Quantitative proteomic analysis of cerebrospinal fluid from patients with idiopathic facial nerve palsy.

Overview

abstract

BACKGROUND: Idiopathic facial palsy (IFP) accounts for over 60% of peripheral facial palsy (FP) cases. The cause of IFP remains to be determined. Possible etiologies are nerve swelling due to inflammation and/or viral infection. Here, we applied an integrative mass spectrometry approach to identify possibly altered protein patterns in the CSF of IFP patients. METHODS: CSF samples were obtained from 34 patients suffering from FP. In 4 patients, varicella zoster virus was the cause (VZV-FP). Among the 30 patients diagnosed with IFP, 17 had normal CSF parameters, 5 had slightly elevated CSF cell counts and normal or elevated CSF protein, and 8 had normal CSF cell counts but elevated CSF protein. Five patients with primary headache served as controls. All samples were tested for viral pathogens by PCR and subjected to liquid chromatography tandem mass spectrometry and bioinformatics analysis and multiplex cytokine/chemokine arrays. RESULTS: All CSF samples, except those from VZV-FP patients, were negative for all tested pathogens. The protein composition of CSF samples from IFP patients with normal CSF was comparable to controls. IFP patients with elevated CSF protein showed dysregulated proteins involved in inflammatory pathways similar to that of VZV-FP patients. Multiplex analysis revealed similarly elevated cytokine levels in the CSF of IFP patients with elevated CSF protein and VZV-FP. CONCLUSIONS: Our study revealed a subgroup of IFP patients with elevated CSF protein that showed upregulated inflammatory pathways, suggesting an inflammatory/infectious cause. However, no evidence for an inflammatory cause was found in IFP patients with normal CSF.