ExploreCME: Diving deep into PANCE Prep!
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ExploreCME: Diving deep into PANCE Prep!
Seizures, Sorted
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Get access to our entire back catalogueWelcome to the deep dive. Today we're really taking a scalpel to a very high stakes and knowledge-intensive area, seizure disorders.
SPEAKER_00:It really is. This is core material. And our goal today is to build that clinical framework, you know, from the moment the patient presents all the way through to that long-term management.
SPEAKER_01:Absolutely. And it's critical because, well, seizures are incredibly common. I think the estimate is something like 10% of people will have one in their lifetime.
SPEAKER_00:That's right. So this isn't some rare diagnosis. And today we're focused on the why, the thinking behind the decisions you'll have to make.
SPEAKER_01:Okay, so let's start with the absolute basics. Let's get our terminology rock solid. Seizure, epilepsy, and the one everyone fears, status epilepticus.
SPEAKER_00:So a seizure, that's the event itself. It's a brief paroxysmal spell, usually less than five minutes, sudder onset, very stereotyped. It's a symptom, not the disease.
SPEAKER_01:Aaron Powell And when does that symptom become a disease? When do we call it epilepsy?
SPEAKER_00:That's the key distinction. Epilepsy is the disease. It's defined by recurrent seizures that are unprovoked. So two or more seizures without an immediate, obvious cause.
SPEAKER_01:And that unprovoked part is huge because a lot of seizures are provoked.
SPEAKER_00:A huge number. About a quarter of them. I think alcohol withdrawal, a critically low sodium level, a bad infection. Those don't necessarily mean you have epilepsy.
SPEAKER_01:Okay. And the third one, status epilepticus, S E. The definition here has changed a lot.
SPEAKER_00:Aaron Powell It has, and for very good reason. We used to say 30 minutes, which is uh dangerously outdated. The data is clear. Irreversible brain injury starts to accumulate after the five-minute mark.
SPEAKER_01:Aaron Powell So what's the clinical definition now?
SPEAKER_00:Any convulsive seizure that goes past five to ten minutes is status epilepticus. You have to act and you have to act fast. Time is brain. It's that simple.
SPEAKER_01:With that foundation, let's get into what is often the hardest part the initial history and physical. The patient usually can't tell you what happened.
SPEAKER_00:No, they're amnestic. So your diagnosis depends almost entirely on what an eyewitness tells you.
SPEAKER_01:So how do you guide that conversation beyond just they were shaking?
SPEAKER_00:You're digging for specifics. Two goals right away. Confirm it was a seizure, then classify it. So you ask about focal features, lateralizing signs. Was the shaking just on one side?
SPEAKER_01:Or did their head turn to one side?
SPEAKER_00:Or their eyes.
SPEAKER_01:Exactly. Forced gaze or head deviation. That points you toward a focal onset. And then you have to ask about what happened after.
SPEAKER_00:Todd paralysis.
SPEAKER_01:Yes. You have to ask about todd paralysis. Was there weakness on one side after the shaking stopped? Or difficulty speaking. That's a huge clue for a focal seizure in the motor or speech cortex.
SPEAKER_00:Aaron Powell And you also need to know if they were aware during the event. Could they talk or interact?
SPEAKER_01:Right, because that's the difference between a focal aware seizure and a focal impaired awareness seizure. It's all in the history.
SPEAKER_00:Aaron Powell At the same time, you're on the hunt for those acute triggers. The idea that a seizure is provoked until proven otherwise.
SPEAKER_01:Absolutely. Guilty until proven innocent. You're looking for a metabolic bomb or an intoxication. So recent fever, head trauma. Any drug use, cocaine, meth, or alcohol withdrawal are all high on that list. So the physical exam is really an extension of that hunt. You're looking for structural clues.
SPEAKER_00:You're hunting for the underlying cause. Any signs of trauma, skull deformities, and abnormal head circumference. And in kids especially, you look at their skin.
SPEAKER_01:For neurocutaneous disorders.
SPEAKER_00:Right. Specific birthmarks can point you straight to a diagnosis like tuberosclerosis, which is a known structural cause of epilepsy.
SPEAKER_01:Okay, let's talk about the big pitfall, the classic faint versus fit, syncope versus seizure.
SPEAKER_00:It's the most common misdiagnosis by far. Syncope is a perfusion problem, a faint. It's usually triggered by something standing too long, pain, the sight of blood, and the recovery is fast.
SPEAKER_01:They're back to normal almost immediately.
SPEAKER_00:Within seconds. With a seizure, you have that long, drawn-out period of confusion afterwards, the postdictal state. That's a huge differentiator.
SPEAKER_01:And what about distinguishing it from a TIA, a transient ischemic attack?
SPEAKER_00:The key there is thinking positive versus negative phenomena. TIAs are almost always negative, a loss of function, loss of vision, loss of sensation weakness.
SPEAKER_01:Whereas seizures are positive.
SPEAKER_00:Exactly. An addition of something tingling, sea lights, involuntary movements, and TIAs almost never cause a loss of awareness or confusion. They feel very different.
SPEAKER_01:So once you're confident it was a seizure, you have to classify it. The standard is the ILA classification.
SPEAKER_00:Right. And the first big split in the road is focal versus generalized. Did it start in one spot or did it involve both hemispheres right from the get-go?
SPEAKER_01:Let's walk through some classic examples. Let's start with the most common focal type, temporal lobe seizures.
SPEAKER_00:Temporal lobe seizures are fascinating. They often start with a very specific feeling, an aura, which is actually a small focal seizure itself.
SPEAKER_01:And that can be a smell or a feeling.
SPEAKER_00:It can. A strange burning odor or a sudden intense feeling of fear because the amygdala is involved, or that classic epigastric rising sensation.
SPEAKER_01:And the seizure itself can be surprisingly subtle.
SPEAKER_00:Very subtle. We call the motor features bland, things like lip smacking, chewing, picking at their clothes. These are called automatisms. Then they're unresponsive and confused afterwards. Easy to miss if you don't know what you're looking for.
SPEAKER_01:Now, let's contrast that with frontal lobe seizures. I mean, these are the opposite of subtle.
SPEAKER_00:Oh, they couldn't be more different. Frontal lobe seizures are often nocturnal. They're very brief, maybe 15 to 45 seconds, and they are dramatic.
SPEAKER_01:What do you mean by dramatic?
SPEAKER_00:Prominent, intense motor features. Loud vocalizations, really vigorous bicycling movements with the legs, forced head turning. The textbook example is the Jacksonian march.
SPEAKER_01:Where it spreads across the body.
SPEAKER_00:Yes, like a wave. Might start with the thumb jerking, then it marches to the hand, then the arm, then the face as the electrical activity spreads across the motor cortex.
SPEAKER_01:Okay. Let's shift to generalized seizures. We all know the classic generalized tonic clonic or GTC, the sudden collapse, rigidity, then shaking.
SPEAKER_00:Right, the one everyone thinks of, often with tongue biting incontinence. Yeah. But the one that gets missed all the time, especially in kids, is the absence seizure.
SPEAKER_01:Aaron Ross Powell The one that just looks like daydreaming.
SPEAKER_00:Exactly. It's a non-motor seizure, just a sudden behavioral arrest. They just stare unresponsive for about 10 or 20 seconds, and then they're right back to normal. No post dictal confusion.
SPEAKER_01:And there's a classic way to trigger one in the clinic, right?
SPEAKER_00:There is. This is a very high yield fact. You can often bring on an absent seizure by having the child hyperventilate for two or three minutes.
SPEAKER_01:That's a perfect transition into using diagnostic and lab studies. So for any new onset seizure, what are the first tests you're ordering?
SPEAKER_00:First thing you rule out the acute stuff. So you need blood work, a chem panel for sodium and glucose, kidney function, a CBC, and a toxicology screen. Always.
SPEAKER_01:And for imaging, MRI or CT.
SPEAKER_00:MRI is the gold standard, hands down. It's just so much more sensitive than a CT for finding the subtle things, small tumors, old strokes, and especially for finding mesial temporal sclerosis.
SPEAKER_01:Which is scarring in the hippocampus.
SPEAKER_00:Right. And it's the most common cause of focal epilepsy that doesn't respond to medication. A CT is really only for the emergency setting if you're worried about an acute bleed or a large mass.
SPEAKER_01:Aaron Powell And then, of course, the EEG, the essential tool.
SPEAKER_00:Aaron Powell It's the electrical signature of the brain. You're looking for clues between seizures. We call that the interrectal EEG or hoping to actually capture a seizure, the ictal recording.
SPEAKER_01:And for those absence seizures we just talked about, the EEG is a slam dunk.
SPEAKER_00:It's pathognomonic. You see this beautiful, regular, generalized three hertz spike and wave pattern. It's unmistakable.
SPEAKER_01:Aaron Powell But there's a really important caveat about the EEG that we have to mention.
SPEAKER_00:Yes. A normal EEG does not, and I repeat, does not rule out epilepsy. The seizure focus might be too deep for the scalp electrodes to see, or you just might not capture an event in a 30-minute test.
SPEAKER_01:Right. It's a piece of the puzzle, not the whole picture.
SPEAKER_00:Exactly.
SPEAKER_01:Okay, let's pivot to clinical intervention, the acute crisis. Generalized convulsive status epilepticus, or GCSE. We said the clock starts at five minutes. Walk us through that protocol.
SPEAKER_00:It's all about moving fast and in parallel. You're evaluating and treating at the same time. Think of it in stages.
SPEAKER_01:Stage one, the first five minutes.
SPEAKER_00:Zero to five minutes, it's all about the ABCs. Airway, breathing, circulation, get IV access, check a finger stick glucose. If it's low, give dextrose. And always if thiamine first.
SPEAKER_01:Then we hit the five-minute mark, six to ten minutes, first line treatment.
SPEAKER_00:This is when you terminate the seizure. The drug of choice in the hospital is IV lorazipam, four milligrams. If you're pre-hospital, I am midazolam works just as well and is easier to give.
SPEAKER_01:And if that doesn't work, we're at 10 to 20 minutes now. Second line.
SPEAKER_00:If the benzodiazepine fails, you move to your second line agent. Usually that's intravenous phosphenotoin.
SPEAKER_01:And if that fails, we're in refractory status epilepticus.
SPEAKER_00:That's a true medical emergency. The patient needs to go to the ICU, be intubated, and put on a continuous IV drip of a sedative like midazolum or propofol. You need continuous EEG monitoring to guide therapy. You're essentially inducing a coma to quiet the brain.
SPEAKER_01:Let's talk about the less traumatic side, chronic management. Pharmaceutical therapeutics. The goal is always seizure control with minimal side effects, but the big challenge is drug drug interactions.
SPEAKER_00:This is a huge minefield, especially with the older drugs. Many of them are potent inducers or inhibitors of the cytochrome P450 system in the liver.
SPEAKER_01:Give us the must-know interactions, the ones that always show up.
SPEAKER_00:Okay, so valproic acid is a potent inhibitor. If you add it to Lamatrogene, the lamatrogen level will skyrocket, and you risk a life-threatening rash. On the flip side, drugs like carbamazepine and phenytoin are inducers.
SPEAKER_01:They speed up metabolism.
SPEAKER_00:Right. So they'll chew through other drugs like warfarin or oral contraceptives, making them less effective. This is a big reason why newer drugs like levitoracetem are so popular. They don't have these messy P450 interactions.
SPEAKER_01:Let's single out Phenitoin for a second. Its pharmacology is unique and tricky.
SPEAKER_00:It's dangerous if you don't respect it. Phoeni toine has zero order kinetics. What that means is at therapeutic doses, the liver gets saturated. It can't clear any more of it.
SPEAKER_01:So a small dose increase leads to a huge jump in the blood level.
SPEAKER_00:A huge, unpredictable jump. You can go from therapeutic to toxic very, very quickly. You have to make dose changes and tiny increments.
SPEAKER_01:And when we're checking drug levels, the mantra is always treat the patient, not the number.
SPEAKER_00:Precisely. The level is a guide. This is especially true for drugs like phenetoin and valproic acid that are highly protein bound. The part that works is the unbound or free fraction. So if a patient has low albumin or kidney failure, their total level might look normal, but their free active level could be toxic. You have to check an unbound level in those patients.
SPEAKER_01:Okay, what if drugs fail? What about surgery?
SPEAKER_00:For the right patient, surgery is a game changer. If you have focal epilepsy, especially that mesial temporal lobe epilepsy with hippocampal sclerosis, and you fail two appropriate drugs, surgery is the standard of care.
SPEAKER_01:And the success rates are high.
SPEAKER_00:They can be amazing. Up to 80 or 90 percent seizure freedom. That's life-changing, and it's far better than just trying a third or fourth drug that's likely to fail.
SPEAKER_01:And for patients who aren't surgical candidates.
SPEAKER_00:We have devices. The most common is the vagal nerve stimulator or VNS. It's like a pacemaker for the brain circuitry. It rarely makes someone seizure free, but it's often as good as adding another medication with fewer side effects.
SPEAKER_01:You also hear about the ketogenic diet.
SPEAKER_00:Yes. That's a great option, primarily for children with certain severe refractory epilepsy syndromes. It's a very high-fat, low carbohydrate diet that can be remarkably effective.
SPEAKER_01:Let's move to our final section: health maintenance, patient education, and prevention. Let's start with a really common one: febral seizures in kids.
SPEAKER_00:Right. This is all about educating anxious parents. A febral seizure happens in young kids three months to five years because of a high fever. The most important thing to tell parents is that this is not a brain infection.
SPEAKER_01:And that a simple one doesn't cause brain damage.
SPEAKER_00:Crucial point. A simple, brief febral seizure does not cause brain damage and does not mean the child will develop epilepsy. We separate them into simple versus complex, but for a simple one, the prognosis is excellent.
SPEAKER_01:So what's the intervention? Do you put them on daily medication?
SPEAKER_00:Generally, no. Chronic medication is not recommended. What you do is educate the parents on rescue therapy. They can be given reptal diacopam to administer at home if a seizure lasts longer than, say, five to ten minutes.
SPEAKER_01:Let's talk about prevention after a severe head injury. The risk of epilepsy goes way up.
SPEAKER_00:It goes up 15 to 30 fold after severe traumatic brain injury. So we do recommend prophylactic anticonvulsants like phenytoin. But, and this is key, only for the first seven days.
SPEAKER_01:Why only seven days?
SPEAKER_00:Because it's effective at preventing those immediate, acute post-traumatic seizures. But studies show that continuing it longer doesn't prevent the development of chronic epilepsy down the road, and it can actually slow down the rehabilitation.
SPEAKER_01:And finally, a really complex topic: managing epilepsy in women of childbearing age.
SPEAKER_00:It's a constant balancing act. First, contraception. Remember those enzyme-inducing drugs? Phenetoin, carbamazopine?
SPEAKER_01:Yeah.
SPEAKER_00:They can make birth control pills fail. That's a critical piece of counseling.
SPEAKER_01:And then there's the issue of the drugs themselves being harmful to a developing fetus, teratogenicity.
SPEAKER_00:Yes. We know some drugs carry a higher risk. Valproic acid is the biggest offender associated with neural tube defects. Topyramate and phenobarbital also carry higher risks. You avoid them if you possibly can in a woman who might become pregnant.
SPEAKER_01:So what's the most important preventative step for any woman of reproductive age on these medications?
SPEAKER_00:High dose folic acid, one to four milligrams a day, every day. It helps mitigate that risk of neural tube defects. And you have to monitor their drug levels very closely during pregnancy because their metabolism changes and levels can drop, putting them at risk for seizures.
SPEAKER_01:This has been a huge tour. We've gone from the absolute importance of that first eyewitness account through classification, EEG patterns, the high-stakes protocol for status epilepticus, and the nuances of chronic drug therapy.
SPEAKER_00:Aaron Powell It really is a field where you have to balance potent medications against life-altering side effects and risks, the whole spectrum of care.
SPEAKER_01:It is. And to leave our listeners with one final thought, it's a sobering one, but it really underscores why aggressive, effective management of this disease is so critical.
SPEAKER_00:Aaron Powell We're talking about CESUD, sudden unexpected death and epilepsy.
SPEAKER_01:Exactly. The risk factors are there, poorly controlled seizures, especially GTCs, but we still don't fully understand why it happens.
SPEAKER_00:Aaron Powell We don't. The leading theories are of fatal cardiac arrhythmia or a central respiratory shutdown right after a seizure. It's this mystery, this risk, that highlights that what we're doing isn't just stopping the shaking, it's about preserving life.
SPEAKER_01:And it's a powerful motivator for research into stopping the process of epilepogenesis itself, that cascade that turns a normal brain into a hyperexcitable one. The hope is that one day we won't just be treating epilepsy, but preventing it from ever starting.