Abstract: Bell’s Palsy is the most common cause of facial nerve paralysis. Recent clinical studies have suggested that the causative feature may be a long term thickening of the facial nerve sheath in the mastoid air cell system. Computed Tomography (CT) can easily identify the diameter of the vertical facial nerve in the mastoid – the putative site of compression. This retrospective study will examine the effectiveness of a single, blinded neuro-radiologist in identifying widened vertical facial nerve canals on thin cut high resolution CT scans. In the first phase of the study, the neuroradiologist will measure the diameters of facial nerve canals in the mastoid region bilaterally in patients who were not diagnosed with facial nerve pathology. A second set of specific CT scans will be provided to a radiologist with no information or medical history of the subject. These CT scans will include subjects with and without Bell’s Palsy. The study PI will compare the radiologist’s measurements of the vertical facial nerve canal diameter with the known facial nerve status. Results of the study will be recorded and shared with the medical community through presentation and/or publication.
Objectives: The purpose of this research is to determine 1) the range and average diameters of the vertical facial nerve canal in the mastoid region of normal/control patients using thin cut, high resolutions CT, 2) the range and average diameters of the vertical facial nerve canal in the mastoid region of patients diagnosed with Bell’s Palsy using thin cut, high resolutions CT. A neuroradiologist will use CT scans to measure facial nerve diameter and to determine whether the nerve has a normal or enlarged diameter. The study will involve a single, blinded neuro-radiologist performing these measurements on fine-cut CT imaging. The study will in include both a control group and a test group in order to obtain more powerful data.