Electromyography (EMG) and sialometry in the prognosis of Bell's palsy. A methodological study of early investigated, untreated patients.

The degree of remaining motor unit activity at maximal voluntary contraction of the face was examined in three of the facial muscles in 43 untreated patients with Bell's palsy. All the patients were examined within 10 days of the onset of the paresis. In 40 patients the EMG activity was compared with the clinical evaluation of the paresis and in 33 patients with the results from sialometry. EMG revealed remaining motor activity in several patients who had clinically total paresis. It was concluded that EMG can be used as a prognostic indicator at an early stage in Bell's palsy. Sialometry was found to predict the final outcome of the paresis with a slightly better accuracy than EMG.