Lyme meningitis can happen when Lyme disease is left untreated. It can cause symptoms like severe headache, fever, and light sensitivity. Lyme meningitis can be treated with a course of antibiotics.

Lyme disease is a bacterial infection spread through tick bites. In 2023, the Centers for Disease Control and Prevention (CDC) reported over 89,000 cases of Lyme disease, although the actual number is likely much higher.

If Lyme disease is left untreated, it can go on to cause complications impacting the nervous system, heart, and joints. One aspect of neurological Lyme disease is Lyme meningitis.

Keep reading below to learn more about Lyme meningitis, including its symptoms, what causes it, and how it’s diagnosed and treated.

Lyme meningitis falls under the umbrella of neurological Lyme disease. Neurologic Lyme disease, or Lyme neuroborreliosis, is when Lyme disease affects your nervous system.

It happens when Lyme disease isn’t treated, allowing the infection to spread into the nervous system.

A 2017 report on over 275,000 people diagnosed with Lyme disease in the United States between 2008 and 2015 found that 12.5% of people reported experiencing neurological symptoms.

Meningitis is an inflammation of the tissues that line the brain and spinal cord (the meninges). According to the CDC, roughly 3% of people with a reported diagnosis of Lyme disease have either meningitis or encephalitis.

A 2022 review notes that the symptoms of Lyme meningitis can vary greatly, ranging from minimal to severe.

The symptoms of Lyme meningitis can include:

Lyme meningitis may happen with other symptoms of neurologic Lyme disease, such as:

Lyme disease itself is caused by a bacterial infection that’s transmitted to humans by the bite of a black-legged (deer) tick. The scientific name of the bacteria is Borrelia burgdorferi.

Within a month of the tick bite, about 70% of people with Lyme disease develop a characteristic bull’s-eye rash. They may also experience flu-like symptoms like fever, headache, and body aches and pains.

If Lyme disease is left untreated, the bacteria can spread to other parts of the body, including the nervous system. This is called early disseminated Lyme disease.

Early disseminated Lyme disease occurs about 3 to 12 weeks after the tick bite and is when Lyme meningitis can happen.

Having untreated Lyme disease boosts the risk of Lyme meningitis. That’s why it’s important to see a doctor if you:

  • get a rash that looks like a bullseye, whether or not you’ve had a known tick bite
  • develop a rash or fever in the weeks following a known tick bite

You’re at a higher risk of Lyme disease in general if you:

  • live in an area where Lyme disease is common, such as the Northeastern or upper Midwestern United States (although the range of deer ticks is expanding)
  • are outside in wooded or grassy areas between April to September

To diagnose Lyme meningitis, a doctor will consider factors like:

  • whether or not you’ve had a known or suspected tick bite
  • if your symptoms are consistent with those of Lyme meningitis (or Lyme disease in general)
  • the results of testing

When it comes to testing, a doctor will use a series of two blood tests to help make a diagnosis. These tests look for antibodies to the B. burgdorferi bacteria.

If the first test is negative, no additional testing is needed. However, if the first test is positive or inconclusive, the second test will be done. A positive result on the second test can help confirm a diagnosis.

A CSF analysis may also be done if neurologic Lyme disease is suspected. Cerebrospinal fluid (CSF) is the fluid that surrounds the brain and spinal cord. It’s collected using a procedure called a lumbar puncture.

Lyme meningitis is treated using a course of antibiotics. These are medications that kill bacteria.

According to the CDC, the treatment of Lyme meningitis can involve one of the following antibiotics:

  • doxycycline given by mouth once or twice daily for 14 to 21 days
  • ceftriaxone given intravenously once daily for 14 to 21 days

The same two antibiotics can be used in both adults and children with Lyme meningitis. However, dosing in children is based on weight.

The CDC notes that most people who take antibiotics for Lyme disease have a full recovery. However, delayed treatment can lead to permanent nervous system damage, so it’s vital to seek care if you think you may have Lyme meningitis.

Lyme meningitis is one facet of neurologic Lyme disease. It happens when Lyme disease is untreated and can spread to other areas of the body.

Some of the symptoms of Lyme meningitis include severe headache, light sensitivity, fever, and stiff neck. Other neurological symptoms, such as facial drooping, numbness and tingling in the limbs, and vision problems, may also occur.

Lyme meningitis can be treated with antibiotics. To avoid getting it, limit your time outside in areas where deer ticks are common and seek care if a bullseye rash develops, whether or not you’ve had a known tick bite.