Ricerc@Sapienza

Introduction
Most cases of Hepatitis E virus (HEV) infection in humans are asymptomatic, whereas some lead to acute hepatitis and only a minority to extrahepatic manifestations. Interestingly, the most common extrahepatic features of HEV infection are neurologic diseases, mostly involving the peripheral nervous system (i.e. amyotrophic neuralgia, Guillain Barrè syndrome, meningo-encephalitis and cranial nerves neuropathies). Facial nerve palsy is the most common cranial nerve disorder. The etiology is frequently unknown, although associations with viral or bacterial infection and autoimmune diseases has been demonstrated in a subset of patients.
Objectives
The aim of this prospective, pilot study is to investigate the occurrence of HEV infection in idiopathic facial nerve palsy, whose etiology and pathopsysiology is still debated. We would also like to study its clinical, serological, epidemiologic, neurophysiologic and radiologic features.
Study design
Patient clinically diagnosed of peripheral facial nerve palsy with will be enrolled in the study. All patient will undergo a complete neurological examination, a serum screening and a brain TC scan. The grading of facial palsy will be assessed by the House-Brackmann facial nerve grading system (HBS) at baseline visit, after one and 6 months from the clinical onset. At the same timepoints, we will collect serum for testing viral RNA and for anti-HEV IgM and IgG assessment, as weel as a specimen of saliva, that will be analyzed for HEV RNA too. Neurophysiological study will be performed to assess the facial nerve prognosis. We would also like to study all patients with a functional magnetic resonance imaging (fMRI) by examining functional connectivity (FC) at rest, and through the analysis of both the amplitude and the fractional amplitude of low-frequency fluctuation (ALFF, fALFF). Finally, we will investigate habits and lifestyle factors associated with HEV infection through specific questionnaires.