Erythema chronicus migrans (ECM): migrating erythematous circular rash, with appearance of “bull’s-eye,” or “target,” 3 to 30 days after tick bite. Headache, myalgia, stiff neck, cranial nerve palsies (almost always seventh nerve) may occur. CSF usually normal.

Several weeks after onset of ECM.

Heart conduction defects; meningism, often afebrile; radiculitis (multiple or isolated, root pain or focal weakness). Seventh cranial nerve frequently involved, usually bilateral. Polyneuritis or mononeuritis multiplex. Decreased concentration, irritability, emotional lability, memory, sleep disorders.