The Significance of Recording Electrode Placement in ENoG Measurement / 대한이비인후과학회지

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.

The Significance of Recording Electrode Placement in Test-Retest of Electroneuronography / 대한이비인후과학회지

ENoG is regarded as a valuable method for quantitatively assessing facial nerve function, however it is occasionally discorrelated with clinical findings. So its utility may be diminished, especially in the serial tests. So, we endeavored to find the suitable position of recording electrode in test-retest variability of ENoG. We performed the test five times individually in 18 healthy adults(all males) volunteers. The recording electrodes were placed at 3 different positions(whole nasolabial fold(A), 2/3 portion of the nasolabial fold(B), 1/2 portion of the nasolabial fold(C)). And then we compared the results between action potentials of 3 different positions. The amplitude was more stable at B or C than A. The mean interside variance(ISV) of individuals was less than 50% except one case at A, and there was no significant difference among them(p>or=0.05) except two persons between A and C(p<0.05). In the test-retest variability, the mean was 20.03%(A:20.66+/-10.72%, B:23.75+/-12.60%, C:15.69+/-10.21%). There was more smaller mean and standard deviation at C than others. So, we recommand the 1/2 of the nasolabial fold as the available position in the serial ENoG recordings.

A Case of Spontaneous Intracerebral Hemorrhage during Ear Surgery under General Anesthesia

There are many complications after the ear surgery to correct chronic otitis media(COM). They include facial nerve paralysis, perichondritis, injury of the dura or the sigmoid sinus, chocolate cyst or mucocele in the healed mastoid cavity, recurrence of cholesteatoma, granulation tissue and otorrhea. However, there has been no report of spontaneous intracerebral hemorrhage during ear surgery to correct COM under general anesthesia. We had encountered one case of spontaneous intracerebral hemorrhage after COM ear surgery under general anesthesia. There was no problem during the operation. We suspected that certain cerebral vascular anomaly triggered the intracerebral hemorrhage while under the general aesthsia. However, the speculation remains verified.