title: Bell's palsy: what is the prognostic value of measurements of signal intensity increases with contrast enhancement on MRI?
abstract: Our objective was to assess the prognostic value of measurements of the degree of contrast enhancement of the intratemporal segments of the facial nerve. We prospectively obtained MRI, slice thickness <1 mm of 20 patients with a facial palsy on the first day of inpatient treatment, and measured contrast enhancement of the nerve. The data were compared with compound muscle action potential (CMAP) measurements and the clinical course. Analysis of the initial enabled differentiation of three patients whose palsy was to show no improvement from 17 whose palsy was to resolve as expected. No patient with a poor outcome showed lesser increase in signal in the internal auditory canal, pars tympanica and pars mastoidea than patients who fully recovered. In no patient who had been diagnosed on the basis of the initial MRI as having a "normal" palsy was the amplitude of the (CMAP) reduced to less than 20% that of the normal side. Measurement of contrast enhancement was thus shown to be a prognostic indicator and may provide a basis for a differential treatment of facial palsy.
authors.affiliation: Department of Radiology, Armed Forces Hospital, Deutsche Bundeswehr, Oberer Eselsberg 40, 89081 Ulm, Germany. DrmedBodoKress@bwb.org
authors.forename: B P J
authors.initials: BP
authors.lastname: Kress
authors.forename: F
authors.initials: F
authors.lastname: Griesbeck
authors.forename: K
authors.initials: K
authors.lastname: Efinger
authors.forename: T
authors.initials: T
authors.lastname: Solbach
authors.forename: A
authors.initials: A
authors.lastname: Gottschalk
authors.forename: A W
authors.initials: AW
authors.lastname: Kornhuber
authors.forename: W
authors.initials: W
authors.lastname: Bähren
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020330:Bell Palsy / Q000175:diagnosis* / Q000503:physiopathology; D003287:Contrast Media; D005154:Facial Nerve / Q000503:physiopathology*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA