The actual causes of bell palsy still cannot be detected yet. As people thought, bell palsy occurs because of herpes simplex virus infections. However, there are a lot of possibilities that lead to bell palsy such as HIV infection, diabetes, sarcoid, and various cancers.
Besides that, CNS disorder, neoplasm, infectious disease (Lyme disease) and trauma also may cause
bell palsy. Moreover, other viruses that believed as bell palsy’s causes are Epstein-Barr which is causes mononucleosis and also cytomegalovirus.