Psychogenic nonepileptic seizures are episodes of movement, sensation, or behaviors that are similar to epileptic seizures but do not have a neurologic origin; rather, they are somatic manifestations of psychologic distress. Patients with psychogenic nonepileptic seizures frequently are misdiagnosed and treated for epilepsy. Video-electroencephalography monitoring is preferred for diagnosis. From 5 to 10 percent of outpatient epilepsy patients and 20 to 40 percent of inpatient epilepsy patients have psychogenic nonepileptic seizures.
Unformatted text preview: 373. Explain the function of the auditory tube. The function of the auditory tube ( Eustachian tube ) is to maintain equal air pressure on both sides of the tympanic membrane, which is necessary for normal hearing. 374. Distinguish between the osseous and the membranous labyrinths.
Objectives: The external ear is the entry way to the auditory receptors of the inner ear. Thus, it plays an important role in normal hearing. Because it is a structure that is frequently examined in the clinic, understanding of its functions is important.At the end of this section you should be able to: 1. Describe the two functions of the external ear, including the effects of the pinnae and ear canals on incoming sound waves.ecause it is a structure that is frequently examined in the clinic, understanding of its functions is important. At the end of this section you should be able to: 1. Describe the two functions of the external ear, including the effects of the pinnae and ear canals on incoming sound waves.