The Significance of Recording Electrode Placement in ENoG Measurement / 대한이비인후과학회지

ABSTRACT

ENoG is the objective electrophysiologic measurement of the muscle compound action potential(CAP) to assess the rate of degenerated nerve fibers. However, occasional discorrelation with clinical findings may diminish the utility of the ENoG. So, we studied the significance of recording electrode placement, which is considered to affect the result of the ENoG. We performed the interside variance in 20 healthy adults(20 males) volunteers and retest was performed in 6 adults of 20 volunteers. The recording electrode was placed at 3 positions.(whole nasolabial fold(A), 2 / 3 of the nasolabial fold(B), 1 / 2 of the nasolabial fold(C)) And then we compared the results: 1) In the first measurement, the mean CAP was 3.02+/-0.98mV(A), 2.80+/-0.75mV(B), 2.56+/-0.57mV(C) on the right side, 2.70+/-1.02mV(A), 2.50+/-0.90mV(B), 2.33+/-0.86mV(C) on the left side, and there was no significant difference between right and left inter-side amplitude(p>or=0.05). 2) In the first measurement, the mean interside variance(ISV) was 32.7%(37.55+/-16.32%(A), 29.88+/-17.15%(B), and 30.67+/-18.56(C)) and there was no significant difference among them(A, B, C)(p>or=0.05). The minimal individual ISV was 20.35+/-12.44%. There was significant difference between it and the other individual 3 positions(por=0.05). The minimal individual ISV was varied in each testing at 3 positions. And the value was 14.32+/-2.69%. There was no significant difference between it and other 3 postions(p>or=0.05). So we recommand that the recording electrode may be fixed at the bilateral same position of the nasolabial fold. But if there is any indication of facial nerve decompression, you must find the best recording electrode position to get the minimal ISV before operation.