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Anterior Circulation Strokes
Blood Supply:
- Internal carotid artery branches:
- Middle cerebral artery (MCA): Supplies the lateral aspects of the frontal, parietal, and temporal lobes.
- Anterior cerebral artery (ACA): Supplies the medial frontal and parietal lobes.
Clinical Features:
- MCA Stroke (Most Common):
- Contralateral weakness and sensory loss (face and arm > leg).
- Aphasia if the dominant hemisphere (usually left) is involved.
- Hemineglect if the non-dominant hemisphere (usually right) is involved.
- Gaze preference toward the side of the lesion.
- ACA Stroke:
- Contralateral weakness and sensory loss (leg > face and arm).
- Behavioral changes or personality disturbances (e.g., apathy, disinhibition).
- Urinary incontinence (due to involvement of the medial frontal lobe).
Posterior Circulation Strokes
Blood Supply:
- Vertebrobasilar system:
- Vertebral arteries join to form the basilar artery.
- Supplies the brainstem, cerebellum, occipital lobes, and thalamus.
Clinical Features:
- Brainstem Strokes:
- Cranial nerve deficits (e.g., dysphagia, dysarthria, facial weakness).
- Contralateral motor or sensory deficits.
- Vertigo, nystagmus, ataxia.
- Decreased level of consciousness or coma in severe cases.
- Cerebellar Strokes:
- Ataxia, dysmetria, intention tremor.
- Vertigo and nystagmus.
- Posterior Cerebral Artery (PCA) Stroke:
- Contralateral homonymous hemianopia (loss of the same visual field in both eyes).
- Visual agnosia or cortical blindness in bilateral PCA strokes.
- Thalamic involvement can cause contralateral sensory loss.
Cerebral Aneurysms
A weak area in a blood vessel wall that enlarges over time, creating a bulging or ballooning effect. A ruptured cerebral aneurysm is a common cause of subarachnoid hemorrhage (SAH).
Types:
- Berry Aneurysms (Saccular Aneurysms):
- The most common type of cerebral aneurysm, accounting for ~75% of nontraumatic SAH.
- Typically small and round, creating a “berry-like” appearance.
- Frequently found in the Circle of Willis.
- Fusiform Aneurysms:
- Less common, involving circumferential widening of a segment of the artery.
- Found more often in larger arteries like the basilar or vertebral arteries.
Risk Factors:
- Smoking
- Alcohol (ETOH) use
- Hypertension (HTN)
- Obesity
- Polycystic ovary syndrome (PCOS)
- Marfan syndrome
- Ehlers-Danlos syndrome
Clinical Presentation:
- Unruptured Aneurysms: Often asymptomatic or cause visual disturbances, headaches, or cranial nerve palsies.
- Ruptured Aneurysms: Severe headache, nausea, vomiting, neck stiffness, photophobia, altered mental status, seizures.
Labs, Studies, and Physical Exam Findings:
Physical Exam:
- May reveal signs of increased ICP or cranial nerve palsies in larger aneurysms.
Bloodwork:
- PT/PTT and INR: Assess coagulation status before interventions.
- CBC: Rule out anemia or infection.
Imaging:
- CT Angiography (CTA): Preferred
- MR Angiography (MRA): Alternative, especially in patients unable to tolerate contrast.
- Cerebral Angiogram: Gold standard for definitive diagnosis and precise localization.
- Non-contrast CT: First-line for suspected rupture to identify SAH.
- Look for hyperdensity in the subarachnoid spaces.
- Lumbar Puncture:
- Xanthochromia: Yellow discoloration of CSF confirms SAH.
- Elevated opening pressure: Suggests increased ICP.
Treatment:
Management of unruptured aneurysm:
- Blood pressure control: Target <140/90 mmHg.
- Cholesterol control.
- Regular imaging follow-up for small, stable aneurysms.
Management of ruptured aneurysm:
- Emergency Interventions:
- Prevent rebleeding: Strict blood pressure control.
- Treat increased ICP: Mannitol or hypertonic saline.
- Surgical Options:
- Clipping: Open surgical procedure to place a clip at the aneurysm base, preventing rupture or rebleeding.
- Endovascular coiling: Minimally invasive approach to induce clotting within the aneurysm.
Arteriovenous Malformation (AVM)
An abnormal tangle of blood vessels where arteries connect directly to veins without the normal capillary bed in between, leading to high-pressure blood flow in veins, increasing the risk of rupture. These are usually congenital defects.
Clinical Presentation:
- Typically asymptomatic until complications develop
Pathophysiology:
- Direct artery-to-vein connection
- Leads to increased venous pressure and potential venous rupture
- Steal phenomenon
- Blood is diverted away from surrounding normal brain tissue, causing ischemic symptoms
Symptoms of an Unruptured AVM:
- Headache: May be localized or resemble migraines
- Seizures: Partial or generalized seizures are common presenting symptoms
- Focal Neurological Deficits:
- Weakness, sensory loss, or visual field deficits, depending on location
Symptoms of a Ruptured AVM:
- Sudden, severe headache: “Worst headache of life” (similar to subarachnoid hemorrhage)
- Nausea and vomiting
- Altered mental status: Confusion to coma
- Focal neurologic deficits: Weakness, numbness, or aphasia, depending on location
- Seizures
- Loss of consciousness in severe cases
Common Locations:
- Can occur anywhere in the central nervous system, but most are found in the brain
- Supratentorial regions (cerebral hemispheres):
- Frequently located in the frontal, temporal, or parietal lobes
- Infratentorial regions:
- Less common, but AVMs here can affect the brainstem or cerebellum, leading to significant deficits
Treatment:
Medical Management:
- Anticonvulsants for seizures
- Blood pressure control to reduce rupture risk in ruptured AVMs (target systolic BP <140 mmHg)
Interventional/Surgical Options:
- Surgical Resection: Preferred for accessible AVMs with low surgical risk
- Endovascular Embolization: Blocks blood flow to the AVM; often used preoperatively or for inoperable AVMs
- Stereotactic Radiosurgery: Focused radiation to shrink the AVM over months to years
Post-Treatment:
- Regular imaging to monitor for residual AVM or recurrence
Intracranial Hemorrhage
Bleeding that occurs within the skull, either inside the brain tissue (intra-axial) or outside the brain tissue but within the skull (extra-axial).
Causes:
- Aneurysm
- Head trauma
- Chronic hypertension (HTN)
- Blood vessel abnormalities, including arteriovenous malformations (AVMs)
- Brain tumors
- Bleeding disorders
Classification:
Intra-axial Hemorrhage:
- Bleeding occurs within the brain itself; more dangerous and difficult to treat
- Intraparenchymal Hemorrhage: Bleeding within the brain tissue
- Intraventricular Hemorrhage: Bleeding within the brain’s ventricles
Extra-axial Hemorrhage:
- Bleeding occurs within the skull but outside the brain tissue
- Epidural Hemorrhage: Bleeding between the dura mater and the skull; most commonly caused by trauma
- Subdural Hemorrhage: Bleeding in the subdural space between the dura and arachnoid mater
- Subarachnoid Hemorrhage: Bleeding between the arachnoid and pia mater; often caused by a ruptured cerebral aneurysm
Clinical Presentation:
- Key Presentation of Subarachnoid Hemorrhage (SAH):
- Severe headache: “The Worst Headache of My Life!” (thunderclap headache)
- Nausea and vomiting
- Neck stiffness and photophobia
- Altered mental status: Ranges from lethargy to coma
- Seizures with no prior history
- Other Possible Symptoms Across Hemorrhage Types:
- Weakness in an arm or leg
- Tingling or numbness
- Changes in vision
- Difficulty speaking, understanding speech, or swallowing
- Loss of coordination or balance
- Loss of fine motor skills (e.g., hand tremors)
- An abnormal sense of taste
- Loss of consciousness
Labs, Studies, and Physical Exam Findings:
- Neurological Examination: Assess for focal deficits or altered mental status
- Eye Examination: May reveal bleeding in the optic nerve (papilledema)
Imaging:
- Non-contrast CT (gold standard):
- Crescent-shaped hemorrhage: Suggests subdural hematoma
- Biconcave hemorrhage or else shaped: Suggests epidural hematoma
- Hyperdensity in subarachnoid space: Indicates subarachnoid hemorrhage
- Angiography: Evaluates vascular abnormalities (e.g., aneurysms, AVMs)
- MRI with contrast / MRA: Used for further evaluation when CT is inconclusive
- Lumbar Puncture (SAH only):
- Xanthochromia: Confirms SAH if CT is negative
- Elevated opening pressure: Indicates increased intracranial pressure
Treatment:
- Goals:
- Reduce intracranial pressure (ICP)
- Proper blood pressure management to prevent rebleeding
- Medications:
- Painkillers for symptom management
- Corticosteroids to reduce swelling
- Anti-seizure medications
- Mannitol and hypertonic saline: To reduce ICP
- Neurosurgery:
- Craniotomy: Removes clot and relieves pressure
Full Transcript (click to expand)
Good morning and welcome to the Physician Assistant Exam Review Podcast. Today we’re covering hemorrhages, arteriovenous malformations, and aneurysms. My name is Brian Wallace. I’m the host and creator here at Physician Assistant Exam Review. And my journey began way back in PA school, where during my first semester, I knew something had to change or they were not going to ask me to return after Christmas. And as this is the winter holiday season, it sort of reminded me of that time in my career. And since then, I’ve been researching, practicing, and developing methods and tools and philosophies and all of these different techniques to help struggling students do more than just tread water, do more than just survive, but to really excel in PA school on the PANCE and beyond.
And with that in mind, as we move into 2025, oh, first of all, happy New Year’s Eve. Excited for 2025 and what’s to come. And that’s part of why I started recording these podcasts again and what I’m putting forward in 2025. There’s a couple of really exciting things coming in the first month of the year. Number one, I’m going to be hosting a Master Class on passing the PANCE. There’s going to be two sessions. They’ll be the same, so you only have to register for one if you’re interested.
They will be on January 14th and 16th, both at 8 p.m. If you go to physicianassistantexamreview.com/masterclass, you’ll get taken right to the information registration page. It’s really simple. But that’s going to be an amazing class on passing the PANCE, on building your testing skills, and building your study skills. I’ve gotten a lot of great reviews on that program in the past. And if you haven’t been through it, I strongly recommend that you come one of those two days. Again, physicianassistantexamreview.com/masterclass to get all the information there.
I’m also going to be opening registration for the 33 Days to Pass the PANCE program in January. It’ll actually open on the registration will open on the 14th and the first cohort of 2025 will be the February cohort will begin on the 1st, but obviously we need a couple of days before that to get everything lined up. So registration for that will open on the 14th, but it will close on the 22nd because, like I said, I have to get everybody in and set up and make sure everyone knows exactly what’s going on and what they’re doing. It’s going to be a ton of fun. Those cohorts have just been an absolute blast. Students have been absolutely killing it. From the November 2024 cohort, the students who had to retake their PANCE and then came through that program, the average increase in scores, I think, is at 53.5 points.
And from the September cohort, it’s over 70 points. I think it’s like 75 points increase for students taking their PANCE for the second, third, or even fourth time. I’ve had a lot of success with this program over the years. So if you’re looking to increase your scores, one, I strongly recommend you attend the Master Class. But two, consider signing up for the 33 Days program in that February cohort. The information for that you can find at physicianassistantexamreview.com/33. Will be all the information for that.
All right. So that’s the exciting things coming in January, 2025. I run that cohort about four times a year. Usually it’s a February, April, and then a September, November kind of thing. The dates will be published and you’ll be able to see those, but that’s sort of what I usually do. It’s pretty typical. Sometimes I’ll run one in June, depending on how many people ask me to do that and how available I am over the summer.
It is a lot of involvement from me.
All right, we’ve been talking about strokes, both hemorrhagic and ischemic strokes in the last session. A lot of this, well, first of all, I’m looking at the notes that I have coming up, and there was a section that I probably should have included in the talk about strokes. But all of this is really cyclical. It really wraps around itself. So today we’re going to be talking about aneurysms and AVMs and cerebral hemorrhages. Well, really what we’re kind of talking about are hemorrhagic strokes, right? And different ways you can acquire them.
So this whole section and the next section on cardiovascular is very, very, very cyclical. We go around and around, but it’s good because I love that. The idea of going back and forth over the material because it ingrains it more in your mind. It’s that repetition that’s really important. So this section really lends itself nicely to that and allows you to get good, decent scores because all of it feeds back on itself. So if you get it, it’s a place you can score well. Unfortunately, and like I was just this morning looking back through my PANRE scores and my PANCE scores, because I was looking at something and saw that my neuro scores were near the bottom of my list.
And one of the reasons was I just didn’t get it at the time. And I’m looking at it now thinking, geez, if you understand this section, you can really pick up a lot of points and make this pretty easy on yourself.
All right. Well, with that, let’s jump into our priming questions to get us ready for today. And like I said, because this is cyclical, hopefully, if you were here for last week’s episode, you should be able to know a handful of these. What is the most common type of cerebral aneurysm? What is the most common type of cerebral aneurysm? Which which imaging modality is the gold standard for diagnosing a cerebral aneurysm? Which imaging modality is the gold standard for diagnosing a cerebral aneurysm?
What is the hallmark symptom of a subarachnoid hemorrhage? What’s the hallmark symptom of a subarachnoid hemorrhage? You got to get that one. What’s the most common site for a berry aneurysm in the circle of Willis? Not the circle of Willis, but what’s the most common site for a berry aneurysm within the circle of Willis? And which condition is characterized by arteries connecting directly to veins without a capillary bed? Which condition is characterized by arteries connecting directly to veins without a capillary bed?
So depending on where you are in your work, in your program, some of these will be super easy, some of them will be impossible, or all of them will be impossible. Those are sort of the options. Well, let’s just jump right into it.
All right, let’s talk about anterior circulation strokes. What I want to talk a little bit here is to pick up where we left off last time talking about strokes. One of the important things and one of the places you can get test questions is on which area of the brain is affected. Most importantly, is it an anterior circulation problem or a posterior circulation problem? That’s how you can get tested and quizzed on this stuff. So that’s the way I’m going to structure this part. So although we talked about ischemic strokes and hemorrhagic strokes last week, we’re actually going to pick up this week kind of talking about sort of ischemic strokes with anterior and posterior circulation issues, and then sort of hemorrhagic strokes as we get into cerebral aneurysms, AVMs, and intracranial hemorrhages, right?
So I hope that that is clear. So it’s important to understand that there are two, when we talk about strokes and symptoms and the way we deal with things, but a lot of times we talk about them as an anterior circulation problem or a posterior circulation problem. In an anterior circulation problem, we’re looking at the internal carotid arteries is the blood supply that we’re talking about. And off of that, it branches into the middle cerebral artery and the anterior cerebral artery. So the MCA and the ACA, middle cerebral artery, anterior cerebral artery. The middle cerebral artery supplies the lateral aspect of the frontal parietal and temporal lobes. The anterior cerebral artery supplies the medial frontal and parietal lobes.
You’re not going to get all that from listening to me once. If you want to go through that in more detail, head over to the website, physicianassistantexamreview.com. If you go to, I think it’s labeled podcast in the menu, you will find, or blueprint in the menu, you’ll be able to find all of the notes and information. Or you know what, even easier, physicianassistantexamreview.com/125. We’ll bring you right to the notes on this section so you can review it or go over it again and see that layout because you’re going to need more than just hearing it once to get it. The clinical features are going to be different for depending on where the blood supply is affected, right? I don’t want to go too deep down this road.
And this is one of the reasons why I didn’t do well on this section is because it gets complicated quick and it’s hard to know what depths to go down. But I think you can get a lot of questions right by knowing some of the things that are not too complicated. So for a middle cerebral artery, these are more common. And what’s going to happen is you’re going to get contralateral weakness and sensory loss. The face and the arm will have more symptoms than the legs. You can get aphasia if the dominant hemisphere is involved. You can get hemi-neglect if the dominant hemisphere is involved.
And you can get gaze preference toward the side of the lesion. You’ve seen that before, I think, right? Gaze preference toward the side of the lesion. And I think something that’s important to note is that the middle cerebral artery is a little bit more is more common than the anterior cerebral artery. The anterior cerebral artery will give you contralateral weakness and sensory loss, the leg greater than the face and arm. It’ll give you behavioral changes or personality disturbances, and it’ll give you urinary incontinence. So it’s kind of drastically different depending on where in the brain you’re getting that ischemia.
And it makes sense, right? So, that’s the anterior circulation. Posterior circulation, the blood supply here comes from the vertebrobasilar system. So, vertebral arteries join to form the basilar artery. This supplies the brain stem, the cerebellum, the occipital lobes, and the thalamus. Again, go over to physicianassistantexamreview.com/125 to get to take a look at the notes and go over that a little bit more. I don’t think you need to spend a ton of time on it, but I don’t think it’s as hard as it sounds.
All right, so clinical features. If you get a brainstem stroke, you get cranial nerve deficits. I talked about this section looping back around on it. I’m not going to go over cranial nerve deficits today as symptoms here because we’re going to cover them in a later episode where we talked specifically about cranial nerve palsies and issues there. It’s a separate total topic on the neuro section of the blueprint, but you can get dysphagia, dysarthria, facial weakness, etc. You can get contralateral motor or sensory deficits, vertigo, nystagmus, ataxia. You can get decreased level of consciousness or coma in severe cases.
Cerebellar strokes. Here you’re going to get ataxia and you can get an intention tremor, vertigo, and nystagmus. Now posterior cerebral artery strokes. You can get a contralateral hemi… homo… Easy for me to say. Homonymous hemianopia.
This is the loss of the same visual field in both eyes. Here’s a little tip because it’s really hard to remember things that you can’t actually say. So I just literally just paused the recording and went over to howjsay, h-o-w-j-s-a-y.com and looked up the pronunciation for that term that I’m fumbling through because it’s a lot easier if you can say the term, right? If you just kind of know it vaguely, it’s not going to help you. You have to be able to say them out loud to really hold onto them and pull them out of your memory. You can get visual agnosia. You can get contralateral sensory loss.
So a lot of differentiation between where the blood supply comes in, which blood supply is affected, how it’s affected. So if you get an ischemic stroke, if one of these arteries gets blocked by an embolus or gets blocked, right, then it’s going to depend on the tissue that becomes ischemic and dies, what type of symptoms you’re going to get. So it makes sense that the anatomy, the blood flow, the blood supply of where you’re feeding and the downstream effects of that would cause the symptoms. So I think it’s worth going through. And at least what I like to do is think about like, what’s the least I could learn here that’s going to might help me get a question, right? So if this whole thing looks complicated and difficult, and maybe you’re better at this than I am, but for me, this does… this looks like a whole bunch of stuff I have to just memorize, and I’m not great at memorization.
So what I might do is I might draw out some pictures for this. I might sketch out the blood supply, not in a real anatomical way, but maybe just in a way that helps me to retain the information. So sketch out the internal carotid arteries and the vertebrobasilar system, and then sketch to a place that shows the symptoms, not necessarily the anatomy at the end or the section of the brain at the end, maybe. But first just maybe the symptoms so I can hold on to that. And then what I would do is concentrate on one or two of these pieces. So can I learn the symptoms for the most common one, which would be the middle cerebral artery, right? So let me learn the clinical features there.
Then when I get a question, I can, if it’s about the middle cerebral artery, great, then I’ll get that one right. But if it’s not, I guarantee that the middle cerebral artery or symptoms thereof will be in your answer choices or in the vignette or something where you have to. So at least then you can remove that as an answer choice and increase your odds of getting the question right, even if you don’t know the question. So that’s kind of how I would handle that today versus how I handled it back in PA school.
All right, let’s hop in and talk about cerebral aneurysm. An aneurysm is a weak area in a blood vessel wall. And what happens is it sort of balloons out. It’s a weak section that over time with pressure, you have that artery that’s sort of like a tube or a tunnel or a hose, right? And there’s a weak spot in that. So that starts to just bulge out a little bit, starts to balloon out a little bit over time. Every time that heart beats, every time the pressure goes up.
And over time, it weakens more and more and more. And this isn’t something that happens right away, but that aneurysm starts to grow and grow and grow over time. And then that weakened area, the more it grows, the more likely it’s going to just let loose and then just bleed, right, and create that hemorrhage. So a ruptured cerebral aneurysm is the most common cause of a subarachnoid hemorrhage. This is where most subarachnoids have, especially your non-traumatic subarachnoid hemorrhages. A couple of different ones I want to talk about, aneurysms I want to talk about. First is the berry aneurysm, and second is the fusiform aneurysm.
The berry aneurysm or saccular aneurysm, these are the most common type of aneurysms accounting for about 75% of non-traumatic subarachnoid hemorrhages. Typically, they’re small and round, so they look kind of like a berry, right? That’s where it comes from. These are frequently found in the circle of Willis. So a lot of people will attach berry aneurysm to the circle of Willis, at least that’s what I always did. And the reason for that is that it’s due to the high number of arterial bifurcations in that system. So you get a lot of turbulent blood flow and stress on the vessel wall.
So there’s a lot of stress through those arteries within the circle of Willis. So that’s why you can get these aneurysms to, you’ll get more of them, right? So your aneurysms tend to be at places in general where you get a bifurcation, right? Where there’s extra pressure on an arterial wall. Within the circle of Willis. Now again, how deep do you want to go? How much do you want to learn this?
How much do you think it’s going to be on your exams? Well, you’re going to have to decide that on your own, right? Depending on what your professors are looking for and what your rotation exams look like and what you believe the PANCE is going to look like. But I think it doesn’t hurt to have a little bit of an understanding here and a little bit of knowledge, just like we did with the previous section where we talked about the circulation and strokes, right? So if we’re talking about aneurysms, the most common location within the circle of Willis is the junction of the anterior communicating artery and the anterior cerebral artery. So where those two arteries come together is the most common site for a berry aneurysm, within the circle of Willis. So if they just ask what’s the most common set of a berry aneurysm in circle of Willis is a possibility.
Great, stick, head, and run. But within that, it’s the junction of the anterior communicating artery and the anterior cerebral artery. After that, you get the junction of the posterior communicating artery and the internal carotid artery, and then the bifurcation of the middle cerebral artery. Again, not things I think you’re going to hold on to from this particular discussion. You’re going to have to go a little bit deeper and get more of a visual on that for it to stick. I don’t think just hearing anatomy is, it’s not a bad way to review. It’s not a bad way to prime, but it’s not certainly not a way to hold onto it forever.
Fusiform aneurysms. So this is less common involving a circumferential widening of a segment of the artery. So what that means is rather than just a bulging in one area, you get all the way around that particular arteries tends to, is now bulging out and widening. This is more often in large arteries. So that would be more like your basilar or vertebral arteries. This is also more associated with chronic conditions like atherosclerosis and less likely to rupture compared to a berry aneurysm. But they can also have issues because they can cause a mass effect.
So what’s a mass effect? Mass effect is when you get pressure in areas from something that’s not supposed to be there. So if you have a tumor, you get mass effect because as that tumor grows, it’s pressing on the tissue surrounding it. Same thing with an aneurysm. As it grows, it’s pressing on the tissue surrounding it. If certain areas of the body, that may or may not matter. But within the brain, obviously, there’s only so much space here.
So we start to have some problems. Risk factors for aneurysms in general. Smoking, alcohol use, hypertension, obesity, polycystic ovary syndrome, Marfan syndrome, Ehlers-Danlos syndrome. The last two are connective tissue disorders, right? So connective tissue is weak and it’s kind of stretchy in those patients. So you can have increased risk for weak and stretchy arteries, which is basically what an aneurysm kind of looks like, right? Clinical presentations.
So for cerebral aneurysms, they’re often asymptomatic, right? There’s not much going on. If they’re not ruptured, if there’s not a problem, you can get some mass effect. We’ll talk about that in a second. But the reality is there’s not a whole lot of symptoms from just an aneurysm on its own.
Now, from mass effect, what can you get? You can get some visual disturbances like blurred or double vision. You can get headaches. You can get cranial nerve palsies. Again, we’re not going to talk about those here. We’ll talk about them in a future episode. And then you can get symptoms of increased intracranial pressure.
So this is something I think you should absolutely know. What are some symptoms of increased intracranial pressure? Not just of intracranial pressure, of increased intracranial pressure. Well, vomiting, nausea, altered mental status are good places to start.
Okay, so that’s with unruptured aneurysms.
Now, what about a rupture? Well, a rupture, we’re now getting back to our stroke, right? Our hemorrhagic stroke. Here we get that sudden onset of a severe headache, the worst headache of my life, that thunderclap headache, if we’re talking about a subarachnoid hemorrhage. We get nausea and vomiting due to that increased intracranial pressure. We get altered mental status. We get neck stiffness and photophobia from meningeal irritation.
You can get seizures and then focal neurological deficits like we talked about, weakness, sensory loss, cranial nerve palsies, loss of consciousness in severe cases. But again, this just loops back to the last discussion. Lab studies and physical exam findings. You can find signs of increased intracranial pressure, right? And nerve palsies. So we’re not going to go through all that now, but certainly possibilities in your physical exam. Blood work, PT, PTT, and INR, because you want to assess the coagulation status before you do any interventions, especially on someone who currently has a brain bleed, right?
CBC, you want to rule out anemia or other infections or other issues. Lots of things we can do there, but really it comes down to the imaging. So the CT angiograph is the preferred method, right? That’s going to with contrast. So you may have to go to the MRA because in a patient who can’t have contrast, that would be sort of your thinking there. A cerebral angiogram is the gold standard for definitive diagnosis and precise localization. A non-contrast CT is a first line for suspected rupture to identify a subarachnoid hemorrhage and look for a hyperdensity in the subarachnoid spaces.
A lumbar puncture would be if you suspect a subarachnoid hemorrhage, but the CT is negative, right? We talked about that before also. You can do a lumbar puncture, in which case you’re looking for xanthochromia, which is a yellow discoloration of the cerebral spinal fluid, which is going to confirm your subarachnoid hemorrhage and an elevated opening pressure, which is going to suggest your increased intracranial pressure, giving you an idea that maybe you’ve got a subarachnoid hemorrhage.
Okay, once again, I put together a table for you in the notes that you can see on the website and to basically walk you through the clinical scenario and the imaging modality of choice, because you can order all these different things, right? But how do you know which one to order and when? And to me, that’s a good place to ask a question, right? A good place to ask a test question is on which of these modalities should you choose in this situation? So if you have a suspected subarachnoid hemorrhage, patient comes out with acute headache, thunderclap headache, they feel terrible, what are you going to choose? Well, your first line here is going to be a non-contrast CT. First line, suspected subarachnoid hemorrhage, acute thunderclap headache, non-contrast CT.
Now we talked about this several times. What about if you have a negative CT, but a strong suspicion of a subarachnoid hemorrhage? Well, then you’re going to do a lumbar puncture. What about a localized, unruptured aneurysm? Here you’re going to do a CT angiography. That’s going to be the first line because we’re looking for that aneurysm. So if you believe it’s ruptured, then you’re going to do non-contrast CT.
But if you’re just looking for the aneurysm itself, you’re going to do a contrast CT. And then that MRA would be the alternative if they can’t have that contrast dye. If you have a complex aneurysm or you’re planning surgery to go after the aneurysm, then you’re going to want a cerebral angiogram. This is going to be the most detailed picture you can get. So then you have your chronic follow-ups is going to be an MRA because there’s no contrast, so we can just follow up with them there. And a patient with contrast allergy or renal issues is going to get an MRA as well because you don’t want to use that dye. So, that’s going to be sort of your algorithm, your thinking process for which one to choose.
And I think that table is totally worth knowing and absolutely worth your time to learn and understand. Treatments here. So, again, we’re talking about aneurysms. So, we talked about some of the symptoms of them, depending on where they’re located, depending on if they’re ruptured or unruptured. We talked about how to diagnose them using a CT angiogram or CT non-contrast, depending on what we think is going on. So a management of an unruptured aneurysm, the number one issue here is we need to get the blood pressure under control. This makes sense, right?
Because if we have an unruptured aneurysm, we want to keep it from rupturing. So what’s the best way we can keep an aneurysm from rupturing? We can keep the blood pressure low, so less than 140 over 90. We want to control cholesterol. And then we’re going to do follow-up imaging to make sure the thing isn’t growing, right? That’s where that MRA comes in over time. Management of a ruptured aneurysm is basically back to where we were last week, or two weeks ago, talking about strokes, right, and hemorrhagic strokes.
So, emergency interventions, we want to prevent re-bleeding or making things worse. So, again, strict blood pressure control is going to be number one regardless. Then we’re going to treat that increased intracranial pressure with mannitol or hypertonic saline, and then we’re going to move on to surgery. So, either clipping, which is an open procedure, to clip the aneurysm itself, or endovascular coiling. This is more minimally invasive, but we’re going to get that bleeding under control one way or another if we need to.
All right, cool. So that should wrap up aneurysms for you. And hopefully that’s a clear picture in your head of how that functions, how we work them up, what they look like, and then how to treat them.
Next, we have arteriovenous malformations. There’s a lot of words in here for me to stumble over and get wrong. I encourage you to practice them as well, because the more, again, the more you can say them out loud, the better off you are. This is an abnormal tangle of blood vessels where arteries connect directly to veins without the normal capillary bed in between. So think about that for a second. An arteriovenous malformation is where the arteries connect directly to veins. There’s no capillary bed.
So what does that mean happens? I don’t even, I shouldn’t have to even give you the rest of the definition. Think it through and that will make it stick more for you. If we go straight from artery to vein, we get a high pressure blood flow into the veins. If we have a high pressure blood flow into the veins, what happens next? We have increased risk of rupture.
Okay, so AVMs are congenital defects where the arteries connect directly to the veins in this certain section of the vascular system. And at that point, we get an increased risk of rupture because of the pressure gradients. Veins aren’t designed to hold that kind of pressure. So over time, right? So someone’s born with this, but it doesn’t usually affect them until a little bit later in life because as the pressure, as time goes by, this gets worn down, worn down, worn down, just like that wall of that aneurysm. So what else makes sense here? Blood pressure control, right?
So our clinical presentation is typically these are asymptomatic until something happens. There’s another issue where you may get some symptoms from what’s known as steal phenomenon. Right? So first of all, the first problem is you get that direct artery to vein connection, right which can be a issue for a rupture. But then the other problem is you can get steal phenomenon, and some of you will recognize that term from other areas. But here’s where blood is diverted away from surrounding normal tissue, causing ischemic symptoms. So, because you don’t have that normal blood flow for the area, you can get some ischemic symptoms in the tissue.
So, obviously, in the brain, this can be a major problem. So, symptoms of an unruptured AVM, just like we talked about an unruptured aneurysm. Here you can get headaches. You can get seizures. You can get focal neurological deficits. And all of that has to do with that ischemia, that mild ischemia that’s going on and growing.
Now, to me, I would be surprised if you got questions about symptoms of an unruptured AVM. It just seems sort of, I don’t know, maybe you would, but doesn’t seem like high level, what would you call it? High yield information to me on that one. But some of those of a ruptured AVM, well, here we’re back to our stroke symptoms, right? Sudden or severe headaches, nausea, vomiting, confusion, coma, seizures, loss of consciousness, focal neurological deficits, et cetera, all back to that hemorrhagic stroke. Common locations here, these can occur anywhere in the central nervous system, but are most often found in the brain. Complications would be the hemorrhages, right?
Like we talked about. Treatments here. You can do anticonvulsants for possible seizures and then tight blood pressure control to reduce the risk of rupture. You may also, if they have ruptured, we need to do some intervention or before you can do a surgical resection. So you can go in and… So, in this case, you just go in and you take those vessels out and just remove them. This is all more complicated, right?
But we’re not going to get that detailed for your studies at this point. Usually, as far as the PANCE, EORs, and everything else is concerned, when we talk about surgery, we just say, you know, call the vascular guy. We don’t actually go into detail on the specific surgeries. And this is not an area that I do. As you guys know, or maybe you don’t, I work in the operating room in multi-specialty practice. Is my practice outside of running Physician Assistant Exam Review. And I assist on hundreds of cases a year on all different subspecialties, but not in, not really in neuro, not really in vascular.
Those are two areas that, our group doesn’t, doesn’t really cover. So this is not something that’s super familiar to me, but again, I don’t think you need to know the ins and outs of it. It’s just, we go in and remove that AVM. You can also do an endovascular embolization if it’s a deeper or harder to access area. There’s also stereotactic radiosurgery, so focused radiation to shrink the AVM over months or years, depending on how things are going. And then you’re going to want to do regular imaging to monitor or check for residual AVMs or reoccurrences or things. So keep an eye out for that.
Okay, cool. Moving along. So this is a longer episode. I understand that. And the cerebrovascular stuff is a little tough to keep straight in your head, but I want to press on and talk about intracranial hemorrhages because I just think, because we did strokes last week, we can zip right through this and it’s not really that complicated and I don’t want to head into the next episode. So this is bleeding that occurs within the skull, either inside the brain tissue, which is intraaxial or outside the brain tissue, but within the skull, which is extra axial causes. I think you should be able to come up with a few now, right?
If I asked you to come up with four causes of intracranial hemorrhages, I’m guessing you can do that. So we have aneurysms, we have head trauma, we have chronic hypertension, we have blood vessel abnormalities like an AVM, we have brain tumors, we have bleeding disorders, all of these things. So as far as classifications go, you can have intraaxial hemorrhages, which is bleeding which occurs within the brain tissue itself, more dangerous and more difficult to deal with. This is intraparenchymal hemorrhages or intraventricular hemorrhages. Those are your two options there. You can have extra axial hemorrhages, which is your epidural hemorrhages, subdural hemorrhages, or subarachnoid hemorrhages. Clinical presentation.
Here again, the symptoms depend on the location, just like we talked about all throughout this section. Really everything focuses on that subarachnoid hemorrhage because it’s the most common. It’s the one that comes up the most. So we’re not going to go through all the steps there. But you could just get all these neurological changes, nausea, vomiting, seizures. And no matter what the hemorrhage type is, though, you can get tingling, numbness, weakness, changes in vision, difficulty of speech, loss of coordination or balance, all of the things that you commonly associate with a stroke, right? Loss of consciousness and a sense of taste comes up.
Loss of fine motor skills, hand tremors, all of these things, neurological deficits. And again, the labs and studies and physical exam findings are the same as what we’ve talked about, right? So you’re looking for focal neurological deficits or altered mental status. You’re doing imaging like we talked about. So that non-contrast CT, if you believe that there’s a hemorrhage, right, that was a non-contrast CT. The crescent-shaped hemorrhage suggests a subdural hematoma. The biconcave hemorrhage suggests an epidural hematoma.
The hyperdensity in the subarachnoid space indicates a subarachnoid hemorrhage. Probably you could know that. I don’t think that’s that complicated. Just depending on the shape of the hemorrhage on the imaging on that non-contrast CT.
Now, if we were thinking that it may be from a more vascular issue, from an AVM or an aneurysm, you might get angiography or an MRI with contrast, so used for further evaluation when CT is inconclusive. Again, we can talk about that lumbar puncture if we really think we have a subarachnoid hemorrhage and we can confirm it that way. What’s our treatment here? So it’s like the fifth time we’ve gone through this so hopefully you have a handle on treatments for intracranial hemorrhages, right? We want to manage the blood pressure to keep it from bleeding more excessively or re-bleeding once we get the bleeding under control. We want to reduce intracranial pressure. We can give painkillers and steroids for swelling, anti-seizure meds.
And then we’re going to do surgery if we need to, to get that bleeding under control. We can do a craniotomy and remove the clot and relieve the pressure. We can clip the aneurysm to prevent ruptures or bleedings, and we can do endovascular coiling. A lot of possibilities here, but really what I like to do is think about all of this stuff in groupings is like, okay, how do I diagnose it and how am I going to treat it? Well, all of these, essentially the treatments are going to be the same, right? No matter what the location of the bleed is, no matter what’s going on, we’re going to want to reduce blood pressure. We’re going to want to reduce intracranial pressure, and we’re going to want to go in and stop the bleeding, right?
So it should be pretty straightforward depending on the diagnosis. Diagnosis might be harder because they may be asking you for like the location and where it is and how do you find it, all those things, but the treatment part should be pretty easy. So that’s what I would be looking for as I’m studying. What is this? Can I group together and understand more clearly. And then it doesn’t seem so overwhelming. It doesn’t seem like so much.
All right, we’ve covered a lot of ground. So that was a little bit on anterior posterior circulation, cerebral aneurysms, AVMs, and intracranial hemorrhages going all the way back into strokes from last week and covering all of this material. So hopefully neuro is coming together for you. But again, this is not something you can listen to one time. It’s something that you need some repetition in, something you need to maybe draw some pictures, get to the whiteboard, and spend some time with some classmates going over. Things, discussing them, teaching them to each other, that sort of thing. Oh, you know what?
While we’re talking about it, let’s move on to our study tip for today. Our study tip for today is to use timers. I use timers all the time when I’m doing work and I use them in multiple ways. One way that a lot of people talk about is to set a timer for while you’re working, right? So there’s the 20, you can set it for 25 minutes on, five minutes off, that sort of thing. The Pomodoro technique. I usually run it more like 45 minutes on.
And then if I’m feeling good, I kind of keep going generally. But what I find is setting that timer does more than give me a time to work it. It forces me to focus. It forces me to bring it in and say, look, you only have 45 minutes. You only have 30 minutes. You can’t spend time fiddling around and other things because this is all the time that you have. And it sort of makes that very finite and very clear and gives me a really good focus and pacing on what I need to get done.
The other thing that you can use a timer for, and I’ve done frequently, is a timer to get started. So if I find myself wandering around the house and I’m not able to sit and get the work done that I need to get done, sometimes what I’ll do is I’ll actually start a startup timer. So I’ll set a timer for 10 minutes and say, okay, in 10 minutes, no matter how you feel, because I don’t care how you feel we have to get this work done in 10 minutes, I’m going to sit down and get to work. And that can be really powerful. So both a starting timer, and then a length of study session timer, those two things can be really, really helpful. I actually have a hexagon timer sitting on my desk. It does, I bought it on Amazon, I think it was like 10, 15 bucks.
And it is shaped like a hexagon. But what’s cool about it is, it has different, the different sides, you can rotate it and it sits flat and each side is a separate timer. So you can physically turn it, set it down. It’s a five minute timer, turn it another to the other side. It’s a 15 minute timer, turn to the next side. It’s a 30 minute timer. So it’s very easy to work with sits right in front of me.
I can watch that countdown and then it beeps at me when it’s done. And what’s important for me a lot of times is one is to have that timer to keep me working. But the other is once I get working, I become very focused on what I’m doing and I can lose a lot of time. So it’s nice to have that reminder, oh, that 30 minute timer went off. It doesn’t mean I necessarily have to stop, but it’s a, oh, do I still want to be working on this 30 minutes from now? Or do I need to move on to something else?
Okay, no, I’ll reset it for 15. And then I’m going to try and wrap this up is sort of how I use it. So a couple of different methods, but test it out for you. Having some sort of timer as you work can be very, very powerful.
All right, let’s talk about our priming questions and get the answers to those. What is the most common type of cerebral aneurysm? We covered this right at the top. What is the most common type of cerebral aneurysm? It is a berry aneurysm. Which imaging modality is the gold standard for diagnosing a cerebral aneurysm? Which imaging modality is the gold standard for diagnosing a cerebral aneurysm?
Not a hemorrhage, but an aneurysm. The cerebral angiogram. What’s the hallmark symptom of subarachnoid hemorrhage? That’s that worst headache of your life, the thunderclap headache. What is the most common site for a berry aneurysm within the circle of Willis? The junction of the anterior communicating artery and the anterior cerebral artery, of course. The junction of the anterior communicating artery and anterior cerebral artery.
Which condition is characterized by arteries connecting directly to veins without a capillary bed? That one should be very low-hanging fruit at this point. This is an arteriovenous malformation or an AVM.
Perfect. Well done. I want to just let you know this has been an absolute pleasure for me getting back behind the microphone after so much time. And I love that you are out there. You’re there for me and so that I can share this with you. You’re the community makes such a big difference in my ability to do this work in my interest in in my motivation to keep working. So thank you so much for your feedback for your replies.
Absolutely love it. And it has just been so much fun. I also do want to remind you that January is going to be very exciting because I’m hosting that Master Class, oops, on the 14th and the 16th. So definitely head over to physicianassistantexamreview.com/masterclass to register for that. And the February cohort of the 33 Days to Pass the PANCE registration will be opening also on the 14th of January. So there’s a lot going on, a lot to keep up with. Definitely head over to the website and get on the email list to get all the information.
All right. Thank you so much. And I look forward to talking to you guys next week when we do our companion episode and go through some questions. Thank you.
Get 19 Neurology questions straight from The Final Step.
- Craniotomy: Removes clot and relieves pressure
