Peripheral facial palsy in patients with tick-borne encephalitis

Although tick-borne encephalitis (TBE) has been recognized in Europe for more than 70 years and has been the topic of numerous reports, information on the involvement of facial nerves in the course of the disease is limited. Our study conducted at a single medical centre revealed that facial nerve involvement in the course of TBE in Central Europe is (i) infrequent-it was found in only 11 of 1218 (0.9%) consecutive adult patients diagnosed with TBE; (ii) manifests with unilateral or rarely bilateral peripheral facial palsy (PFP) (nine and two patients, respectively); (iii) appears late in the course of acute illness-in our patients 10-20 days after the onset of the meningoencephalitic phase of TBE, and often after defervescence (in 8/11 patients; 6-13 days after normalization of body temperature); (iv) develops more often in patients with more severe illness, i.e. more frequently in those with encephalitic than in those with meningitic clinical presentation, and more commonly in patients with monophasic than biphasic illness; and (v) has a favourable outcome-our patients had a clinically complete recovery from PFP within 7-90 (median 30) days after its onset. Moreover, the finding of Borrelia infection in 3/11 (27.3%) patients (diagnosis of confirmed Lyme neuroborreliosis was established in 1/11 patients and two patients fulfilled criteria for possible Lyme neuroborreliosis) suggests that in countries where TBE and Lyme borreliosis are endemic, concomitant infection with Borrelia burgdorferi sensu lato should be considered and searched for in patients who develop PFP in the course of TBE.