Value of the facial nerve latency test in the prognosis of childhood Bell's palsy.

In the present study we evaluated the facial nerve latency test (FNLT) as a prognostic tool in cases of childhood Bell's palsy. Twenty-five children aged 4-14 years were studied. We divided our subjects into three groups according to duration of latency time (LT). Group A patients had an LT within the normal range, with average of 3.27 ms, group B a slightly prolonged LT averaging 5.7 ms, and group C a markedly prolonged LT averaging 10.5 ms. Analysis of the recovery index by group showed that group A patients experienced complete and quick recovery, while in group B 50% had complete but delayed recovery and 50% slightly impaired facial nerve function, and in group C 50% had slightly impaired function and 50% incomplete recovery. The more prolonged the LT, the worse the clinical results. The FNLT is thus a valuable prognostic tool in cases of Bell's palsy in childhood.