Peripheral facial palsy caused by the Borrelia spirochete.

Forty-three consecutive patients with peripheral facial palsy were examined to evaluate the incidence of facial palsy caused by the tick-borne Borrelia spirochete in a non-coastal area in the south of Sweden. Six (14%) of the patients were found to have a Borrelia infection. The incidence of Borrelia-induced facial palsy was 0.39/10,000 inhabitants, which is less than in neighbouring coastal areas but still high enough to cause serious concern when dealing with facial palsies. In contrast to Bell's palsy, a Borrelia infection can cause serious generalized illness if not properly treated. Negative Borrelia serology of the serum and the cerebrospinal fluid (CSF) and a normal CSF analysis did not exclude the Borrelia etiology. Tick bites, signs of polyneuropathy, meningeal symptoms and Borrelia-associated erythema proved to be important signs for the diagnosis.