Acute motor and sensory axonal neuropathy and concomitant encephalopathy during tumor necrosis factor-alpha antagonist therapy

Neurological Side Effects of TNF-α Inhibitors Revisited: A Review of Case Reports

Over the past two decades, the use of tumor necrosis factor alpha (TNF-α) inhibitors has significantly improved the treatment of patients with immune-mediated inflammatory diseases. Firstly, introduced for rheumatoid arthritis, these inhibitors are currently approved and used for a variety of conditions, including ankylosing spondylitis, Crohn's disease, juvenile idiopathic arthritis, psoriasis, psoriatic arthritis, ulcerative colitis, and chronic uveitis. Despite their immense therapeutic efficacy, TNF-α inhibitors have been associated with neurological adverse effects that bring new clinical challenges. The present review collects data from multiple studies to evaluate the incidence and the relationship between TNF-α inhibitors and neurological side effects and to explore the potential underlying mechanisms of this association. Moreover, it highlights the importance of patient selection, particularly in the case of individuals with a history of demyelinating diseases, raises awareness for clinicians, and calls for ongoing research that will improve TNF-α targeting strategies and offer safer and more effective therapeutic options.

A Case of Acute Motor and Sensory Axonal Neuropathy Secondary to SGN-LIV1A Therapy

Antibody-drug conjugate therapy is rarely associated with neurologic immune-related phenomena. In this case report, we present a patient on treatment with SGN-LIV1A antibody-drug conjugate for breast cancer who developed progressive asymmetric quadriparesis, more severe in the bilateral upper extremities. Acute motor and sensory axonal neuropathy (AMSAN), a sub-variant of Guillain-Barré syndrome, was diagnosed via electro-diagnostic studies. Serological studies were significant for vitamin B1, B2 and B6 deficiencies, and cerebrospinal fluid studies were significant for albuminocytologic dissociation. The patient was treated with intravenous immunoglobulin (IVIg), B complex supplementation, and aggressive physical therapy. There was recovery of muscle strength in all extremities over the course of three months. Our case explores the biologic response to treatment of experimental immunotherapy-induced AMSAN with intravenous immunoglobulin.

Axonal sensorimotor polyneuropathy after starting guselkumab

Guselkumab is an IL-23 inhibitor that binds to the p19 subunit of IL-23 that is highly efficacious and well tolerated for the treatment of moderate-to-severe plaque psoriasis. We report a 20-year-old male who developed sensorimotor axonal polyneuropathy starting treatment with guselkumab, confirmed by neurological examination and serial neurophysiologic studies. His symptoms improved within 5 months of stopping the treatment. The neurophysiologic studies also showed improvement but with continued neuropathy and re-innervation changes on electromyography after about 10 months of stopping treatment. The time line of symptoms and a positive de-challenge are strong but not definitive evidence of guselkumab as a cause.

Imaging spectrum of immunomodulating, chemotherapeutic and radiation therapy-related intracranial effects

OBJECTIVE

A wide range of treatment-related side effects result in specific neurologic symptoms and signs and neuroimaging features. Even to the most seasoned neuroradiologist, elucidating therapy-related side effects from other common mimics can be challenging. We provide a pictorial survey of some common and uncommon medication-induced and therapy-related neuroimaging manifestations, discuss pathophysiology and common pitfalls in imaging and diagnosis.

METHODS

A case-based review is utilized to depict scenarios on a routine basis in a general radiology or neuroradiology practice such as medication-induced posterior reversible encephalopathy syndrome to the more challenging cases of pseudoprogression and pseudoregression in temozolmide and bevacizumab therapy in gliobastoma treatment protocols.

CONCLUSION

Knowledge of the treatment-induced imaging abnormalities is essential in the accurate interpretation and diagnosis from the most routine to most challenging of clinical situations. We provide a pictorial review for the radiologist to employ in order to be an invaluable provider to our clinical colleagues and patients.

Cerebrospinal fluid findings in Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathies

The classic immunologic alteration of the cerebrospinal fluid (CSF) in Guillain-Barré syndrome (GBS), albuminocytologic dissociation, has been known since the original paper by Guillain, Barré, and Strohl. Albuminocytologic dissociation has been also described in other forms of the GBS spectrum, such as axonal motor or motor-sensory forms (AMAN, AMSAN), the anti-GQ1b spectrum of Miller Fisher syndrome, and Bickerstaff brainstem encephalitis. Cytokines, chemokines, antibodies, complement components, and molecules with a putative neuroprotective role or indicating axonal damage have also been examined using different methods. Besides these candidate approaches, proteomics has been recently applied to discover potential biomarkers. The overall results support the immunopathogenesis of GBS, but albuminocytologic dissociation remained the only consistent CSF biomarker supporting the diagnosis of GBS. Chronic inflammatory neuropathies also comprise a heterogeneous group of diseases. Increased protein in the CSF is a supportive factor of chronic inflammatory demyelinating polyneuropathy, especially in the absence of definite electrophysiologic criteria. A number of other markers have also been investigated in the CSF of patients with chronic inflammatory neuropathies, similar to GBS. However, none has been used in supporting diagnosis, differentiating among syndromes, or predicting the clinical course and treatment responses.

Peripheral neuropathy: an underreported neurologic manifestation of inflammatory bowel disease

BACKGROUND AND AIMS

One of the most frequent neurologic complications reported in inflammatory bowel disease population is peripheral neuropathy; however, clinical aspects of peripheral nerve damage are not well characterized. The aim of the review is to present the existing literature on peripheral neuropathy in inflammatory bowel disease patients.

METHODS

A literature search identified the publications reporting on epidemiology, clinical features, underlying mechanisms and management of ulcerative colitis and Crohn's disease patients with peripheral nerve involvement.

RESULTS

The pathogenesis of peripheral nervous system damage in inflammatory bowel disease has yet to be elucidated, although it seems to be related to immune mechanisms; therefore, treatment with immunotherapy is recommended. In addition, peripheral neuropathy may appear as iatrogenic-related disorders associated with several drugs used in controlling inflammatory bowel disease activity; finally, peripheral neuropathy may also be caused by micronutrient deficiencies secondary to malabsorption-related disorders.

CONCLUSIONS

Although peripheral nervous nerve damage associated with inflammatory bowel disease is rarely reported, clinicians should be aware of the peripheral neuropathy clinical manifestations in order to recognize it and provide early treatment, which is crucial for preventing major neurologic morbidity. Heightened awareness is necessary for the successful management of these patients.

Inflammatory bowel disease: An increased risk factor for neurologic complications

Only a very few systematic studies have investigated the frequency of neurologic disorders in patients with Crohn’s disease (CD) and ulcerative colitis (UC), which are the two main types of inflammatory bowel disease (IBD). Results have been inconsistent and variable, owing to differences in case-finding methods and evaluated outcomes in different studies. The most frequent neurologic manifestations reported in CD and UC populations are cerebrovascular disease (with either arterial or venous events), demyelinating central nervous system disease, and peripheral neuropathy (whether axonal or demyelinating); however, the literature describes numerous nervous system disorders as being associated with IBD. The pathogenesis of nervous system tissue involvement in IBD has yet to be elucidated, although it seems to be related to immune mechanisms or prothrombotic states. The recently-introduced tumor necrosis factor (TNF) inhibitors have proven successful in controlling moderate to severe IBD activity. However, severe neurologic disorders associated with TNF inhibitors have been reported, which therefore raises concerns regarding the effect of anti-TNF-α antibodies on the nervous system. Although neurological involvement associated with IBD is rarely reported, gastroenterologists should be aware of the neurologic manifestations of IBD in order to provide early treatment, which is crucial for preventing major neurologic morbidity.

Multifocal encephalopathy and autoimmune-mediated limbic encephalitis following tocilizumab therapy

A 63-year-old man with rheumatoid arthritis developed multifocal encephalopathy and limbic encephalitis following therapy with tocilizumab, a humanized anti-interleukin-6 receptor antibody. Anti-glutamate receptor ε2 antibodies were later found to be positive in both the serum and cerebrospinal fluid. This case highlights the possibility of the development of encephalopathy after treatment with tocilizumab, which may also induce autoimmune limbic encephalitis.

Non-length-dependent and length-dependent small-fiber neuropathies associated with tumor necrosis factor (TNF)-inhibitor therapy in patients with rheumatoid arthritis: expanding the spectrum of neurological disease associated with TNF-inhibitors

OBJECTIVE

Small-fiber neuropathy causes severe burning pain, requires diagnostic approaches such as skin biopsy, and encompasses two subtypes based on distribution of neuropathic pain. Such biopsy-proven subtypes of small-fiber neuropathies have not been previously described as complications of tumor necrosis factor (TNF)-inhibitor therapy.

METHODS

We therefore characterized clinical and skin biopsy findings in three rheumatoid arthritis (RA) patients who developed small-fiber neuropathies associated with TNF-inhibitors. We also conducted a systematic review of the literature to characterize subtypes of neuropathies previously reported in association with TNF-inhibitor therapy.

RESULTS

Two patients presented with a "non-length-dependent" small-fiber neuropathy, experiencing unorthodox patterns of burning pain affecting the face, torso, and proximal extremities. Abnormal skin biopsy findings were limited to the proximal thigh, which is a marker of proximal-most dorsal root ganglia degeneration. In contrast, one patient presented with a "length-dependent" small-fiber neuropathy, experiencing burning pain only in the feet. Abnormal skin biopsy findings were limited to the distal feet, which is a marker of distal-most axonal degeneration. One patient developed a small-fiber neuropathy in the context of TNF-inhibitor-induced lupus. In all patients, neuropathies occurred during TNF-inhibitor-induced remission of RA disease activity and improved on withdrawal of TNF-inhibitors.

CONCLUSIONS

We describe a spectrum of small-fiber neuropathies not previously reported in association with TNF-inhibitor therapy, with clinical and skin biopsy findings suggestive of dorsal root ganglia as well as axonal degeneration. The development of small-fiber neuropathies during inactive joint disease and improvement of neuropathic pain upon withdrawal of TNF-inhibitor suggest a causative role of TNF-inhibitors.

Importance of glial activation in neuropathic pain

Glia plays a crucial role in the maintenance of neuronal homeostasis in the central nervous system. The microglial production of immune factors is believed to play an important role in nociceptive transmission. Pain may now be considered a neuro-immune disorder, since it is known that the activation of immune and immune-like glial cells in the dorsal root ganglia and spinal cord results in the release of both pro- and anti-inflammatory cytokines, as well as algesic and analgesic mediators. In this review we presented an important role of cytokines (IL-1alfa, IL-1beta, IL-2, IL-4, IL-6, IL-10, IL-15, IL-18, TNFalpha, IFNgamma, TGF-beta 1, fractalkine and CCL2); complement components (C1q, C3, C5); metaloproteinases (MMP-2,-9) and many other factors, which become activated on spinal cord and DRG level under neuropathic pain. We discussed the role of the immune system in modulating chronic pain. At present, unsatisfactory treatment of neuropathic pain will seek alternative targets for new drugs and it is possible that anti-inflammatory factors like IL-10, IL-4, IL-1alpha, TGF-beta 1 would fulfill this role. Another novel approach for controlling neuropathic pain can be pharmacological attenuation of glial and immune cell activation. It has been found that propentofylline, pentoxifylline, minocycline and fluorocitrate suppress the development of neuropathic pain. The other way of pain control can be the decrease of pro-nociceptive agents like transcription factor synthesis (NF-kappaB, AP-1); kinase synthesis (MEK, p38MAPK, JNK) and protease activation (cathepsin S, MMP9, MMP2). Additionally, since it is known that the opioid-induced glial activation opposes opioid analgesia, some glial inhibitors, which are safe and clinically well tolerated, are proposed as potential useful ko-analgesic agents for opioid treatment of neuropathic pain. This review pointed to some important mechanisms underlying the development of neuropathic pain, which led to identify some possible new approaches to the treatment of neuropathic pain, based on the more comprehensive knowledge of the interaction between the nervous system and glial and immune cells.

Neurological deficits during treatment with tumor necrosis factor-alpha antagonists

INTRODUCTION

Neurological deficits that occur during treatment with tumor necrosis factor (TNF)-α antagonists are rare, and their clinical features have not been fully elucidated.

METHODS

Retrospective review of medical records of 9 patients who were given TNF-α antagonists, subsequently developed neurological deficits and were cared for at the Medical University of South Carolina between January 2002 and May 2010. Adverse drug reaction probability scale was used for the assessment of their causal connection.

RESULTS

The underlying diseases for which TNF-α antagonists were administered included rheumatologic disorders (4), sarcoidosis (3), psoriasis (1) and Crohn's disease (1). Etanercept, infliximab or adalimumab was administered to these patients. Neurological complications included central or peripheral demyelination (5), antiphospholipid syndrome/central nervous system lupus (1), Epstein-Barr virus encephalitis (1), axonal sensory polyneuropathy (1) and small fiber polyneuropathy (1). TNF-α antagonists were discontinued in 8 patients and clinical improvement was seen in 3 of them. Additional therapies were given in 4 patients. An adverse drug reaction probability score suggested probable (3/9) and possible (6/9) causal relationships.

CONCLUSIONS

Neurological deficits that develop during treatment with TNF-α antagonists are relatively rare but important potential complications of these drugs. Determining if the relationship between the neurological deficits and TNF-α antagonist therapy is causal can be challenging and can impact patient care.

Inflammatory neurological disease in patients treated with tumor necrosis factor alpha inhibitors

Background: TNF alpha inhibitor (TNFAI) therapy has been associated with inflammatory neurological syndromes.

Objectives: To present 10 new cases of TNFAI associated neurological disease and a review of the literature.

Methods: The design and methods were based on case series collected from Oregon Health & Sciences University and the Department of Veterans Affairs Hospital in Portland, Oregon and PubMed review.

Results: We describe eight demyelinating central nervous system syndromes and two peripheral nervous system syndromes associated with TNFAI therapy. Characteristics from these cases are analyzed with data from 141 additional cases from the literature. Onset was between the ages of 36 and 65 years in 84% of CNS cases, distinguishing TNFAI-associated disease from sporadic multiple sclerosis. Symptoms occurred within one year of TNFAI therapy in 71%. Etanercept therapy was reported in the majority of cases of CNS syndromes and infliximab therapy in the majority of neuromuscular syndromes. Significant disability remained in 67% of cases although 82% had been followed for less than one year.

Conclusions: Our case series and literature review demonstrates an association between TNFAI therapy and inflammatory neurological disease. While a causal relationship is suggested, this remains uncertain. TNFAI-associated neurological syndromes are associated with significant disability and longer follow-up is needed to better determine natural history and evaluate appropriate treatment interventions.

Novel insights on diagnosis, cause and treatment of diabetic neuropathy: focus on painful diabetic neuropathy

Diabetic neuropathy is common, under or misdiagnosed, and causes substantial morbidity with increased mortality. Defining and developing sensitive diagnostic tests for diabetic neuropathy is not only key to implementing earlier interventions but also to ensure that the most appropriate endpoints are employed in clinical intervention trials. This is critical as many potentially effective therapies may never progress to the clinic, not due to a lack of therapeutic effect, but because the endpoints were not sufficiently sensitive or robust to identify benefit. Apart from improving glycaemic control, there is no licensed treatment for diabetic neuropathy, however, a number of pathogenetic pathways remain under active study. Painful diabetic neuropathy is a cause of considerable morbidity and whilst many pharmacological and nonpharmacological interventions are currently used, only two are approved by the US Food and Drug Administration. We address the important issue of the 'placebo effect' and also consider potential new pharmacological therapies as well as nonpharmacological interventions in the treatment of painful diabetic neuropathy.