Infectious Neuropathies

A great simulator in clinical practice: mononeuritis multiplex in HIV infection

HIV infection is a chameleon, mimicking several diseases. Herein, we report a previously healthy 39-year-old woman who, over 2 months, developed arthritis, weight loss, and confluent multiple mononeuropathy. Extensive laboratory investigation showed positive serology for HIV, with a CD4 count of 100 cells, and necrotizing vasculitis on a nerve biopsy not associated with CMV co-infection, allowing the diagnosis of polyarteritis nodosa-like vasculitis in an HIV-infected patient. Apart from the infection, HIV-related autoimmunity can affect any organ and contribute to the complexity of the clinical presentation of HIV infection.

Focal inflammatory neuropathies

This chapter focuses on neuropathies that present with focal involvement of nerve roots, plexus, and/or peripheral nerves associated with autoimmune and inflammatory mechanisms that present with focal involvement of nerve roots, plexus and/or peripheral nerves. The clinical presentation, diagnosis, and treatment of focal autoimmune demyelinating neuropathies, focal nonsystemic vasculitic disorders (diabetic and nondiabetic radiculoplexus neuropathies, postsurgical inflammatory neuropathy, and neuralgic amyotrophy), and focal neuropathies associated with sarcoidosis and bacterial and viral infections are reviewed.

Axonal Sensorimotor Polyneuropathies

PURPOSE OF REVIEW

This article describes clinical features of axonal sensorimotor polyneuropathies based on selected etiologies.

RECENT FINDINGS

Axonal sensorimotor polyneuropathies have been well described for some time. Recent advances include the assessment of the incidence of peripheral neuropathy in the elderly, the recognition of the limited influence of electrodiagnostic testing on the clinical management of uncomplicated axonal sensorimotor polyneuropathy, the development of guidelines for treatment of painful neuropathy, the identification of risk factors predisposing patients for chemotherapy-induced neuropathy, a report on the association of metabolic syndrome and idiopathic axonal sensorimotor neuropathy, and the availability of more cost-effective genetic testing for identifying inherited polyneuropathies.

SUMMARY

Axonal sensorimotor polyneuropathies carry an extensive list of differential diagnoses. Diagnosis is based on detailed history, physical examination, recognition of associated neurologic and non-neurologic features, and appropriate testing. Disease-modifying treatments are lacking in many cases. Management focuses on modification of predisposing lifestyle and medical factors, rehabilitation, and pain relief.

The Importance of Rare Subtypes in Diagnosis and Treatment of Peripheral Neuropathy: A Review

IMPORTANCE

Peripheral neuropathy is a prevalent condition that usually warrants a thorough history and examination but has limited diagnostic evaluation. However, rare localizations of peripheral neuropathy often require more extensive diagnostic testing and different treatments.

OBJECTIVE

To describe rare localizations of peripheral neuropathy, including the appropriate diagnostic evaluation and available treatments.

EVIDENCE REVIEW

References were identified from PubMed searches conducted on May 29, 2015, with an emphasis on systematic reviews and randomized clinical trials. Articles were also identified through the use of the authors' own files. Search terms included common rare neuropathy localizations and their causes, as well as epidemiology, pathophysiology, diagnosis, and treatment.

FINDINGS

Diffuse, nonlength-dependent neuropathies, multiple mononeuropathies, polyradiculopathies, plexopathies, and radiculoplexus neuropathies are rare peripheral neuropathy localizations that often require extensive diagnostic testing. Atypical neuropathy features, such as acute/subacute onset, asymmetry, and/or motor predominant signs, are frequently present. The most common diffuse, nonlength-dependent neuropathies are Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and amyotrophic lateral sclerosis. Effective disease-modifying therapies exist for many diffuse, nonlength-dependent neuropathies including Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and some paraprotein-associated demyelinating neuropathies. Vasculitic neuropathy (multiple mononeuropathy) also has efficacious treatment options, but definitive evidence of a treatment effect for IgM anti-MAG neuropathy and diabetic amyotrophy (radiculoplexus neuropathy) is lacking.

CONCLUSIONS AND RELEVANCE

Recognition of rare localizations of peripheral neuropathy is essential given the implications for diagnostic testing and treatment. Electrodiagnostic studies are an important early step in the diagnostic evaluation and provide information on the localization and pathophysiology of nerve injury.

Trypanosoma cruzi Causes Paralyzing Systemic Necrotizing Vasculitis Driven by Pathogen-Specific Type I Immunity in Mice

Infectious agents are often considered potential triggers of chronic inflammatory disease, including autoimmunity; however, direct evidence is usually lacking. Here we show that following control of acute infection of mice with the myotropic Colombiana strain of Trypanosoma cruzi, parasites persisted in tissue at low levels associated with development of systemic necrotizing vasculitis. Lesions occurred in many but not all organs and tissues, with skeletal muscle arteries being the most severely affected, and were associated with myositis, atrophy, paresis/paralysis, and death. Histopathology showed fibrinoid vascular necrosis, rare amastigote nests within skeletal muscle myocytes, and massive leukocyte infiltrates composed mainly of inflammatory monocytes, F4/80(+)macrophages, and T. cruzi tetramer-specific CD8(+) T lymphocytes capable of producing gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) but not interleukin-17 (IL-17). T. cruzi-specific IgG was detected in sera from infected mice, but antibody deposits and neutrophilic inflammation were not features of the lesions. Thus,T. cruzi infection of mice may be a specific infectious trigger of paralyzing systemic necrotizing vasculitis most severely affecting skeletal muscle, driven by pathogen-specific type I immune responses.

Infectious neuropathies

PURPOSE OF REVIEW

Infections are important, potentially treatable causes of peripheral nervous system disease. This article reviews the clinical presentation and management of several common peripheral nervous system diseases due to viral, bacterial, spirochetal, and parasitic infections.

RECENT FINDINGS

The clinical presentation and evaluation of infectious peripheral nervous system diseases are well established. Advances in the treatment and, in some cases, the prevention of these diseases are still evolving.

SUMMARY

A diverse range of peripheral nervous system diseases, including peripheral neuropathy, radiculopathy, radiculomyelopathy, cranial neuropathy, and motor neuropathy, are caused by numerous infectious agents. In some patients, peripheral neuropathy may be a side effect of anti-infectious drugs. Infectious neuropathies are important to recognize as they are potentially treatable. This article discusses the clinical presentation, evaluation, and treatment of several common peripheral nervous system diseases caused by viral, bacterial, spirochetal, and parasitic infections, as well as some peripheral nerve disorders caused by adverse effects of the treatments of these infectious diseases.

rhesus cytomegalovirus (macacine herpesvirus 3)-associated facial neuritis in simian immunodeficiency virus-infected rhesus macaques (Macaca mulatta)

Peripheral neuropathies are common sequelae to human immunodeficiency virus (HIV) infection in humans and are due to a variety of mechanisms, including direct antiretroviral toxicity, HIV-mediated damage, immune-mediated disorders, and opportunistic viral infections. Rhesus macaques (Macaca mulatta) infected with simian immunodeficiency virus (SIV) remain the most consistent animal model for unraveling the pathogenesis of lentiviral-associated disease and its associated opportunistic infections. Rhesus cytomegalovirus (RhCMV) is the most common opportunistic viral infection in rhesus macaques infected with SIV and causes multiorgan pathology; however, its role in peripheral nerve pathology has not been explored. We have identified 115 coinfected cases with SIV and RhCMV, of which 10 cases of RhCMV-associated facial neuritis were found (8.7% prevalence). Histologic lesions were consistent in all cases and ranged from partial to complete obliteration of the nerves of the tongue, lacrimal gland, and other facial tissues with a mixed inflammatory population of neutrophils and macrophages, of which the latter commonly contained intranuclear inclusion bodies. Luxol fast blue staining and myelin basic protein immunohistochemistry confirmed the progressive myelin loss in the peripheral nerves. Bielschowsky silver stain revealed progressive loss of axons directly related to the severity of inflammation. Double immunohistochemistry with spectral imaging analysis revealed RhCMV-infected macrophages directly associated with the neuritis, and there was no evidence to support RhCMV infection of Schwann cells. These results suggest that peripheral nerve damage is a bystander effect secondary to inflammation rather than a direct infection of Schwann cells and warrants further investigations into the pathogenesis of RhCMV-induced peripheral neuropathy.

[Peripheral nerve lesions of the lower leg due to tibiofibular ganglion]

Cystic formations around the knee are a common object of orthopedic treatment. When associated with neurological or vascular deficits further diagnostic imaging is required. This case study demonstrates the appearance of an intramuscular ganglion causing drop foot, arising from the tibio-fibular joint.

A community-based epidemiological study of peripheral neuropathies in Assiut, Egypt

BACKGROUND

There is very little published information about the prevalence, patterns, and predictors of peripheral neuropathies. The current study is a community-based survey was conducted in the Assiut Governorate to estimate their prevalence and clinical profile.

MATERIAL AND METHODS

A door-to-door study was carried out on 42,223 persons from rural and urban communities in the Assiut Governorate, Egypt. There were 13,288 (31.5%) subjects from the urban and 28,935 (68·5%) from the rural area. All subjects filled in a questionnaire designed specifically for diagnosis of peripheral neuropathy. Positive cases were then given a complete medical and neurological examination, routine laboratory tests, neurophysiology, and neuroimaging (magnetic resonance).

RESULTS

The crude prevalence rate (CPR) of peripheral neuropathy was 3181/100,000 inhabitants. There was a significantly higher prevalence in the rural compared with the urban population (3795 versus 1844/100,000) and in females than males (4473 versus 1943/100,000; P<0.001 for both). The most common type reported was entrapment neuropathy (736 cases with CPR of 1743/100,000), particularly carpal tunnel syndrome (1686/100,000). Diabetic neuropathy was the most common non-compressive neuropathy with a CPR of 649/100,000. Type II diabetes was recorded in 241 patients with a CPR of 571/100,000. Compressive radiculopathy had a crude prevalence of 358/100,000; traumatic and iatrogenic radiculopathy had a prevalence rate of 149/100,000. Less common conditions were: uremic neuropathy (21/100,000) hepatic neuropathy (14/100,000), Bell's palsy (28/100,000), Guillian-Barre' syndrome (12/100,000), chronic inflammatory demyelinating polyneuropathy (12/100,000), hereditary sensory motor neuropathy (12/100,000), and idiopathic neuropathy (92/100,000).

CONCLUSION

The overall prevalence of peripheral neuropathies was high in comparison to other studies. Entrapment neuropathy, diabetic neuropathy, and spondylotic radiculopathy were the most common. Overall, the prevalence of peripheral neuropathy was higher in the rural than in the urban population.

Lyme neuroborreliosis

Lyme neuroborreliosis (LNB) designates the nervous system disorders caused by the tick-borne spirochete Borrelia burgdorferi (Bb). The clinical syndromes are usually distinct and are classified as early and the rare late or chronic LNB. Early LNB occurs 3-6 weeks after infection most frequently as a lymphocytic meningoradiculoneuritis (LMR). Symptoms are mainly due to a painful sensory radiculitis and a multifocal motor radiculo-neuritis. Fifty percent have cranial nerve involvement predominantly uni- or bilateral facial nerve palsies. Meningitic symptoms occur primarily in children. Nerve biopsies, autopsies, animal models, and nerve conduction studies showed that the pathology is a lymphocytic perineuritis leading to multisegmental axonal injury of nerve roots, spinal ganglia, and distal nerve segments. Due to meningeal and root inflammation cerebrospinal fluid (CSF) shows lymphocytic inflammation. The only evidence that Bb causes peripheral neuropathy without CSF inflammation is seen in patients with acrodermatitis chronica atrophicans (ACA), a chronic dermatoborreliosis. In the rare chronic or late LNB the pathology and thus the clinical presentation is primarily due to chronic meningitis and meningovascular CNS involvement, whereas the peripheral nervous system is not primarily affected. In early and late LNB the diagnosis is based on a characteristic clinical appearance and CSF inflammation with Bb-specific intrathecal antibody production. Both conditions, but not the ACA-associated neuropathy, respond to antibiotic therapy.

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.

Leprous neuropathy

Leprous neuropathy, which is due to infection of nerve cells by Mycobacterium leprae, still affects millions of people in many developing countries. The clinical and pathological manifestations are determined by the natural resistance of the host to invasion of M. Leprae. Failure of early detection of leprosy often leads to severe disability in spite of eradication of mycobacterium at a later date. In the lepromatous type, bacilli are easily found in the skin and in nerve cells including Schwann cells, endothelial cells, and macrophages. In the tuberculoid type, a strong cell-mediated immune reaction leads to formation of granulomas and destruction of cells harboring bacilli and neighboring nerve fibers. In many cases, treatment of patients with the multibacillary leprosy is complicated by reversal reaction and further nerve damage. Nerve lesions lead to a symmetrical, pseudo-polyneuritic pattern in most cases of lepromatous leprosy, which is usually associated with typical skin lesions, but pure neuritic forms occur in up to 10% of patients with lepromatous leprosy. In the pure neuropathic cases, only nerve biopsy permits diagnosis. The multifocal pattern is more common in tuberculoid leprosy. Treatment is currently based on multidrug therapy with dapsone, rifampicin, and clofazimine. The use of corticosteroids can reduce or prevent nerve damage in reversal reactions. It is important to remember that sequelae, especially sensory loss, are extremely common, which can lead to secondary trophic changes due to repeated trauma in painless areas.

Leprosy late-onset neuropathy: an uncommon presentation of leprosy

Clinical and pathological findings in leprosy are determined by the natural host immune response to Mycobacterium leprae. We previously described cases of painful neuropathy (PN) with no concurrent cause apart from a past history of leprosy successfully treated. Four leprosy previously treated patients who developed a PN years after multidrug therapy (MDT) are reported. The mean patient age was 52.75 years (47-64). The mean time interval of the recent neuropathy from the previous MDT was 19 years (12-26). A painful multiplex neuritis or polyneuropathy were observed respectively in two cases. Electrophysiological studies disclosed a sensory axonal neuropathy in two cases. Microvasculitis with no bacilli was seen in nerve biopsy. Neuropathic symptoms were improved with prednisone. We consider these cases as being a leprosy late-onset neuropathy (LLON) form of presentation. A delayed immune reaction could explain the late appearance of LLON.

Unilateral palatal and abducens palsy in childhood hepatitis A virus infection

Isolated cranial nerve paresis in childhood hepatitis A virus infection is rare. The authors report an instance of concomitant right-hand side palatal and abducens palsy, developing in the course of an otherwise uncomplicated hepatitis A virus infection in a 5-year-old girl. The neurological complications were transient, and she recovered completely with supportive therapy.

Infectious neuropathy

PURPOSE OF REVIEW

Infectious neuropathy affects a large number of people worldwide. There is evidence of direct involvement of nerves by the infective agent, from the immune reaction of the patient or secondary to the toxicity of the drugs used during treatment. This group of neuropathies is often treatable or preventable.

RECENT FINDINGS

There is a complex clinical picture of the neuropathy of leprosy, different pathological features and immunological mechanisms. If the skin is unaffected in leprosy it is not always easy to demonstrate that the neuropathy is due to leprosy. Peripheral neuropathy in patients with chronic infection with hepatitis C virus may be due to the virus, the development of vasculitis or direct neurotoxic effects of the treatment. Peripheral neuropathy has become the chief neurological syndrome in individuals infected with HIV-1. The antiretroviral therapies themselves can cause peripheral neuropathies clinically indistinguishable from those caused by the virus. The occurrence of chronic polyneuropathy as a late manifestation in Lyme disease is extremely rare and is not well understood.

SUMMARY

Although infectious neuropathies are very frequent, mainly in developing countries, further studies are needed to elucidate their mechanisms of action, focusing on preventive interventions.

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.