Visual/Auditory/Vestibular Systems Flashcards
Scotoma
Pathological blind spots in one eye from ocular, retinal or nerve disorder
Papilledema
Optic disc swelling that is caused by increased intracranial pressure
What impairment of visual acuity is NOT improved with looking through a pinhole?
Lesion of optic nerve or macula
Perimetry
Computed visual test that puts together a visual field of a patient using lights and the response of the patient
What is suspected if the visual field enlarges as a cone with increased distance?
- Glaucoma
- Retinal Degeneration
What is suspected with tunnel vision?
Psychiatric cause
What lesion causes left eye blindness?
Left Optic Nerve
What lesion causes bitemporal heteronymous hemianopia?
Lesion of Inner Optic Chiasm
What lesion causes left nasal hemianopia?
Lesion of the Outer Optic Chiasm on the Left Side
What lesion causes right homonymous hemianopia?
Left Optic Tract
What lesion causes right superior homonymous quadrantanopia?
Left Inferior Optic Radiation - Meyer’s Loop (Temporal Lobe)
What lesion causes right inferior homonymous quadrantanopia?
Left Superior Optic Radiation - Parietal Lobe
What lesion causes right homonymous hemianopia with macular sparing?
Left Occipital Lobe
What are the characteristics of optic neuritis?
- Associated with MS
- Scotoma in one eye with pain
- Optic disc is swollen unilaterally
What is optic atrophy?
Occurs weeks after optic nerve lesion with a pale optic disc with sharp, distinct margins - due to destruction of retinal ganglion cell axon
Papilledema
- Bilateral swollen discs (neuritis will rarely be bilateral)
- Increased intracranial pressure
- Flame hemorrhages can be seen
- Vision loss will occur if untreated
What is a common lesion that can affect the optic chiasm?
Pituitary Tumor
What can cause cortical blindness?
Stroke of the posterior cerebral arteries
What is a finding with cortical blindness?
Despite total blindness, the pupillary light reflex is normal because the optic nerve is normal
Weber Test
Tuning fork on the top of the head and if one side is heard better it indicates conductive deafness on that side OR nerve problem on the contralateral side
Rinne Test
Tuning fork at mastoid bone and when the sound stops, hold it in the air and the sound should be heard again because air conduction is better than bone conduction in normal patients. If nothing is heard -> conduction deafness
Acute Labyrinthitis
Viral infection or inflammation of inner ear labyrinth; leading to asymmetrical nystagmus, unilateral hearing loss and gait ataxia on examination
Benign Positional Vertigo
Minor movements of head creates impulses in vestibular
system due to lodged Ca2+ crystals - common in elderly patients
- Dix Hallpike can be used to test for this
