What Is Aseptic Meningitis?

Aseptic meningitis is nonbacterial inflammation of the meninges, the tissue layers and fluid that protect the brain and spinal cord. It’s usually not life-threatening, but the symptoms can be distressing.

Often, aseptic meningitis improves on its own without causing brain or spinal cord damage. It’s important to rest while you’re recovering. Symptomatic treatment, like pain medication or intravenous fluids, can help you to stay comfortable and avoid complications as the inflammation subsides.

Types of Aseptic Meningitis 

"Aseptic" means that the condition is not caused by a bacterial infection. In contrast, bacterial meningitis is described as septic meningitis.

There are several types of aseptic meningitis, including:

• Viral meningitis (caused by a virus)
• Inflammatory meningitis (caused by an autoimmune disease, such as systemic lupus erythematosus, or SLE, and sarcoidosis)
• Medication-induced meningitis (caused by an inflammatory response to medication, such as steroids, certain antibiotics, and chemotherapy)
• Meningitis caused by a medical procedure (such as a blood patch that's used to treat a spinal fluid leak) 
• Reactive meningitis (caused by radiation therapy) 
• Fungal meningitis (caused by a fungus)
• Parasitic meningitis (caused by a parasite, such as in diseased meat)
• Meningeal carcinomatosis (the spread of cancer cells into the CSF and the meninges) 
• Mollaret's meningitis (a rare type of recurrent aseptic meningitis)

Aseptic Meningitis Symptoms 

Meningitis of any type can cause severe distress and discomfort. The symptoms can begin gradually or abruptly. 

The symptoms of aseptic meningitis can be similar to the symptoms of any other type of meningitis. However, some types of bacterial meningitis are accompanied by a rash or high fever, which is not common in aseptic meningitis (although some types of viral meningitis have rashes).

Common symptoms of aseptic meningitis include: 

• Stiff neck
• Head and neck pain 
• Photophobia (discomfort when looking at bright light)
• Phonophobia (distress when hearing loud noises)
• Nausea and vomiting 
• Back pain, especially when bending the neck or the legs 
• Loss of appetite
• Fatigue, sleepiness, low energy, trouble concentrating 
• Low-grade fever below 101 degrees Fahrenheit

Babies and young children with aseptic meningitis may be fussy and lose interest in eating.

Complications 

In some instances, aseptic meningitis can cause serious complications. The complications can occur if an infection spreads to other areas of the brain or body or if the inflammation becomes so severe that it leads to brain damage. 

Complications of aseptic meningitis can include: 

• Hydrocephalus, which is excess fluid in the brain that can develop due to inflammatory blockage of CSF flow 
• Stroke due to blood clots or bleeding in the brain
• Meningoencephalitis, which occurs if the infection or inflammation begins to involve the brain
• Seizures
• Spread of the infection to other areas of the body, such as the kidneys 

Causes

Usually, aseptic meningitis occurs due to viral exposure. For example, it can occur after a cold. 

Viruses that commonly cause aseptic meningitis include:

• Enterovirus
• Varicella zoster
• Herpesviruses
• Cytomegalovirus
• Coronavirus
  

Most of the time, the virus is not identified with tests, even if a cerebrospinal fluid analysis is done on a lumbar puncture sample. 

Some people are at increased risk of aseptic meningitis due to underlying conditions, such as a weak immune system or an autoimmune disorder. Other risk factors include having a spinal procedure or taking medication that may cause aseptic meningitis. 

How Aseptic Meningitis Develops 

Aseptic meningitis can be caused by an excessive inflammatory response to a virus, medication, or damage to the meninges after radiation treatment for cancer.

Sometimes immune suppression from human immunodeficiency virus (HIV), immunosuppressive medications, or a severe illness that weakens the immune system can make you susceptible to a severe infection if you're exposed to a fungus or virus.

Parasitic meningitis can occur after exposure to a parasite, which is not a common occurrence.

Diagnosis 

The symptoms of aseptic meningitis are often nonspecific, and your healthcare provider will take a thorough history and perform a full medical evaluation to identify what’s going on. 

Some signs of meningitis that might be seen on your physical examination include:

• Photophobia
• Brisk reflexes (a strong response during a reflex test)
• Kernig’s sign (not being able to straighten your leg at the knee while lying down with your hip flexed)
• Brudzinski’s sign (the knees or hips flex when you bend your neck while lying down)

Diagnostic tests may include brain imaging, such as magnetic resonance imaging (MRI) or computed tomography (CT). These tests can identify problems like a stroke, and they might show signs of meningeal inflammation. 

A routine complete blood count (CBC) is usually normal in uncomplicated aseptic meningitis, but it may show signs of systemic infection or inflammation if the infection spreads in the body.  

A lumbar puncture is a test in which CSF is collected and examined. It is the definitive way to diagnose an infection or inflammation in the CSF. This can show protein and white blood cell changes consistent with meningitis. Infectious viruses, fungus, or parasites might be identified in the fluid. 

Treatment 

Medical management of aseptic meningitis involves symptomatic therapy and possibly treatment for the cause. If complications arise, they need to be treated. 

Most of the time, mild viral meningitis is managed with rest, fluids, and mild pain medication at home. If you become dehydrated from lack of appetite or vomiting, you may need to be admitted to the hospital to get intravenous (IV) fluids and closer medical care. 

Specific antimicrobial treatments may be needed for certain infectious types of aseptic meningitis. Anti-inflammatory or immunosuppressive medication, such as steroids, might sometimes be used to treat inflammation. Since a weak immune system can predispose you to severe infections, this type of therapy is used with caution, depending on the situation.

Treatments for complications of aseptic meningitis: 

• Surgery or shunt placement for hydrocephalus 
• Blood thinners and/or management of brain swelling for treatment of a blood clot 
• Antiepileptic drugs for seizures 
• Close monitoring and management of brain swelling for encephalitis 
• Control of electrolytes, blood pressure, and breathing if an infection spreads to other areas of the body 

Prognosis 

Aseptic meningitis is generally distressing, but it’s not usually dangerous. Most people experience complete recovery within a few weeks. 

However, this condition can lead to serious problems, including blood clots in the brain, encephalitis, systemic spread of the infection, and lasting brain damage. Anyone can experience complications, even with the best medical care.

Risk factors for these complications include a serious underlying illness (such as cancer), immune suppression (such as having HIV), or an especially aggressive infection. 

If you are at risk of complications, your healthcare provider will monitor you closely to reduce the chance of an adverse outcome. You will need prompt treatment if you experience early signs of a complication.

Coping

Aseptic meningitis can cause a great deal of pain and discomfort. You can take mild anti-inflammatory medication to reduce your head and neck pain as directed by your healthcare provider.

Let yourself get some rest and stay comfortable. A warm blanket, dim lights, and a quiet environment will help you feel a little better. 

While it can be challenging, it’s important to stay hydrated. Be sure to sip on fluids. 

Call your healthcare provider immediately if your symptoms get worse or you develop new symptoms. Aseptic meningitis can worsen or cause serious health problems. Any complications must be diagnosed and treated promptly. 

When your meningitis resolves, you might have residual head or neck pain, photophobia, or trouble concentrating. These effects should fully resolve within a few months. In the meantime, your healthcare provider may recommend treatment for comfort until these issues improve. 

Summary 

Aseptic meningitis is nonbacterial inflammation or infection of the meninges and CSF. The condition is usually mild and self-limited, typically resolving on its own. Sometimes treatment is necessary to control symptoms and prevent long-term effects.

If a serious complication develops, it needs to be treated. For example, after a blood clot in the brain, a person may have stroke symptoms, such as weakness on one side of the body, necessitating physical therapy. Meningitis may cause persistent seizures, necessitating long-term treatment with anti-seizure medication. 

A Word From Verywell

If you or a loved one is diagnosed with aseptic meningitis, know that the symptoms will likely improve after a few days of rest. But you do need to get medical attention for this condition. As you recover, take it easy, and tell your healthcare provider if you are not improving as quickly as you would like to.