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Electroneuronography or electroneurography (ENoG) is a neurological non-invasive test that was first described by Esslen and Fisch in 1979 and is used to examine the integrity and conductivity of a peripheral nerve. It consists of a brief electrical stimulation of the nerve in one point underneath the skin, and at the same time recording the electrical activity (compound action potentials) at another point of the nerve's trajectory in the body. The response is displayed in a cathode ray tube (CRT) or through the video monitor of a computer. The stimulation as well as the recording are carried out by disc electrodes taped to the skin, and the technician may use electrically conducting gel or paste to bolster the signals being input and output. Alternatively, the recording electrodes may also be used to pick up the electrical activity of a muscle innervated by that nerve. In such instances electroneuronography is closely related to electromyography. Usually, nerves in the limbs (arms and legs) are tested in this way, but one of the most common applications of electroneuronography is the test of the facial nerve, such as in cases of muscle weakness in one side of the face (Bell's palsy). It is performed by an audiologist, who carries out tests to compare the two sides of the face. The stimulation electrode is located at the stylomastoid foramen and the recording electrode is located near the nasolabial fold. The ENoG test is the only objective measure of facial nerve integrity. ==Background== In the human body there are twelve pairs of cranial nerves. Audiologists generally focus their expertise on the seventh and eighth nerves, which are known as the facial nerve and vestibulocochlear nerve, respectively. Electroneuronography is typically concerned with the amount of degradation in the facial nerves, each of which consists of thousands of fibers. Motor and sensory fibers are typically found in a 2:1 ratio, and it has been proposed that only half of the motor units need to be functional for normal nerve conduction to take place. The facial nerves originate in the brainstem, cross through the auditory canal, exit the skull at the stylomastoid foramen, and terminate face in 2 main branches on each side of the face. These control muscle contractions and facial expressions. Facial nerve paralysis can impact a several aspects of a person’s life, ranging from emotional or psychological effects to the actual physical limitations themselves. People who have been affected by such conditions often have difficulty speaking, drinking, eating, and showing the simplest of facial expressions. All of these combine to limit socialization and active involvement in the public domain. The proper assessment of facial nerve integrity is, therefore, vital to the detection and treatment of such disorders. Electroneuronography is used as a basis for a physician’s course of action in managing disease. A doctor may opt for continued observation of the patient following initial testing, or they may recommend surgery to deal with the damage. Facial nerve disorders may stem from a myriad of contributing factors: Bell’s palsy, injury resulting from surgical error, trauma to the temporal bone, otitis media, multiple sclerosis, mumps, chicken pox, and other conditions. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Electroneuronography」の詳細全文を読む スポンサード リンク
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