Peripheral nervous system manifestations of Sjögren syndrome: clinical patterns, diagnostic paradigms, etiopathogenesis, and therapeutic strategies

The eye as a window to oral and pain symptoms in Sjögren's disease

BACKGROUND

To investigate whether certain dry eye (DE) metrics relate to oral and pain manifestations of Sjögren's disease (SjD).

METHODS

Secondary analysis of the Sjögren's International Collaborative Clinical Alliance dataset containing 1541 individuals with 2016 American College of Rheumatology/European League Against Rheumatism defined SjD. Binary logistic regression analyses examined which of 13 DE features related to various extraocular metrics.

RESULTS

The mean age of the population was 52±13.5 years; 45% identified as white and 94% as women. Heterogeneity in DE symptoms and signs was noted in individuals with SjD, with approximately one-third of individuals reporting significant spontaneous and/or evoked pain using various descriptors and indicating certain triggers, and approximately half having low tear production. Similarly, heterogeneity was noted with respect to oral and pain complaints, with extraocular pain symptoms found in approximately one-third of the population. Different ocular phenotypes aligned with different extraocular findings. Specifically, grittiness or scratchiness in the eyes (OR=1.6), blurred vision (OR=1.4) and low tear production (OR=1.8) most closely aligned with oral dryness ('Does your mouth feel dry?). On the other hand, burning or stinging in the eyes (OR=1.6), discomfort in low humidity (OR=1.2) and the absence of DE signs (normal tear production, OR=0.7; lack of ocular surface staining, OR=0.6) most closely aligned with pain outside the eye ('Do you experience persistent or frequent burning discomfort?').

CONCLUSIONS

Our findings suggest heterogeneity in SjD ocular presentations that predict extraocular features of disease and hint at mechanisms that underlie heterogeneity, namely divergent neurosensory processes.

Global Trends and Insights Into the Neurological Manifestations of Sjögren's Syndrome: A Bibliometric Review

Neurological symptoms in Sjögren's syndrome (SS) present across a spectrum of severity, posing diagnostic and therapeutic challenges. This bibliometric review adopts a comprehensive approach to analyze the research landscape related to these symptoms. The data source utilized for this bibliometric review was the Web of Science Core Collection. The study selection encompassed English-language articles and reviews published between January 1, 2006, and June 30, 2023. Data extraction involved a systematic analysis of a total of 910 publications, which included 625 research articles and 285 reviews. The publication trends indicate a steady growth in research output, peaking with 122 papers in 2022. Geographic contributions primarily originate from the United States, followed by robust European contributions and increasing input from Asian countries, particularly China and Japan. Influential researchers such as Smith JM from Johns Hopkins University, Brown L from Harvard University, and Wang Q from Peking University have significantly shaped this field. Key institutions driving substantial publication volume and citation impact include Johns Hopkins University, Harvard University, and the University of Tokyo. Furthermore, journals such as Neurology, Journal of Autoimmunity, and Clinical Rheumatology play pivotal roles in disseminating advancements in SS-related neurological research. Future research priorities should focus on primary prevention, emphasizing the need for global cooperation and collaboration in neurological SS workup. There is a call for encouraging interdisciplinary, internationally focused investigative efforts specifically targeting SS neurologists. Key focus areas include potential preventive therapies aimed at significant neural dysfunctions (e.g., sensory neuropathy), mechanisms of microvascular dysfunction, and cognitive profiles/immunomodulation against autoantibodies. This analysis underscores the continued necessity for further research to optimize diagnosis and treatment in cases involving the complexities of neurological involvement with SS.

Top 10 Clinical Pearls in Vasculitic Neuropathies

Vasculitic neuropathies are a diverse group of inflammatory polyneuropathies that result from systemic vasculitis (e.g., polyarteritis nodosa, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, microscopic polyangiitis), vasculitis resulting from rheumatological disorders (e.g., rheumatoid arthritis and Sjögren's syndrome), paraneoplastic conditions, viruses, and medications. Occasionally, vasculitis is restricted to the peripheral nerves and termed nonsystemic vasculitic neuropathy. Presenting with an acute or subacute onset of painful sensory and motor deficits, ischemia to individual peripheral nerves results in the classic "mononeuritis multiplex" pattern. Over time, overlapping mononeuropathies will result in a symmetrical or asymmetrical sensorimotor axonal polyneuropathy. The diagnosis of vasculitic neuropathies relies on extensive laboratory testing, electrodiagnostic testing, and nerve and/or other tissue biopsy. Treatment consists primarily of immunosuppressant medications such as corticosteroids, cyclophosphamide, rituximab, methotrexate, or azathioprine, in addition to neuropathic pain treatments. Frequently, other specialists such as rheumatologists, pulmonologists, and nephrologists will comanage these complex patients with systemic vasculitis. Prompt recognition of these conditions is imperative, as delays in treatment may result in permanent deficits and even death.

Neurological and Psychiatric Clinical Manifestations of Sjögren Syndrome

PURPOSE OF REVIEW

Sjögren Syndrome is a systemic autoimmune disorder that presents mainly with sicca symptoms, but frequently affects other body systems which can lead to a wide variety of manifestations. Understanding the neurological and psychiatric manifestations of Sjögren Syndrome can help with an earlier diagnosis of this disease and leads to better clinical outcomes.

RECENT FINDINGS

We provide an updated overview of the central neurological manifestations, peripheral neurological manifestations and psychiatric manifestations and their diagnosis when associated with primary Sjögren Syndrome. The epidemiology and clinical features of the neurological and psychiatric manifestations are derived from different cohort studies and review articles that were selected from PubMed searches conducted between January 2024 and March 2024. The absence of diagnostic criteria and the scarcity of large, robust studies makes the recognition of the neurological and psychiatric manifestations of Sjögren Syndrome more difficult. Maintaining a high index of suspicion in clinical practice and a close collaboration between the Neurologist and the Rheumatologist will facilitate the diagnosis and management of these patients.

Small Fiber Neuropathy Associated with Post-COVID-19 and Post-COVID-19 Vaccination Arthritis: A Rare Post-Infective Syndrome or a New-Onset Disease?

Post-COVID-19 (PC) and post-COVID-19 vaccination (PCV) syndromes are considered emergent multidisciplinary disorders. PC/PCV small fiber neuropathy (SFN) was rarely described and its association with undifferentiated arthritis (UA) was never defined. We aimed to evaluate PC/PCV-UA associated with the recent onset of severe lower limb paresthesia, compare SFN positive (+) to negative (-) patients, and evaluate changes in biomarkers in SFN+ during treatments. Nineteen PC/PCV-UA-patients with possible SFN underwent skin biopsy at the Usl Tuscany Center (Florence) early arthritis outpatient clinic from September 2021 to March 2024. Eight selected SFN+ were compared to ten SFN- patients. In SFN+ patients, baseline joint ultrasound (US), electromyography (EMG), optical coherence tomography (OCT), and skin biopsy were repeated at six months. Moreover, SFN+ patients were clinically assessed by a 0-10 numeric rating scale for neurological symptoms and DAS28/ESR up to 12 months follow-up. SFN+ patients showed a lower intraepidermal nerve fiber density at histopathological examination of skin biopsies and a higher frequency of OCT and EMG abnormalities in comparison to SFN- patients. In SFN+ patients, US and DAS28/ESR significantly improved, while intraepidermal nerve fiber density did not significantly change at the six-month follow-up. Fatigue, motor impairment, burning pain, brain fog, and sensitivity disorders decreased at long-term follow-up (12 months).

Sjogren's syndrome: a neurological perspective

Sjogren's syndrome (SS) is a complex autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands, resulting in sicca symptoms. Additionally, SS presents with neurological manifestations that significantly impact the nervous system. This review aims to provide a comprehensive overview of the neurological aspects of SSj, covering both the peripheral and central nervous system involvement, while emphasizing diagnosis, treatment, and prognosis.

Comparative Analysis of Hematological and Immunological Parameters in Patients with Primary Sjögren's Syndrome and Peripheral Neuropathy

BACKGROUND

Primary Sjögren syndrome (pSS) is a multisystem disorder of autoimmune etiology, frequently involving peripheral nerves. Early detection of peripheral neuropathy (PN) manifestations might improve prognosis and disease control. The purpose of the study was to evaluate the predictive potential of hematological and immunological parameters associated with PN development in pSS patients.

METHODS

This single-center retrospective study included patients with pSS who were divided into two groups, according to the occurrence of neurological manifestations throughout the follow-up period.

RESULTS

From the total of 121 pSS patients included in the study, 31 (25.61%) developed neurological manifestations (PN+ group) during the follow-up period. At the moment of pSS diagnosis, 80.64% of PN+ patients exhibited increased disease activity, with ESSDAI scores above 14 (p = 0.001), and significantly higher values for VASp score (p = 0.001), with a mean value of 4.90 ± 2.45, compared to 1.27 ± 1.32 in the PN- group. The hematological assessment at the moment of pSS diagnosis revealed that neutrophils and neutrophil-to-lymphocyte ratio (NLR) were significantly higher in the PN+ group (p = 0.001), while lymphocytes, monocytes and monocyte-to-lymphocyte ratio (MLR) were significantly lower (p = 0.025, p = 0.13 and p = 0.003, respectively). Immuno-inflammatory parameters-gammaglobulins, complement fractions C3, C4, total proteins and vitamin D were significantly lower in the PN+ patients' group. In multivariate analysis, the independent predictive character for PN development in pSS patients was confirmed for NLR (95% CI 0.033 to 0.263, p = 0.012), MLR (95% CI -1.289 to -0.194, p = 0.008), gammaglobulins (95% CI -0.426 to -0.088, p < 0.003), complement fraction C4 (95% CI -0.018 to -0.001, p < 0.030) and vitamin D (95% CI -0.017 to -0.003, p < 0.009).

CONCLUSIONS

Readily available and frequently used hematological and immunological markers, such as NLR, MLR, gammaglobulins, C4 and vitamin D could be helpful in predicting the neurological involvement in pSS patients. These biological parameters might become useful tools for clinicians to monitor disease progression and identify potentially severe extraglandular manifestations in pSS patients.

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.

Comparison of cutaneous silent period parameters in patients with primary Sjögren's syndrome with the healthy population and determination of ıts relationship with clinical parameters

Small fiber neuropathy (SFN) is one of the main neurological manifestations in primary Sjögren's Syndrome (pSS). For the detection of SFN, cutaneous silent period (CSP) measurement is gaining popularity recently due to its non-invasiveness and practical application. Evaluating SFN involvement in patients with pSS using CSP and evaluating its relationship with clinical parameters. Patients with a diagnosis of pSS and healthy volunteers demographically homogeneous with the patient group were included in the study. The CSP responses were recorded over the abductor pollicis brevis muscle. The latency and duration values of the responses were obtained. In patient group, EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI), Hospital Anxiety and Depression Scale (HADS), Short Form-36 (SF-36) questionnaire, Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) and Central Sensitization Inventory (CSI) were applied for the evaluation of symptom severity, mood, quality of life, presence of neuropathic pain and central sensitization, respectively. The mean CSP latency was significantly longer in patient group compared to control group (p < 0.001). Mean CSP duration was also significantly shorter in patient group (p < 0.001). There were no significant differences in CSP parameters according to patients' neuropathic pain or central sensitization profile. There were significant correlations of CSP parameters (latency and duration, respectively) with ESSPRI dryness (ρ = 0.469, p = 0.004; ρ =  -0.553, p < 0.001), fatigue (ρ = 0.42, p = 0.011; ρ =  -0.505, p = 0.002), pain (ρ = 0.428, p = 0.009; ρ =  -0.57, p < 0.001) subscores and mean ESSPRI score (ρ = 0.631, p < 0.001; ρ = -0.749, p < 0.001). When SF-36 subscores and CSP parameters were investigated, a significant correlation was found only between "bodily pain" subscore and CSP duration (ρ =  -0.395, p = 0.017). In HADS, LANSS and CSI evaluations, a significant correlation was found only between HADS anxiety score and the CSP duration (ρ = 0.364, p = 0.02). As indicated by CSP measurement, SFN is more prominent in patients with pSS than in the healthy population. It is important to investigate the presence of SFN because of its correlation with the leading symptoms in the clinical spectrum of pSS.

Headache and immunological/autoimmune disorders: a comprehensive review of available epidemiological evidence with insights on potential underlying mechanisms

Several lines of evidence support a role of the immune system in headache pathogenesis, with particular regard to migraine. Firstly, alterations in cytokine profile and in lymphocyte subsets have been reported in headache patients. Secondly, several genetic and environmental pathogenic factors seem to be frequently shared by headache and immunological/autoimmune diseases. Accordingly, immunological alterations in primary headaches, in particular in migraine, have been suggested to predispose some patients to the development of immunological and autoimmune diseases. On the other hand, pathogenic mechanisms underlying autoimmune disorders, in some cases, seem to favour the onset of headache. Therefore, an association between headache and immunological/autoimmune disorders has been thoroughly investigated in the last years. The knowledge of this possible association may have relevant implications in the clinical practice when deciding diagnostic and therapeutic approaches. The present review summarizes findings to date regarding the plausible relationship between headache and immunological/autoimmune disorders, starting from a description of immunological alteration of primary headaches, and moving onward to the evidence supporting a potential link between headache and each specific autoimmune/immunological disease.

Neuropathic Pain in the Eyes, Body, and Mouth: Insights from the Sjögren's International Collaborative Clinical Alliance

OBJECTIVE

To evaluate how ocular, oral, and bodily neuropathic pain symptoms, which characterize small fiber neuropathies, are associated with Sjögren's syndrome (SS) classification based on the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria.

METHODS

Participants enrolled in the Sjögren's International Collaborative Clinical Alliance (SICCA) registry had ocular, rheumatologic, oral, and labial salivary gland (LSG) biopsy examinations, blood and saliva samples collected, and completed questionnaires at baseline. We used mixed effects modeling with age, country, gender, and depression being fixed effects and study site, a random effect, to determine if neuropathic pain indicators (assessed via questionnaires) were associated with being classified as SS.

RESULTS

A total of 3,514 participants were enrolled into SICCA, with 1,541 (52.9%) meeting the 2016 ACR/EULAR classification criteria for SS. There was a negative association between being classified as SS and experiencing bodily neuropathic pain features of needle-like pain, prickling/tingling sensation, ocular neuropathic pain of constant burning, and constant light sensitivity, and having a presumptive diagnosis of neuropathic oral pain.

CONCLUSIONS

We found that those classified as SS had lower scores/reports of painful neuropathies compared with those classified as non-SS. Non-SS patients with dry eye disease or symptoms could benefit from pain assessment as they may experience painful small-fiber neuropathies (SFNs). Pain questionnaires may help identify pain associated with SFNs in patients with SS and non-SS dry eye. Future studies would be helpful to correlate self-reports of pain to objective measures of SFNs in those with SS, non-SS dry eye, and healthy controls.

Autoimmune Neurologic Emergencies

Over the past decade, understanding of autoimmune neurologic disorders has exponentially increased. Many patients present as a neurologic emergency and require timely evaluation with rapid management and intensive care. However, the diagnosis is often either missed or delayed, which may lead to a significant burden of disabling morbidity and even mortality. A high level of suspicion in the at-risk population should be maintained to facilitate more rapid diagnosis and prompt treatment. At present, there is no all-encompassing algorithm specifically applicable to the management of fulminant autoimmune neurologic disorders. This article discusses manifestations and management of various autoimmune neurologic emergencies.

Differences in clinical features between small fiber and sensitive large fiber neuropathies in Sjögren's syndrome

BACKGROUND

To distinguish large (LFN) and small fiber neuropathies (SFN) in Sjögren's syndrome (SS) requires electroneuromyography (EMG) first, but this is time-consuming and has sometimes a limited accessibility, which can lead to a diagnostic delay. We aimed to identify clinical features that could distinguish SFN from sensitive LFN in SS.

METHODS

The study included patients with SS who were monitored in the internal medicine and neurology departments at Angers University Hospital between 2010 and 2016, and who were tested for suspected peripheral neuropathy. Patients with clinical motor involvement were excluded. LFN diagnosis was based on EMG. SFN diagnosis was based on intraepidermal nerve fiber density on skin biopsies in patients with no abnormality on EMG.

RESULTS

LFN and SFN were diagnosed respectively in 22 (6.9%) and 17 (5.4%) patients among 317 patients with SS. Prevalence of anti-SSA antibodies was lower in the SFN group compared to the LFN group (p=0.002). The types of paresthesia did not differ between the 2 groups. After adjustment for age and sex, SFN was associated with dysautonomia (p=0.01, OR 8.4 [CI 95%: 1.7-42.4]) and without length-dependent topography (p=0.03, OR 0.2 [0.04-0.8] in comparison with the LFN group.

CONCLUSIONS

An association of non-length-dependent pattern and dysautonomia seems to predict the absence of LFN in SS and encourages the search for SFN. In contrary, patients with length-dependent involvement and without dysautonomia should be prioritized for EMG.

Immune-mediated axonal dysfunction in seropositive and seronegative primary Sjögren's syndrome

OBJECTIVE

The present study investigates the peripheral neuropathy in Primary Sjögren's syndrome (pSS) using the nerve excitability test to further elucidate how peripheral nerves are affected by the autoantibodies.

METHODS

Each patient received clinical evaluation, examination for anti-SSA/Ro and anti-SSB/La antibodies titer, paired motor and sensory nerve excitability test, thermal quantitative sensory test (QST), and nerve conduction study (NCS).

RESULTS

A total of 40 pSS patients wasenrolled. Motor axonal study of the pSS with positive anti-SSA/Ro or anti-SSB/La antibodies (n = 28) was found to have increased stimulus for 50% compound muscle action potential (CMAP) (P < 0.05), increased rheobase (P < 0.01), increased minimum I/V slope (P < 0.01) and hyperpolarizing I/V slope (P < 0.05), increased relative refractory period (RRP, P < 0.001), decreased accommodation of threshold electrotonus toward depolarizing current (P < 0.05), and increased accommodation toward hyperpolarizing current (P < 0.05). Seronegative pSS (n = 10) showed much less prominent motor axonal changes, showing only increased minimum I/V slope (P < 0.05). Sensory axonal study in seropositive pSS patients is found to have increased stimulus for 50% sensory nerve action potential (SNAP) (P < 0.01), decreased latency (P < 0.01), increased RRP (P < 0.01), and increased subexcitability (P < 0.05). Seronegative pSS patients have shown no significant sensory axonal changes. Thermal QST showed more prominent abnormalities in seronegative pSS compared to seropositive pSS.

INTERPRETATION

Anti-SSA/Ro and anti-SSB/La autoantibodies might cause dysfunction in nodal and internodal region of the axon and small nerve fibers; meanwhile, autoreactive antibodies in seronegative pSS mainly affect small nerve fibers. Thus, the underlying pathophysiology for the two types of pSS is different.

Biopsy-Proven Small-Fiber Neuropathy in Primary Sjögren's Syndrome: Neuropathic Pain Characteristics, Autoantibody Findings, and Histopathologic Features

OBJECTIVE

Painful small-fiber neuropathies (SFNs) in primary Sjögren's syndrome (SS) may present as pure or mixed with concurrent large-fiber involvement. SFN can be diagnosed by punch skin biopsy results that identify decreased intra-epidermal nerve-fiber density (IENFD) of unmyelinated nerves.

METHODS

We compared 23 consecutively evaluated patients with SS with pure and mixed SFN versus 98 patients without SFN. We distinguished between markers of dorsal root ganglia (DRG) degeneration (decreased IENFD in the proximal thigh versus the distal leg) versus axonal degeneration (decreased IENFD in the distal leg versus the proximal thigh).

RESULTS

There were no differences in pain intensity, pain quality, and treatment characteristics in the comparison of 13 patients with pure SFN versus 10 patients with mixed SFN. Ten patients with SFN (approximately 45%) had neuropathic pain preceding sicca symptoms. Opioid analgesics were prescribed to approximately 45% of patients with SFN. When compared to 98 patients without SFN, the 23 patients with SFN had an increased frequency of male sex (30% versus 9%; P < 0.01), a decreased frequency of anti-Ro 52 (P = 0.01) and anti-Ro 60 antibodies (P = 0.01), rheumatoid factor positivity (P < 0.01), and polyclonal gammopathy (P < 0.01). Eleven patients had stocking-and-glove pain, and 12 patients had nonstocking-and-glove pain. Skin biopsy results disclosed patterns of axonal (16 patients) and DRG injury (7 patients).

CONCLUSION

SS SFN had an increased frequency among male patients, a decreased frequency of multiple antibodies, frequent treatment with opioid analgesics, and the presence of nonstocking-and-glove pain. Distinguishing between DRG versus axonal injury is significant, especially given that mechanisms targeting the DRG may result in irreversible neuronal cell death. Altogether, these findings highlight clinical, autoantibody, and pathologic features that can help to define mechanisms and treatment strategies.

[Peripheral nerve involvement in rheumatic diseases]

Peripheral neuropathies are probably an under-diagnosed complication of many rheumatic diseases. In some cases they take a mild clinical course, in others they cause severe impairment of patients' quality of life. A precise diagnosis and etiological classification are of major importance for successful treatment and prognosis of peripheral neuropathies. A detailed patient history and physical examination are the foundation of every diagnostic approach. Electrophysiological studies are obligatory when peripheral neuropathy is suspected, whereas nerve or nerve-muscle biopsies are indicated only in selected cases. Therapeutic approaches are often complicated by a lack of evidence. They correspond to frequently tested immunosuppressive treatment of the underlying disease, such as glucocorticoids, cyclophosphamide, mycophenolate mofetil and intravenous immunoglobulins and are based on the symptomatic pain treatment of other neuropathies. As first-line treatment gabapentin, pregabalin, duloxetine, venlafaxine and tricyclic antidepressants are frequently used.

Sjögren's syndrome

This review discusses important aspects of the diagnosis and management of Sjögren's syndrome, covering clinical features, diagnosis and management, and summarizes recent developments in diagnosis, prognostication and treatment.

Peripheral and central nervous system involvement in a patient with primary Sjögren's syndrome: a case report

Background

Primary Sjögren’s syndrome is the second most common rheumatological disorder after rheumatoid arthritis. It typically presents as xerophthalmia and xerostomia in postmenopausal women. Involvement of the central nervous system has been recognized, although its pathogenesis and characteristics are poorly understood. Central nervous system complications are a diagnostic challenge and emphasize the need for systematic screening of patients with new peripheral and central neurological symptoms.

Case report

We report a case of a 58-year-old Swiss woman presenting with rapidly progressive sensorimotor distal polyneuropathy together with new-onset generalized seizures. Initial magnetic resonance imaging (MRI) of the brain performed after the first seizure showed multiple, bihemispheric, confluent white matter hyperintensities with contrast enhancement. Follow-up imaging 3 days after the initial magnetic resonance imaging demonstrated a fulminant disease progression associated with the serious clinical deterioration of the patient. In light of the results of a minor salivary gland biopsy, autoantibody testing, nerve conduction studies, and cranial magnetic resonance imaging, primary Sjögren’s syndrome with cryoglobulinemia type II was diagnosed. Response to plasmapheresis and subsequent administration of cyclophosphamide was favorable.

Conclusion

Even though exocrinopathy is the hallmark of Sjögren’s syndrome, systemic symptoms are observed in one-third of patients. There is an urgent need to better characterize the mechanisms underlying different disease phenotypes and to perform randomized controlled trials in order to provide tailored and evidence-based treatment for primary Sjögren’s syndrome.

Diagnosis and management of sensory polyneuropathy

Sensory polyneuropathies, which are caused by dysfunction of peripheral sensory nerve fibers, are a heterogeneous group of disorders that range from the common diabetic neuropathy to the rare sensory neuronopathies. The presenting symptoms, acuity, time course, severity, and subsequent morbidity vary and depend on the type of fiber that is affected and the underlying cause. Damage to small thinly myelinated and unmyelinated nerve fibers results in neuropathic pain, whereas damage to large myelinated sensory afferents results in proprioceptive deficits and ataxia. The causes of these disorders are diverse and include metabolic, toxic, infectious, inflammatory, autoimmune, and genetic conditions. Idiopathic sensory polyneuropathies are common although they should be considered a diagnosis of exclusion. The diagnostic evaluation involves electrophysiologic testing including nerve conduction studies, histopathologic analysis of nerve tissue, serum studies, and sometimes autonomic testing and cerebrospinal fluid analysis. The treatment of these diseases depends on the underlying cause and may include immunotherapy, mitigation of risk factors, symptomatic treatment, and gene therapy, such as the recently developed RNA interference and antisense oligonucleotide therapies for transthyretin familial amyloid polyneuropathy. Many of these disorders have no directed treatment, in which case management remains symptomatic and supportive. More research is needed into the underlying pathophysiology of nerve damage in these polyneuropathies to guide advances in treatment.

Brief Report: Anti-Calponin 3 Autoantibodies: A Newly Identified Specificity in Patients With Sjögren's Syndrome

OBJECTIVE

Autoantibodies are clinically useful for phenotyping patients across the spectrum of autoimmune rheumatic diseases. Using serum from a patient with Sjögren's syndrome (SS), we detected a new specificity by immunoblotting. This study was undertaken to identify this autoantibody and to evaluate its disease specificity.

METHODS

A prominent 40-kd band was detected when immunoblotting was performed using SS patient serum and lysate from rat dorsal root ganglia (DRGs). Using 2-dimensional gel electrophoresis and liquid chromatography tandem mass spectrometry peptide sequencing, the autoantigen was identified as calponin 3. Anti-calponin 3 antibodies were evaluated in sera from patients with primary SS (n = 209), patients with systemic lupus erythematosus (SLE; n = 138), patients with myositis (n = 138), patients with multiple sclerosis (MS; n = 44), and healthy controls (n = 46) by enzyme-linked immunosorbent assay. Expression of calponin 3 was assessed by immunohistochemistry.

RESULTS

Calponin 3 was identified as a new autoantigen. Anti-calponin 3 antibodies were detected in 23 (11.0%) of the 209 SS patients, 12 (8.7%) of the 138 SLE patients, 7 (5.1%) of the 138 myositis patients, 3 (6.8%) of the 44 MS patients, and 1 (2.2%) of the 46 healthy controls. Among SS patients, the frequency of anti-calponin 3 antibodies was highest in those with neuropathies (7 [17.9%] of 39). In this subset, the frequency of anti-calponin 3 antibodies differed significantly from that in the control group (P = 0.02). Calponin 3 was expressed primarily in rat DRG perineuronal satellite cells but not neurons.

CONCLUSION

Calponin 3 is a novel autoantigen. Antibodies against this protein are found in SS and associate with the subset of patients experiencing neuropathies. Intriguingly, we found that calponin 3 is expressed in DRG perineuronal satellite cells, suggesting that these may be a target in SS.

Sensory Polyneuropathies

PURPOSE OF REVIEW

This article describes the methods of diagnosis and management of the sensory-predominant polyneuropathies. To simplify the approach to this category of patients, sensory-predominant polyneuropathies are divided broadly into either small fiber (or pain-predominant) neuropathies and large fiber (or ataxia-predominant) neuropathies, of which the sensory neuronopathies (dorsal root ganglionopathies) are highlighted.

RECENT FINDINGS

Physicians can now easily perform skin biopsies in their offices, allowing access to the gold standard pathologic diagnostic tool for small fiber neuropathies. Additional diagnostic techniques, such as corneal confocal microscopy, are emerging. Recently, small fiber neuropathies have been associated with a broader spectrum of diseases, including fibromyalgia, sodium channel mutations, and voltage-gated potassium channel antibody autoimmune disease.

SUMMARY

Despite advances in diagnosing small fiber neuropathies and sensory neuronopathies, many of these neuropathies remain refractory to treatment. In select cases, early identification and treatment may result in better outcomes. "Idiopathic" should be a diagnosis of exclusion and a thorough investigation for treatable causes pursued.

Evaluation of postural tachycardia syndrome (POTS)

The diagnostic evaluation of a patient with suspected postural tachycardia syndrome (POTS) requires a thoughtful diagnostic approach utilizing a careful clinical history and examination, laboratory, and autonomic testing. This article outlines the importance of a thorough history in identifying mechanism of symptom onset, clinical features, associated clinical conditions or disorders, and factors that may result in symptom exacerbation. The clinical examination involves an assessment of pupillary responses, an evaluation for sudomotor and vasomotor signs, and an assessment for joint hypermobility. Laboratory testing helps to exclude mimics of autonomic dysfunction, recognize conditions that may exacerbate symptoms, and to identify conditions that may cause or be associated with autonomic nervous system disease. The purpose of autonomic testing is to confirm a POTS diagnosis, exclude other causes of orthostatic intolerance, and may provide for characterization of POTS into neuropathic and hyperadrenergic subtypes. Other diagnostic studies, such as epidermal skin punch biopsy, exercise testing, radiographic studies, sleep studies, gastrointestinal motility studies, and urodynamic studies should be considered when clinically appropriate.

Sjögren's syndrome X-chromosome dose effect: An epigenetic perspective

Sjögren's syndrome (SS) is a chronic autoimmune disease affecting exocrine glands leading to mouth and eyes dryness. The extent to which epigenetic DNA methylation changes are responsible for an X-chromosome dose effect has yet to be determined. Our objectives were to (i) describe how epigenetic DNA methylation changes could explain an X-chromosome dose effect in SS for women with normal 46,XX genotype and (ii) determine the relevant relationships to this dose effect, between X-linked genes, genes controlling X-chromosome inactivation (XCI) and genes encoding associated transcription factors, all of which are differentially expressed and/or differentially methylated in the salivary glands of patients with SS. We identified 58 upregulated X-chromosome genes, including 22 genes previously shown to escape XCI, based on the analysis of SS patient salivary gland GEO2R gene expression datasets. Moreover, we found XIST and its cis regulators RLIM, FTX, and CHIC1, and polycomb repressor genes of the PRC1/2 complexes to be upregulated. Many of the X-chromosome genes implicated in SS pathogenesis can be regulated by transcription factors which we found to be overexpressed and/or differentially methylated in patients with SS. Determination of the mechanisms underlying methylation-dependent gene expression and impaired XCI is needed to further elucidate the etiopathogenesis of SS.

Parameters of Somatosensory Evoked Potentials in Patients with Primary Sjӧgren's Syndrome: Preliminary Results

Primary Sjogren's syndrome (pSS) is a chronic autoimmune disease. The aim of the study was to establish whether in patients with pSS without central nervous system (CNS) involvement, the function of the central portion of the sensory pathway can be challenged. In 33 patients with pSS without clinical features of CNS damage and normal head computed tomography scan, somatosensory evoked potentials (SEP) were studied. The results were compared to other clinical parameters of the disease, particularly to immunological status. The control group consisted of 20 healthy volunteers. Mean latency of all components of SEP was considerably prolonged in patients compared to the control group. Mean interpeak latency N20-N13 (duration of central conduction TT) did not differ significantly between the groups. However, in the study group, mean amplitude of N20P22 and N13P16 was significantly higher compared to healthy individuals. In patients with pSS, significant differences in SEP parameters depending on the duration of the disease and presence of SSA and SSB antibodies were noted. The authors confirmed CNS involvement often observed in patients with pSS. They also showed dysfunction of the central sensory neuron as a difference in the amplitude of cortical response, which indicates subclinical damage to the CNS.

Autonomic neuropathy-in its many guises-as the initial manifestation of the antiphospholipid syndrome

Autonomic disorders have previously been described in association with the antiphospholipid syndrome. The present study aimed to determine the clinical phenotype of patients in whom autonomic dysfunction was the initial manifestation of the antiphospholipid syndrome and to evaluate for autonomic neuropathy in these patients. This was a retrospective study of 22 patients evaluated at the University of Colorado who were found to have a disorder of the autonomic nervous system as the initial manifestation of antiphospholipid syndrome. All patients had persistent antiphospholipid antibody positivity and all patients who underwent skin biopsy were found to have reduced sweat gland nerve fiber density suggestive of an autonomic neuropathy. All patients underwent an extensive evaluation to rule out other causes for their autonomic dysfunction. Patients presented with multiple different autonomic disorders, including postural tachycardia syndrome, gastrointestinal dysmotility, and complex regional pain syndrome. Despite most having low-titer IgM antiphospholipid antibodies, 13 of the 22 patients (59%) suffered one or more thrombotic event, but pregnancy morbidity was minimal. Prothrombin-associated antibodies were helpful in confirming the diagnosis of antiphospholipid syndrome. We conclude that autonomic neuropathy may occur in association with antiphospholipid antibodies and may be the initial manifestation of the syndrome. Increased awareness of this association is important, because it is associated with a significant thrombotic risk and a high degree of disability. In addition, anecdotal experience has suggested that antithrombotic therapy and intravenous immunoglobulin therapy may result in significant clinical improvement in these patients.

Neurological Complications of Sjögren's Syndrome: Diagnosis and Management

Opinion statement

Purpose of review

Neurologic disease is a common extraglandular manifestation of Sjögren's syndrome (SS), the study of which has been hampered both by the lack of uniform definitions for specific neurologic complications and by the imprecision of the tools used to diagnose SS. There is a great need to develop consensus criteria for classifying these varied neurologic manifestations, as has been done in systemic lupus erythematosus (SLE) "Arthritis and rheumatism 42:599-608, 1999". SS patients with certain forms of neurologic involvement, such as small fiber neuropathy and sensory ataxic ganglionopathy, frequently lack anti-SSA and anti-SSB antibodies and other serologic abnormalities. In these patients, neurologic disease is often their presenting manifestation, triggering a search for underlying SS. Given the frequent seronegativity of such patients, their diagnosis of SS rests heavily on the interpretation of a labial gland biopsy. However, these biopsies are prone to misinterpretation "Vivino etal. J Rheumatol 29:938-44, 2002", and "positive" ones are found in up to 15% of healthy volunteers "Radfar et al. Arthrit Rheumatu 47:520-4, 2002". Better diagnostic tools are needed to determine if the frequent seronegative status of these SS patients may be related to a unique disease pathogenesis.

Recent findings

Recent advances in diagnostic techniques have served to define a likely pathogenetic basis for certain neurologic manifestations of SS. The advent of punch skin biopsies to analyze intraepidermal nerve fiber density and morphology has helped define pure sensory small fiber neuropathy as common in SS and the basis for both length- and non-length-dependent patterns of neuropathic pain. New protocols for magnetic resonance imaging (MRI) have enabled the recognition of dorsal root ganglionitis, a finding originally detected in pathologic studies. The advent of the anti-aquaporin-4 (AQP4) antibody test in 2004 has Led to the appreciation that demyelinating disease in SS is often related to the presence of neuromyelitis optica spectrum disorder. The anti-AQP4 antibody is considered to be directly pathogenic in the brain, targeting the primary water channel proteins in the brain, expressed prominently on astrocytic foot processes.

Summary

There are no clinical trials evaluating the efficacy of systemic immune suppressive therapy for peripheral or central nervous system involvement. With the recent increase in clinical trials of biologic agents for SS, which utilize systemic disease manifestations as standardized outcome measures, there is an urgency to deveLop appropriate definitions of neuroLogic compLications of SS and cLear parameters for clinical improvement.

Aire-deficient mice provide a model of corneal and lacrimal gland neuropathy in Sjögren's syndrome

Sjögren's syndrome (SS) is a chronic, autoimmune exocrinopathy that leads to severe dryness of the mouth and eyes. Exocrine function is highly regulated by neuronal mechanisms but little is known about the link between chronic inflammation, innervation and altered exocrine function in the diseased eyes and exocrine glands of SS patients. To gain a better understanding of neuronal regulation in the immunopathogenesis of autoimmune exocrinopathy, we profiled a mouse model of spontaneous, autoimmune exocrinopathy that possess key characteristics of peripheral neuropathy experienced by SS patients. Mice deficient in the autoimmune regulator (Aire) gene developed spontaneous, CD4+ T cell-mediated exocrinopathy and aqueous-deficient dry eye that were associated with loss of nerves innervating the cornea and lacrimal gland. Changes in innervation and tear secretion were accompanied by increased proliferation of corneal epithelial basal cells, limbal expansion of KRT19-positive progenitor cells, increased vascularization of the peripheral cornea and reduced nerve function in the lacrimal gland. In addition, we found extensive loss of MIST1+ secretory acinar cells in the Aire -/- lacrimal gland suggesting that acinar cells are a primary target of the disease, Finally, topical application of ophthalmic steroid effectively restored corneal innervation in Aire -/- mice thereby functionally linking nerve loss with local inflammation in the aqueous-deficient dry eye. These data provide important insight regarding the relationship between chronic inflammation and neuropathic changes in autoimmune-mediated dry eye. Peripheral neuropathies characteristic of SS appear to be tightly linked with the underlying immunopathological mechanism and Aire -/- mice provide an excellent tool to explore the interplay between SS-associated immunopathology and peripheral neuropathy.

Comparisons of presentations and outcomes of neuromyelitis optica patients with and without Sjögren's syndrome

Patients with neuromyelitis optica (NMO) often have an accompanying autoimmune disease, most commonly, but not limited to Sjögren's syndrome (SS). The aim of this study was to compare clinical and laboratory features between NMO patients with and without SS and to investigate the prognosis of NMO in patients with and without SS. Twenty-three NMO patients with SS and 42 NMO patients without SS were included. Clinical and laboratory profiles were compared, including annual relapse rate and time from onset of NMO to Expanded Disability Status Scale (EDSS) scores of 4.0 and 6.0. More NMO patients with SS than those without SS had anti-nuclear antibody, anti-SS-A/Ro and anti-SS-B/La antibodies (91.3 vs. 35.7%, p < 0.001, 87.0 vs. 2.3%, p < 0.001, and 34.8 vs. 0.0%, p < 0.001, respectively). Serum immunoglobulins (IgA, IgM and IgG) were markedly increased in NMO patients with SS in comparison with those without SS. Annual relapse rate and the time from disease onset to an EDSS score of 4.0 and 6.0 were not significantly different between the two groups. No differences between the two groups were found for the other parameters, including AQP-4 antibody status, length of spinal cord lesion and brain lesions. These results imply that NMO in SS more likely represents coexistence with SS rather than representing the result of direct central nervous system involvement in SS. Autoimmune response appears to be more intense in the NMO group with SS, but did not cause a more severe prognosis in comparison with the group without SS, indicating that we should pay attention to the potential benefit of the antinuclear antibodies in NMO.

Primary Sjögren's Syndrome White Matter Changes and Cognitive Dysfunction

This case report describes a 52-year-old, female applicant for long term-care insurance with a history of an autoimmune connective tissue disease initially diagnosed as systemic lupus erythematosus (SLE). Over several years, the signs and symptoms evolved into a clear diagnosis of primary Sjögren's syndrome (PSS). The specific criteria for this diagnosis are reviewed including the symptoms, antinuclear antibodies (ANA), extractable nuclear antigen antibodies (ENA), abnormal salivary scintigraphy and positive Schirmer test. Symptoms of neuropathy and the possibility of a cognitive dysfunction are discussed as part of PSS. The association of white matter lesions (WML) with PSS is significant for underwriting consideration.

Sjögren Sensory Neuronopathy (Sjögren Ganglionopathy): Long-Term Outcome and Treatment Response in a Series of 13 Cases

Primary Sjögren syndrome (SS) is an autoimmune disease mainly affecting the exocrine glands causing a sicca syndrome. Neurological manifestations are rarely seen in SS although they are debilitating. Peripheral neuropathies namely sensory axonal neuropathy and painful small fiber neuropathy are the most frequent neurological manifestations. Sensory neuronopathy (SN) is less frequently seen although leading to more severe handicap.The aim of the study was to analyze the clinical presentation and treatment efficacy in a series of SS-related SN.We retrospectively studied patients with SS fulfilling the American-European Classification Criteria and SN according to recent criteria. Studied variables were neurological findings, associated autoimmune diseases, biological profiles, nerve conduction and sensory/motor amplitudes study, treatments received, and outcomes. Handicap scores were studied at beginning and end of each treatment using the modified Rankin Scale (mRS).Thirteen patients were included (12 women, 1 man; median age 55 years at SN diagnosis) presenting with SN with a median follow-up of 3 years (range 2-17). In 11 patients, SN preceded or coincided with SS diagnosis. Most common neurological findings were ataxia and areflexia followed by paresthesia and pain. Lower limbs were more affected than upper limbs, neurological deficits were often symmetric and cranial nerves were affected in 3 patients. Seven patients were treated with corticosteroids, 7 with mycophenolate mofetil, 6 with hydroxychloroquine, 5 with intravenous immunoglobulins, 4 with cyclophosphamide, and 2 patients received other immunosuppressive drugs. At the beginning and at the end of follow-up, average mRS was 2.15 (median 2) and 2.38 (median 2), respectively.SS-related SN progression is heterogeneous but tends to be chronic, insidious, and debilitating despite treatment. From these data concerning a small number of patients, treatment strategies with corticosteroids in association with immunosuppressive drugs, namely mycophenolate mofetil, had positive results. In contrast, intravenous immunoglobulins had disappointing results.

Immunotherapy Prospects for Painful Small-fiber Sensory Neuropathies and Ganglionopathies

The best-known peripheral neuropathies are those affecting the large, myelinated motor and sensory fibers. These have well-established immunological causes and therapies. Far less is known about the somatic and autonomic "small fibers"; the unmyelinated C-fibers, thinly myelinated A-deltas, and postganglionic sympathetics. The small fibers sense pain and itch, innervate internal organs and tissues, and modulate the inflammatory and immune responses. Symptoms of small-fiber neuropathy include chronic pain and itch, sensory impairment, edema, and skin color, temperature, and sweating changes. Small-fiber polyneuropathy (SFPN) also causes cardiovascular, gastrointestinal, and urological symptoms, the neurologic origin of which often remains unrecognized. Routine electrodiagnostic study does not detect SFPN, so skin biopsies immunolabeled to reveal axons are recommended for diagnostic confirmation. Preliminary evidence suggests that dysimmunity causes some cases of small-fiber neuropathy. Several autoimmune diseases, including Sjögren and celiac, are associated with painful small-fiber ganglionopathy and distal axonopathy, and some patients with "idiopathic" SFPN have evidence of organ-specific dysimmunity, including serological markers. Dysimmune SFPN first came into focus in children and teenagers as they lack other risk factors, for example diabetes or toxic exposures. In them, the rudimentary evidence suggests humoral rather than cellular mechanisms and complement consumption. Preliminary evidence supports efficacy of corticosteroids and immunoglobulins in carefully selected children and adult patients. This paper reviews the evidence of immune causality and the limited data regarding immunotherapy for small-fiber-predominant ganglionitis, regional neuropathy (complex regional pain syndrome), and distal SFPN. These demonstrate the need to develop case definitions and outcome metrics to improve diagnosis, enable prospective trials, and dissect the mechanisms of small-fiber neuropathy.

Immunotherapies for Neurological Manifestations in the Context of Systemic Autoimmunity

Neurological involvement is relatively common in the majority of systemic autoimmune diseases and may lead to severe morbidity and mortality, if not promptly treated. Treatment options vary greatly, depending on the underlying systemic pathophysiology and the associated neurological symptoms. Selecting the appropriate therapeutic scheme is further complicated by the lack of definite therapeutic guidelines, the necessity to differentiate primary neurological syndromes from those related to the underlying systemic disease, and to sort out adverse neurological manifestations caused by immunosuppressants or the biological agents used to treat the primary disease. Immunotherapy is a sine qua non for treating most, if not all, neurological conditions presenting in the context of systemic autoimmunity. Specific agents include classical immune modulators such as corticosteroids, cyclophosphamide, intravenous immunoglobulin, and plasma exchange, as well as numerous biological therapies, for example anti-tumor necrosis factor agents and monoclonal antibodies that target various immune pathways such as B cells, cytokines, and co-stimulatory molecules. However, experience regarding the use of these agents in neurological complications of systemic diseases is mainly empirical or based on small uncontrolled studies and case series. The aim of this review is to present the state-of-the-art therapies applied in various neurological manifestations encountered in the context of systemic autoimmune diseases; evaluate all treatment options on the basis of existing guidelines; and compliment these data with our personal experience derived from a large number of patients.

Limbic Encephalitis Associated with Sjögren's Syndrome: Report of Three Cases

Sjögren's syndrome (SS) may be complicated by neurological manifestations. We herein report three women (age range 26-60 years old) who all presented with limbic encephalitis (LE) as the predominant clinical feature 3 months to 15 years after the diagnosis of SS. The 26-year-old patient also developed acute motor axonal neuropathy one week after autoimmune encephalitis. All three patients showed contrast-enhanced MRI lesions and inflammatory cerebrospinal fluid findings, while not displaying any anti-neuronal antibodies and showing a remarkable response to immunotherapy. SS is often overlooked when the symptoms are mild. Therefore, in LE cases with no identifiable cause, serological screening for rheumatologic disorders is recommended.

Facial Weakness, Otalgia, and Hemifacial Spasm: A Novel Neurological Syndrome in a Case-Series of 3 Patients With Rheumatic Disease

Bell palsy occurs in different rheumatic diseases, causes hemifacial weakness, and targets the motor branch of the 7th cranial nerve. Severe, persistent, and refractory otalgia having features of neuropathic pain (ie, burning and allodynic) does not characteristically occur with Bell palsy. Whereas aberrant regeneration of the 7th cranial nerve occurring after a Bell palsy may lead to a variety of clinical findings, hemifacial spasm only rarely occurs. We identified in 3 rheumatic disease patients (2 with Sjögren syndrome, 1 with rheumatoid arthritis) a previously unreported neurological syndrome of facial weakness, otalgia with neuropathic pain features, and hemifacial spasm. We characterized symptoms, examination findings, and response to therapy. All 3 patients experienced vertigo, as well as severe otalgia which persisted after mild facial weakness had completely resolved within 1 to 4 weeks. The allodynic nature of otalgia was striking. Two patients were rendered homebound, as even the barest graze of outdoor breezes caused intolerable ear pain. Patients developed hemifacial spasm either at the time of or within 3 months of facial weakness. Two patients had a polyphasic course, with recurrent episodes of facial weakness and increased otalgia. In all cases, otalgia and hemifacial spasm were unresponsive to neuropathic pain regimens, but responded in 1 case to intravenous immunoglobulin therapy. No patients had vesicles or varicella zoster virus in spinal-fluid studies. We have defined a novel neurological syndrome in 3 rheumatic disease patients, characterized by facial weakness, otalgia, and hemifacial spasm. As described in infectious disorders, the combination of otalgia, facial weakness, and 8th cranial nerve deficits suggests damage to the geniculate ganglia (ie, the sensory ganglia of the 7th cranial nerve), with contiguous involvement of other cranial nerves causing facial weakness and vertigo. However, the relapsing nature and association with hemifacial spasm constitute a unique part of this neurological syndrome.

Movement and Other Neurodegenerative Syndromes in Patients with Systemic Rheumatic Diseases: A Case Series of 8 Patients and Review of the Literature

Patients with rheumatic diseases can present with movement and other neurodegenerative disorders. It may be underappreciated that movement and other neurodegenerative disorders can encompass a wide variety of disease entities. Such disorders are strikingly heterogeneous and lead to a wider spectrum of clinical injury than seen in Parkinson's disease. Therefore, we sought to stringently phenotype movement and other neurodegenerative disorders presenting in a case series of rheumatic disease patients. We integrated our findings with a review of the literature to understand mechanisms which may account for such a ubiquitous pattern of clinical injury.Seven rheumatic disease patients (5 Sjögren's syndrome patients, 2 undifferentiated connective tissue disease patients) were referred and could be misdiagnosed as having Parkinson's disease. However, all of these patients were ultimately diagnosed as having other movement or neurodegenerative disorders. Findings inconsistent with and more expansive than Parkinson's disease included cerebellar degeneration, dystonia with an alien-limb phenomenon, and nonfluent aphasias.A notable finding was that individual patients could be affected by cooccurring movement and other neurodegenerative disorders, each of which could be exceptionally rare (ie, prevalence of ∼1:1000), and therefore with the collective probability that such disorders were merely coincidental and causally unrelated being as low as ∼1-per-billion. Whereas our review of the literature revealed that ubiquitous patterns of clinical injury were frequently associated with magnetic resonance imaging (MRI) findings suggestive of a widespread vasculopathy, our patients did not have such neuroimaging findings. Instead, our patients could have syndromes which phenotypically resembled paraneoplastic and other inflammatory disorders which are known to be associated with antineuronal antibodies. We similarly identified immune-mediated and inflammatory markers of injury in a psoriatic arthritis patient who developed an amyotrophic lateral sclerosis (ALS)-plus syndrome after tumor necrosis factor (TNF)-inhibitor therapy.We have described a diverse spectrum of movement and other neurodegenerative disorders in our rheumatic disease patients. The widespread pattern of clinical injury, the propensity of our patients to present with co-occurring movement disorders, and the lack of MRI neuroimaging findings suggestive of a vasculopathy collectively suggest unique patterns of immune-mediated injury.

Acquired immune axonal neuropathies

PURPOSE OF REVIEW

This article discusses the clinical features, pathophysiology, and management of primary and secondary acquired immune axonal neuropathies.

RECENT FINDINGS

Although there are many collagen vascular disorders associated with vasculitic neuropathy, a quarter of cases have been described to be due to nonsystemic vasculitis of the peripheral nervous system. Enhanced surveillance and aggressive treatment of conditions such as cryoglobulin-related vasculitic neuropathy with cyclophosphamide, rituximab, and alfa interferons has led to improved morbidity and mortality, however, many cases of immune axonal acquired neuropathy are still associated with poor outcomes. Acute motor axonal neuropathy (AMAN) and acute motor sensory axonal neuropathy (AMSAN) are well-characterized variants of Guillain-Barré syndrome.

SUMMARY

Characterizing the clinical and electrophysiologic phenotype can help diagnose conditions such as nonsystemic vasculitic neuropathy, AMAN, AMSAN, and immune small fiber neuropathy, while careful evaluation of systemic features is key to identifying secondary immune axonal neuropathies such as vasculitic neuropathy related to collagen vascular disease. Additional research is needed to determine the exact immune pathogenesis and optimized treatment regimens for all acquired immune axonal neuropathies.