the most efficient readings possible by optimizing results with a minimal input stimulus. The amount of damage is calculated as a ratio of how much nerve conduction has been retained by the affected side compared to the healthy value. Massive amounts of clinical experience may be required to accurately interpret the data received from testing, and misreading the results may put the patient at serious risk of developing further damage or creating a problem in otherwise healthy facial nerves. Analyzing the Results Amplitude is the key component in the interpretation of electroneuronography tests. The resulting waveforms are analyzed and reported as a percentage using the following formula: Dysfunctional Side (volts) / Healthy Side (volts) = Percentage of Response Other forms of recording the output include using a percentage of fibers that are no longer active. This is essentially the same as subtracting the percentage of response from 100%. Either method is clinically accepted, provided the terminology is consistent and not interchanged. Any responsive level above 10% is regarded as being able to spontaneously recover and does not typically require surgical intervention. Anything beneath the threshold usually requires active and invasive means to correct. To ensure accurate results, and consequently an appropriate course of action, readings may need to be taken every few days until fairly constant values are recorded. Diagnostic Uses Alternative Tests Several alternative procedures exist for testing facial nerve integrity. Electromyography, Acoustic reflex testing (formerly the gold standard), MRI, CT scanning, transcranial magnetic stimulation, blink reflex tests, and maximal/minimal stimulation tests may also be used to assess the viability of the nerves. Currently, however, electroneuronography serves as the only objective test compared to these options, and the test is preferentially performed before the others. House-Brackmann Facial Grading Scale The House-Brackmann (HB) scale is the standard used by medical professionals to evaluate facial nerve function. It is a measure of the range of intentional motion the patient's facial muscles have, and is based largely on the observations of the physician. Because of the subjective nature of the scale, there may be discrepancies between assessments by different doctors, but the overall reliability and ease of use has made this scale the most commonly employed by medical professionals. The scale itself consists of six levels of facial nerve function, ranging from healthy (level 1) to a total lack of movement (level 6). When performing a visual examination, the level at which