Disorders of sensory function Flashcards

1
Q

conjunctivitis

A
Conjuctivitis:
Inflammation of the conjunctiva
Causes of bilateral 
Infection (bacterial/fungal/viral), allergens, radiant energy
Causes of unilateral 
Foreign body, chemical irritation/damage
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2
Q

Manifestations of conjunctivitis

A
Sensation of foreign body
Scratching/burning/itching
Pain 
Photophobia
Tearing 
Hyperemia of peripheral conjunctiva
Bacterial/fungal infection = mucopurulent discharge

Viral infection, allergy, foreign body = watery discharge

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3
Q

Causes and manifestations of bacterial conjunctivitis

A

> Streptococcus pneumonia, Staphylococcus aureus, H. influenza
Acute - manifestations
++ yellow-green exudate = sticky eyelids
Excoriation possible

> Chronic (often unilateral)
> Causes 
- Obstruction of nasolacrimal duct
- Chronic infection of lacrimal sac
> Manifestations
Burning, itching, morning crusting, eyelash loss, redness
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4
Q

Manifestations and tx of hyperacute bacterial conjunctivitis

A
  • Neisseria gonorrhoeae (common), Neisseria meningitidis
    > Manifestations (progressive)
  • Chemosis (edema) of conjunctiva, with redness
  • Lid swelling, tenderness
  • Swollen preauricular lymph nodes

> Treatment

  • Systemic and topical antimicrobial
  • Based on C&S swab as penicillin resistant N. gonorrhoeae common
  • If untreated, corneal ulceration, perforation, vision loss
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5
Q

Chlamydial conjunctivitis transmission

A
Chlamydia trachomatis (also causes STIs)
- Leading cause of preventable blindness in the world

> Transmission

  • Direct contact
  • Fomites, flies
  • Mom to newborns
  • Unchlorinated pools

> Self-limiting/mild

  • More serious (stronger strain)
  • Ulceration/scarring/blindness
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6
Q

Viral Epidemic Keratoconjunctivitis: Adenoviruses, manifestations of mild & epidemic

A

> Adenoviruses

  • Inadequately chlorinated swimming pools
  • Highly contagious (no specific treatment)

> Manifestations of mild form
Generalized hyperemia
++ tearing with little discharge
Pharyngitis, fever, malaise

> Manifestations of “epidemic” keratoconjunctivitis
Visual disturbances
Self-limiting but lasts for weeks

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7
Q

Corneal Trauma & Manifestations

A
- Minor if epithelial layer damaged as can regenerate with no scarring
> Damage to endothelia 
- Edema (dull/hazy cornea)
- Slow healing, scarring
> Manifestations
- Pain
- Decreased visual acuity
- Iridescent vision (rainbow)
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8
Q

Keratitis (inflammation of cornea) & causes

A
  • Bacteria, viruses
  • Herpes simplex virus, acanthamoeba (rare)
> Causes
Infections, tearing defects
Contact lenses
Hypersensitivity reaction
Ischemia, trauma
Local anesthesia
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9
Q

Keratitis: Non-ulcerative & ulcerative

A

Non-Ulcerative – all layers of epithelium but leaves it intact

Ulcerative
epithelium, stroma (outer layer of iris), or both
Results in scarring, impaired vision, blindness

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10
Q

Disorders of refraction: Hyperopia & Myopia

A

> Hyperopia (farsighted- clear distance vision)
- Anterior-posterior distance of eye too short
- Image is focused behind retina
- Correct with convex lens
Myopia (nearsighted- up close objects are clear)
- Anterior-posterior distance of eye is too long
- Image is focused in front retina
- Correct with concave lens

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11
Q

Disorders of refraction: Astigmatism

A
  • Asymmetric bowing/defect of cornea or lens
  • Congenital
  • scarring

Non-uniform refraction of light onto retina = blurred vision

Contact Lens or Surgery (to remove epithelial section)

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12
Q

Accommodation

A

Accommodation is the ability of the eye to adjust through contraction of ciliary muscles
Controlled by oculomotor nerve (CN III)
Adjusts the shape of the lens and size of pupil

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13
Q

Disorders of Accommodation

A
  1. Cycloplegia – paralysis of ciliary muscle results in loss of accomodation
  2. Presbyopia – age-related decreased accommodation (lens thickens and hardens)
    - Ability to see near objects improves
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14
Q

Describe the etiologies and eye structure changes that occur with cataract & causes

A
  • Most common cause of blindness
  • Most are bilateral
  • Fiber build-up causes layered sclerosis
    Causes
  • Aging most common
  • Hereditary, congenital
  • Environmental (trauma, heat, ionizing radiation)
  • Metabolic
  • Drugs
  • Smoking
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15
Q

Discuss the manifestations, diagnosis, and treatment of persons with cataract.

A
Manifestations
- Blurred/distorted vision
- Acquired myopia (second sight)
- Loss of far-vision
- Glare
- of color discrimination
Diagnosis
- Snellen vision test: degree of visual impairment
Treatment
- Corrective lens
- Surgical implants
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16
Q

Cite the etiology, resulting changes that occur with papilledema, & causes

A
  • Edema of optic papilla resulting in compression of blood vessels and nerves
  • Tissue surrounding optic nerve entrance to optic disc
    Causes
  • Increased intracranial pressure!
  • Tumors, subdural hematomas, hydrocephalus, malignant hypertension
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17
Q

Describe the change is retinal blood vessel structure that result in retinopathies

A
- Changes in retinal blood vessel structures
Results in:
- Microaneurysms:
Leak plasma; edema causes haziness
- Neovascularization:
Fragile; leak proteins and blood
- Hemorrhages:
Result in ischemia
- Retinal opacities:
d/t all of the above
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18
Q

Diabetic Retinopathy (DR) due to…

A
> A leading cause of blindness
Due to
- Hyperglycemia
- Hypertension
- Hypercholesterolemia
- Smoking

Non-proliferative: confined to retina
Proliferative: more severe d/t neovascularization

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19
Q

Describe the pathogenesis of non-proliferative and proliferative diabetic retinopathies and their mechanisms of visual impairment.

A

> Non-proliferative/background DR
- Retinal vein engorgement
- Thickened capillary membranes
- Capillary microaneurysms/hemorrhage
- Hemorrhage/microinfarcts causing leakage of exudate
- “cotton-wool spots” d/t damage to nerve fibers
Symptoms of glare
- Macular edema d/t leakage at capillary level

> Proliferative Diabetic Retinopathy
- New vessels attach vitreous too tightly to retina and resulting tension causing detachment

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20
Q

Discuss the pathogenesis of hypertensive retinopathy

A
  • Increased pressure results in:
    > Initial vasospasm
    Ischemia/necrosis
    hemorrhage

> Persistent/chronic
Compensatory arteriolar wall thickening
Ischemia/necrosis

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21
Q

Discuss the etiology, pathogenesis, types and risk factors of retinal detachment.

A

Separation of retina from blood vessels behind it (epithelium)
Resulting painless ischemia and loss of vision in that area
Risk Factors
- Age
- Myopia (d/t stretch of retina)
1. Exudative type
- Hypertension, inflammation, neoplasm
2. Traction type
- Fibrotic tissue/scarring from injury, infection, surgery
3. Rhegmatogenous (rhegma = hole) most common
- Vitreous shrinks with age, separates from retina, causes tear

22
Q

Discuss the manifestations and treatment of retinal detachment

A

Symptoms

  • Slow painless changes in vision
  • Beginning in peripheral vision
  • Flashing lights, sparks
  • Floaters or spots in field of vision
  • Shadow or dark curtain with progression

Treatment = early detection

  • Laser or cryotherapy to seal retinal tear
  • Scleral buckling
  • Silicone is placed on sclera so it attaches to retina that is “loose”
23
Q

Macular Degeneration Risks

A
Destructive changes to central fovea
- Risks
- Aging
- Female
- Caucasian
- Smoker
- Heredity
Results in loss of central vision
24
Q

Explain the pathology and visual changes associated with macular degeneration: non-neovascular & vascular

A
  1. Non-neovascular MD: Dry
    - Degeneration/atrophy of retinal cells
    - Drusen spots enlarge over time
    > Manifestations
    Minimal vision changes, but may worsen suddenly
  2. Vascular MD: Wet
    - Age-related neovascularization of the choroid
    - Blood vessels leak
    - Fluid buildup pushes retina away from choroid, scarring
    > Manifestations:
    Slow progression to irreversible loss of vision
25
Q

Describe the formation and outflow of aqueous humor from the eye and relate to the development of glaucoma.

A
  • Chronic, degenerative optic neuropathy d/t increased intraocular pressure
  • Second leading cause of blindness in the world
  • Optic disk rim thins, increases “cupping”
  • Damages optic nerve axons
    > Causes
  • Congental
  • Acquired
26
Q

Open angle glaucoma & Risk Factors/Manifestations

A
  • Most common
  • Trabecular meshwork decreases absorption of aqueous humor resulting in increased pressure
  • Iridocorneal angle remains open
    Risk Factors
    1. Primary: family history, age, severe myopia
    2. Secondary: anything increasing intraocular pressure
    Inflammation, trauma, tumor, htn, DM, hyperthyroidism, migraine h/a, corticosteroid (topical, inhaled)
    Manifestations
  • Asymptomatic, chronic, slow damage optic nerve cupping
  • Loss of visual field unless treated
  • Light-sensitivity
27
Q

Closed Angel (Angel-Closure) Glaucoma Causes/Manifestations

A
  • Iris occludes flow of aqueous humor to trabecular meshwork
    Causes
  • Inherited defect of angle or structures
  • Results in age related iris thickening
  • Conditions that cause prolonged dilation of pupil
  • Atropine dilates pupils (mydriasis), displaces iris
    Manifestations
  • Pain
  • Blurred vision
  • Enlarged/fixed pupil
  • Some relief with sleep
28
Q

Explain why glaucoma leads to blindness.

A

Optic disk rim thins, increases “cupping”

Damages optic nerve axons

29
Q

Define the terms anopia, hemianopia, quadrantanopia, and tunnel vision

A

Anopia = blindness one eye

Hemianopia = half visual field is lost in one eye

Quadrantanopia = quarter of visual field in one eye is lost

Tunnel Vision = narrowed binocular field

30
Q

Discuss the pupil deviations that can occur with strabismus

A

Loss of binocular vision d/t abnormal coordination or alignment
Often children
Can result in partial loss of vision

Esotropia: medial deviation
Exotropia: lateral deviation
Hypertropia: upward deviation
Hypotropia: downward deviation
Cyclotropia: torsional deviation
31
Q

Strabismus Types

A
1. Concomitant 
Equal deviation in all direction of gaze
2. Nonconcomitant
Varies with direction of gaze
3. Intermittent/periodic 
Periods where eyes are parallel
4. Monocular
Same eye always deviates and the other always fixates
32
Q

Explain the difference between paralytic and nonparalytic strabismus.

A
  1. Nonparalytic Strabismus (most common)
    - No obvious defect of muscles
    - Possibly genetic
    - Amount of deviation is relatively constant
    - Both eyes can be different
    - Secondary symptoms may result if persistent
  2. Paralytic Strabismus
    - Paresis or plegia of one or more extraocular muscles
    - Uncommon in children; possible from birth trauma
    - Causes: stroke, myasthynia gravis, Graves disease, trauma, childhood nonparalytic strabismus
33
Q

Describe amblyopia and list its causes.

A
  • Abnormal visual development in infancy or early childhood
  • Mostly reversible but can progress to partial or full loss of vision
    Causes
  • Visual deprivation: cataracts, ptosis (droopy eyelid)
  • Binocular problems: strabismus, anisometropia (refractive indexes of two eyes are different)
34
Q

Describe nystagmus and list its causes

A
  • Spontaneous involuntary rhythmic & oscillatory eye movements occurring without head movement or visual stimuli
    Causes
  • Fatigue
  • Psychological factors
  • CNS damage (Multiple Sclerosis d/t demyelination, hyperosmolar hyperglycemic state)
35
Q

Compare the causes and symptoms of impacted cerumen and otitis externa.

A
  1. Impacted Cerumen
    Asymptomatic unless total occlusion or hardens onto the tympanic membrane
    Pain, itchiness, sensation of fullness, hearing loss, tinitis
  2. Otitis externa:
    Causes
    - Infection (bacteria or fungi)
    - Frequent exposure to water
    - Irritation (cleaning with other than your elbow, hearing aides)
    - Allergies/skin reactions

Manifestations

  • Itching, redness, tenderness, edema, pain
  • Watery/purulent drainage
  • Intermittent hearing loss
  • “Acute cellulitis” often d/t S. aureus
  • More severe symptoms
36
Q

Relate the functions of the Eustachian tube to the development of middle ear problems, including acute otitis media and otitis media with effusion.

A
  • Abnormal patency
  • Does not close enough
    Obstruction
    1. Functional
  • Persistent collapse d/t lax tube or muscles
  • Often with infants as collagen hasn’t developed fully
  • Cleft palate alters structure
    2. Mechanical
  • Allergic reaction or viral infection (fluids)
37
Q

Describe anatomic variations as well as risk factors that make infants and young children more prone to develop acute otitis media.

A
- Usually d/t dysfunction eustachian tube allowing reflux
Risk Factors
- Infants: bottle (horizontal, lack protective maternal antibodies, usually swallow more air), vs breast fed - structure of ET
- Premature birth 
- Children 5 years old*
- Males
- Ethnicity
- Family history of same
- Siblings in household
- Genetic syndromes 
- Low socioeconomic status
38
Q

Otitis media manifestations

A

Usually post upper respiratory infection
Rhinoviruses & respiratory syncytial virus (RSV)
Manifestations
- Otalgia (ear pain), irritability, poor eating & sleeping habits
- Fever, hearing loss
- Erythemic tympanic membrane
- Pain, increasing with perforation of tympanic membrane
- Purulent drainage
- Rhinorrhea/vomiting, diarrhea if older child
- Otitis Media with Effusion (OME)
- Fluid in middle ear with out signs of infection

39
Q

Complications of otitis media

A
  • Hearing loss
  • Mastoiditis (inflammation of mastoid process)
  • Cholesteatoma cysts of middle ear
  • Erosion of ossicles (anvil, hammer, stirrup)
  • Labyrinthitis (inflammation of inner ear)
  • Otogenic meningitis
  • Brain abscess
  • Sinus thrombophlebitis (clots in sinuses)
  • Facial nerve paralysis
40
Q

Tx. of otitis media

A
  • Analgesia, heat
  • Myringotomy (incision of eardrum to relieve pressure) with immediate relief
  • Antimicrobial needs careful consideration
  • Surgery
  • Typanostomy tubes
  • Adenodiectomy
41
Q

Characterize tinnitus.

A
Perception of abnormal ear/head noises
Ringing, buzzing, roaring
Constant, intermittent
Unilateral, bilateral
Objective
- Detectable by others ie. Turbulant blood flow

Subjective
No noise stimulation of cochlea

42
Q

Causes of Subjective Tinnitis

A
Impacted cerumen
Medications (ASA, nicotine, caffeine)
Foods (MSG, red wine, cheese)
Presbycusis (hearing loss d/t aging)
Hypertension
Atherosclerosis
Head injury
Cochlear or labyrinthine infection
43
Q

Differentiate between conductive and sensorineura hearing loss and cite the more common causes of each.

A
  1. Conductive Hearing Loss
    Transmission failure through outer/middle to inner ear
    - Impacted cerumen, foreign body, fluid in middle ear, etc.
  2. Sensorineural Hearing Loss
    Sound waves travel through outer/middle ear but are distorted by:
    -Cochlear damage
    -Nerve damage
    -Damage to auditory pathway of brain
44
Q

Causes of Sensorineural Hearing Loss

A
  • Intrauterine infections (maternal rubella)
  • Congenital malformation of inner ear
  • Genetic mutation
  • Trauma (physical, noise)
  • Tumor
  • Hemorrhage, Thrombosis
  • Infections (bacterial meningitis)
  • Drugs (labelled ototoxic)
45
Q

Define the term presbycusis and describe factors that contribute to its development

A
  • Sensorineuroal loss of hearing in elderly
  • Impaired localization of sound sources
  • Slowed central processing
  • High-frequency sound loss
46
Q

Damage to Vestibular System

A
Skull fracture (temporal bone)
Infection of nearby structures
Toxins carried in bloodstream
Drugs (ie: gentamycin)
Alcohol

Irritation of vestibular organs or nerves results in balance issues & vertigo

Adaptation occurs with time

47
Q

Compare objective vertigo, subjective vertigo, and motion sickness.

A
  1. Objective vertigo
    Sensation that person is stationary but environment moves
  2. Subjective vertigo
    Sensation that person is in motion & environment is stationary
    Causes: motion sickness, moving objects
  3. Motion sickness: form of normal physiologic vertigo
    d/t repeated rhythmic stimulation of vestibular system
    -Vertigo, nausea
    -Rapid resps causes v/d
    -Hypotension, tachycardia, diaphoresis
48
Q

Benign Paroxysmal Positional Vertigo

A

Most common cause of vertigo in 40+ year olds
Cause
-Damage to calcium crystals (otoliths) than line labyrinth
-Float in endolymph of posterior canal
Manifestations
-Change in position of head results in
-Vertigo & rotary nystagmus
-Relief when motion ceases, or with continued motion

49
Q

Acute Vestibular Neuronitis & causes/manifestations

A
- Inflammation of vestibular nerve
Causes
-Recent upper respiratory tract illness
-Herpes zoster
Manifestations
-vertigo, nausea, vomiting
-No auditory or neurological symptoms
-Lasts for days
-Repeated attacks without predictability
50
Q

Meniere Disease & Causes

A

-Due to distension of endolymphatic compartment of inner ear (dt excess fluid)
-Increased production of endolymph
-Decreased absorption of endolymph
-Decreased production of perilymph
Causes:
Trauma, infection, endocrine insufficiency, vascular disorders, autoimmune

51
Q

Meniere Disease Manifestations

A

Hearing loss
Vertigo: violent rotary
Tinnitus: fluctuating
Feelings of ear fullness

ANS symptoms: pallor, sweating, nausea, vomiting

Initially unilateral = imbalance
Progression = bilateral hearing loss, lessening vertigo