Peripheral facial palsy as an initial symptom of Lyme neuroborreliosis in an Austrian endemic area

BACKGROUND: The objective of this study was to analyze the percentage as well as clinical and laboratory characteristics of Lyme neuroborreliosis (LNB) in patients admitted with peripheral facial palsy. Additionally, we looked for diagnostic criteria to distinguish Bell's palsy from facial palsy due to LNB.

METHODS: Data collection was done retrospectively from 2007 until 2012. We identified 278 consecutive patients, who were admitted to the department of Neurology due to peripheral facial palsy. Patients were routinely investigated for LNB including clinical neurological examination and cerebral spinal fluid (CSF) analysis. Demographic and clinical data were analyzed according to a standardized protocol.

RESULTS: In 19 (male (m) = 14/female (f) = 5) out of 278 patients (7 %), a diagnosis of LNB was established. There were 8 patients (3 %) identified with varicella zoster (VZV) (m = 7/f = 1) and 13 patients (5 %) with facial palsy due to diabetic mononeuropathy (m = 5/f = 8). A total of 207 patients (75 %) were diagnosed as Bell's palsy (m = 110/f = 97). Compared with CSF of patients with facial palsy due to VZV and diabetic mononeuropathy, patients with LNB showed higher cell count, protein and lactate levels, whereas patients with facial palsy due to diabetic mononeuropathy showed higher glucose level. With respect to seasonal clustering, an accumulation of 74 % of the LNB cases was detected from June to October, whereas in the rest of the year there were only 26 % of the LNB cases. Patients with Bell's palsy are more evenly distributed over the year. Regarding neurological signs and symptoms, radicular symptoms were only reported in the LNB group. Despite radicular symptoms for LNB, no specific signs or symptoms were found for facial palsy due to VZV, Bell's palsy, or diabetic mononeuropathy.

CONCLUSIONS: According to the results of our study, we recommend CSF testing in any case for patients with facial palsy in an endemic area from June to October especially if additional radicular symptoms are present. To establish recommendations for a diagnostic workup in patients with facial palsy in areas endemic for Borrelia, the seasonal clustering of LNB as well as specific clinical features should also be confirmed in a future prospective trial.