Evaluation of facial nerve function in bell's palsy patients with serial GD-DTPA enhanced MRI

ABSTRACT

To find out the role of Magnetic Resonance Imaging [MRI] in diagnosing and investigating Bell's palsy. Ten patients with mild to moderate acute idiopathic facial palsy, so called Bell's palsy, were serially examined with gadolinium-DTPA-enhanced MRI [Gd-MRI] on mean days 12,35 and 92 after the onset of palsy [second follow-up n=9]. Seven out of the 10 patients demonstrated ipsilateral facial nerve enhancement, exclusively in the internal auditory canal including meatal portion [IAC/Me] at the initial examination. Four patients out of them also exhibited facial nerve enhancement at the second examination. Only one patient showed enhancement at the third examination. The reduction in facial nerve enhancement was found to be correlated with clinical and neurophysiologic improvements in the nerve function during recovery from Bell's palsy. On the other hand, the three patients who did not exhibit facial nerve enhancement had the lowest electroneurography values at the initial examination in spite of the fact that there was no clinical difference between their palsy and that of the patients with positive findings. Those three patients did not exhibit enhancement at serial follow-up examination. These findings showed the presence of enhancement does not necessarily indicate poor prognosis for recovery and that the disappearance of facial nerve enhancement was related to improved facial nerve function during recovery from mild and moderate cases with Bell's palsy