Cranial nerve involvement, most commonly involving the facial nerves, occurs in about 50 to 80 percent of patients with Lyme neuroborreliosis. Facial palsy is considered by some to represent a peripheral neuropathy, although most patients are found to have cerebrospinal fluid (CSF) abnormalities when a spinal tap is performed. The optimal therapy for this aspect of Lyme disease remains unclear. A few studies have investigated the use of oral doxycycline because of its excellent oral absorption and CSF penetration. Dotevall and Hagberg performed a prospective, nonrandomized trial to study the efficacy of therapy with oral doxycycline in patients with Lyme-disease–associated meningitis and facial palsy.

Study participants were selected from a group of patients diagnosed with Lyme neuroborreliosis who were referred to a hospital-based infectious disease department in Sweden. Diagnostic criteria included neurologic symptoms compatible with the disease, inflammatory findings on CSF examination and immunologic evidence (IgG and IgM antibody) by serum or CSF testing of exposure to Borrelia burgdorferi, and verified erythema migrans. Excluded from the study were children younger than eight years of age, pregnant patients and anyone who had received an intravenous beta-lactam antibiotic within two weeks of admission. A lumbar puncture was performed at the start of antibiotic therapy and repeated anywhere from day 33 to day 102 after treatment in 90 percent of patients. The treatment regimen consisted of 200 mg of oral doxycycline, taken twice daily.

Twenty-nine patients enrolled in the study: 11 women and 18 men, with a mean age of 50 years. Most patients (86 percent) presented with painful meningoradiculoneuritis. Eight patients had bilateral facial palsy. Regarding CSF findings, the mean lymphocyte count decreased from 240 × 10⁶ per L to 12 × 10⁶ per L during antibiotic therapy. The mean protein concentration decreased from a pretreatment level of 1,649 mg per L (16.49 g per L) to a post-treatment level of 536 mg per L (5.36 g per L). The duration of antibiotic therapy ranged from 9 to 17 days, with a mean of 10.8 days. No photosensitivity reactions were reported; however, one patient did experience a Jarisch-Herxheimer reaction after the first dose of doxycycline. Two patients were retreated because of progression of facial palsy; one was given an additional 13 days of oral therapy and the second received seven days of treatment with intravenous cefotaxime. Both patients recovered fully without sequelae.

Six months after treatment, 90 percent of the patients had no residual signs of Lyme-disease–associated facial palsy. Three patients still had facial palsy at 24 months, including one patient with very mild unilateral paresis. The pretreatment duration of symptoms as well as CSF examination findings did not differ among patients, regardless of outcome.

The authors conclude from this study that oral doxycycline is an effective and easily administered treatment for patients with Lyme-disease–associated facial paresis. Advantages to oral antibiotics include lower costs and the ability to avoid hospitalization. The authors' findings are consistent with a previously published study finding that 200 mg of oral doxycycline daily was as effective as intravenous ceftriaxone. The higher dosage (400 mg per day) of doxycycline used in the current study resulted in greater CSF levels of the drug, which exceeded the minimum inhibitory concentration for B. burgdorferi.