Aseptic MeningitisLast Updated: March 14, 2005

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Author: Prem C Shukla, MD, Associate Chairman, Associate Professor, Department of Emergency Medicine, University of Arkansas for Medical Sciences Coauthor(s): Tarakad S Ramachandran, MD, Chief, Department of Neurology, Crouse Irving Memorial Hospital; Professor, Department of Neurology, State University of New York Upstate Medical University; Uma Iyer, MD, Staff Physician, Department of Neurology, State University of New York Upstate Medical Center Prem C Shukla, MD, is a member of the following medical societies: American Academy of Emergency Medicine Editor(s): Norman C Reynolds Jr, MD, Professor, Department of Neurology, Medical College of Wisconsin; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Glenn Lopate, MD, Associate Professor, Department of Neurology, Division of Neuromuscular Diseases, Washington University School of Medicine; Chief of Neurology, St Louis ConnectCar; Consulting Staff, Barnes Jewish Hospital; Selim R Benbadis, MD, Professor of Neurology, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida College of Medicine, Tampa General Hospital; and Nicholas Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and

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  INTRODUCTION Section 2 of 9   

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Definition

Aseptic meningitis is an illness characterized by serous inflammation of the linings of the brain (ie, meninges), usually with an accompanying mononuclear pleocytosis. Clinical symptomatology is varied and includes predominantly headache and fever. The illness is usually mild and runs its course without treatment; however, some cases can be severe and life threatening.

Aseptic meningitis syndrome is not caused by pyogenic bacteria, but can be caused by multiple conditions including infectious viral and nonviral causes and many noninfectious etiologies. Hence, this term is no longer synonymous with viral meningitis, although the two often are used interchangeably.

Background

Aseptic meningitis is a common, rarely fatal condition usually caused by certain viruses. Fortunately, most people exposed to these viruses experience no symptoms or only mild symptoms without meningitis. Meningitis means inflammation of the membranes covering the brain and spinal cord.

 OVERVIEW AND GENERAL INFORMATION

Section 3 of 9   

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Frequency

Aseptic meningitis is one of the most common infections of the meninges. It occurs in individuals of all ages, although it is more common in children, especially during summer. No racial differences are reported. Aseptic meningitis tends to occur 3 times more frequently in males than in females. In meningitis caused by the mumps virus, both sexes are affected equally.

Causes, incidence, and risk factors

The most common causes of viral meningitis are the enteroviruses, herpesviruses, and HIV. HIV may cause aseptic meningitis, mostly at the time of seroconversion. While HIV spreads via the hematogenous route, rabies, polio, and herpesviruses are neurotrophic (ie, spread through neurons). Coxsackieviruses and echoviruses, which are types of enteroviruses, account for approximately half of cases of aseptic meningitis. Other enteroviruses and mumps are additional causes. The incidence of these infections increases in the summer and early fall. Enteroviruses are spread by hand-to-mouth contact and to a lesser extent by respiratory and fecal routes. Among viruses, enteroviruses are the most common cause of aseptic meningitis. These are small, nonenveloped RNA viruses of the picornavirus family with various serotypes. More than 50 subtypes have been linked with meningitis. Adenoviruses are respiratory viruses that rarely cause meningitis.

Mumps was a common cause of aseptic meningitis in the United States until the mumps vaccination came into use. In several countries, mumps virus remains a common pathogen in aseptic meningitis. It is spread by respiratory secretions, with increased incidence in the spring.

Herpesvirus, both type 1 (herpes simplex [HSV] or herpes labialis) and type 2 (genital herpes), can cause meningitis in children and especially infants. Varicella-zoster virus, another herpesvirus, causes encephalitis but only in those who are immunocompromised.

Geographic and seasonal patterns of arbovirus infection depend on the life cycle of arthropod vectors, animal

reservoirs, and their contact with human subjects. Eastern equine encephalitis virus (EEEV) usually is observed in Atlantic and Gulf regions, whereas western equine encephalitis virus (WEEV) is prevalent in the western part of the United States. WEEV is responsible for more aseptic meningitis cases than EEEV. Approximately 15% of St Louis encephalitis virus (SLEV) infections result in meningitis. In children, this incidence is as high as 60%.

SLEV infection can occur in both rural and urban areas. In the rural setting, the virus tends to follow the same pattern as WEEV. Conversely, in urban settings, outbreaks tend to be more explosive. Approximately 18% of people infected with Colorado tick fever develop meningitis. This infection primarily occurs in the Rocky Mountain area, because Dermacentor andersoni ticks that are infected by the virus are limited to the western mountainous areas.

Only 3% of patients with Venezuelan encephalitis are known to develop acute meningitis. This virus has spread into Florida and some southwestern states. Initially, it leads to influenzalike illness in most people.

Lymphocytic choriomeningitis virus (LCMV), an arenavirus, is an extremely rare cause of meningitis. LCMV infection occurs by contact with dust or food contaminated by excreta of rodents. These cases tend to be more common in the winter. Human infections tend to occur in both laboratory and home settings.

Viral meningitis is a relatively common disorder. In one county in Minnesota, the incidence of viral meningitis was 10.9 per 100,000 person-years from 1950 to 1981, with most cases occurring in the summer months. Incidence of aseptic meningitis has been reported as 11 per 100,000 person-years, compared to a rate of 8.6 per 100,000 for bacterial meningitis. In the United States, a specific cause is usually identifiable in 10-15% of cases of meningitis.

Pathophysiology

When the protecting barriers of the brain, including the skull, meninges, and blood-brain barrier, are broached by a pathogen, meningitis can result. Predisposing factors include preexisting diabetes mellitus, immunosuppression,

otitis media, pneumonia, sinusitis, and alcohol abuse. Meningeal inflammation and irritation elicit a protective reflex to prevent stretching of the inflamed and hypersensitive nerve roots, which is detectable clinically as neck stiffness or meningeal signs. Meningeal irritation due to inflammation also may cause headache and cranial nerve palsies. When cerebral edema and elevated intracranial pressure occur, alterations in mental status, headache, vomiting, seizures, and cranial nerve palsies may ensue.

Clinical features

Most acute viral meningitides produce symptoms with variations depending on the particular virus. Some individuals may experience a biphasic type of illness with nonspecific constitutional symptoms followed by meningitis.

The viruses that commonly cause aseptic meningitis may be spread for weeks after infection.

The time course of acute viral meningitis varies. The onset may occur within a matter of hours or evolve more slowly over a few days. Usually, maximum deficit appears within 3-6 days after exposure.

Headache, fever, stiff neck, photophobia, drowsiness, myalgias, malaise, chills, sore throat, abdominal pain, nausea, and vomiting usually characterize acute viral meningitis. Focal signs, seizures, and profound lethargy are rarely a part of this syndrome. The diagnosis may be suggested by associated skin manifestations such as the rash of varicella zoster, genital lesions for HSV-2, or a mild maculopapular rash occurring in the summer and fall months with enteroviruses. Occasionally, patients may exhibit altered levels of consciousness including confusion and visual hallucinations.

Meningeal signs

Neck stiffness in meningitis is tested by gentle forward flexion of the neck with the patient lying in the supine position. Meningeal irritation also can be tested by the jolt accentuation of headache. This is tested by asking the patient to turn his or her head horizontally at a frequency of

2-3 rotations per second. Worsening of a baseline headache represents a positive sign.

Severe meningeal irritation may result in the patient assuming the tripod position (termed Amoss sign or Hoyne sign) with the knees and hips flexed, the back arched lordotically, the neck extended, and the arms brought back to support the thorax.

When passive neck flexion in a supine patient results in flexion of the knees and hips, a positive Brudzinski sign is entertained. Yet another sign, the contralateral reflex, is present if passive flexion of one hip and knee causes flexion of the contralateral leg.

Kernig sign is elicited with the patient lying supine and the hip flexed at 90°. A positive sign is present when extension of the knee from this position elicits resistance or pain in the lower back or posterior thigh.

Papilledema or absence of venous pulsations upon funduscopic examination indicates increased intracranial pressure.

Rash

Some enteroviral infections produce a rash that usually accompanies the onset of fever and persists for 4-10 days. In infections due to coxsackieviruses A5, 9, or 16 or echoviruses 4, 6, 9, 16, or 30, the rash is typically maculopapular and nonpruritic, may be confined to the face and trunk, or may involve extremities, including the palms and soles. In coxsackievirus A16 and, rarely, in other group A serotype infections, a vesicular rash may involve the hands, feet, and oropharynx. Herpangina, characterized by gray vesicular lesions on the tonsillar fossae, soft palate, and uvula, can accompany infection caused by group A coxsackievirus.

With echovirus 9 infections, a petechial rash resembling meningococcemia typically is observed.

The epidemiologic setting (eg, time of year, exposure to insects, local community) and accompanying systemic manifestations may be helpful in making a presumptive

diagnosis.

Most importantly, remember that with a few exceptions, the clinical and laboratory findings accompanying acute viral meningitis are insufficiently distinct to allow an etiologic diagnosis, and distinguishing these disorders from a number of nonviral diseases may be difficult.

  SPECIFIC CAUSES Section 4 of 9   

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Human immunodeficiency virus infections

HIV infects and selectively destroys T4 lymphocytes, causing immunodeficiency. As a result of this acquired immunodeficiency, patients are prone to opportunistic infections. In particular, patients are susceptible to toxoplasmosis, cryptococcosis, other fungal infections, cytomegalovirus, and papovavirus infections. They also develop cerebral or other extranodal B-cell lymphomas. This is due to loss of the surveillance function of T cells. HIV also infects the CNS directly, causing aseptic meningitis, encephalitis, leukoencephalopathy, and myelopathy.

HIV encephalitis is characterized by progressive intellectual impairment, behavior disturbances, and sensorimotor deficits. DNA analysis helps to detect HIV in the brains of these patients, and HIV-specific immunoglobulin is produced intrathecally. Congenital HIV encephalitis is more severe than the adult forms and may result in microcephaly and basal ganglia calcification.

Nonviral infectious etiologies

In contrast to the viral causes of aseptic meningitis, nonviral causes of meningitis usually have a more complicated course and always must be considered because they can be managed with specific treatments.

Consider partially treated bacterial meningitis, especially in the presence of a history of previous oral antimicrobial therapy and when cerebrospinal fluid (CSF) exhibits

persistently low glucose or polymorphonuclear pleocytosis. Latex agglutination tests may be useful in these patients.

Tuberculous meningitis

In a healthy host, CNS tuberculosis usually takes the form of a meningitis that causes an acute-to-subacute illness characterized by fever, headache, drowsiness, meningism, and confusion over a period of approximately 2-3 weeks. Less frequent presentations include atypical febrile seizures in children, isolated cranial nerve palsies, bilateral papilledema, and acute confusional states. Tuberculous meningitis (TBM) is difficult to diagnose, and a high index of suspicion is needed for making an early diagnosis. Elucidate the patient's recent contact with tuberculosis. The prodrome is usually nonspecific, including headache, vomiting, photophobia, and fever. In one study, only 2% of subjects reported meningitic symptoms. The duration of presenting symptoms may vary from 1 day to 9 months, although 55% of individuals presented with symptoms of fewer than 2 weeks' duration.

In 1948, British Medical Research Council developed a method for staging the severity of the disease. Stage I describes the early nonspecific symptoms and signs including apathy, irritability, headache, malaise, fever, anorexia, nausea, and vomiting, without any alteration in the level of consciousness. Stage II describes altered consciousness without coma or delirium but with minor focal neurological signs. Symptoms and signs of meningism and meningitis are present, in addition to focal neurological deficits, isolated cranial nerve palsies, and abnormal involuntary movements. Stage III describes an advanced state with stupor or coma, dense neurological deficits, seizures, posturing, and/or abnormal movements. The prognosis is related directly to the clinical stage of diagnosis. The occurrence of the syndrome of inappropriate antidiuretic hormone secretion is common and also is linked to a poor prognosis.

Apart from papilledema, fundus examination occasionally may reveal the presence of a retinal tuberculoid, a small grayish white choroidal nodule, highly suggestive of tuberculosis. These lesions are said to be more common in

miliary disease than in other forms.

Tremor is the most common movement disorder observed in the course of TBM. Chorea more frequently is found in young children. Deep vascular lesions are more common among patients with movement disorders.

Tuberculous radiculomyelitis (TBRM) is a complication of TBM that rarely has been reported in the modern medical literature. TBRM develops at various periods after TBM, even in patients who are treated adequately after sterilization of the CSF. The most common symptoms are subacute paraparesis, radicular pain, bladder disturbance, and subsequent paralysis. CSF evaluation usually demonstrates an active inflammatory response with a very high protein level. MRI and CT scans are critical in making the diagnosis, revealing loculation and obliteration of the subarachnoid space along with linear intradural enhancement. As in other forms of paradoxical reactions to antituberculous treatment, evidence exists that steroid treatment may have a beneficial effect.

In addition, 2 rare forms of TBM include tuberculous serous meningitis, characterized by signs and symptoms of a mild meningitis with spontaneous recovery, and tuberculous encephalopathy, which usually occurs in a young child with progressive primary TB: the presentation of a reduced level of consciousness with few focal signs and meningismus is typical. Diffuse edema and white matter pallor with demyelination are found pathologically. The pathogenesis is uncertain but is presumed to be immune mediated. Diagnosis is important, because anecdotal reports suggest a good response to corticosteroids.

TBM may have an acute presentation. Sometimes it may present with cranial nerve deficits, or it may have a more indolent course involving headache, meningismus, and altered mental status. CSF findings include elevated opening pressure, protein levels of 100-500 mg/dL, WBC count of 10-500/mm3, and hypoglycorrhachia. Since bacterial cultures require several weeks, the polymerase chain reaction (PCR) technique for Mycobacterium tuberculosis may be very useful.

Brucellosis

Brucellosis is an infection with a bacterium of one of the Brucella species, usually Brucella abortus (cattle), Brucella melitensis, Brucella ovis (sheep, goats), Brucella suis (pigs), or rarely Brucella canis (dogs). Its distribution is worldwide, but it is most common in the Mediterranean regions, Africa, the Middle East, India, Central Asia, Mexico, and Central and South America. Persons at highest risk of brucellosis are those who work with animals that are infected, such as veterinarians and ranchers, and persons who consume raw milk or cheeses made with raw milk. Brucellosis also may be transmitted to humans if they are exposed inadvertently to live brucellosis vaccine by a needlestick or other accident.

The incidence in the United States is fewer than 0.5 cases per 100,000 population.

Clinical symptoms are extremely variable. The most common presentation is of symptoms appearing 1-2 months after exposure. In the acute form, brucellosis takes the form of a flulike illness, with fever, sweats, malaise, anorexia, headache, myalgia, and back pain. In the undulant form (<1 year from onset of illness), symptoms include undulant fevers, arthritis, and orchiepididymitis in males. Neurological sequelae occur in as many as 5% of patients. In the chronic form (>1 year from onset), a chronic fatigue syndrome-like picture with depression and arthritis is typical.

Other complications of brucellosis include granulomatous hepatitis, spondylitis, anemia, leukopenia, thrombocytopenia, uveitis, optic neuritis, papilledema, and endocarditis. Diagnosis is confirmed by the isolation of bacteria from the Brucellaceae family from a bacterial culture or an increase over time in antibodies in the blood that are specific for Brucella species.

Other etiologies

Lyme meningitis manifests several weeks after the skin lesions have appeared but may occur while erythema migrans lesions are still present. Hypoglycorrhachia is not a prominent finding in the

CSF. Facial nerve palsy, sometimes bilaterally, may be observed.

Acute monocytic ehrlichiosis is another tick-borne infection that may present similarly to aseptic meningitis. Laboratory tests may reveal pancytopenia and elevated hepatic transaminases, BUN, and creatinine.

Syphilitic meningitis is becoming more common in the AIDS era. It may coexist with the primary infection or follow it by as many as 2 years. Because of the lack of a typical clinical presentation, CSF Venereal Disease Research Laboratory test (VDRL) always must be included in the workup of aseptic meningitis.

Fungal meningitis occurs primarily in patients with AIDS and after organ transplantation, immunosuppressive chemotherapy, or long-term corticosteroid therapy. Nonetheless, the most common fungal meningitis pathogen, Cryptococcus neoformans, can occur in immunocompetent patients. Cryptococcal antigen assay on CSF can be helpful in these situations.

Summary - Differential diagnosis of aseptic meningitis syndrome

Infectious etiologies o Viruses

Enteroviruses - Polio, coxsackievirus, echovirus

HSV types 1 and 2 Varicella-zoster virus Adenovirus Epstein-Barr virus LCMV HIV Influenza virus types A and B

o Bacteria Partially treated meningitis Parameningeal infection Endocarditis Mycoplasma pneumoniae M tuberculosis Ehrlichiosis - Monocytic, granulocytic Borrelia burgdorferi Treponema pallidum

Brucella specieso Fungi

C neoformans Histoplasma capsulatum Coccidioides immitis Blastomyces dermatitides

o Parasites Toxoplasma gondii Taenia solium (cysticercosis)

Noninfectious causes o Drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Trimethoprim-sulfamethoxazole, amoxicillin

OKT3 Azathioprine Intravenous immunoglobulin Isoniazid Intrathecal methotrexate Intrathecal cystine arabinoside Vaccination Allopurinol

o Systemic diseases Sarcoidosis Leptomeningeal cancer Posttransplantation lymphoproliferative

disorder Systemic lupus erythematosus Wegener granulomatosis CNS vasculitis Behçet disease Vogt-Koyanagi-Harada syndrome

o Miscellaneous Arachnoiditis Migraine

Postinfectious syndromes

  EVALUATION AND DIAGNOSIS Section 5 of 9   

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Suspicion of viral meningitis is based on the clinical presentation and presence of certain CSF findings.

Presence of less than 500 mononuclear cells/mm3 of CSF (pleocytosis) is characteristic. Occasionally, early examination may reveal acellular fluid or predominance of polymorphonuclear leukocytes, but the typical mononuclear pleocytosis develops in 8-48 hours.

CSF pressure may be elevated, whereas the glucose level is characteristically normal or only modestly decreased.

CSF protein level usually is elevated (50-100 mg/dL). Other test results include negative bacterial antigen tests and low levels of

tumor necrosis factor (TNF) and lactate. If performed, immunoglobulin concentration and oligoclonal bands may be

noted. Increased protein content and pleocytosis may persist for months after

convalescence; oligoclonal bands may remain detectable even longer. PCR screening of CSF has become an important diagnostic tool and can

help in the isolation of several viruses.

Sometimes, the organism may be detected directly in the CSF, blood, or stool, but usually the diagnosis is based on serologic tests. Choice of tests and their interpretation depend on the particular organism involved.

Culture is the criterion standard for diagnosis, but it may not be positive in all patients.

Direct viral isolation is of limited value in making the diagnosis, since it takes several days. Arboviruses and enteroviruses can be isolated from the blood but seldom are recoverable at the time of clinically evident meningitis.

Coxsackievirus and echovirus can be isolated from stool or CSF and sometimes from throat swabs.

Mumps virus can be isolated from saliva, throat swabs, or CSF. HSV-2 can be cultured from CSF or swabs taken from genital lesions. LCMV can be isolated from CSF or blood.

Seroconversion, demonstrated by a 4-fold or higher increase in antibody titer between acute and convalescent sera, can be helpful in making a diagnosis. However, virus-specific immunoglobulin M (IgM) antibodies provide a quick and more accurate early diagnosis.

Serum laboratory findings can be highly variable and depend on the causative agent. The WBC count usually is not elevated, but an increase or decrease can occur, usually with a lymphocytic predominance. A high serum amylase level is observed in patients with mumps because of involvement of the salivary glands or pancreas.

CT scan and MRI are not helpful in making the diagnosis of aseptic meningitis. They are performed for excluding alternative diagnoses in certain situations. Chest x-ray may be indicated when tuberculosis is suspected as an underlying

cause. Tuberculin skin test also may be indicated when tuberculosis is suspected as an underlying cause of aseptic meningitis.

Summary of appropriate diagnostic investigations

Lab tests o CBC, differential, platelet count o Sedimentation rate, antinuclear antibody, rheumatoid factor o Sjögren syndrome antigens A and B o Serum protein electrophoresis o Lyme titer (enzyme-linked immunosorbent assay [ELISA]) o VDRL, fluorescent treponemal antibody absorption test (FTA-ABS) o Acute and convalescent sera for virus-specific IgG or IgM to

enteroviruses, arboviruses, adenoviruses, LCMV, Epstein-Barr virus, and HSV-2

Imaging studies o Chest x-ray, posteroanterior and lateral o MRI of brain/spine

Other - Intradermal tuberculin test (purified protein derivative [PPD]) CSF studies

o Gram stain, bacterial culture and sensitivity o Acid-fast bacillus, India ink o Cryptococcal antigen o Cell count o Protein, glucose, and gamma globulin o Latex agglutination test for Haemophilus influenzae type b o VDRL, FTA-ABS o PCR for HSV (varicella-zoster virus also in immunocompromised

patients), M tuberculosis o Virus-specific IgM antibodies to B burgdorferi and Brucella,

Histoplasma, and Coccidioides species o Angiotensin-converting enzyme (ACE) level o Tuberculostearic acid o Cytology

Clinical diagnosis

The diagnosis of viral meningitis is based on the clinical presentation and CSF findings that include lymphocyte-predominant pleocytosis of fewer than 500 cells per mm3, normal glucose concentration, normal or slightly elevated protein, and negative bacterial antigen tests. Other findings, including low concentrations of TNF and lactic acid, add further validity.

As a potent mediator of inflammation, the cytopathic cytokine TNF has been considered to be a strong candidate in the pathogenesis of CNS diseases such

as meningitis as well as demyelinating disease (and its animal model, experimental autoimmune encephalomyelitis). In patients with multiple sclerosis, production of TNF alpha is significantly higher before exacerbation than in stable disease.

TNF alpha has been demonstrated to have potential as a predictor of clinical outcome in children with acute bacterial meningitis. TNF alpha was markedly higher in children with acute bacterial meningitis than in controls. All patients with TNF alpha levels greater than 1500 pg/mL died.

  TREATMENT Section 6 of 9   

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Empiric antibiotic coverage

Given the potential for serious neurological morbidity and the persistently high mortality rates of bacterial meningitis, rapid institution of antibiotic coverage is essential when the diagnosis of bacterial meningitis is suspected. Most studies suggest that rapid sterilization of CSF reduces mortality and long-term sequelae rates. Generally, if imaging studies are indicated before lumbar puncture, blood cultures and empiric antibiotic therapy should be instituted before the imaging studies; these are unlikely to decrease diagnostic sensitivity if CSF is tested for bacterial antigens.

No specific treatment exists for most of the viruses; therefore, treatment, for the most part, is supportive and includes analgesics, antinausea medications, intravenous fluids, and prevention and treatment of complications.

Headache and fever usually can be treated with judicious doses of acetaminophen. Severe hyperthermia (>40°C) may require vigorous therapy, but mild temperature elevation may serve as a natural defense mechanism, and some people believe it should be left untreated.

Strict isolation is not necessary. When enteroviral infection is suspected, take precautions in handling stools and wash hands carefully. Persons with measles, chickenpox, rubella, or mumps virus infections also should observe the usual precaution of isolation from susceptible individuals.

Antiviral therapy

Effective antiviral therapy is available against HSV-1, varicella, and cytomegalovirus. In immunosuppressed patients, long-term therapy may be necessary.

Acyclovir antiviral therapy is recommended for immunocompetent hosts

with HSV-2 meningitis and a primary genital herpes infection. Valacyclovir has become available for recurrent genital herpes but provides no advantage over acyclovir.

The general trend is to avoid corticosteroids because of their inhibitory effects on host immune responses.

Nucleoside analogs, such as acyclovir, initially are phosphorylated by viral thymidine kinase to eventually form a nucleoside triphosphate. These molecules inhibit HSV polymerase with 30-50 times the potency of human alpha-DNA polymerase.

For meningitis caused by HSV-2, acyclovir is the drug of choice. Valacyclovir and foscarnet are alternative antiviral agents.

Triple drug therapy, using isoniazid, rifampin, and pyrazinamide, is the most appropriate choice for tuberculosis.

For unusual bacteria, broad-spectrum antibiotics are excellent. Penicillin and ceftriaxone are used for meningitis caused by actinomycetes

and spirochetes. Doxycycline or rifampin is an excellent choice for Brucella infection. Gentamicin can be used for infections caused by Pasteurella tularensis.

Antifungal agents of choice include amphotericin B, fluconazole, and flucytosine.

Occasionally, glucocorticoids, such as dexamethasone, are useful when meningitis is associated with signs of increased intracranial pressure.

Remarkable recovery may be achieved in some patients who become comatose. Vigorous support and avoidance of complications are very important in these patients.

For severe cases, meticulous care in an intensive care setting with respiratory and nutritional support is warranted.

Many patients who have aseptic meningitis can be cared for on an outpatient basis, but those who have profound headache, nausea, vomiting, or CSF pleocytosis with a polymorphonuclear leukocyte predominance should be admitted for observation with antibiotic coverage for bacterial meningitis at the discretion of the managing clinician.

Specific diagnosis is useful for prognosis of an individual patient and for epidemiologic aspects of the population that is at risk. Patients with measles, chickenpox, rubella, or mumps virus infections must be isolated from susceptible individuals.

Effective vaccines are available for polio, measles, mumps, and rubella. Illnesses related to these viruses have declined dramatically in countries with effective vaccination strategies.

Vaccination against Japanese encephalitis has been effective in

controlling the infection in Asia. A vaccine against varicella recently has been introduced. Rabies is the only infection in which the vaccine is given after exposure to

the virus.

 DIFFERENTIAL DIAGNOSIS, COMPLICATIONS, PROGNOSIS, AND PREVENTION

Section 7 of 9   

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Differential diagnosis

Since no specific treatment is available for acute viral meningitis in immunocompetent individuals (except meningitis due to herpes) and since the presentation is often nonspecific, exclusion of other conditions becomes highly important.

Until CSF findings become available, the differential diagnosis of aseptic meningitis is very broad, encompassing many toxic and vascular diseases including those listed in Specific Causes.

Complications

Seizures sometimes can complicate meningitis; however, prophylactic anticonvulsants are not recommended routinely. If seizures develop, they can be controlled with phenytoin and phenobarbital. If status epilepticus develops, appropriate therapy should be provided to prevent secondary brain injury.

Encephalitis may develop in some patients. The most common sequela following mumps meningoencephalitis is sensorineural deafness. Hydrocephalus from aqueductal stenosis has been reported as a late sequela of mumps meningitis and encephalitis in children.

If persistent cognitive problems occur after recovery from acute meningitis, especially in terms of residual suboptimal functioning in the workplace or in school, referral for formal neuropsychological testing clarifies the nature of the complaint both to the physician and to the patient and helps separate psychological adjustment factors from organic dysfunction.

Full recovery from viral meningitis usually occurs within 1-2 weeks of onset, though fatigue, lightheadedness, and asthenia may persist for months in some patients. Aseptic meningitis has low rates of morbidity and mortality, except when it occurs in the perinatal period.

Advise individuals to call their health care provider if symptoms of aseptic

meningitis develop.

Prognosis

Aseptic meningitis is usually a benign disease; most people exposed to these viruses experience either no symptoms or mild symptoms, and they usually experience full recovery in 5-14 days after onset of symptoms. However, fatigue and lightheadedness may persist longer in some people.

Prevention

Hand washing, immunization (eg, against mumps), and other general good health measures may reduce the risk of developing an infection that can progress to meningitis.

Many of the causes of meningitis are communicable and, if one case of meningitis is diagnosed within a community, appropriate steps may need to be taken immediately to prevent the further spread of the disease. Since viruses that are passed in the stool cause most cases, people diagnosed with aseptic meningitis should be sure to wash their hands thoroughly after using the toilet. Always wash hands after changing diapers.

  RELATED CONDITIONS Section 8 of 9   

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Drug-induced aseptic meningitis

The incidence of drug-induced meningitis (DIAM) is unknown. Many antimicrobials, such as trimethoprim-sulfamethoxazole, ciprofloxacin, cephalexin, metronidazole, amoxicillin, penicillin, and isoniazid, are causes of aseptic meningitis. In addition, the xanthine oxidase inhibitor allopurinol has been implicated in causing aseptic meningitis. DIAM is a complication in which numerous other drugs, namely nonsteroidal anti-inflammatory drugs (NSAIDs), ranitidine, carbamazepine, vaccines against hepatitis B and mumps, immunoglobulins, OKT3 monoclonal antibodies (ie, directed against the T3 receptor and, therefore, pan T-cell antibodies), co-trimoxazole, radiographic agents, and muromonab-CD3, also have been associated. A high index of suspicion is needed to make an accurate diagnosis of DIAM. Diagnostic accuracy in clinical care depends on a complete history and physical examination.

The clinical presentation does not help in differentiating DIAM from infectious meningitis. The CSF profile (ie, neutrophilic pleocytosis) does not allow DIAM to be distinguished from infectious meningitis. Systemic lupus erythematosus is the

single most frequent underlying condition associated with DIAM. Recurrent DIAM is well known; females usually predominate, and the frequency varies with the different underlying conditions.

Pathophysiology

The pathogenic mechanisms of DIAM are diverse and presumably differ from drug to drug. A hypersensitivity mechanism (especially types 1 and 3) is considered for cases related to NSAIDs, intravenous immunoglobulin, and antibiotics. OKT3 cases are believed to be mediated, at least in part, by cytokine release. Why such reactions are confined selectively to the CSF compartment is unclear.

Treatment includes discontinuation of the offending drug and a search for potential etiology of the meningitis. Patients should be treated with a third-generation cephalosporin if bacterial meningitis remains a possibility. Full recovery without sequelae is typical.

Vogt-Koyanagi-Harada syndrome

Exact etiology of this condition remains uncertain. Originally, the Vogt-Koyanagi syndrome was described independently of the Harada syndrome. However, the clinical manifestations of both overlap sufficiently to justify their combination into one single entity.

Typically, it affects dark-skinned individuals or those of Asian races. Symptoms consist of impaired vision, headache, tinnitus, impaired hearing, photophobia, vertigo, vomiting, and seizures. Findings include alopecia, cavities, vitiligo, iridocyclitis, uveitis, and serous retinal detachments. Occasionally, elevated protein and pleocytosis have been found in the CSF. The disease usually occurs in the third decade of life and follows a recurrent course. Many neurological manifestations are believed to be secondary to adhesive arachnoiditis. Cranial nerve palsies and hemipareses may result. Confusion, psychosis, and seizures also have been reported.

Prednisone therapy in moderate to high doses improves this condition.

Behçet syndrome

The cause of Behçet syndrome remains uncertain. A triad of uveitis, painful oral ulcers, and genital ulcers characterizes this disease. Other manifestations include arthritis and thrombophlebitis. CNS manifestations occur in 18% of patients with Behçet syndrome and include meningoencephalitis, benign intracranial hypertension, papilledema, brainstem lesions, cranial nerve palsies,

spinal cord lesions, and mental status changes.

Mollaret meningitis

Mollaret meningitis is a rare form of recurrent meningitis originally described by Mollaret in 1944. According to Bryun, who further refined the clinical diagnostic criteria, the condition is characterized by (1) recurrent episodes of severe headache, meningismus, and fever; (2) CSF pleocytosis with large endothelial cells (ie, Mollaret cells), neutrophils, and lymphocytes; (3) recurrent attacks separated by symptom-free periods of weeks to months; (4) spontaneous remission of symptoms and signs; and (5) no known causative agent. Cases without fever, with increased CSF gamma globulin and transient neurological signs and symptoms, have been reported. Transient neurological abnormalities, including seizures, diplopia, pathologic reflexes, cranial nerve pareses, hallucinations, and coma, occur in as many as 50% of patients.

Mollaret cells, considered by many to be the hallmark of Mollaret meningitis (although not pathognomonic), are observed early and may comprise 60-70% of cells in the CSF. These cells are usually present for only the first 24 hours and can be missed easily. After the first 24 hours, the CSF shows a lymphocytic predominance with cell counts usually less than 3000/mm3. Hypoglycorrhachia (ie, low CSF glucose concentration) is reported in one third of the patients. CSF protein usually is elevated mildly. Recent data suggest that HSV-2 and, less frequently, HSV-1 may be etiologic in some if not most cases of Mollaret meningitis. Hence, acyclovir (intravenous or oral) or valacyclovir (oral only) are worthy of consideration for both therapy and prophylaxis.

  BIBLIOGRAPHY Section 9 of 9   

Author Information Introduction Overview And General Information Specific Causes Evaluation And Diagnosis Treatment Differential Diagnosis, Complications, Prognosis, And Prevention Related Conditions Bibliography

Abram SE, O'Connor TC: Complications associated with epidural steroid injections. Reg Anesth 1996 Mar-Apr; 21(2): 149-62[Medline].

Alloway JA, Mitchell SR: Sulfasalazine neurotoxicity: a report of aseptic meningitis and a review of the literature. J Rheumatol 1993 Feb; 20(2): 409-11[Medline].

Bahri O, Rezig D, Nejma-Oueslati BB, et al: Enteroviruses in Tunisia: virological surveillance over 12 years (1992-2003). J Med Microbiol 2005 Jan; 54(Pt 1): 63-9[Medline].

Bathon JM, Moreland LW, DiBartolomeo AG: Inflammatory central nervous system involvement in rheumatoid arthritis. Semin Arthritis Rheum 1989 May; 18(4): 258-66[Medline].

Booss J, Harris SA: Neurology of AIDS virus infection: a clinical classification. Yale J Biol Med 1987 Nov-Dec; 60(6): 537-43[Medline].

Chaudhry HJ, Cunha BA: Drug-induced aseptic meningitis. Diagnosis leads to quick resolution. Postgrad Med 1991 Nov 15; 90(7): 65-

70[Medline]. Chonmaitree T, Baldwin CD, Lucia HL: Role of the virology laboratory in

diagnosis and management of patients with central nervous system disease. Clin Microbiol Rev 1989 Jan; 2(1): 1-14[Medline].

Christen HJ: Bacterial meningitis and Lyme neuroborreliosis in childhood. Curr Opin Neurol Neurosurg 1993 Jun; 6(3): 403-9[Medline].

Comu S, Verstraeten T, Rinkoff JS, Busis NA: Neurological manifestations of acute posterior multifocal placoid pigment epitheliopathy. Stroke 1996 May; 27(5): 996-1001[Medline].

Connolly KJ, Hammer SM: The acute aseptic meningitis syndrome. Infect Dis Clin North Am 1990 Dec; 4(4): 599-622[Medline].

Corey L, Adams HG, Brown ZA, Holmes KK: Genital herpes simplex virus infections: clinical manifestations, course, and complications. Ann Intern Med 1983 Jun; 98(6): 958-72[Medline].

Dalakas MC: Intravenous immune globulin therapy for neurologic diseases. Ann Intern Med 1997 May 1; 126(9): 721-30[Medline].

Dalakas MC: Mechanism of action of intravenous immunoglobulin and therapeutic considerations in the treatment of autoimmune neurologic diseases. Neurology 1998 Dec; 51(6 Suppl 5): S2-8[Medline].

Dalton M, Newton RW: Aseptic meningitis. Dev Med Child Neurol 1991 May; 33(5): 446-51[Medline].

Dang CT, Riley DK: Aseptic meningitis secondary to carbamazepine therapy. Clin Infect Dis 1996 Apr; 22(4): 729-30[Medline].

De Vlieghere FC, Peetermans WE, Vermylen J: Aseptic granulocytic meningitis following treatment with intravenous immunoglobulin. Clin Infect Dis 1994 Jun; 18(6): 1008-10[Medline].

Denning DW: The neurological features of acute HIV infection. Biomed Pharmacother 1988; 42(1): 11-4[Medline].

Drees C, Haley CJ: Aseptic meningitis and muromonab-CD3 therapy. DICP 1991 Feb; 25(2): 138-9[Medline].

Echevarria JM, Casas I, Martinez-Martin P: Infections of the nervous system caused by varicella-zoster virus: a review. Intervirology 1997; 40(2-3): 72-84[Medline].

Elfaitouri A, Mohamed N, Fohlman J, et al: Quantitative PCR-Enhanced Immunoassay for Measurement of Enteroviral Immunoglobulin M Antibody and Diagnosis of Aseptic Meningitis. Clin Diagn Lab Immunol 2005 Feb; 12(2): 235-41[Medline].

Foy HM, Nolan CM, Allan ID: Epidemiologic aspects of M. pneumoniae disease complications: a review. Yale J Biol Med 1983 Sep-Dec; 56(5-6): 469-73[Medline].

Gabuzda DH: Neurologic disorders associated with HIV infections. J Am Acad Dermatol 1990 Jun; 22(6 Pt 2): 1232-6[Medline].

Gelber AC, Schachna L, Mitchell L, et al: Behcet's disease complicated by pylephlebitis and hepatic abscesses. Clin Exp Rheumatol 2001 Sep-Oct; 19(5 Suppl 24): S59-61[Medline].

Hammer SM, Connolly KJ: Viral aseptic meningitis in the United States:

clinical features, viral etiologies, and differential diagnosis. Curr Clin Top Infect Dis 1992; 12: 1-25[Medline].

Harrison MS, Simonte SJ, Kauffman CA: Trimethoprim-induced aseptic meningitis in a patient with AIDS: case report and review. Clin Infect Dis 1994 Sep; 19(3): 431-4[Medline].

Heinze EG Jr, Quinn EL: Aseptic meningitis in siblings with infectious mononucleosis. Henry Ford Hosp Med J 1966 Sep; 14(3): 229-44[Medline].

Higashi K, Yamagami T, Satoh G, et al: Cerebral cysticercosis: a case report. Surg Neurol 1993 Jun; 39(6): 474-8[Medline].

Hoffman MA, Valderrama E, Fuchs A, et al: Leukemic meningitis in B-cell prolymphocytic leukemia. A clinical, pathologic, and ultrastructural case study and a review of the literature. Cancer 1995 Mar 1; 75(5): 1100-3[Medline].

Honegger J, Fahlbusch R, Bornemann A, et al: Lymphocytic and granulomatous hypophysitis: experience with nine cases. Neurosurgery 1997 Apr; 40(4): 713-22; discussion 722-3[Medline].

Hoppmann RA, Peden JG, Ober SK: Central nervous system side effects of nonsteroidal anti-inflammatory drugs. Aseptic meningitis, psychosis, and cognitive dysfunction. Arch Intern Med 1991 Jul; 151(7): 1309-13[Medline].

Huang ST, Lee HC, Liu KH, et al: Acute human immunodeficiency virus infection. J Microbiol Immunol Infect 2005 Feb; 38(1): 65-8[Medline].

Iannetti P, Falconieri P, Imperato C: Acquired immune deficiency syndrome in childhood. Neurological aspects. Childs Nerv Syst 1989 Oct; 5(5): 281-7[Medline].

Joffe AM, Farley JD, Linden D, Goldsand G: Trimethoprim-sulfamethoxazole-associated aseptic meningitis: case reports and review of the literature. Am J Med 1989 Sep; 87(3): 332-8[Medline].

Jolles S, Sewell WA, Leighton C: Drug-induced aseptic meningitis: diagnosis and management. Drug Saf 2000 Mar; 22(3): 215-26[Medline].

Kaplan MH, Klein SW, McPhee J, Harper RG: Group B coxsackievirus infections in infants younger than three months of age: a serious childhood illness. Rev Infect Dis 1983 Nov-Dec; 5(6): 1019-32[Medline].

Klein JO: Antimicrobial treatment and prevention of meningitis. Pediatr Ann 1994 Feb; 23(2): 76-81[Medline].

Levy RM, Bredesen DE, Rosenblum ML: Neurologic complications of HIV infection. Am Fam Physician 1990 Feb; 41(2): 517-36[Medline].

Lipton JD, Schafermeyer RW: Central nervous system infections. The usual and the unusual. Emerg Med Clin North Am 1995 May; 13(2): 417-43[Medline].

Lunardi P, Missori P, Fraioli B: Chemical meningitis: unusual presentation of a cerebellar astrocytoma: case report and review of the literature. Neurosurgery 1989 Aug; 25(2): 264-70[Medline].

Marinac JS: Drug- and chemical-induced aseptic meningitis: a review of the literature. Ann Pharmacother 1992 Jun; 26(6): 813-22[Medline].

Marra CM: Neurologic complications of Bartonella henselae infection. Curr Opin Neurol 1995 Jun; 8(3): 164-9[Medline].

Michaels J, Sharer LR, Epstein LG: Human immunodeficiency virus type 1 (HIV-1) infection of the nervous system: a review. Immunodefic Rev 1988; 1(1): 71-104[Medline].

Miller K, Budke H, Orazi A: Leukemic meningitis complicating early stage chronic lymphocytic leukemia. Arch Pathol Lab Med 1997 May; 121(5): 524-7[Medline].

Min DI, Monaco AP: Complications associated with immunosuppressive therapy and their management. Pharmacotherapy 1991; 11(5): 119S-125S[Medline].

Misbah SA, Chapel HM: Adverse effects of intravenous immunoglobulin. Drug Saf 1993 Oct; 9(4): 254-62[Medline].

Moots PL, Harrison MB, Vandenberg SR: Prolonged survival in carcinomatous meningitis associated with breast cancer. South Med J 1995 Mar; 88(3): 357-62[Medline].

Moris G, Garcia-Monco JC: The challenge of drug-induced aseptic meningitis. Arch Intern Med 1999 Jun 14; 159(11): 1185-94[Medline].

Muir P, van Loon AM: Enterovirus infections of the central nervous system. Intervirology 1997; 40(2-3): 153-66[Medline].

Naruse H, Miwata H, Ozaki T, et al: Varicella infection complicated with meningitis after immunization. Acta Paediatr Jpn 1993 Aug; 35(4): 345-7[Medline].

Nelsen S, Sealy DP, Schneider EF: The aseptic meningitis syndrome. Am Fam Physician 1993 Oct; 48(5): 809-15[Medline].

Newton HB: Common neurologic complications of HIV-1 infection and AIDS. Am Fam Physician 1995 Feb 1; 51(2): 387-98[Medline].

Noone J: Diagnosis and treatment of leptospirosis in the primary care setting. Nurse Pract 1998 May; 23(5): 62-4, 66, 68 passim[Medline].

Norris CM, Danis PG, Gardner TD: Aseptic meningitis in the newborn and young infant. Am Fam Physician 1999 May 15; 59(10): 2761-70[Medline].

Nydegger UE, Sturzenegger M: Adverse effects of intravenous immunoglobulin therapy. Drug Saf 1999 Sep; 21(3): 171-85[Medline].

Oka Y, Fukui K, Shoda D, et al: Cerebral cysticercosis manifesting as hydrocephalus--case report. Neurol Med Chir (Tokyo) 1996 Sep; 36(9): 654-8[Medline].

Pachner AR: Neurologic manifestations of Lyme disease, the new "great imitator". Rev Infect Dis 1989 Sep-Oct; 11 Suppl 6: S1482-6[Medline].

Petito CK: Review of central nervous system pathology in human immunodeficiency virus infection. Ann Neurol 1988; 23 Suppl: S54-7[Medline].

Phuah HK, Chong CY, Lim KW, Cheng HK: Complicated varicella zoster infection in 8 paediatric patients and review of literature. Singapore Med J 1998 Mar; 39(3): 115-20[Medline].

Roos KL: Pearls and pitfalls in the diagnosis and management of central nervous system infectious diseases. Semin Neurol 1998; 18(2): 185-

96[Medline]. Rotbart HA: Enteroviral infections of the central nervous system. Clin

Infect Dis 1995 Apr; 20(4): 971-81[Medline]. Schiavotto C, Ruggeri M, Rodeghiero F: Adverse reactions after high-dose

intravenous immunoglobulin: incidence in 83 patients treated for idiopathic thrombocytopenic purpura (ITP) and review of the literature. Haematologica 1993 Nov-Dec; 78(6 Suppl 2): 35-40[Medline].

Shapiro WR, Young DF: Neurological complications of antineoplastic therapy. Acta Neurol Scand Suppl 1984; 100: 125-32[Medline].

Sperber SJ, Schleupner CJ: Leptospirosis: a forgotten cause of aseptic meningitis and multisystem febrile illness. South Med J 1989 Oct; 82(10): 1285-8[Medline].

Stern BJ, Krumholz A, Johns C, et al: Sarcoidosis and its neurological manifestations. Arch Neurol 1985 Sep; 42(9): 909-17[Medline].

Stiehm ER: Human intravenous immunoglobulin in primary and secondary antibody deficiencies. Pediatr Infect Dis J 1997 Jul; 16(7): 696-707[Medline].

Weber T, Frye S, Bodemer M, et al: Clinical implications of nucleic acid amplification methods for the diagnosis of viral infections of the nervous system. J Neurovirol 1996 Jun; 2(3): 175-90[Medline].

Wittmann A, Wooten GF: Amoxicillin-induced aseptic meningitis. Neurology 2001 Nov 13; 57(9): 1734[Medline].

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