What Is Aseptic Meningitis?
Aseptic meningitis refers to inflammation of the meninges caused by something other than a bacterial infection, most commonly, a viral infection. Meningitis in itself is a broad term that refers to inflammation of the meninges, the membrane surrounding the brain and spinal cord.
The symptoms of meningitis, regardless of the cause, include fever, headache, stiff neck, confusion, and sensitivity to light.
Some viral causes of aseptic meningitis can be treated with antiviral medications, but typically the disease resolves on its own. The mainstay of treatment is supportive therapy. A few viruses causing aseptic meningitis can be prevented with vaccines, but most causes of aseptic meningitis cannot be prevented.
You should go to the ER as soon as possible in order to take a sample of the fluid bathing the nervous system to characterize the type of infection it is. A non-bacterial meningitis typically has no need for antibiotics.
How common is Aseptic Meningitis?
Aseptic Meningitis is also known as
- Viral Meningitis
- Parameningeal infection
- Carcinomatous meningitis
- Neoplastic meningitis
Aseptic Meningitis Symptoms
The following are the main symptoms of aseptic meningitis.
- Altered mental status
- Stiff neck (meningismus)
- Photophobia (light sensitivity)
- Double vision
- Facial Droop
- Skin rash
- Arthritis (pain in joints)
Encephalitis is a similar condition and refers to inflammation of the meningeal lining as well as the actual brain tissue. Encephalitis includes the symptoms of meningitis, but also presents with abnormal brain function, including altered mental status, motor or sensory dysfunction, altered behavior, and personality changes. While people with meningitis can have some mild confusion or lethargy, people with encephalitis have more pronounced neurologic dysfunction. However, these two diseases are on a spectrum, and the line between them is often blurry. Meningoencephalitis is a term that refers to the overlap of these two diseases.
Aseptic Meningitis Causes
Many people think of bacterial meningitis when they hear the term meningitis, which refers to a serious bacterial infection of the meninges requiring intravenous antibiotics for treatment. However, aseptic meningitis, commonly caused by a viral infection, cannot be treated in the same manner. Other causes include fungal infection, cancer, and medication side effects [3,4].
Enteroviruses are a group of viruses that are transmitted through the gastrointestinal system and can cause a variety of viral illnesses in children and adults. They usually cause mild self-limited flu-like illness. However, these viruses have the ability to infect the meninges and cause aseptic meningitis. Enteroviruses are the most common cause of aseptic meningitis, particularly in the summer and fall months .
Herpes virus type 2 (HSV-2) is another common cause of aseptic meningitis. HSV-2 is classically thought of as genital herpes, however, it can be spread via the mouth and saliva just like herpes virus type 1 (HSV-1) and is not necessarily a sexually transmitted infection. HSV-2 is typically asymptomatic but can cause a rash or blisters around the mouth or genitals. HSV-2 can also infect the meninges and cause aseptic meningitis .
Fungal spores can be inhaled leading to a variety of infectious symptoms including pneumonia and meningitis. Fungal infections are generally more common in people who are immunocompromised.
- Coccidiomycosis: This can cause meningitis and is common in the Southwest United States and Central America.
- Cryptococcus: This can cause meningitis and commonly infects immunocompromised patients .
Sometimes, an infection that is close to the meninges can lead to inflammation and meningitis symptoms. Some examples include an abscess in the epidural space around the spinal cord or an abscess in the subdural space below the skull. Sinus infections or ear infections can occasionally lead to meningitis symptoms as well. These infections are often bacterial, but bacteria will not actually be present in the meninges .
Other infectious causes
Other less common infections that can cause aseptic meningitis include Lyme disease, syphilis, and tuberculosis (TB) .
Neoplastic (cancerous) meningitis
Cancer of the blood, including lymphoma and leukemia, can spread to the meninges causing meningitis symptoms. Breast cancer, lung cancer, and skin cancer can also spread to the meninges and cause meningitis. This is much less common than infectious aseptic meningitis .
Drug-induced meningitis is uncommon and infectious and neoplastic (cancerous) causes must be ruled out before this diagnosis can be made. Some drugs that are known to cause meningitis include :
- NSAIDs: Non-steroidal anti-inflammatory drugs like ibuprofen (Advil, Motrin)
- Antibiotics: Such as Bactrim
- Chemotherapy agents: Such as cetuximab and rofecoxib
Treatment Options and Prevention for Aseptic Meningitis
The diagnostic process for meningitis has been detailed in this section, as well as methods of treatment, prevention, and the prognosis. Treatment options include antibiotics, antiviral or antifungal medications, cancer treatments, and supportive treatments.
The mainstay of diagnosing meningitis is by examining cerebral spinal fluid (CSF) for signs of inflammation, viruses, fungus, or cancer cells. All people suspected to have meningitis need to have CSF tested to rule out bacterial meningitis, which can be life-threatening, and requires intravenous antibiotic treatment. CSF surrounds the brain and spinal cord underneath the meninges. Markers of inflammation and infectious causes will be present in the fluid and can indicate the cause of meningitis.
- Lumbar puncture/spinal tap: In order to obtain CSF, a physician will perform a lumbar puncture (LP). This involves you lying on your side or bending over a table. Your physician will place a small needle through your back into the spinal canal to obtain a sample of CSF. Once the fluid sample is obtained, various tests including white blood cell counts, and tests for viruses, bacteria, or fungus can be done to determine the cause of meningitis.
- Head imaging: A physician may obtain a CT scan or MRI of the brain. Typically, this is used to rule out other causes of the symptoms including masses, bleeding, or fluid collections in the brain. An MRI may help with the diagnosis for neoplastic (cancerous) causes of aseptic meningitis.
The best course of medical treatment will be determined by your healthcare team and will likely include the following.
- Antibiotics: When people have symptoms of meningitis, they are typically started on empiric antibiotics in case the cause of meningitis is bacterial. Bacterial meningitis can be life-threatening and a rapid initiation of antibiotic treatment improves outcomes. Therefore, until the cause of meningitis has been determined, antibiotics are typically continued.
- Antiviral medication: Acyclovir is an effective treatment for meningitis caused by herpes virus. When the cause of meningitis is unknown, people are typically started on acyclovir. If the cause of meningitis is determined to be herpes virus, acyclovir will be continued for 10 to 21 days .
- Antifungal medication: Antifungal medications can be used if the cause of aseptic meningitis is suspected or confirmed to be fungal.
- Cancer treatment: The treatment of neoplastic (cancerous) meningitis varies widely depending on the type of underlying cancer and the stage of disease .
- Supportive treatment: Many causes of aseptic meningitis will resolve on their own and do not have a specific treatment. The mainstays of treatment in these cases include adequate pain control, intravenous fluids, and observation to monitor for neurologic deficits and cognitive impairment. Some people may need to be admitted to the hospital while others can do supportive treatment as an outpatient .
Most causes of aseptic meningitis are not preventable. Some causes of viral meningitis including measles and mumps can be prevented by routine childhood vaccinations.
Generally, the prognosis for aseptic meningitis is very good with significantly less mortality and morbidity than bacterial meningitis. There is a small risk for residual cognitive impairment in adults with aseptic meningitis, including subtle deficits in learning, memory, attention span and cognitive speed. However, these impairments are typically less common and less severe than with bacterial meningitis. Fungal meningitis is associated with slightly worse outcomes than viral meningitis [1,2]. The prognosis for neoplastic meningitis depends on the underlying cancer type and stage.
When to Seek Further Consultation for Aseptic Meningitis
If you have any combination of symptoms suggestive of meningitis, seek urgent medical treatment. In particular, seek medical treatment if you have a fever along with a headache, neck stiffness, or confusion. Some causes of meningitis require urgent medical intervention to prevent severe permanent neurological complications or death. It is important to be seen by a physician as soon as possible if meningitis is suspected.
Questions Your Doctor May Ask to Determine Aseptic Meningitis
To diagnose this condition, your doctor would likely ask about the following symptoms and risk factors.
- Do you look very sick (pale, sweaty, sleepy, unusual etc.)?
- Are you feeling less alert than normal?
- Have you been exposed to any kids that go to daycare?
- Do you have a rash?
- Have you traveled anywhere in the last week?
The above questions are also covered by our A.I. Health Assistant.
- Holmquist L, Russo CA, Elixhauser A. Statistical brief #57: Meningitis-related hospitalizations in the United States, 2006. Healthcare Cost and Utilization Project. Published July 2008. HCUP Link
- Schmidt H, Heimann B, Djukic M, et al. Neuropsychological sequelae of bacterial and viral meningitis. Brain. 2006;129(Pt 2):333-345. PubMed Link
- Viral meningitis. Centers for Disease Control and Prevention. Updated July 31, 2018. CDC Link
- Shukla B, Aguilera EA, Salazar L, Wootton SH, Kaewpoowat Q, Hasbun R. Aseptic meningitis in adults and children: Diagnostic and management challenges. J Clin Virol. 2017;94:110-4. NCBI Link
- Tunkel AR, Glaser CA, Bloch KC, et al. The management of encephalitis: Clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2008;47(3):303-327. NCBI Link