Prognostic value of electrical tests in acute facial paralysis.

The prognostic value of electroneurography has to be based on repeated tests performed as soon as the palsy has become clinically complete. The sun should not set over a complete facial palsy without an electrical test being performed and a decision reached on when to perform the next. The time course (velocity) and the end point (maximal value) of denervation as well as the early return of voluntary movements (early deblocking) are the best prognostic signs in acute facial palsy. The practical implications of the prognostic guidelines obtained by serial electroneurograms are demonstrated for facial paralysis secondary to fractures, iatrogenic injury, and Bell's palsy.