Neuroimaging in facial nerve neuropathy

Abstract

The timing and volume of neuroimaging for patients with facial nerve neuropathy (FNN) are a cause for discussion.Aim. To study the current volume of neuroimaging in patients with FNN and to determine the essential diagnostic protocol.Material and methods. Magnetic resonance imaging (MRI) data analysis of adult patients with FNN (n = 833). Protocols were taken from the Uni fi ed Medical Information and Analytical System of Moscow (EMIAS). The essential diagnostic protocol was created. A prospective study was conducted with new protocol.Results. According to EMIAS, the timing of MRI was 3 months from the fi rst symptoms to do diagnostics, the longest period from diagnosis to appointment to MRI was 83 days. The list of pulse sequences was given in the protocol in ¾ of cases. The most indicated regimes were T1 WI (80.7%), T2 WI (90.6%), T2 FLAIR (73.2%), less often DWI (54.9%). Studies with contrast amounted to 22.8%. In total, the pathology was detected in 429 (51.5%) patients, including 88 (20.5%) intracranial tumors. In 216 (25.9%) patients, the changes were most likely associated with FNN, of which in 44.5% of cases were in fl ammatory, 21.3% — tumor, 16.2% — demyelinating process, 11.2% — postoperative changes.According to the new protocol, the cause of FNN was directly identi fi ed in 56.6% of patients, of which in idiopathic — 31,6% of cases, in symptomatic — 70.6% (p = 0.005). Changes that cannot be associated with FNN, but require the participation of a specialist, were detected in a 1/4 of patients. Only in 20.8% of cases, the MRI results were normal.Conclusion. Recommended volume of neuroimaging for patients with FNN is MRI of the brain and parotid salivary glands with contrast within 1 month from the fi st symptoms. Regimes: T1 WI, T2 WI, FLAIR (with a slice thickness of 1 mm), DWI, 3D TOF, free recession in equilibrium (SSFP, FIESTA-C, CISS, FFE, etc.), sensitive to magnetic fi eld inhomogeneity (T2*, SWI, SWAN, etc.), and also T1 WI after intravenous contrast.