Findings
Pre- and postcontrast MR was performed of the brain and internal auditory canal.
Brain: Sagittal T1-weighted images demonstrate corpus callosum to be intact. No evidence of Chiari malformation. No abnormal pineal region masses. Pituitary gland is not enlarged. Diffusion imaging demonstrates no evidence of recent infarct. Susceptibility weighted imaging shows no evidence of hemosiderin staining. Axial FLAIR and T2 weighted images show the ventricular size, shape and configuration to be within normal limits. No evidence of vasogenic edema or mass effect. Contrast-enhanced T1 weighted images show no abnormal intra-axial enhancing masses.
Internal Auditory Canals: Pre- and postcontrast images were performed through the internal auditory canals.
Thin-section imaging through the facial nerve demonstrates asymmetric increased enhancement of the right distal canalicular, labyrinthine, anterior genu, tympanic, posterior genu and descending portion of the right facial nerve consistent with Bell’s palsy. No abnormal leptomeningeal enhancement is seen. No definite evidence of parotid masses is identified on the sagittal images.
Noncontrast T1-weighted images show no evidence of increased T1 signal in either cochlea or vestibule to suggest spontaneous intralabyrinthine hemorrhage. Contrast-enhanced T1-weighted images show no abnormal enhancement in either cochlea or vestibule to suggest labyrinthitis. No evidence of pericochlear enhancement to suggest retrofenestral otosclerosis. No evidence of vestibular schwannoma. No evidence of aggressive skull-base masses. Heavily T2-weighted images show normal appearance of cochlea and vestibule. Cochlea appears to have 2-1/2 turns. Basilar membrane is visualized. Modiolus is intact. No obvious evidence of congenital inner-ear malformation is identified. No evidence of enlarged vestibular aqueduct.
Conclusions
Asymmetric increased enhancement of the right distal canalicular, labyrinthine, anterior genu, tympanic, posterior genu and descending portion of the right facial nerve consistent with Bell’s palsy.
Dedicated MRI of the parotid glands would be helpful for further evaluation if the patient has “atypical” Bell’s palsy that lasts greater than 3 months.