Department: Ask the Experts
Q What kinds of neurological problems can be caused by Lyme disease?
A The typical starting point of Lyme disease is a bite by a small hard-shelled tick. The wound often goes unnoticed because ticks are small and inject local anesthesia when they bite. The hallmark sign of the disease is a red skin rash called erythema migrans. The rash can appear any time within the first 30 days after the bite. When an infected tick bites, it can inject Lyme bacteria (known as Borrelia burgdorferi) into the skin. As the bacteria spread from that primary site, they may cause flu-like symptoms, including a low-grade fever, aches and pains, and a headache.
What happens next depends on where in your body the bacteria go and how you react to them. About 10 percent of infected people will get meningitis, which can include a severe headache with flu-like symptoms. If left untreated, this bacterial infection can cause loss of muscle tone on one or both sides of the face (thankfully, this facial nerve paralysis is almost always reversible). Between 5 and 10 percent of people will experience pain in the distribution of a nerve root (called Lyme radiculitis) either in a limb or in the chest and abdomen. This feels similar to when you get a pinched nerve in your neck or back, except with Lyme disease, the pain is due to inflammation instead of pinching. Also, patients with a Lyme infection that has been left untreated for many months or even years can get arthritis.
Some people will also experience encephalopathy as a general reaction to the infection. You may feel mentally drained, lethargic, and unable to concentrate. About one person in a million will get brain or spinal-cord inflammation, which can cause more severe neurologic problems but is usually responsive to treatment.
Remember that ticks only bite when the weather is reasonably warm, so these symptoms will usually occur between spring and fall and only in defined geographic regions. Ticks live in grassy regions—such as suburbs and rural areas—along the eastern seaboard, in the Midwest, and in Northern California.