Introduction
Bell’s palsy accounts for approximately 65% of acute facial palsies.1 Diagnosis of Bell’s palsy is still one of exclusion. Its etiology has been the subject of debates for years .2-4 Nowadays, most authors refer to the theory of inflammatory demyelinating neuritis caused by reactivated latent viral infection (herpex simplex virus 1, herpes zoster virus) or other pathogens like Coxsackie virus, adenovirus or Epstein-Barr virus. Among non-infectious causes atherosclerosis and autoimmunological disorders (like Hashimoto or Sjogren disease) leading to facial nerve edema are listed.3 Facial nerve palsy (FNP) has occasionally been reported as a complication following the administration of some vaccinations, including mRNA vaccines (BNT162b2 and mRNA-1273) against coronavirus disease 2019 (COVID-19).5-6 Most researchers show that over 70% of patients with Bell’s palsy make a full recovery in one week to six months.2,4 In some groups, involving people over 60, patients with severe pain or pregnant at onset, with complete paralysis, suffering from diabetes and high blood pressure, the course of the disease may be more severe, even with cases of permanent FNP.2,4All patients with irreversible palsy need further diagnostics to exclude organic, infectious, metabolic and autoimmunological cause of such a process. The detailed evaluation should be based on in-depth history, clinical neurological and otolaryngological examination, laboratory tests and imagings to check for any viral (HIV, human herpesvirus 6, mumps virus, cytomegalovirus, and rubella virus), bacterial (Borrelia burgdorferi, Rickettsia, otogenic process), autoimmunological / metabolic (sarcoidosis, Sjogren’s syndrome, sclerosis multiplex, GPA), and organic (tumors in the region of cerebellopontine angle, parotid gland, petrous bone, brainstem) pathologies.2-4
The goal of the study was to assess the frequency of malignancies hidden under the diagnosis of “Bell’s palsy”. We aimed to create diagnostic algorithm to avoid failures concerning patients whose only symptom of parotid gland cancer was irreversible FNP. One can use the algorithm for daily clinical practice and initiation of further studies.