From The MS Information Sourcebook, produced by the National MS Society.
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. Some of the neurologic symptoms of Lyme disease are similar to those of MS.
The first signs of Lyme disease develop within days to months after the tick bite. From 60-80% 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.
Neurologic Symptoms Can Be Similar to Those of MS
Lyme disease occasionally produces similar abnormalities in tests that are used to diagnose MS. These include MRI (magnetic resonance imaging) scans of the brain and analysis of cerebrospinal fluid.
All of these similarities in symptoms and test results have led some people with MS to be tested for the presence of antibodies to Borrelia, with the expectation that their neurologic symptoms are the result of Lyme disease rather than MS. The distinction is important because Lyme disease, especially when treated early, often responds to antibiotic therapy, whereas MS does not.
Studies Examine Overlap in Diagnosis of Lyme Disease and MS
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, and cerebrospinal fluid 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 evoked potentials 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 bacteria.
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."
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Last updated October 2005