range, 541-400) months. The most frequent manifestation was polyneuropathy (36.6%), followed by non-compression mononeuropathy (23.7%), cranial neuropathy and myasthenia gravis (7.5%, each), and Guillain-Barré syndrome (1.1%). The most frequent electrodiagnostic tests (EDX) pattern was axonal degeneration, present in 49 patients that corresponded to 80.3% of the overall EDX patterns. Mixed sensory-motor neuropathy was the most common type of involvement accounted for 56% of cases. Thirty-six out of 90 (40%) received glucocorticoids and/or immunosuppressant agents. Overall, global response (complete and/or partial) to treatments was achieved in 77.4% of patients without differences between the types of PNS-SLE involvement. Older age at SLE diagnosis (37.3±14.8 versus 30.8±12; p=0.001) and absence of hematologic involvement as cumulative SLE manifestation (11.8% versus 21.5%; p=0.034) had independent statistical significant associations with PNS-SLE development. The PNS-SLE involvement is not uncommon. Its most frequent manifestation is sensory-motor axonal polyneuropathy. The involvement occurs more frequently in patients who are diagnosed with SLE at older age. Prospective studies are needed to establish the incidence of PNS-SLE syndromes and the role of hematological manifestations in their development.

An update of neurological manifestations of vasculitides and connective tissue diseases: a literature review

Vasculitides comprise a heterogeneous group of autoimmune disorders, occurring as primary or secondary to a broad variety of systemic infectious, malignant or connective tissue diseases. The latter occur more often but their pathogenic mechanisms have not been fully established. Frequent and varied central and peripheral nervous system complications occur in vasculitides and connective tissue diseases. In many cases, the neurological disorders have an atypical clinical course or even an early onset, and the healthcare professionals should be aware of them. The purpose of this brief review was to give an update of the main neurological disorders of common vasculitis and connective tissue diseases, aiming at accurate diagnosis and management, with an emphasis on pathophysiologic mechanisms.

Brachial Neuritis With Phrenic Nerve Involvement in a Patient With a Possible Connective Tissue Disease

Background. Brachial neuritis (BN) is a rare inflammatory condition of peripheral nerves, usually involving the cervicobrachial plexus. These patients present with sudden onset of shoulder and arm pain that evolves into muscle weakness and atrophy.. Case Report. A 33-year-old woman presented with a 1-month history of diffuse pain in her thorax. She had no trauma or inciting incident prior to the onset of this pain and was initially treated for muscle spasms. The patient was seen in the emergency room multiple times and was treated with several courses of antibiotics for pneumonia on the basis of clinical symptoms and abnormal x-rays. The pleuritic chest pain persisted for at least 4 months, and the patient was eventually admitted for worsening pain and dyspnea. On physical examination, crackles were heard at both lung bases, and chest inspection revealed increased expansion in the upper thorax but poor expansion of the lower thorax and mild paradoxical respiration. “Sniff” test revealed no motion of the left hemidiaphragm and reduced motion on the right hemidiaphragm. Her computed tomography scan revealed bilateral atelectasis, more severe at the left base. She reported no symptoms involving her joints or skin or abdomen. Her presentation and clinical course are best explained by BN with a bilateral diaphragmatic weakness. However, she had a positive ANA, RF, anti-RNP antibody, and anti SS-A. Conclusion. Patients with BN can present with diffuse thoracic pain, pleuritic chest pain, and diaphragmatic weakness. Our patient may represent a case of connective tissue disease presenting with brachial plexus neuritis.

Vasculitic neuropathies

The vasculitic neuropathies are a diverse group of disorders characterised by the acute-to-subacute onset of painful sensory and motor deficits that result from inflammatory destruction of nerve blood vessels and subsequent ischaemic injury. They are common in patients with primary systemic vasculitis and are seen in vasculitis secondary to disorders such as rheumatoid arthritis, viral infections, and diabetic inflammatory neuropathies. It is imperative that neurologists recognise these disorders to initiate treatment promptly and thereby prevent morbidity and mortality. To simplify the approach to patients with vasculitis of the peripheral nerves, a straightforward, dichotomous classification scheme can be used in which the vasculitic neuropathies are divided into two groups-nerve large arteriole vasculitis and nerve microvasculitis-on the basis of the size of the involved vessels. The size of the affected blood vessels correlates with the clinical course and prognosis in patients with vasculitic neuropathy.

Peripheral neuropathy: clinical and electrophysiological considerations

This article is a primer on the pathophysiology and clinical evaluation of peripheral neuropathy for the radiologist. Magnetic resonance neurography has utility in the diagnosis of many focal peripheral nerve lesions. When combined with history, examination, electrophysiology, and laboratory data, future advancements in high-field magnetic resonance neurography may play an increasingly important role in the evaluation of patients with peripheral neuropathy.

Vasculitic neuropathy

Vasculitis is a primary phenomenon in autoimmune diseases such as polyarteritis nodosa, Wegener's granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, and essential mixed cryoglobulinemia. As a secondary feature vasculitis may complicate, for example, connective tissue diseases, infections, malignancies, and diabetes. Vasculitic neuropathy is a consequence of destruction of the vessel wall and occlusion of the vessel lumen of small epineurial arteries. Sometimes patients present with nonsystemic vasculitic neuropathy, i.e., vasculitis limited to peripheral nerves and muscles with no evidence of further systemic involvement. Treatment with corticosteroids, sometimes in combination with other immunosuppressants, is required to control the inflammatory process and prevent further ischemic nerve damage.

Mononeuropathy multiplex in sickle cell disease: a complication in need of recognition

Peripheral nervous system involvement is rare in sickle cell disease. A review of the literature has uncovered only a few reports of nerve deficit in association with sickle cell disease, and often a clear relationship between the neuropathy and the anemia is absent. Mononeuropathy resulting from peripheral nerve infarction, as a complication of sickle vaso-occlusive crisis, seemingly is uncommon and, to our knowledge, has been reported only once. We report two patients who developed acute mononeuropathy multiplex in the setting of sickle cell pain crisis. The clinical and electrodiagnostic findings were consistent with a multifocal nerve disorder resulting from an ischemic process caused by a sickle cell vaso-occlusive crisis. We describe the clinical course, electrophysiological findings, diagnosis, and management of these patients. We also analyze the anatomic and pathophysiological basis of this disorder and offer a possible clinical explanation for its infrequent and exceptional diagnosis.

Peripheral neuropathy in patients with systemic lupus erythematosus

OBJECTIVE

In patients with systemic lupus erythematosus (SLE), to determine 1) the prevalence and clinical features of peripheral neuropathies (PN) and whether they were SLE related, 2) whether there are associations between other SLE features and PN.

METHODS

Patients who met the American College of Rheumatology case definition criteria for SLE peripheral neuropsychiatric syndromes were selected from the University of Toronto Lupus Clinic database. Demographic data and SLE-related clinical and laboratory data were extracted. Health-related quality of life was assessed using the mental and physical component summary score of the SF-36 questionnaire. In a nested case-control study, SLE patients with PN were matched by disease duration and compared with those without PN.

RESULTS

Of 1533 patients in the database, 207 (14%) had PN. Of these, 40% were non-SLE-related. Polyneuropathy was diagnosed in 56%, mononeuritis multiplex in 9%, cranial neuropathy in 13%, and mononeuropathy in 11% of patients. Asymmetric presentation was most common (59%) and distal weakness occurred in 34%. Electrophysiologic studies indicated axonal neuropathy in 70% and signs of demyelination in 20% of patients. Compared with patients without PN, those with PN had significantly more central nervous system involvement, higher SLE-disease activity index 2000 and lower SF-36-PCS.

CONCLUSIONS

The prevalence of PN is relatively high in SLE and occurs more frequently in patients with central nervous system involvement and high SLE-disease activity index. There is a predilection for asymmetric and lower extremities involvement, especially peroneal and sural nerves. This manifestation of the disease has a significant impact on the patient's quality of life.

Ataxic sensory neuronopathy in a patient with systemic lupus erythematosus

The occurrence of ataxic sensory neuronopathy (ASN) is rare in patients with connective tissue diseases (CTDs). ASN has been described in case reports and case series in patients with CTDs, mostly Sjögren's syndrome, and most often occurring during middle or old age. ASN in association with systemic lupus erythematosus (SLE) is extremely rare; there has been only one reported case in the literature. In addition, to our knowledge, adolescent onset of symptoms in CTD-associated ASN has not been reported previously. We report the case of a young woman who presented with ASN, characterized by sensory ataxia, with elevated antinuclear antibodies, leukopenia and anemia; she fulfilled the diagnostic criteria for SLE about 7 years after the onset of sensory ataxia. Our case points out that ASN may be the initial presenting feature of SLE. SLE should be included in the differential diagnosis of ASN, especially in patients of young age.

Peripheral neuropathy in patients with primary antiphospholipid (Hughes') syndrome

The involvement of the peripheral nervous system in diverse autoimmune diseases is well established. However, no appropriately designed studies have been performed in primary antiphospholipid syndrome (PAPS)-related peripheral neuropathy. We aimed to investigate the occurrence of peripheral neuropathy in patients diagnosed with PAPS. Twenty-six consecutive patients with PAPS (Sapporo criteria) and 20 age- and gender-matched healthy controls were enrolled at two referral centers. Exclusion criteria were secondary causes of peripheral neuropathy. A complete clinical neurologic exam followed by nerve conduction studies (NCS) was performed. Paresthesias were reported in eight patients (31%). Objective mild distal weakness and abnormal symmetric deep tendon reflexes were observed in three patients (11.5%). With regard to the electrophysiologic evidence of peripheral neuropathy, nine patients (35.0%) had alterations: four (15.5%) had pure sensory or sensorimotor distal axonal neuropathy (in two of them a carpal tunnel syndrome was also present) and one (4%) had sensorimotor demyelinating and axonal neuropathy involving upper and lower extremities, while four patients (15.5%) showed isolated carpal tunnel syndrome. Clinical and serologic results were similar in all the patients with PAPS, regardless of the presence of electrophysiologic alterations. In conclusion, peripheral neuropathy is a common asymptomatic abnormality in patients with PAPS. The routine performance of NCS may be considered when evaluating such patients.

Not all neuropathy in diabetes is of diabetic etiology: differential diagnosis of diabetic neuropathy

Diabetic peripheral neuropathy is the most common peripheral neuropathy in the developed world; however, not all patients with diabetes and peripheral nerve disease have a peripheral neuropathy caused by diabetes. Several (although not all) studies have drawn attention to the presence of other potential causes of a neuropathy in individuals with diabetes; 10% to 50% of individuals with diabetes may have an additional potential cause of a peripheral neuropathy and some may have more than one cause. Neurotoxic medications, alcohol abuse, vitamin B(12) deficiency, renal disease, chronic inflammatory demyelinating neuropathy, inherited neuropathy, and vasculitis are the most common additional potential causes of a peripheral neuropathy in these series. The most common disorders in the differential diagnosis of a generalized diabetic peripheral neuropathy are discussed in this article. Prospective studies to investigate the prevalence of other disorders that might be responsible for a peripheral neuropathy in individuals with diabetes are warranted.

Assessment of recovery from burn-related neuropathy by electrodiagnostic testing

The purpose of this study was to investigate the recovery of burn-related neuropathies by electrodiagnostic testing. Burn patients who presented to an American Burn Association verified burn center were interviewed and examined for clinical evidence of peripheral neuropathies by a physiatrist. Patients whom consented to participate were tested for electrodiagnostic evidence of peripheral neuropathy. Repeated studies were performed to assess for evidence of recovery. A total of 370 patients were screened. Thirty-six (9.73%) patients had clinical evidence of neuropathy. Eighteen male patients with a mean TBSA burn of 42% had nerve conduction studies performed. Etiologies of the injuries included eight flame, eight electrical, and three others. Seventy-three nerve conduction studies were performed and 58 of the tests were abnormal. The most commonly affected nerve was the median sensory (10). For patients with repeated tests, the mean time between tests was 169 days (SD, 140 days). There was a significant difference between the initial and follow-up test (McNemar's change test P=.009). In subset analysis of motor and sensory abnormalities, there was no significant difference (P=.07). The most common neuropathy identified in this cohort was the median sensory. Overall, there was improvement in the nerve conduction abnormalities examined. This study suggests that the prognosis for recovery after burn-related neuropathy is good.

Psoriatic arthritis-associated polyneuropathy: a report of three cases

Psoriatic arthritis (PA) occurs in about 30% of patients with psoriasis. Although polyneuropathy is described in association with many connective tissue diseases, it is rarely reported in the autoimmune dermatoses. We describe 3 patients with polyneuropathy associated with PA. The clinical and electrophysiologic features are consistent with a chronic distal symmetric sensorimotor axonal process. PA-associated neuropathy should be considered in the differential diagnosis of chronic length-dependent axonal polyneuropathies.

Vasculitic Neuropathies

The classification of vasculitis and the clinical features of vasculitic neuropathy are reviewed. Vasculitic neuropathy usually presents with painful mononeuropathies or an asymmetric polyneuropathy of acute or subacute onset. Neurologists should categorize vasculitic neuropathy in terms of clinical features (eg, systemic or non systemic) and in terms of histopathology (eg, nerve large arteriole vasculitis or nerve microvasculitis). Systemic vasculitis should be classified further into one of the primary and secondary forms. Steroids and cytotoxic agents have been the mainstay of therapy for most forms of vasculitic neuropathy. Dosing, potential side effects, and management recommendations of conventional therapies are provided.

Immunosuppressive treatment for non-systemic vasculitic neuropathy

BACKGROUND

Non-systemic vasculitic neuropathy is a rare disabling disease that usually has a subacute onset of progressive or relapsing-remitting sensory or sensorimotor deficits. Asymmetry, pain and weakness are key features. The diagnosis can only be made by exclusion of other causes, the absence of systemic vasculitis or other rheumatic diseases, and the demonstration of vasculitis in a nerve or a combined nerve and muscle biopsy. There is a need for efficacious therapy to prevent disease progression and to improve prognosis.

OBJECTIVES

To assess if immunosuppressive treatment in non-systemic vasculitic neuropathy reduces disability, and ameliorates neurological symptoms, and if such therapy can be given safely.

SEARCH STRATEGY

The Cochrane Neuromuscular Disease Group Trials Register (March 2006), The Cochrane Library (Issue 1, 2006), MEDLINE, EMBASE, LILACS, and ISI were searched from January 1980 until April 2006. In addition, the reference lists of relevant articles, reviews and textbooks were handsearched.

SELECTION CRITERIA

All randomised or quasi-randomised trials that examined the efficacy of immunosuppressive treatment for non-systemic vasculitic neuropathy at least one year after the onset of therapy were sought. Participants had to fulfill the following criteria: absence of systemic or neurological disease, exclusion of any recognised cause of the neuropathy by appropriate clinical or laboratory investigations, electrophysiological studies in agreement with axonal neuropathy, confirmation of vasculitis in a nerve or a combined nerve and muscle biopsy. The primary outcome measure was to be improvement in disability. Secondary outcome measures were to be change in the mean disability score, change in muscle strength measured with the Medical Research Council sum score, change in pain or other positive sensory symptoms, number of relapses, and adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed and extracted details of all potentially relevant trials. For included studies pooled relative risks and pooled weighted standardised mean differences were to be calculated to assess treatment efficacy.

MAIN RESULTS

Fifty-nine studies were identified and assessed for possible inclusion in the review, but all were excluded because of insufficient quality or lack of relevance.

AUTHORS' CONCLUSIONS

No adequate randomised or quasi-randomised controlled clinical trials have been performed on which to base treatment for non-systemic vasculitic neuropathy. Randomised trials of corticosteroids and other immunosuppressive agents are needed.

Neuropathie périphérique au cours du lupus érythémateux disséminé avec vascularite épineurale et anticorps antiphospholipides

Neurological manifestations of systemic lupus erythematosus are frequent and polymorphic. Their frequency varies according to authors (24-75p.cent). Central nervous system complications predominate; peripheral features are rare, classically symmetrical polyneuropathy, multiple mononeuropathies or cranial nerve involvement. We report a case of a 48-year-old woman presenting a histologically documented sensitivo-motor polyneuropathy with severe motor involvement complicating lupus associated with antiphospholipides antibodies. Outcome was good after cyclophosphamid pulse. We discuss the frequency of peripheral involvement in systemic lupus erythematosus, pathogenic mechanisms, therapeutic possibilities and outcome of this complication.

Vasculitic Neuropathies

BACKGROUND

Systemic vasculitis has been classically categorized as a primary disorder, such as polyarteritis nodosa, Churg-Strauss syndrome, and Wegener granulomatous, or as a secondary process, representing a complication from a connective tissue disorder (eg, rheumatoid vasculitis), infection, medication, or malignancy. Peripheral neuropathy is a well-recognized consequence of systemic vasculitis due to peripheral nerve infarction with Wallerian degeneration. Rarely, neuropathy is the sole manifestation of vasculitis, referred to as nonsystemic vasculitic neuropathy (NSVN). These conditions are defined pathologically by tissue biopsy demonstrating disruption or destruction of the vessel wall with inflammatory cell infiltrates.

REVIEW SUMMARY

The diagnosis of vasculitic neuropathy is straightforward in patients with an established diagnosis of systemic vasculitis and classic features of mononeuritis multiplex. Most patients have clinical features of a subacute, progressive, generalized but asymmetric, painful, sensorimotor polyneuropathy. Laboratory tests often indicate features of systemic inflammation, such as an elevated sedimentation rate or positive anti-neutrophil cytoplasmic antibody, and electrodiagnostic evaluation shows multiple mononeuropathies or a confluent, asymmetric axonal neuropathy. Nerve biopsy is necessary to establish the diagnosis in most cases, particularly in patients with NSVN. This review summarizes the current treatment of vasculitic neuropathy.

CONCLUSION

Long-term immunosuppressive therapy is required in most cases. High-dose prednisone combined with intravenous pulse or oral daily cyclophosphamide is standard initial therapy. In those with NSVN, cyclophosphamide also should be used if prednisone monotherapy is ineffective or the patient relapses with tapering. Other agents, such as azathioprine, methotrexate, intravenous immunoglobulin, mycophenolate mofetil, plasma exchange, and rituximab can be offered to patients who are intolerant or have a contraindication to cyclophosphamide. However, evidence for the benefit of these agents is limited to case reports and small case series.

Peripheral nervous system lesion syndromes and the mechanisms of their formation in connective tissue diseases

Systemic rheumatological diseases are often accompanied by the development of central and peripheral nervous system pathology. Data providing evidence of the high incidence of peripheral nervous system lesions in systemic lupus erythematosus and systemic scleroderma are presented. These diseases in particular are characterized by polyneuropathies and tunnel syndromes. Our own observations, along with published data, revealed the following major pathogenetic mechanisms of peripheral nervous system lesions in diffuse connective tissue diseases - ischemic, immunological, and metabolic. Consideration of these mechanisms will lead to pathogenetically based treatment and improved therapeutic outcomes.

Auditory neuropathy in systemic sclerosis: a speech perception and evoked potential study before and after cochlear implantation

We report the results of speech perception and electrophysiological evaluation of the auditory periphery performed before and after cochlear implantation in a 18-year-old girl with systemic sclerosis (SS) who presented the clinical picture of auditory neuropathy. Transtympanic electrocochleography (ECochG) in response to 0.1 ms clicks was recorded 1 month before cochlear implantation on both sides while the electrically evoked neural response was obtained intraoperatively in the right ear through cochlear implant stimulation. The ECochG recordings revealed the presence of the cochlear microphonic with normal amplitude and threshold on both sides. A compound action potential was only detected in the left ear at high stimulation intensity, while the electrically evoked neural response was clearly identifiable at all the recording sites during neural response telemetry. Standardized speech perception tests were performed 1 month before cochlear implantation and several times after cochlear implant connection. Speech perception scores were close to chance before cochlear implantation while they showed a remarkable improvement thereafter. The results of this study show that subjects affected by SS could present the clinical picture of auditory neuropathy which is possibly underlain by lesions involving the distal portion of auditory nerve fibers and/or synapses with inner hair cells. The restoration of synchronous neural discharge could be achieved by electrical stimulation through cochlear implant.

Therapy for vasculitic neuropathies

The term vasculitis refers to a pathologic condition defined by inflammatory cell infiltration and destruction of blood vessels. Systemic vasculitis is classified as primary (eg, polyarteritis nodosa, Churg-Strauss syndrome) or secondary, the latter associated with connective tissue disorders, infections, medications, and rarely, as a paraneoplastic phenomenon. Neuropathy is a common complication of systemic vasculitis and is related to ischemic nerve fiber damage with axon loss. Peripheral neuropathy may be the sole manifestation of vasculitis, a condition termed nonsystemic vasculitic neuropathy (NSVN). Treatment of vasculitic neuropathy requires long-term immunosuppressive therapies with potential side effects. The diagnosis of vasculitis should be established by tissue (preferably nerve) biopsy. High-dose prednisone is the standard platform therapy for patients with systemic and NSVN; for those with systemic vasculitis, at least 3 to 12 months of treatment with cyclophosphamide (monthly intravenous pulse or daily oral therapy) is also necessary to sustain remission and allow successful prednisone tapering. The use of cyclophosphamide in patients with NSVN is controversial, but recent retrospective data suggest that those treated with prednisone and cyclophosphamide from the outset fare better than those initially treated only with prednisone. If prednisone is administered as monotherapy, cyclophosphamide should be added after several months if there is no improvement or relapse occurs with tapering of prednisone. Intravenous pulse and daily oral cyclophosphamide probably offer similar efficacy, although the risk of complications is greater with oral therapy. Azathioprine can be safely substituted for cyclophosphamide after 3 months without an increased relapse rate. Azathioprine, methotrexate, intravenous immune globulin, mycophenolate mofetil, plasma exchange, and rituximab can be offered to patients who are intolerant or have a contraindication to cyclophosphamide. However, efficacy is unproven for any of these therapies. Interferon-alpha, sometimes combined with plasma exchange, is used to treat vasculitis associated with hepatitis B infection. Some patients also may improve with corticosteroids. The classification of diabetic lumbosacral radiculoplexus neuropathy as a vasculitic disorder remains controversial. However, there is compelling pathological evidence that this condition represents a T-cell-mediated microvasculitis. Some patients treated with intravenous corticosteroids may have greater recovery and improved pain control.

Chronic progressive sensory ataxic neuropathy associated with limited systemic sclerosis

We report the case of a 33-year-old woman with limited systemic sclerosis and chronic progressive sensory ataxic neuropathy. Sural nerve biopsy showed loss of myelinated fibers mostly those of large diameter, axonal degeneration and infiltration of macrophages, but no signs of vasculitis. Physical examination, laboratory testing, neurophysiological and neuroradiological examinations suggested that the dorsal root was primarily affected in this patient. Cytokine analysis by multiplex bead array assay revealed that IL-1beta and GM-CSF were increased both in serum and CSF. Although her symptoms did not respond to corticosteroid therapy, intravenous immunoglobulin (IVIg) therapy resulted in marked improvement. IVIg could be effective in case of immune-mediated reversible neuronal dysfunction associated with collagen disease without vasculitis.

Clinicopathologic features of nonsystemic vasculitic neuropathy and microscopic polyangiitis-associated neuropathy: a comparative study

OBJECTIVE

To compare clinicopathologic findings in nonsystemic vasculitic neuropathy (NSVN) and microscopic polyangiitis-associated neuropathy (MPAN).

METHODS

Patients clinicopathologically confirmed to have NSVN (n=23) or MPAN (n=40) were compared with respect to clinical, electrophysiologic, and histopathologic features.

RESULTS

Clinical features of neuropathy such as initial symptoms, progression, and distribution of sensory and motor deficits were similar in both groups, while functional compromise was greater in MPAN than NSVN. Abnormalities of laboratory data including those reflecting severity and extent of inflammation such as C-reactive protein were more conspicuous in MPAN than NSVN. Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) were positive in two-thirds of patients with MPAN but negative in all NSVN. Electrophysiologic and histopathologic findings indicated axonal neuropathy in both groups, whereas the reduction of compound muscle action potentials in the tibial nerve and sensory nerve action potentials in the median nerve was significantly more profound in MPAN than NSVN. As for the epineurial perivascular infiltration, frequencies of cell-specific markers for T lymphocytes, macrophages, and B lymphocytes among cells infiltrating the vasculitic lesions were essentially similar between groups.

CONCLUSIONS

Clinicopathologic profiles and vascular pathology were similar between NSVN and MPAN but the age at onset, severity, and presence of p-ANCA were clearly different. Further study is needed to clarify the pathogenesis of NSVN and its place in the vasculitic spectrum of diseases.

An update on the classification and treatment of vasculitic neuropathy

Vasculitic neuropathy usually presents with painful mononeuropathies or an asymmetric polyneuropathy of acute or subacute onset. The disorder should be classified as being systemic or non-systemic. Systemic vasculitis should be further classified into one of the primary and secondary forms. Although specific treatment regimens vary among neurologists, basic principles can be applied. Corticosteroids and cytotoxic drugs have been the mainstay of treatment for most forms of vasculitic neuropathy. Here we discuss dosing, potential side-effects, and management recommendations of conventional treatments. New treatments showing promise include intravenous immunoglobulin and biological agents and trials of the newest treatments are being reviewed. Future trials should compare commonly used treatment regimens and better establish the efficacy of newer, potentially safer, treatments.

Plantar sensitivity, foot loading and walking pain in rheumatoid arthritis

OBJECTIVE

The aim of the present study was to investigate the tactile sensitivity of the plantar surface in rheumatoid feet and its relationship to walking pain and plantar foot loading characteristics.

METHODS

In 25 patients with rheumatoid arthritis (RA) and 21 healthy controls, Semmes-Weinstein monofilaments were used to assess tactile sensitivity in six foot regions. Walking pain was examined clinically. Pedography was used to analyse foot loading parameters during barefoot walking.

RESULTS

In RA patients, plantar sensitivity was significantly decreased under all foot regions examined compared with the control group (P<0.05). A loss of protective sensation was found in a total of 10 regions in seven patients but not in the control group. In the RA patients, foot loading was reduced in the hindfoot (P<0.05) but was slightly increased in the forefoot (not significant). Average walking pain was 3.8 +/- 2.1 on a scale from 0 to 10 but did not correlate with the sensitivity levels.

CONCLUSION

In patients with RA, no direct relationship between pain intensity and plantar foot loading was found. The decreased tactile sensitivity may be indicative of a disturbed sensation for high plantar pressures. Therefore, pedography can be useful as an additional tool in the detection of excessive forefoot loading before complications are manifested.

Central nervous system manifestations of rheumatologic diseases

PURPOSE OF REVIEW

To summarize the current literature on central nervous system manifestations of vasculitides and connective tissue diseases.

RECENT FINDINGS

There have been advances in understanding the mechanisms behind the initiation and perpetuation of inflammatory processes in vasculitic neuropathy. Clinically relevant data have been obtained on the predictive criteria for a positive biopsy result in giant cell arteritis, the imaging characteristics of primary angiitis of the central nervous system, and Behçet disease, and the clinical and radiologic features of neuro-Behçet disease. There is more clarity about the central nervous system syndromes attributable to systemic lupus erythematosus and new insights into the central mechanisms involved in the manifestations of Sjögren syndrome and rheumatoid arthritis. Novel immunomodulatory agents, such as infliximab, have shown some benefit in rheumatoid vasculitis and Sjögren syndrome.

SUMMARY

A better understanding of the clinical, radiographic, and serologic characteristics of various central nervous system complications of rheumatologic diseases has been gained in the past year. Recent advances in understanding the pathophysiology of peripheral nervous system complications and their treatment may affect the management of the central nervous system complications.

Pharmacotherapy for pain in rheumatologic conditions: the neuropathic component

Nociceptive and neuropathic types of pain occur in rheumatologic conditions. Most clinicians are familiar with the former, but many are not aware of the prevalence of the latter. The literature reports numerous examples of the occurrence of rheumatologic neuropathic pain, but little has been published on its management. In this article, neuropathic and nociceptive pain in rheumatologic conditions are differentiated and treatment recommendations are discussed. Common rheumatologic conditions and their pathophysiology in relation to pain mechanisms also are described. Pharmacotherapeutic recommendations for the treatment of both types of pain in the common rheumatologic conditions are presented.