sensory and perceptual disorders

conductive hearing impairment

• nothing is wrong with the nerves

• dysfunction with decreased sensitivity to sound in external or middle ear

• problem is sound cannot be conducted

• occurs when sound cannot reach the cochlea

how is conductive hearing impairment corrected?

• corrected with medical or surgical therapy

what 4 mechanisms are involved in conductive hearing impairment

• stiffness effect (otosclerosis)

• obstruction (ear wax blockage)

• mass loading (fluid)

• discontinuity (ossicular disruption; certain areas of the ear arent able to connect with each other)

etiologies of conductive hearing impairment

• wax in outer ear, ossification of bones, middle ear infections and edema

Sensorineural hearing impairment

• hearing impairment disturbed by inner ear

• sound waves cannot get transmitted into inner ear

etiologies of sensorineural hearing impairment

• long term exposure to loud sounds, trauma, ototoxic reactions, aging, metabolic causes, certain due states

• often irreversible due too drugs or trauma (loud sounds)

otitis media

• inflammation of infection of middle ear with presence of effusion, children at risk due to shorter, horizontally positioned eustachian tubes

risk factors for otitis media

• pacifiers, second hand smoke, GI reflux, daycare, propped bottles, ( the sucking motion and the position they are in makes them more vulnerable with a short horizontal Eustachian tube

what is acute otitis media

• most often acute is seen

• usually a shorter duration

• follows a upper respiratory infection

• puss forms

chronic otitis media

• you have chronic obstruction of the Eustachian tube which impairs equalization of air pressure in middle ear

• damage is due too atrophy or perforated TM

what are clinical manifestations of chronic otitis media

• people often describe hearing a snapping and popping sound, poor hearing, upon examination with an otoscope they will see purulent discharge, pain, and vertigo

clinical manifestations of acute otitis media

sudden onset of ear pain, fever, dizziness, vertigo, mastoid pain, poor hearing

otitis externa

• inflammation of the outer ear (swimmers ear)

• more common in the summer

• you basically have excess moisture in the ear canal which allows bacteria to grow and experience trauma

• most commonly fungal

common manifestations of otitis externa

• pain, pain will worsen if you put pressure on trigs and tension on the pinna, fullness in ear, white particles on side of canal

meniere disease

• chronic disorder of the inner ear

• you have an accumulation of endolymph in labyrinth which causes cochlea degenerates

• defining thing is the vertigo

clinical manifestations for meniere disease

• tinnitus, vertigo, feeling of fullness, fluctuating hearing loss

• onset of vertigo is usually sudden - usually lasts for an hour or more and is followed by nausea and vomiting

• tinnitus: low buzzing/blowing sound; louder before vertigo attack

what is Myopia

• nearsightedness

• you have an elongated eye so the image focuses in of the retina rather than on it so as a result the image is fuzzy

what is hyperopia

• farsightedness

• shortened eye so image focuses in front of the retina making near things blurry

what is presbyopia

• unable to see near objects clearly

• happens to everyone with age

• over time your lens becomes less flexible so its less able to accommodate that

• starts somewhere in your 40s and will progress until 65 which is as bad as its going to get

• get this even if your nearsided

what is strabismus

• ocular misalignment

• most common in children under 6

• common versions are being cross eyes, walleyes, or just one eye can have one of these

what are manifestations of strabismus?

• squinting, close 1 eye to see, difficulty picking up objects, dizziness, headache

what are etiologies of strabismus

• abnormal fusion mechanism of visuals system

what are cataracts

• common consequence of age

• affects 50% of people between 65-74

• clouding or making the lens opaque instead of transparent of the eyes

• eventually will cause a loss of eyesight

• usually bilateral

what are etiologies of cataracts

• aging, trauma, congenital factors, metabolic, prescriptions

what are clinical manifestations of cataracts

• white opacity of the lens, gradual blurred vision, report altered color perception, visual distortion, decreased night vision and increased glare at night, decline in near and distant vision

what is macular degeneration

• degeneration of macular area of retina with progressive loss of central vision

• leading cause of blindness in those over 55 years

• peripheral vision is fine, central vision is lost

what are etiologies of macular degeneration

• idiopathic, injury, inflammation, nutritional

what is the pathogenesis of macular degeneration

• failure of outer layer of retina, waste product/toxins accumulate and cause cell death which is why you lose central vision

clinical manifestations of macular degeneration

• loss of central vision(black or grey spot), yellow spots on macula upon scope exam, visual distortion

what is glaucoma

• increased intraocular pressure leading to progressive vision loss

• accounts for 12-15% of cases of blindness in the u.s

• big risk factor for aging and family history

• common to see chronic open angle glaucoma

• you have a gradual loss of vision in the periphery which results in tunnel vision

what is acute angle closure

• the angle between pupil and the cornea is quite narrow

• when the pupil dilates the change in the thickness of the pupil can completely block that angle

• dilation of the pupil blocks the drainage of the aqueous humor

• will be a sudden onset of severe eye pain and people will report n/v, blurred vision, halos, red eye, dilated pupil is non responsive to light

• medical emergency so needs to be treated or it will cause blindness