Flashcards in otology Deck (16):
How do you make the dx of acute otitis media?
• Rapid onset of signs and symptoms
○ Inflammation of TM
○ Hearing loss
• Ear infection
• Presence of middle ear effusion
How does sensory hearing loss typically manifest?
• Changes in pure tone hearing thresholds
Inner hair cell loss is considered what type of hearing loss?
• Neural (they consider it the same as the nerves)
How does neural hearing typically present?
• Changes in word recognition scores or the clarity of hearing
What are the varieties of aphasia?
• Naming is impaired in all forms, so inability to name common items is the most sensitive indicator of language impairment
• First and more important 4:
○ Broca's aphasia
§ Nonfluent speech good comp
○ Wernicke's aphasia
§ Fluent speech, bad comp
○ Conduction aphasia
§ Loss of repetition in the presence of preserved fluency and comp
○ Global aphasia
§ Disabling disruption of ALL aspects of language
In the physical exam, where do you look to see different middle ear pathology?
• identify the short process of the malleus and inspect the pars flaccid portion of the drum that lies superior.
*This area is commonly involved in cholesteatoma formation.
*Finally, I look thru the TM and inspect the middle ear for fluid, cholesteatoma or tumors.
What does the word recognition part of the audiogram tell you as a clinician?
This is a critical part of the hearing assessment and represents the “neural” aspect of hearing ability (inner hair cell, 8th nerve and central auditory pathways)
What does the pure tone thresholds part of the audiogram tell you as a clinician?
Pure tone thresholds represent the “sensory” or cochlear aspect of hearing function
what does "sensorineural" hearing loss mean?
The term sensorineural hearing loss is used to describe the mixture of sensory and neural aspects of hearing loss we frequently observe.
what is sensory hearing loss?
Sensory hearing loss involves the sensory transduction apparatus within the cochlea. Sensory hearing loss typically manifests with changes in pure tone hearing thresholds
*does not include IHC loss as that is considered "neural"
What is neural hearing loss?
Neural hearing loss involves disorders of the 8th nerve and central auditory pathways. The inner hair cell is often considered part of the neural component as it is directly linked to the auditory nerve.
Neural hearing loss typically manifests as changes in word recognition scores or the clarity of hearing.
what is the functional unit of the chochlea?
organ of Corti, the function unit of the cochlea.
There is a single row of inner hair cells and 3 rows of outer air cells. There are approximately 100,000 hairs cells in the human cochlea.
what are common ototoxic agents?
Common ototoxic agents include the aminoglycosodes (gentamicin), cancer agents (cis-platinum), macrolides (erthromycin), ASA, quinine, loop diuretics, hydrocodone, viagra.
what is the most common genetic cause of non-syndromic hearing loss?
The most common cause of non-syndromic hearing loss is connexion 26 hearing loss (10-20% of all genetic hearing loss)
what is endolymphatic hydrops?
Endolymphatic hydrops refers to a pathologic condition characterized by expansion of the endolymphatic compartment of the inner ear. This is illustrated in the cross section of the cochlea where the red doted line represents the normal position of Reisner’s Membrane that separates scala media from scala vestibuli.
*Endolymphatic hydrops is associated with recurrent episodes of vertigo, sensorineural hearing loss, tinnitus and aural fullness that is refered to as Meneire’s disease
how is the endocochlear potential formed?
The endocochlear potential (about +80MV) is critical for normal functioning of the Organ of Corti and serves as a driving force for ion movements involved in sensory transduction. The Stria Vascularis functions to maintain proper endolymph fluid homeostasis and the endocochlear potential by pumping potassium ions into the scala media thereby creating an extra-cellular compartment with ion concentrations and electrical potentials similar to an intracellular milieu
impaired blood flow as a result of any disease process that would impede blood flow to the ear may cause what?
Disordered inner ear homeostasis causes dysfunction of the stria vascularis. (thus the endocochlear potential cannot be maintained)
*This may be largely mediated through impaired blood flow associated with many diseases.