Neuro-ophthalmology Flashcards
horner syndrome triad
route to eye
1) dilation lag
2) ptosis
3) anhidrosis
1) start in hypothal –> brainstem –> cervical cord to C8-T1 –> superior cevical ganglion –> carotid, trigeminal, cavernous sinus
aniscoria cause/not vision loss?
does not cause
pupillary anisocoria result of?
efferent nervous system disturbance to iris muscles or local iris injury/damage
vessels emerge from optic disk and move…
superior/inferior and temporally
examination steps for pupillary disturbances
1) look for anisocoria (diff in size btwn pupils)
2) check normal reaction of pupil in light and dark
3) observe pupillary response to light
4) check for segmental palsy (unequal constriction of pupil)
5) check for light-near dissociation (better constriction when viewing near object than light stim)
check for tonic dilation at distant target
if anisocoria is greater in dark and both pupil have normal light response, then which is abnormal pupill
due to?
smaller pupil = abnormal
due to sympath dysfunction from Horner syndrome
if anisocoria is greater in light and large pupil has poor response to light then which is abnormal puil
larger pupil = abnormal
parasympathetic problems
sympathetic disturbances
sympathetic innerv normally causes (dilation/constrict pupil)
if damaged sympathetic, abnormal pupil appears ____ and anisocoria worse when?
normally = dilation
if damaged, abnormal pupil = miotic and abnormal dark reaction so won’t fully dilate –> makes anisocoria worse in dark
parasymapthd isturbances
parasympath innerv normally causes (dilation/constrict pupil)
if damaged parasympathetic, abnormal pupil appears ____ and anisocoria worse when?
normally = pupillary constriction
if damaged pupil mydriatic and poorly responsive to light
anisocoria worse in LIGHT
horner syndrome
1) symp or parasymp problem
2) anisocoria
3) light reaction
4) other signs
1) symp problem
2) miosis
3) abnormal dark reaction
4) accompanied by ptosis and anhidrosis usu unilat
iris damage
1) symp or parasymp problem
2) anisocoria
3) light reaction
4) other signs
1) parasymp problem
2) mydriasis
3) abnormal light reaction
4) non-neuro
3rd nerve palsy
1) symp or parasymp problem
2) anisocoria
3) light reaction
4) other signs
1) parasymp problem
2) mydriasis
3) abnormal light reaction
4) ptosis and EOM paresis
tonic pupil
1) symp or parasymp problem
2) anisocoria
3) light reaction
4) other signs
1) parasymp problem
2) mydriasis
3) abnormal light reaction
4) light-near dissoc from regrowth of nerve fibers and segmental constriction
hallmarks of visual field defects
1) defect respects vertical and horizontal meridian (optic nerve and beyond)
2) homonymous field loss (optic tract and beyond)
3) defect = combo of homonymous field loss + respect of vertical meridian (optic tract and beyond)
exception to visual field defect
optic nerve
optic nerve disturbance
1) complaints
2)
assoc symptoms
assoc signs
appearance of nerve
3) exam for
1) monocular vision loss (blurred, missing, dim)
decr brightness or color vision impaired
2) assoc symptoms = HA
assoc signs = proptosis, retinal disease
appearance of nerve = swollen or normal
optic nerve disturbance
APD= marcus gunn syndrome
1) where is dysfunction
2) test using…
3) other exam findings
1) dysfunction prior to synapse of retinal ganglion in thalamus (btwn LGN and pupil)
2) test using swinging light test
if light shined at one side and both pupi constrict then light is shined in other eye and it dilate –> APD
LGN sees relatively less light than other side and dilates
3) color vision loss
visual acuity loss
pale or hemorrhage optic nerve
ANISOCORIA NEVER OCCURS BECAUSE OF ___
vision loss
if optic chiasm compressed what does visual field look like
bitemporal hemianopsia
if left optic radiation (meyer’s loop affected)
affects upper right quadrant in both eyes
vision loss in field opposite of retinal pathways
if left inferior occipital lobe affected
right upper quadrant sparing macula
has macular sparing so posterior calcarine sulcus problem
oppsoite visual field =
4 questions to address in diplopia evaluation
1) is diplopia binocular
2) is diplopia horiz or vertical
3) is diplopia worse in specific positiosn of gaze
4) is diplopia worse at near or distance viewing
if diplopia binocular this could be ___
eyes misaligned due to NEJM of causes
1) nerve (CN 3, 4, 6 palsy)
2) eye displaced
3) NMJ (myasthenia gravis)
4) muscle (thyroid)
oscillopia is ___
most common type?
appearance of movement in someone’s visual world due to eye movement disturbance
nystagmus = involuntary rhythmic oscillation
3 types of nystagmus
1) pendular (slow-slow)
2) jerk (fat-slow)
3) mixed (slow-slow and fast-slow)
nystagmus is localized to ___
downbeat nystagmus is localized to ___ with what diseases
affects what brain area why?
CN 8 or CNS
downbeat nystagmus = cervical medullary junction causing eye to go up and down due to MS, chiari malform, tumor
affects flocculus which normally inhib anterior semicircular canals connection (which stim eyes to move up) so eyes drift up and then down
