末梢性顔面神経麻痺の予後診断法

―生体インピーダンス測定装置を用いて―

抄録

A satisfactory prognostic test for peripheral facial paralysis has not yet been established. Using an impedance meter (NEG Sanei, Type 4134), we attempted to quantify the movement of the upper lip to judge the prognosis more accurately (impedance method: IM).
The deviation of the upper lip correlates well with the amount of change in impedance (ΔZ) when supramaximal stimulation is applied to the facial nerve. We expressed the ratio of ΔZ on the affected side to that on the healthy side as ΔZ% and used this ratio as an indicator to judge the prognosis.
The subjects were 61 patients with Bell's palsy or Hunt's syndrome. All patients received conservative treatment.
Patients with an ENoG value less than 18.7% were defined as the poor prognosis group. Seventeen patients were judged to belong to this poor prognosis group, and 8 of them had a complete recovery after treatment. The accuracy of selecting poor prognosis patients by means of ENoG was 56%.
Then the prognostic diagnosis was carried out with a combination of ENoG and TM. The patients with an ENoG value less than 18.7% and those with a ΔZ% less than 43.2% were defined as the poor prognosis group. This time, 11 patients were judged to belong to the poor prognosis group, and only 2 patients had a complete recovery. The accuracy of selecting the poor prognosis patients with a combination of ENoG and IM was 82%.
In conclusion, with a combination of ENoG and IM the prognosis of facial palsy can be predicted more accurately than with ENoG alone.