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, 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 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.