[The prognostic value of quantified MRI at an early stage of Bell's palsy]

The aim of the study was to assess whether MRI has a prognostic value at an early stage of Bell's palsy.

Prospective, blinded study on 30 patients suffering from Bell's palsy, who came to hospital until the sixth day of illness, to receive high doses steroid therapy. MRI was done on the first day of inpatient treatment as a gradient-echo-sequence with a slice thickness of 0.7 mm before and after i. v. administration of 0.1 mmol GdDTPA/kg weight. The signal intensity increase was evaluated quantitatively by region on interest (ROI). The results were compared to the clinical outcome and the results of electrophysiology.

The examinations of all patients could be evaluated. The 3 patients who developed a chronic facial paralysis were detected by MRI on the first day of inpatient treatment. The patients, who showed MR signs for an unfavorable course, had a highly significant pathologic compound muscle action potential (CMAP) as a result of the electrophysiologic measurement. Rather than using complex measurement procedures it is possible to obtain reliable prognostic information from just one measurement within the Internal auditory canal before and after i. v. administration of contrast.

MRI has a prognostic value at an early stage of the illness. In the clinical setting this measurement is easy to perform, so that it is possible to obtain prognostic information at a stage when causal treatment is still possible.