Lyme Disease and Other Tick-Borne Infections

The neurologic manifestations of selected tick-transmitted infections in North America and Eurasia were reviewed.

Both Powassan virus in North America, and Tick-Borne Encephalitis (TBE) virus in Eurasia can cause encephalitis, often with significant neurologic morbidity. Lyme disease, Ehrlichia chaffeensis (the cause of human monocytic ehrlichiosis [HME]), and Borrelia miyamotoi infections can cause meningitis (the third primarily in immunocompromised individuals). Patients with Lyme disease may also develop cranial neuropathy, and/or radiculoneuropathy. Tick-borne infections are being increasingly recognized in North America and Eurasia. While many tick-borne infections can cause headaches, lethargy or other non-specific symptoms, these are generally not evidence of nervous system infection - i.e., neuroinvasive disease. The latter is less common but may occur in infections due to Powassan and TBE viruses, in HME and in Lyme disease. Patients with symptomatic nervous system infection due to Powassan or TBE virus are at high risk of developing significant neurologic impairment and sequelae.