Painful vasculitic neuropathy in HIV-1 infection: relief of pain with prednisone therapy

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.

Manifestations of HIV infection in the peripheral nervous system

Peripheral nerve disorders are associated with all stages of HIV infection. Distal sensory polyneuropathy is characterised by often-disabling pain that is difficult to treat. It is prevalent in both high-income and low-income settings. In low-income settings, use of potentially neurotoxic antiretrovirals, which are inexpensive and widely available, contributes substantially to incidence. Research has focused on identification of factors that predict risk of distal sensory polyneuropathy and elucidation of the multifactorial mechanisms behind pathogenesis. Sensorimotor polyneuropathies and polyradiculopathies are less frequent than distal sensory polyneuropathy, but still occur in low-income settings and have potentially devastating consequences. However, many of these diseases can be treated successfully with a combination of antiretroviral and immune-modulating therapies. To distinguish between peripheral nerve disorders that have diverse, overlapping, and frequently atypical presentations can be challenging; a framework based on a clinicoanatomical approach might assist in the diagnosis and management of such disorders.

Peripheral neuropathy in the elderly

Peripheral neuropathy is an important factor of disability in the elderly, which is significant now that up to 20% of the population is older than 60 years in industrialized countries. Potentially treatable neuropathies including primary inflammatory polyneuropathies and systemic disorders, especially vasculitic neuropathies, are as common in this age group as in younger patients. Neuropathies associated with diabetes, malignancy, and monoclonal gammopathies are even more common in these patients. It is thus essential to identify the causes of these neuropathies in this group of patients and treat them whenever feasible.

HIV peripheral neuropathy

Peripheral neuropathies are the most common neurological manifestations occurring in HIV-infected individuals. Distal symmetrical sensory neuropathy is the most common form encountered today and is one of the few that are specific to HIV infection or its treatment. The wide variety of other neuropathies is akin to the neuropathies seen in the general population and should be managed accordingly. In the pre-ART era, neuropathies were categorized according to the CD4 count and HIV viral load. In the early stages of HIV infection when CD4 count is high, the inflammatory demyelinating neuropathies predominate and in the late stages with the decline of CD4 count opportunistic infection-related neuropathies prevail. That scenario has changed with the present almost universal use of ART (antiretroviral therapy). Hence, HIV-associated peripheral neuropathies are better classified according to their clinical presentations: distal symmetrical polyneuropathy, acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), mononeuropathies, mononeuropathies multiplex and cranial neuropathies, autonomic neuropathy, lumbosacral polyradiculomyelopathy, and amyotrophic lateral sclerosis (ALS)-like motor neuropathy. Treated with ART, HIV-infected individuals are living longer and are at a higher risk of metabolic and age-related complications; moreover they are also prone to the potentially neurotoxic effects of ART. There are no epidemiological data regarding the incidence and prevalence of the peripheral neuropathies. In the pre-ART era, most data were from case reports, series of patients, and pooled autopsy data. At that time the histopathological evidence of neuropathies in autopsy series was almost 100%. In large prospective cohorts presently being evaluated, it has been found that 57% of HIV-infected individuals have distal symmetrical sensory neuropathy and 38% have neuropathic pain. It is now clear that distal symmetrical sensory neuropathy is caused predominantly by the ART's neurotoxic effect but may also be caused by the HIV itself. With a sizeable morbidity, the neuropathic pain caused by distal symmetrical sensory neuropathy is very difficult to manage; it is often necessary to change the ART regimen before deciding upon the putative role of HIV infection itself. If the change does not improve the pain, there are few options available; the most common drugs used for neuropathic pain are usually not effective. One is left with cannabis, which cannot be recommended as routine therapy, recombinant human nerve growth factor, which is unavailable, and topical capsaicin with its side-effects. Much has been done to and learned from HIV infection in humans; HIV-infected individuals, treated with ART, are now dying mostly from cardiovascular disease and non-AIDS-related cancers. It hence behooves us to find new approaches to mitigate the residual neurological morbidity that still impacts the quality of life of that population.

Processing of nerve biopsies: a practical guide for neuropathologists

Nerve biopsy is a valuable tool in the diagnostic work-up of peripheral neuropathies. Currently, major indications include interstitial pathologies such as suspected vasculitis and amyloidosis, atypical cases of inflammatory neuropathy and the differential diagnosis of hereditary neuropathies that cannot be specified otherwise. However, surgical removal of a piece of nerve causes a sensory deficit and – in some cases – chronic pain. Therefore, a nerve biopsy is usually performed only when other clinical, laboratory and electrophysiological methods have failed to clarify the cause of disease. The neuropathological work-up should include at least paraffin and resin semithin histology using a panel of conventional and immunohistochemical stains. Cryostat section staining, teased fiber preparations, electron microscopy and molecular genetic analyses are potentially useful additional methods in a subset of cases. Being performed, processed and read by experienced physicians and technicians nerve biopsies can provide important information relevant for clinical management.

Pharmacological treatment of painful HIV-associated sensory neuropathy: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Significant pain from HIV-associated sensory neuropathy (HIV-SN) affects ∼40% of HIV infected individuals treated with antiretroviral therapy (ART). The prevalence of HIV-SN has increased despite the more widespread use of ART. With the global HIV prevalence estimated at 33 million, and with infected individuals gaining increased access to ART, painful HIV-SN represents a large and expanding world health problem. There is an urgent need to develop effective pain management strategies for this condition.

METHOD AND FINDINGS

OBJECTIVE

To evaluate the clinical effectiveness of analgesics in treating painful HIV-SN.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Cochrane central register of controlled trials, www.clinicaltrials.gov, www.controlled-trials.com and the reference lists of retrieved articles.

SELECTION CRITERIA

Prospective, double-blinded, randomised controlled trials (RCTs) investigating the pharmacological treatment of painful HIV-SN with sufficient quality assessed using a modified Jadad scoring method.

REVIEW METHODS

Four authors assessed the eligibility of articles for inclusion. Agreement of inclusion was reached by consensus and arbitration. Two authors conducted data extraction and analysis. Dichotomous outcome measures (≥ 30% and ≥ 50% pain reduction) were sought from RCTs reporting interventions with statistically significant efficacies greater than placebo. These data were used to calculate RR and NNT values.

RESULTS

Of 44 studies identified, 19 were RCTs. Of these, 14 fulfilled the inclusion criteria. Interventions demonstrating greater efficacy than placebo were smoked cannabis NNT 3.38 95%CI(1.38 to 4.10), topical capsaicin 8%, and recombinant human nerve growth factor (rhNGF). No superiority over placebo was reported in RCTs that examined amitriptyline (100mg/day), gabapentin (2.4 g/day), pregabalin (1200 mg/day), prosaptide (16 mg/day), peptide-T (6 mg/day), acetyl-L-carnitine (1g/day), mexilitine (600 mg/day), lamotrigine (600 mg/day) and topical capsaicin (0.075% q.d.s.).

CONCLUSIONS

Evidence of efficacy exists only for capsaicin 8%, smoked cannabis and rhNGF. However,rhNGF is clinically unavailable and smoked cannabis cannot be recommended as routine therapy. Evaluation of novel management strategies for painful HIV-SN is urgently needed.

Approach to vasculitic neuropathies

Since vasculitic neuropathy is treatable and potentially debilitating, clinicians should develop an approach to neuropathy that increases the likelihood of uncovering existing systemic or nonsystemic vasculitis. The presence of a connective tissue disease, systemic vasculitis, asymmetric or non--length-dependent axonal polyneuropathy, or multiple axonal mononeuropathies should heighten suspicion, but vasculitic neuropathy can also present as a distal symmetric polyneuropathy with or without other organ involvement. Electrodiagnostic testing utilizing extensive nerve conductions may be helpful in identifying features suggestive of vasculitic neuropathy and in selecting an abnormal nerve and muscle for biopsy confirmation. An array of laboratory tests may lead to identification of a systemic disorder that is either characterized by or predisposes to vasculitic neuropathy. The mainstays of treatment are corticosteroids and cyclophosphamide, but other drugs are used in specific conditions. With early diagnosis and careful monitoring of treatment regimens, the prognosis is usually good.

Infection and musculoskeletal conditions: Rheumatologic complications of HIV infection

The pandemic caused by the human immunodeficiency virus (HIV) has entered its second quarter-century, with 40 million people now affected worldwide - particularly in Africa, where the impact has been most devastating. A complex array of rheumatic disease manifestations has been described, including diseases specific to HIV infection such as HIV-associated arthritis and the diffuse infiltrative lymphocytosis syndrome; other conditions which occur prominently in HIV-positive individuals include vasculitis, reactive and psoriatic arthritis and HIV-associated polymyositis, opportunistic musculoskeletal infections, and finally disorders that were originally ameliorated by HIV infection, such as rheumatoid arthritis and lupus. Effective antiretroviral treatment ameliorates many of these disorders; however, the introduction of highly active antiretroviral treatment (HAART) has introduced a new spectrum of disorders and new challenges confronting the clinician, including osteonecrosis, rhabdomyolysis, and, with immune reconstitution, the appearance de novo of a variety of autoimmune disorders and phenomena.

Vasculitic Neuropathies

BACKGROUND

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

REVIEW SUMMARY

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

CONCLUSION

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

Degenerative and inflammatory lesions in sympathetic ganglia: further morphological evidence for an autonomic neuropathy in AIDS

There is accumulating evidence that autonomic dysfunction occurs in HIV infection. While many studies have demonstrated autonomic abnormalities on clinical basis, only one has studied the morphology of sympathetic ganglia. The superior sympathetic ganglia of 12 randomly selected AIDS patients and those of 6 controls were examined morphologically in order to determine the frequency and severity of their involvement. Although they had not been investigated for autonomic dysfunction, 5 had suffered from non-infectious diarrhoea, one showed bilateral ptosis and another had non-specified visual problems. All cases showed clusters, and perivascular mononuclear inflammatory cells, occasionally infiltrating vessel walls, some evidence of nerve cell degeneration, and proliferation of capsule cells. Immunostainings showed T lymphocytes and an increased number of macrophages. HIV antigens were detected in macrophages, in 6 cases (50%). This study provides further morphological support for the autonomic dysfunction in association with HIV infection. As for the mechanism of this dysfunction, it has been postulated a direct infection, the virus entering the ganglia through macrophages and acting as a reservoir for HIV, and an autoimmune pathogenesis. Since HIV antigens were not detected in 50% of the cases in this and in a previous study, despite the existence of morphological lesions, it is possible that, as in HIV-related sensory-motor peripheral neuropathies, an autoimmune mechanism may also play a role in the development of the autonomic lesions.

Therapy for vasculitic neuropathies

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

Human immunodeficiency virus-associated peripheral neuropathies

Peripheral neuropathy has emerged as the most common neurologic complication of human immunodeficiency virus (HIV) infection. It will continue to play an Important role in HIV Infection given the fact that HIV-infected Individuals are living longer, are at risk of long-term metabolic complications, and face an Increasing exposure to potentially neurotoxic antiretroviral drugs. We review the various types of peripheral neuropathy that have been associated with HIV infection, including distal symmetrical polyneuropathy, toxic neuropathy from antiretroviral drugs, diffuse infiltrative lymphocytosis syndrome, inflammatory demyelinating polyneuropathies, multifocal mononeuropathies, and progressive polyradiculopathy.

Peripheral neuropathies associated with HIV and hepatitis C co-infection: a review

Co-infection with HIV and hepatitis C has become increasingly prevalent. It is a major source of morbidity in HIV-infected populations. Distal symmetric polyneuropathy is the most common form of peripheral neuropathy in HIV as well as hepatitis C mono-infection. There is considerable overlap in the symptoms and signs of HIV and hepatitis C neuropathy. It is not known whether there are additive or synergistic effects on the peripheral nerve by these two viruses. There is a need for studies to further elucidate the mechanisms involved.

The peripheral nerve complications of human immunodeficiency virus (HIV) infection

Peripheral nerve complications occurring in patients with human immunodeficiency virus (HIV) infection are frequent and challenging. This review discusses these various complications according to the degree of advancement of HIV disease. Particular emphasis is placed upon emerging causes of neuropathy found in the context of HIV disease, such as infection with hepatitis C and human T-lymphotropic virus type I, as well as neuropathies related to antiretroviral medications.

Peripheral neuropathy and antiretroviral drugs

Patients treated with nucleoside analogue reverse transcriptase inhibitors (NRTIs) develop a varying degree of myopathy or neuropathy after long-term therapy. Zidovudine (AZT) causes myopathy; zalcitabine (ddC), didanosine (ddl) and lamuvidine (3TC) cause neuropathy; stavudine (d4T) and fialuridine (FIAU) cause neuropathy or myopathy and lactic acidosis. The tissue distribution of phosphorylases responsible for phosphorylation of NRTIs relates to their selective tissue toxicity. The myopathy is characterized by muscle wasting, myalgia, fatigue, weakness and elevation of CK. The neuropathy is painful, sensory and axonal. In vitro, NRTIs inhibit the gamma-DNA polymerase, responsible for replication of mtDNA, and cause mtDNA dysfunction. In vivo, patients treated with AZT, the best studied NRTI, develop a mitochondrial myopathy with mtDNA depletion, deficiency of COX (complex IV), intracellular fat accumulation, high lactate production and marked phosphocreatine depletion, as determined with in vivo MRS spectroscopy, due to impaired oxidative phosphorylation. Animals or cultured cells treated with NRTIs develop neuropathy, myopathy, or cell destruction with similar changes in the mitochondria. There is evidence that the NRTI-related neuropathy is also due to mitochondrial toxicity. The NRTIs (AZT, ddC, ddl, d4T, 3TC) contain azido groups that compete with natural thymidine triphosphate as substrates of DNA pol-gamma and terminate mtDNA synthesis. In contrast, FIAU that contains 3'-OH groups serves as an alternate substrate for thymidine triphosphate with DNA pol-gamma and is incorporated into the DNA causing permanent mtDNA dysfunction. The NRTI-induced mitochondrial dysfunction has an influence on the clinical application of these agents, especially at high doses and when combined. They have produced in humans a new category of acquired mitochondrial toxins that cause clinical manifestations resembling the genetic mitochondrial disorders.

Epidemiology and clinical features of HIV-1 associated neuropathies

Peripheral neuropathy is common in human immunodeficiency virus type-1 (HIV-1) infection. Peripheral neuropathies complicate all stages of the HIV-1 disease and cause considerable morbidity and disability in HIV-1 infected individuals and acquired immunodeficiency syndrome (AIDS) patients. Whereas symptomatic neuropathies occur in approximately 10% to 15% of HIV-1-infected patients overall, pathologic evidence of peripheral nerve involvement is present in virtually all end-stage AIDS patients. There are 6 major clinical types of HIV-associated neuropathies that are regularly seen in large HIV-1 clinics. Distal sensory polyneuropathy (DSP) is the most common among the HIV-1-associated neuropathies. DSP generally occurs in later stages of HIV-1 infection and it follows an indolent and protracted clinical course. The dominant clinical features in DSP include distal pain, paresthesia and numbness in a typical length-dependent fashion with proximal to distal gradient. Whereas toxic neuropathies--secondary to certain antiretroviral agents--are clinically similar to DSP, their temporal relation to neurotoxic medication helps distinguish them from other HIV-1-associated neuropathies. DSP and toxic neuropathy may coexist in a single patient. Acute and chronic inflammatory demyelinating polyradiculoneuropathies (AIDP and CIDP) produce global limb weakness. AIDP may occur at seroconversion and it can therefore be the initial manifestation of HIV-1 infection. CIDP generally occurs in the mid to late stages of HIV-1 infection. Progressive polyradiculopathy (PP) occurs in patients with advanced immunodeficiency and is generally caused by the opportunist cytomegalovirus (CMV) infection. Mononeuropathy multiplex (MM) in early stages of HIV-1 infection is immune mediated, whereas in advanced AIDS it is caused by the CMV infection. Finally, subclinical autonomic nervous system involvement is common in all stages of HIV-1 infection. Because HIV-1-associated neuropathies are diverse in their etiology and pathogenesis, a precise clinical diagnosis is required to formulate a rational therapeutic intervention.

The changing spectrum of rheumatic disease in human immunodeficiency virus infection

CONTEXT

Although it has been known for over 15 years that a number of rheumatic diseases occur in patients with human immunodeficiency virus (HIV) infection, increasing knowledge about these disorders and advances in HIV treatment need to be considered in approaching patients with HIV-associated rheumatic disease.

OBJECTIVE

To examine the clinical, pathologic, and therapeutic features of HIV-associated rheumatic diseases in the context of what is known about the immunology of HIV infection.

DATA SOURCES

The author's own extensive collection of references, supplemented by PubMed Medline searches for articles in English-language journals published between 1985 and 2000. The indexing term HIV and the following coindexing terms were used for searching: arthritis, Reiter's syndrome, psoriatic arthritis, rheumatoid arthritis, osteonecrosis, vasculitis, pulmonary hypertension, myositis, myopathy, fibromyalgia, septic arthritis, parotid enlargement, diffuse infiltrative lymphocytosis syndrome, systemic lupus erythematosus, septic arthritis, mycobacterial arthritis, fungal arthritis, autoantibodies, anti-cardiolipin antibodies, and anti-neutrophilic cytoplasmic antibodies.

STUDY SELECTION

All papers identified in the literature search were reviewed. Studies presenting data that merely confirmed previous studies were not included in the analysis.

DATA EXTRACTION

All identified papers were abstracted by the author. Letters to the editor were included only if a new observation had been made.

DATA SYNTHESIS

This was a qualitative review of papers published, with new knowledge about these disorders summarized and presented.

RESULTS

Despite new treatments for HIV, reports of rheumatic diseases presenting in AIDS patients persist, especially in HIV-associated arthritis, diffuse infiltrative lymphocytosis syndrome, HIV-associated vasculitis, and polymyositis. However, new HIV treatments may ameliorate these diseases.

CONCLUSIONS

The spectrum of HIV-associated rheumatic disease remains a diagnostic and therapeutic challenge for the clinician. The impact of changes in HIV treatment on these disorders requires further assessment.

Rheumatic manifestations of HIV-AIDS

Infection by human immunodeficiency virus is characterized by a myriad of clinical manifestations affecting almost every organ system in the body. If untreated, it follows an inexorable course, leading to a profound state of immunosuppression and eventually death from opportunistic infection and/or development of lymphoproliferative malignancy and Kaposi's sarcoma. Rheumatic manifestations may develop at any time of the clinical spectrum, but usually are more often seen in late stages. A variety of disorders may be seen, particularly Reiter's syndrome and undifferentiated spondyloarthropathy. Most patients do well with conventional anti-inflammatory therapy, but some will require the use of immunosuppressive-cytotoxic therapy.

HIV-1-Associated Neuropathies

Peripheral neuropathy associated with human immunodeficiency virus type 1 (HIV-1) infection is a major cause of morbidity in this patient population. Due to the associated chronic pain, its management has come within the purview of neuropsychiatrists. This paper will focus on the primary pathogenic aspects of HIV-1-associated peripheral neuropathies. The specific syndromes of greatest concern are distal sensory polyneuropathy, toxic neuropathy, inflammatory demyelinating polyradiculoneuropathy, and cytomegalovirus-related progressive polyradiculoneuropathy. The treatments available for these conditions and their efficacy are discussed.

Subacute painful lumbosacral polyradiculoneuropathy in immunocompromised patients

The syndrome of inflammatory subacute lumbosacral polyradiculoneuropathy (SLP) has been reported in acquired immunodeficiency syndrome (AIDS) patients in association with cytomegalovirus infection and is only partially amenable to anti-viral therapy. We report three cases of relatively benign inflammatory painful SLP in two non-AIDS, immunosuppressed patients and one who HIV-seroconversed at the time of clinical presentation. SLP developed: (1) in association with HIV seroconversion; (2) during ECHO virus infection in a patient with common variable immune deficiency; and (3) after a severe systemic infection that induced transient immunosuppression due to Epstein-Barr virus reactivation. This report expands the spectrum of viruses associated with acute and subacute lumbosacral polyradiculoneuropathy and may shed light on its possible pathogenesis.

Morphometric analysis of the peripheral neuropathy of AIDS

A morphometric study of the peripheral nervous system at autopsy was undertaken in 11 AIDS patients and 10 controls. The left L4, L5, and S1 dorsal root ganglia (DRG) and samples of the sciatic nerve at the buttock, tibial nerve at the knee, and sural nerve at the ankle were collected. Indices of neuronal/axonal degeneration and of segmental demyelination/ remyelination were measured at each level. The small number of cases and evidence of neuropathy in a number of the control cases resulted in statistical significance for only a limited number of comparisons. Nodules of Nageotte in the DRG were increased fivefold in AIDS cases compared with controls, and axonal degeneration in single-teased nerve fibers was increased 9-fold in the sciatic nerve, 28-fold in the tibial nerve, and 12-fold in the sural nerve. The ratios of AIDS to controls for the density of remaining DRG neurons and large myelinated axons were reduced to 0.71 in the DRG, 0.84 in the sciatic nerve, 0.84 in the tibial nerve, and 0.66 in the sural nerve. Axonal regeneration in single-teased nerve fibers was increased threefold at the sciatic nerve level in AIDS, but was markedly reduced at distal levels. Acute segmental demyelination in single-teased nerve fibers was present to a greater extent than in controls at all levels of the peripheral nerves in the AIDS cases. Remyelinating fibers were increased compared with controls only in the proximal sciatic nerve. No case showed the changes of cytomegalovirus infection. In a parallel immunohistochemical study of these AIDS peripheral nerves, T-cell and macrophage infiltration, with cytokine expression, was demonstrated. The pathological process in the neuropathy of terminal AIDS appears to be a multifocal immunologically mediated inflammatory disease, with increased density of macrophages and T cells at all levels of the peripheral nervous system, producing segmental demyelination and axonal degeneration. Reparative processes (axonal regeneration and remyelination) occurred only at the most proximal levels of the nerves.

Infections of the nervous system

Epidemiologic trends causing infections of the nervous system remain a significant source of morbidity and mortality one half-century after the introduction of penicillin. This article outlines common causes of bacterial meningitis, aseptic meningitis syndrome, encephalitis, abscess, spinal cord syndromes, and cranial and peripheral nerve problems. Recommendations for diagnostic evaluation and both empiric and definitive antimicrobial therapy are offered; controversial management issues are also discussed. The protean manifestations of varicella-zoster virus and Lyme diseases are outlined. In addition, special considerations in the immunocompromised host, including organ transplant recipients, cancer patients, and HIV-positive persons are explained, and antimicrobial therapy is discussed.

Retroviral-associated vasculitis of the nervous system

Vasculitis may involve the central and peripheral nervous system in HIV-infected patients. Central nervous system vasculitis is rare with HIV infection and most are owing to opportunistic infections including varicella, CMV, fungal, tuberculosis, and syphilis. Vasculitis of the peripheral nerve may cause mononeuritis multiplex or polyneuropathy, sometimes as the first symptom of HIV or after AIDS has developed. Symptoms may be limited to the peripheral nerve. The etiology may be infection of endothelial cells, hepatitis B or HIV-induced immune complexes, or dysregulation of cytokines and adhesion molecules. Treatment with steroids alone is often effective; IVIg and cytotoxic agents have also been used. It is uncertain whether vasculitis of the nervous system is ever due to other retroviruses (HIV-2, HTLV-1, and HTLV-2).