Week 2 Flashcards
What are some of the things that you would want to ask the pt who complains of sudden left eye blindness (like a shade is descending) in HPI/ROS?
Did you suddenly lose strength in your arm or leg?
Have you ever had a seizure?
Have you ever had a heart attack?
Do you ever experience chest pain?
What are some of the things that you would have on differential diagnosis for this patient?
Retinal Vein Occlusion
MS
Stroke
What can Diabetes do to your eyes?
Diabetes can cause a microvascular injury.
It is a chronic progression, however, and not transient.
The chronic isn’t what our patient experienced.
What can a retinal tear do to your vision?
This can cause loss of vision, but it wouldn’t immediately get better too. So, probably not what our pt is experiencing.
If you have double vision, which cranial nerves might be involved?
CN3 CN4 CN6 things that can control extra ocular muscles BUt the pt denies these symptoms.
Why do we think that this pt didn’t have a major stroke?
b/c they didn’t experience any motor or sensory symptoms.
What is a TIA?
transient ischemic attack
transience is what separates it from a major stroke
lasts less than an hour for sure
Why does it matter that our pt smokes?
this matters b/c it puts the pt at risk for an occlusion
What are hollenhorst plaques? Our pt has them–>what is the significance of this?
these are cholesterol emboli that can be seen in the fundoscopic exam
usu comes from carotid bifurcation
What is a bruit? What might it indicate?
bruit–sound from turbulent flow thru an artery
could indicate a high degree of arterial stenosis
What does it mean that our patient has a 4-5 cm pulsatile mass in the abdomen?
the aorta should only be 2 cm.
this is probably an AAA
In a child with monocular loss, you probably wouldn’t think vascular problem—but what?
migraines
A woman who is on birth control & has frequent migraines is at pretty great risk for what?
stroke
Most transient monocular vision loss is caused by _____.
ischemia
What are some common causes of monocular vision loss?
Embolism from cervical carotid artery stenotic opthalmic artery Occlusion to circulation of optic disc optic disk edema vasospasm of retinal arterioles central retinal artery or venous occlusion vitreous hemorrhage ischemic optic neuropathies posterior CVA
What is Amaurosis fugax?
loss of vision in one eye due to a temporary lack of blood flow to the retina. It may be a sign of an impending stroke.
Describe the blood supply to the orbit.
Internal Carotid Artery–>Opthalmic Artery
Which blood vessel supplies the following:
choroid, iris, ciliary muscle, sclera, and rods and cones of the retina? What would blockage to this vessel do?
posterior ciliary vessels ***blockage–>blindness in spots
Which blood vessel supplies the internal retina? What would blockage to this vessel do?
central artery of the retina **blockage–>complete blindness
Which tests should we perform on this patient at this point?
lipid panel
ultrasound to look at arteries.
What is left homonymous hemianopsia?
loss of the left half of the visual field in both eyes
What causes left homonymous hemianopsia?
this is caused by problems in the right brain (controls left hemifield)
right occipital CVA explains this. A posterior CVA>
What is a carotid duplex scan?
A carotid duplex scan assesses by vascular ultrasound the flow of blood through the carotid arteries.
B-mode: pic of vessel
Doppler: direction & velocity of blood flow
What is the basic visual pathway–starting with photoreceptors?
Photoreceptors in Retina Optic Nerve Optic Chiasm Optic Tract Midbrain Lateral Geniculate Nucleus Primary Visual Cortex (Occipital Lobe)
What does visual loss look like with damage to the retina?
loss of vision to the portion of the retina that is damaged
What does visual loss look like with damage to the optic nerve?
loss of vision to the eye that the nerve supplies
What does visual loss look like with damage to the optic chiasm?
loss of vision to the lateral most part of the field of vision
nasal fibers lost
What does visual loss look like with damage to the optic tract?
vision loss on opposite side of the lesion
- *lose right optic tract
- *lose both left hemifields
Visual cortex damage causes losses similar to the optic tract - loss of some what?
loss of some central vision
If you get a right occipital lobe stroke…which arteries were likely compromised?
the vertebral arteries
Can you see the vertebral arteries in an ultrasound?
NO, b/c they are running thru the transverse foramina of the cervical vertebrae.
You can see flow up or flow down, though. Flow up is good, but could still have a problem.
What might you think if you see that flow is going down vertebral arteries in an ultrasound?
think that there is some kind of steal syndrome going on…
If you have a blood brain barrier breakdown…when do you start seeing it on MRI…what does it look like at that point?
see on MRI w/i 4 hours
looks like a white spot-snowball
If you suspect that someone has had a stroke (say an occipital lobe one)…which test should you order (CT OR MRI)?
MRI w/ diffusion-weighted imaging
CT can’t pick up on stroke damage until 24 hours afterwards when the tissue has softened
What are the ABCDs of knowing if you will likely get a stroke following a TIA?
A: age >60 yo B: Blood Pressure C: Cerebral Event D: Duration of TIA longer than 1 hour-considered stroke D: Diabetes
What symptoms did the pt describe that made the doc in this case think occipital lobe stroke?
He had no vision to the left.
Most pts will describe this as losing vision in their left eye.
T/F The headaches produced by strokes will always show up localized to the area of tissue damage.
False. Not localized to area of damage. Posterior cerebral stroke may manifest as frontal headache.
Why is central vision often spared in eye problems/strokes?
b/c this is found in posterior part of the occipital lobe. Area 17.
What are areas 18 & 19 for?
these are visual association areas.
The macula/central vision area has secondary blood flow. What is it?
this secondary blood flow is branches of the posterior cerebral artery
Which artery was compromised in this patient’s first vision loss episode?
the ophthalmic artery
Is it possible that atrial fibrillation caused both of his episodes?
yeah, possible that he has paroxysmal atrial fibrillation (comes & goes)
In research, it is reported that only ____% of strokes are due to thrombi. This number could be low, however, b/c the thrombi clear once you have the time to look for them.
15%
What % stenosis in an artery is really concerning? You will hear a bruit at this %.
70% stenotic is concerning.
What are some meds that this pt may benefit from?
Aspirin, Lipitor, Lisinopril
What are the 2 places that an embolus thru the head & neck could go?
carotid or vertebral
What types of things could cause central vision loss?
central retinal vein thrombosis (HTN or athersclerotic disease)
Papillitis
Tumor around optic nerve (glioma, meningeoma)
trauma to optic nerve
orbital fracture
What is papillitis? What can cause this?
inflammation of the optic nerve
can be caused by MS, other autoimmune disorders
Does papilledema usu manifest itself as central vision loss?
No, usu an increase of the blind spot.
What is tubular vision? How would this present?
psychosomatic cause
can’t see in the middle
optic nerve appears normal
can tell if they can see only the border of a pic on a piece of paper, & when you back them up they can still see the border.
Essentially, regardless of position-field loss remains constant.
What can cause binasal hemopsia?
a lesion anterior to the optic chiasm before the nerves have crossed
can be caused by a pituitary tumor
What can cause left homonymous hemopsia?
right occipital lobe lesion
right optic tract lesion
If a pt has never had sparklers in their eyes…and then they all of a sudden have them…what might you consider?
an impending stroke
T/F Vascular issues w/ sight don’t respect the vertical & horizontal meridians.
False. they do respect them.
If you lose sight in both eyes in the right inferior quadrant…where was the lesion?
a left parietal lesion
superior to the calcarine fissure
40 yo pt presents with fast complete blindness. Can’t find anything on CT. Pupils are reactive to light. Fundus appear normal. What happened?
bilateral occipital stroke
If patients only had vision inferiorly…what else would they have lost?
lost the ability to recognize faces.
