Gadolinium-enhanced magnetic resonance imaging(MRI) was performed in 16 patients with facial nerve paralysis: 7 with Bell's palsy, 3 with herpes zoster oticus(HZO), and 6 with traumatic facial palsy.
Fifteen of the sixteen patients showed the increased signal intensity of their facial nerves, with MRI. The geniculate ganglion(GG) including the distal part of the internal auditory canal segment(IAG) was more intensely enhanced segment in
Bell's
palsy, and the IAC was the greatest enhanced segment in HZO. It is assumed that the IAC is also involved in Bell's palsy, and it tis the mainly involved segment in HZO. In traumatic palsy, the segments proximal to the GG could be seen even with
increased signal intensity present within the mastoid.
Repeated MRI was possible in 8 of 16 patients until complete recovery. The enhancement obtained by the first imaging shifted to the peripheral part of the facial nerve. It is assumed that inflammation or edema, which is shown as enhancement,
shifts
to
the peripheral side of the facial nerve with the passage of time. The enhancement of the facial nerve in the repeated MRI remained present even after complete return of facial function.
It seems that MRI is effective in localizing the site of inflammation and edema during facial paralysis. (Korean J Otolaryngol 39 : 3, 1996)
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