A quick word about Lyme disease
Our show begins with the introduction of the Ixodes tick. A particularly annoying little parasite that’s common in the northeast and mid-west United States, some parts of Europe, and other regions of the world. Most places in the US really don’t have to worry about it. But where I live, in Pennsylvania, it’s a lot more common than you might think.
As you know about ticks and Lyme disease, the longer a tick clings to your body, the more likely you are to acquire Borreliosis (the disease caused by the infectious spirochete, Borrelia burgdorferi). Studies have shown that it takes a minimum of 24-36 hours before the Borrelia species can travel from the tick’s midgut to the salivary glands and cross over into human capillaries. So as long as you check yourself for ticks every day and remove those bloodthirsty arthropods, you should be safe.
Borreliosis is divided into 3 stages of illness:
- Early localized: Patients with early stage borreliosis usually notice non-specific B-type symptoms, things like fatigue, fever, myalgias, arthralgias, and often with the characteristic rash of erythema migrans. This rash, which is noticed in 80% of patients (and is 80-90% specific for the disease), is more homogenously
red than you might think. The classic bull’s eye or target appearance is seen less frequently, but when you see that, it should definitely raise a red flag.
- Early disseminated: This is the part where our show today really takes off. At this point in the illness, the patient develops neurologic, cardiac, and/or rheumatologic manifestations. For the sake of BrainWaves being a neurology-themed program, we only addressed the neurologic symptoms which are seen in about 15% of patients who had erythema migrans.
- Late: After about 6 months, more chronic symptoms of inflammation may ensue. Things like arthritis, and unremitting systemic symptoms. We don’t get into this, but the distinction between this and “Chronic Lyme” is a tricky one to make.
Neurologically, Lyme can do a lot of things. Often we think of it in as it inflames the subarachnoid space.
- Cranial neuropathies (facial nerve being most commonly affected)
- Nuchal rigidity (meningismus)
Besides the subarachnoid involvement, neuroborreliosis has been observed in cases with parenchymal and peripheral nerve disease. More often, cases of encephalitis or myelitis are reported in European serotypes of Borrelia, and these features develop over a few weeks unlike the meningitis seen after 3-14 days of exposure. This is the reason why when we see small amounts of white matter disease on brain MRI, Lyme disease is on the differential diagnosis.
Diagnostic testing. You should really pay attention to this part of the show today. The Centers for Disease Control and Prevention recommend a two-step diagnostic approach for Lyme Disease:
You should make sure your lab (or physician) conducts both sequences of diagnostic testing, and not just the highly sensitive screening test (which is poorly specific. You need that second tier test, which most labs will do when you place the Lyme order, and this means a Western Blot. The proteins identified in the western blot are IgM or IgG antibodies directed against Borrelia antigens and you must have a combination of these proteins present to confirm the diagnosis. 1 band is not enough. You need 2 IgM bands for acute Lyme (<4 weeks of symptoms) and at least 5 IgG bands for subacute Lyme (>4 weeks). And this is just the approach to serum testing. In suspected neuroborreliosis, a LP should be performed and paired antibody testing should be conducted—so the CSF to serum antibody index.
Treatment. As far as antimicrobial therapy goes, the American Academy of Neurology guidelines recommend a 14-day intravenous penicillin-based therapy for cases of neuroborreliosis. In fact the first case of neuroborreliosis was treated successfully with penicillin, so when resources are limited, that’s a good option to choose from. If you have an isolated facial palsy, an oral regimen can also be used and for a shorter course, usually 2-3 weeks. I’ve seen docs offer doxycycline in this case as long as the patient is not pregnant, breastfeeding, or younger than 8.
For more information on prognosis, or even for what it may be like to have (or not have) Lyme disease, I’ll refer you to the audio program. In a few weeks, Dr. Colin Quinn shares his experience… Stay tuned.
BrainWaves podcasts and online content are intended for medical education only and should not be used for clinical decision making.
- Marques A. Chronic Lyme disease: a review. Infect Dis Clin North Am. 2008;22:341-60, vii-viii.
- Marques AR. Lyme Neuroborreliosis. Continuum (Minneap Minn). 2015;21:1729-44.
- Halperin JJ, Shapiro ED, Logigian E, Belman AL, Dotevall L, Wormser GP, Krupp L, Gronseth G, Bever CT, Jr. and Quality Standards Subcommittee of the American Academy of N. Practice parameter: treatment of nervous system Lyme disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2007;69:91-102.