Clinical Value of a Battery Electrodiagnostic Test
For the last 20 years we have used the standardized electrodiagnostic tests to assess grade of nerve injury and prognosis of facial palsy. The tests involve (1) conventional nerve excitability test, (2) strength-duration curve testing at the orbicularis oris, orbicularis oculi, and frontalis muscle and (3) evoked compound muscle action potential of the orbicularis oris and oculi muscle. The test battery was applied to more than 2000 patients with conditions including Bell’s palsy, Hunt’s syndrome, traumatic facial palsy, facial palsy due to otitis media, and other intratemporal facial palsies. Reliability, advantages, and disadvantages of each test are described. We emphasize the importance of a battery test for evaluation of prognosis of facial palsy due to different etiologies.