Alterations in Special Sensory Function Flashcards
what is conductive hearing impairment? mechanisms? etiology?
-Decreased sensitivity to sound in external or middle ear
-Occurs when sound cannot reach cochlea
-Generally correctable with medical or surgical therapy
4 mechanisms
1. Stiffness effect (otosclerosis)
2. Obstruction (cerumen impaction)
3. Mass loading (middle ear effusion)
4. Discontinuity (ossicular disruption)
Etiologies: Wax in outer ear, ossification of bones, middle ear infections & edema
what is otosclerosis? patho? CM?
-abnormal growth in ear that cause progressive conductive sensorineural or mixed hearing impairment.
- >50% family hx, women>men, onset 20-30 yrs.
-May occur following pregnancy.
Patho:
-Bone resorption followed by overgrowth of new, hard sclerotic bone.
-The stapes is immobilized against oval window.
-Decrease in transmission of sound to the inner ear.
Clinical manifestations: Tinnitus, hearing loss, poor speech discrimination
what is otitis media? CM?
-Inflammation or infxn of middle ear with presence of effusion
-Children at risk d/t shorter, horizontally positioned eustachian tubes
-Risk factors: pacifiers, second-hand smoke, GI reflux, daycare, propped bottles
Acute: Usually short duration.
-Often follows URI
-Pathogen enters from pharynx via Eustachian tube.
-Puss forms & possible TM rupture.
Clinical Manifestations:
Sudden onset of ear pain, fever, poor hearing, dizziness, vertigo, mastoid pain.
Chronic
-Chronic E. tube obstruction impairs equalization of air pressure in middle ear.
-Damage d/t atrophy or perforated TM.
Clinical manifestations: Poor
hearing, “snapping & popping”, retracted TM, pain, vertigo, purulent DC
what is otitis externa? etiology? CM?
Inflammation of outer ear, known as swimmer’s ear
Etiology: Excess moisture in ear canal, fungi, bacteria, trauma.
-Common organism Pseudomonas aeruginosa.
-Removal of cerumen
Manifestations: Pain; touching tragus, fullness in ear, decreased hearing, white particles on sides of canal.
what is sensorineural hearing impairment? etiology?
Hearing mechanism disturbed in inner ear
Etiologies: long-term exposure to loud sounds, trauma, ototoxic rxs, aging, metabolic causes, certain disease states.
-Often irreversible: d/t drugs or trauma (loud sounds, CHI).
what is presbycusis? CM? categories?
-Gradual onset, bilateral, degenerative hearing loss
-May be progressive
Clinical manifestations: Hearing loss, dizziness, difficulty hearing high-pitched sounds & conversational speech
Four categories:
1. Sensory: atrophy & degeneration of sensory & supporting cells
2. Neural: loss of neurons in cochlea & CNS
3. Metabolic: atrophy of wall of cochlea
4. Mechanical: middle ear undergoes changes in properties
what is meniere disease? CM?
Chronic disorder of inner ear.
-Accumulation of endolymph in labyrinth; cochlea degenerates
Clinical manifestations: Tinnitus, vertigo, feeling of fullness, fluctuating hearing loss
-Onset of vertigo usually sudden, reaches maximal intensity within few mins, usually lasts for an hour or more
-Tinnitus: low buzzing/blowing sound; louder before vertigo attack
what is vertigo?
-Exaggerated sensation of motion with no actual movement
-Associated with nystagmus & nausea, vomiting, diaphoresis
-Tx aimed at correcting cause.
-Cardinal symptom of disorders of inner ear or cochlear nerve.
what are the types of errors of refraction?
Myopia: Nearsightedness
Elongated eye, image focused in front of retina rather than on it; fuzzy image
Hyperopia: Farsightedness
Shortened eye, image focused behind retina; fuzzy image.
Presbyopia: Unable to see near objects clearly
Loss of accommodative capacity, corrected with reading glasses
Astigmatism: Irregular curvature of cornea or lens
Distorted image, corrected with lens of opposite curvature
what is strabismus disorder (age-related)? CM? etiology? tx?
-Ocular misalignment
Manifestations: Squinting, close 1 eye to see, difficulty picking up objects, dizziness, HA.
Etiology: Abnormal fusion mechanism of visual system.
TX: Occlusion therapy, corrective lenses, surgery or eye exercises.
what is amblyopia disorder (age-related)? etiology? tx?
-Poor vision of 1 or both eyes despite optical correction.
-Normal-appearing retinal & optic nerve pathways.
-Decreased visual acuity with no organic causes.
Etiology: Untreated strabismus
TX: atropine or patching of stronger eye.
what are cataracts? etiology? CM? tx?
-Clouding or opacity of lens; causes eventual loss of sight.
-Usually bilateral and most common > 65 yrs.
Etiologies: Aging, trauma, congenital factors, metabolic dse, rx´s
Clinical Manifestations
-White opacity of the lens
-Gradual blurred vision
-Altered color perception
-Visual distortion
-Decreased night vision & increased glare at night
-Abnormal presence of light in the visual field
-Decline in near and distant vision
-Loss of red reflex
Tx: Surgical removal of cataract with lens replacement.
what is retinal detachment? etiology? patho? cm?
Separation of retina with sudden appearance of floating spots.
-Usually spontaneous but can be d/t trauma.
Etiologies: Tumors, inflammation, trauma, cataract extraction.
Patho: Retina folds back on itself. Breaks in retina allow fluid from vitreous cavity to seep into the defect.
-Separation causes ischemia & death of retinal neurons & total blindness in eye.
Manifestations: floaters, flashes of light in visual fields, loss of visual acuity, sense of veil coming down in visual field.
what is diabetic retinopathy?
-Disorder of the retinal vessels that cause micro aneurysms, hemorrhage (non proliferative) or neovascularization and subsequent leakage and retinal detachment (proliferative)
-Blurred, darkened, distorted vision; visual changes fluctuate.
-Preventive: tight glycemic control & careful monitoring.
-Surgery and laser procedures may be used.
what is macular degeneration? etiology? patho? CM?
Degeneration of macular area of retina with progressive loss of central vision.
-Leading cause of blindness >55yrs.
Etiologies: Idiopathic, injury, inflammation, nutritional, hereditary.
Patho: Failure of outer layer of retina; waste products/toxins accumulate & cell death occurs.
Manifestations: Loss of central vision, yellow spots on macula, visual distortion
