Lyme disease is an illness caused by the organism Borrelia burgdorferi, a bacterium known as a spirochete that is carried by a deer tick. The spirochete can be transmitted to people or animals by the bite of a tick — with the first signs of Lyme disease developing within days or months. Sixty to eighty percent of those infected with Lyme disease get a large, reddish rash sometimes described as a bulls-eye. Other symptoms include a flu-like illness with fever, headache, stiff neck, and muscle and joint pains.
Lyme disease can cause delayed neurologic symptoms similar to those seen in multiple sclerosis (MS) such as weakness, blurred vision caused by optic neuritis, dysesthesias (sensations of itching, burning, stabbing pain, or “pins and needles”), confusion and cognitive dysfunction, and fatigue. Lyme disease symptoms may also have a relapsing-remitting course. In addition, Lyme disease occasionally produces other abnormalities that are similar to those seen in MS, including positive findings on magnetic resonance imaging (MRI) scans of the brain and analysis of cerebrospinal fluid (CSF).
These similarities in symptoms and test results have led some people with MS to seek testing for the presence of antibodies to Borrelia, to determine if their neurologic symptoms are the result of Lyme disease or truly MS. The distinction is important because Lyme disease, especially when treated early, often responds to antibiotic therapy, whereas MS does not.
For more information about Lyme disease, consult the Lyme Disease Association or the Centers for Disease Control and Prevention (CDC).
Studies examining Lyme disease & MS
Two studies have examined the overlap in diagnosis of MS and Lyme disease. The studies were conducted in parts of Long Island, New York, an area where Lyme disease is endemic, or regularly found.
In the first study, people who had Borrelia antibodies in their blood as well as a variety of neurologic symptoms considered to be “MS-like,” were evaluated with MRI, evoked potentials (EP) and CSF analysis, including a test for the presence of Borrelia antibodies in the spinal fluid.
While those with the MS-like illness had the highest incidence of abnormal MRIs and were the only ones among those studied to have abnormal EP and oligoclonal bands in their spinal fluid (indicating an abnormal immune response), they did not prove to have any Borrelia antibody in their spinal fluid.
The researchers concluded that the few patients with the MS-like symptoms probably had these symptoms due to MS and had also been exposed to the Borrelia bacterium.
A companion study looked for the presence of Borrelia antibodies in the blood of 100 people with the diagnosis of possible MS. Of 89 people who in fact turned out to have definite MS, only one had Borrelia antibodies. The researcher concluded that “…infection with Borrelia is infrequent in MS patients who live in an endemic area. Lyme disease is unlikely to be a significant factor in the differential diagnosis of MS.” Furthermore, the presence or antibodies to Borrelia does not prove that Borrelia is causing the neurological symptoms, only that there has been previous infection with the organism.