Immune reactivity in Bell's palsy.

Although the pathogenesis of acute facial (Bell's) palsy is probably multifactorial, some investigators believe that the disorder results from autoimmune demyelination and is perhaps related to previous viral infection. The purpose of this study was to identify immune mechanisms which might contribute to Bell's palsy. The lymphocyte transformation test and immunofluorescence were evaluated with a soluble homogenate of unrefined peripheral nerve antigens. Three antigen-nonspecific tests were also studied. Results in 14 patients with Bell's palsy were compared with those in 21 controls. To be eligible for study, patients with Bell's palsy had to be seen within 10 days of onset of weakness. The control group included 5 patients with facial nerve dysfunction from other causes and 16 normal volunteers. No patient or control had previously received steroids. Five patients with Bell's palsy and one normal volunteer had abnormal lymphocyte transformation (p less than .05). Virtually all other tests were normal. These results. suggest that some instances of Bell's palsy result from cell-mediated immunity against peripheral nerve antigens. They also encourage further research in steroid and other immunotherapy.