1. Anatomy Diagrams of the Inner Ear, Nasal Passages and Sinuses.
2. Glossary of Common ENT Terms
a. Doctor of Audiology
A Doctor of Audiology is a person who, by virtue of academic degree, clinical training and license to practice and/or professional credential, is uniquely qualified to provide a comprehensive array of professional services related to the prevention of hearing loss and the audiologic identification, assessment, diagnosis, and treatment of persons with impairment of auditory and vestibular function, and to the prevention of impairments associated with them.
The central focus of audiology is auditory impairments and their relationship to disorders of communication. Doctors of audiology identify, assess, diagnose and treat individuals with impairment of either peripheral or central auditory and/or vestibular function and strive to prevent such impairments.
Doctors of audiology provide clinical and academic training to students of audiology. They teach physicians, medical students, residents and fellows about the auditory and vestibular system. Specifically, they provide instruction about identification, assessment, diagnosis, prevention and treatment of persons with hearing and/or vestibular impairment. They provide information and training on all aspects of hearing and balance to other professions including psychology, counseling, rehabilitation and education. Doctors of audiology provide information on hearing and balance, hearing loss and disability, prevention of hearing loss and treatment to business and industry. They develop and oversee hearing conservation programs in industry. Further, doctors of audiology serve as expert witnesses within the boundaries of forensic audiology.
b. ABR / ECOG Testing
ABR = Auditory Brainstem-evoked Responses
ABR test both the ear and the brain. They measure the timing of electrical waves from the brainstem in response to clicks or tone bursts in the ear. Wave forms are plotted for each ear and represent specific anatomical points along the auditory neural pathway.
Waves I & II: The cochlear nerve and nuclei
Wave III: Superior olivary nucleus
Wave IV: Lateral lemniscus
Wave V: Inferior colliculi
Delays of one side relative to the other suggest a lesion in the 8th cranial nerve between the ear and the brainstem or in the brainstem itself.
c. VEMP Testing
VEMP = vestibular evoked myogenic potential
The purpose of the VEMP is to determine if the saccule, one portion of the otoliths, as well as the inferior vestibular nerve and central connections, are intact and working normally. The saccule, which is the lower of the two otolithic organs, has a slight sound sensitivity that can be measured.
The uticle and saccule are sensory organs in the inner ears, which primarily respond to linear accelerations (up and down movement) such as orientation to gravity. However, the saccule is also sensitive to sound.
Information courtesy of Dr. Timothy Hain, M.D.
d. VNG Testing
VNG Testing includes the following battery of subtests:
Oculomotor Testing – These tests are performed with the patient sitting upright and looking at both stationary and moving lights across a screen. This is very comfortable and easy for the patient to perform.
Dix-Hall Pike/Positional Testing – The goal of positional testing is first to detect positional nystagmus, and if there is positional nystagmus, to determine if it is due to the ear (usually BPPV), brain (central positional nystagmus) or neck (cervical nystagmus).
Caloric testing – part of the VNG. This test is designed to measure the responses in the vestibular system and to determine how symmetric the responses are between the left and right ears. It is a test of the lateral semicircular canals; it does not test the vertical canal function or otolithic function.
e. OAE (Otoacoustic Emissions)
These are low level, audio-frequency sounds that are produced by the cochlea as part of the normal hearing process. OAEs are a measure of pre-neural function in the inner ear that can be accessed using noninvasive techniques without sedation.