Seizure Disorders and Neurological Conditions Overview

Hello, this is Dr. DeShavo, and we are finishing up with this bear of a chapter, Chapter 11, Part 7. This is a big one, but it's also important. So, as always in Forever, if you have any questions, email me. Otherwise, let's get going here. We're going to be moving into seizure disorders. And so, these are so interesting to me because they are this... burst of abnormal electrical activity in the brain. And we know that ions are going to be the substances which cross over those cell membranes in order to create an action potential. And with seizures, these action potentials happen abnormally in the brain, causing abnormal electrical activity going through circuits in the brain that don't normally get stimulated in that way. And they could present with that loss of cognition. and the tensing and relaxing of the body but it's just interesting that we can't quite figure these out to me um now you can have us anybody could have a seizure god forbid if there's some sort of complication in your physiology but there are certain conditions that are more prone to seizures which we're going to talk about epilepsy is going to be a disorder resulting from that spontaneous abnormal firing of the neurons and they have recurrent seizures where there's no underlying or correctable cause. The one interesting thing that I've learned about this in researching and looking into seizures is there are dogs that they can train that can actually sense before a seizure happens. So people who have seizures repeatedly will actually have one of these specially trained dogs and the dog has a signal. I think it's the dog lays down and puts her head down. It means they're going to have a seizure so that patient knows they could get to a safe place before they have their seizure. That's so amazing to me. So complications with this could be brain damage over a prolonged period of time, TBI if they fall down and they hit their head, aspiration if they vomit a little bit or even just from their saliva, and status epilepticus, which would be seizures that last longer than, 20 minutes or continual seizures can be dangerous for that patient because normal brain activity will be taken over by the seizures. So generalized seizures, same abnormal neuronal activity, can lead to loss of consciousness, falls, or massive muscle spasms. And I'm kind of zipping through this because I'm assuming that you know most of this. So the three type that we will talk about. and I guess they have renamed them but I'm going to give you the new and the old names. Febrile seizures are the same. They're in children usually due to a spike in fever. It's very scary I'm sure for the parents but they actually don't get any damage from it unless they have some sort of injury from falling and children usually do grow out of them. It's probably very bread and butter stuff for you guys. Now there used to be what was called petite mal versus grand mal and the teat means small in french so this would be a teeny tiny seizure i actually had a friend who would get these absent seizures and you would have no idea she was having one she would literally just pause her eyes would get a little vacant and then she'd continue talking after a couple of seconds so they're brief they really don't cause a lot of problems other than that person you know kind of being out of it for a little bit I'm sure this could be a problem while they're driving. I don't know what the complications really are because I've never treated anybody with that. But if you're driving and have one, I'm sure that's a complication. Now, what used to be known as grand mal are those tonic-clonic seizures where they'll have this stiffening of the body and then the repeated jerks of the arms and legs, as well as that loss of consciousness. They obviously don't have control over their bodies, so they will fall down. and it's much, much more intense than those absence seizures. We can test for these, I think, best with an EEG and see the activity of the brain. They'll also go through and do CAT scans or maybe a contrast MRI to make sure that there is nothing, such as a tumor in the brain, complicating the situation. And I do have some pictures of these seizures disorders when we start to do a little less practice in a few slides. So MS or multiple sclerosis is an autoimmune condition. Interestingly enough, there are some links with a lack of sunlight. So it says down a little bit further, you can see most common in women, Caucasians and those living in temperate climates. They mean people that are away from areas with a lot of sun. such as New York State where we live, unfortunately. But there is some correlation with a lack of sunlight. Maybe some vitamin D deficiencies is a possibility. They don't quite know, but they do see those correlations. This usually happens in younger females. You can have this. We have a friend who's an older male and he has it. So, you know, it can vary from person to person. So this is autoimmune. Somehow their immune system is going to start attacking the brain and the spinal cord and potentially the cranial nerves. And what happens is the oligodendrocytes, which produce myelin in the central nervous system. Remember, we have Schwann cells created in the peripheral, oligodendrocytes created in the central nervous system, brain and spinal cord. The oligodendrocytes stop producing adequate myelin around the axons. And what will happen is because you don't have proper myelin there, you will also get damage to this area, which can turn into hardened sclerotic plaques. And this is why it's called multiple sclerosis because of those plaques that take over the area where the myelin should be. So it could be diffuse patches throughout the system. There could be some that don't progress. This disease has very varying degrees of intensity. So symptoms usually between 20 and 40 years of age can also be in older people as well. So epilepsy, paralysis, depression are all complications from this disease. So manifestations, the manifestations with this will vary depending on how much of the central nervous system is affected. but they also have remissions and exacerbations so and once again this is super variable from person to person one thing that i didn't put in there that i really would like to is that vision is usually is one of the first things to be affected it can be very insidious You know, a patient might say, I'm looking somewhere and it goes in and out of focus. You know, it's as simple and as short as that. Okay. Also, fine motor skills. They'll say, yeah, I pick up my coffee and I drop it. Or I pick up my brush and I drop that. You know, fine motor skills are one of the first things to go. Okay. So fever, hot mass, sun exposure, stress can trigger or worsen episodes, may progress without remissions, may totally remit and then not come back. So the degree of variation is huge with MS. Parkinson's disease is a progressive involvement with what is called the substantia nigra in the midbrain. And the substantia nigra in the midbrain. I thought I had put in a picture here of this, the substantia nigra in the midbrain. Okay, so I'm going to pause the tape here. I'm going to get you that picture of substantia nigra. I think it may have not saved. I'll be back in just a second. I am back, and I got a picture of the substantia nigra. So the substantia nigra is part of that basal ganglia, also known as basal nuclei, that help to coordinate our movements. It helps with some emotional responses as well. And the substantia nigra actually is in the midbrain. So this is a little tough to understand this, but this is the bottom of the brain. Okay. And what they've done is they've sectioned right at the midbrain. So we're just above the pons, right in the midbrain. And this right here, these two dark areas are the substantia nigra. And this is what releases dopamine. And dopamine is a neurotransmitter, which is very important to help with the correlation and coordination of voluntary movements. People with Parkinson's you can see the reduced substantia nigra and so if we have less substantia nigra we don't produce as much dopamine okay so just to give you a visual of where that happens and that's deep in the brain and that gray matter deep in the brain which we had learned about previously okay so they have a lack or a decrease in the amount of dopamine when approximately 80% of the dopamine producing cells are destroyed movements and issues including tremors of the hands and head develop so the head moves and the hands move unless they're intentionally moving if they stimulate that voluntary motor pathway what will happen is they will actually stop those tremors it's very interesting okay so there's that picture of substantia nigra those two little bands of gray matter part of the basal nuclei or ganglia. So manifestations are very obvious. They may not be initially, but as it progresses, they will start to present with slowing or stopping of automatic movement, such as blinking. They'll have difficulty swallowing, so therefore they may drool a little bit. They have a very unsteady gait or a shuffling gait. And they may actually slap their foot down a little bit because they know that they're having difficulty with that gait and it helps them to feel the floor a little bit better. With that, I'm also going to add stooped posture. Okay, so they usually tend to build bend forward because once it. they're having difficulty with that walking so they're trying to balance themselves out okay they'll also have a pill rolling or resting tremors and their head may shake back and forth but as they intentionally start to move those tremors go away so they are known as resting tremors they also have a mask like appearance in their face which means they don't respond Usually in conversation, somebody says something, you're like, oh, all right. You know, you have a response. They don't. And they may be feeling those emotions, but they're not showing it on their face. All right. So let's practice. I put some pictures together. Which is which? So out of those diseases that we just spoke about, this one. So think about what we've talked about, what manifests in here. This may be a little tough at first. If you need to pause the tape, go ahead and do so. But what we're seeing there is those plaques that we'll see with multiple sclerosis. And where all four arrows are, they start to show a brighter appearance because of that scarring or plaquing. That happens, it starts to replace the myelin location on the axons. It shows up whiter on an MRI. What do you think this condition might be? And I left the words in there because it might be a little hard to understand what he's doing. But this petite mal or absence seizure is just as simple as that. It's almost like somebody is pausing to think for a minute and then they continue on with their normal conversation. What condition do you think this might be? So you can't see it, but mask-like faces is written there, that stooped posture. Rigidity, short shuffling steps, tremor at rest, might be forward flex, okay, tremor of head and hands. And this indeed is Parkinson's disease. This one you're going to be like, got this, okay. So these are going to be seizures, okay, tonic-clonic seizures. So tonic phase is that tightening where they hold. And then clonic is when they start to go into that jerking of the limbs. And they have other things listed there. I want you to know that tonic is that held contraction, and clonic is when they alternate their contractions back and forth. So that would be what used to be known as grand mal. All right. Now, before we move into the next set of notes, I wanted to go over an important concept. and this applies to the next condition called upper motor neuron versus lower motor neuron okay so don't let this blow your brain too much it's actually pretty simple but it's an important concept clinically that we need to speak about hmm So an upper motor neuron is just that. It is the motor nerve that comes from the primary motor cortex in the frontal lobe. And it's going to come down the cord to the front of the cord at whatever level it's going out to. And remember, you have these coming out at each vertebral level. So don't worry about the vertebral level. It just is going to come to the cord at whatever level it's going to go out to. That is the upper motor neuron. Okay. There's a second nerve in this pathway. There's just two with motor. The second one comes from the front part of the cord out to whatever muscle it's going to. This is, you got it, lower motor neuron. Okay. With upper motor neuron. If this gets damaged, so you have some sort of cord trauma, you could even have a stroke that damages the motor cortex, whatever it may be along that upper motor neuron pathway, if that nerve gets damaged, your patient's going to have spastic paralysis because basically this upper motor neuron will either turn motions on or off. so if it can't turn your motions on or off you get paralysis but you can get involuntary spasticity just as if somebody starts to move back into that fetal position excuse me now this is compared to lower motor neuron which gives us flaccid paralysis this lower motor neuron simply turns the muscle on so if this gets damaged what will happen is you can't send any signal out and you get flaccid paralysis where a patient has a limp extremity that they have no control over okay so upper motor neuron versus lower motor neuron and that's what differentiates plastic versus spastic versus flaccid the reason i wanted to go over that is because now we're going to go into als this is also known as lugeric's disease lugeric's disease can affect either that upper motor neuron the lower motor neurons so they might have spasticity or they might have flaccid paralysis either way it only affects the motor portion so it'll be from the motor cortex down to the front of the cord because once again the front of the cord is motor excuse me so nerves continue to lose their ability to trigger muscle movement which will eventually lead into weakness and possibly death this can lead to paralysis the diaphragm too And intercostal muscles so they are not able to breathe without help This also can increase the risk of dementia. Okay unknown disease, but we're thinking once again, it's probably autoimmune So the way that it manifests is it'll begin and then slowly progress over time You'll lose upper motor neurons which will cause that spastic paralysis. And also hyperreflexia is a good thing to remember with upper motor neurons as well. There's also superficial reflexes. You'll probably learn an orthoneural that can present with upper motor neuron lesion. And then that flaccid paralysis with the lower motor neurons. So you could have foot drop, which simply means when they're walking, instead of... bringing their toes up to their shin, which is what we all do when we're walking, it drops down. So they actually get kind of a slapping gait where they bring their foot up and slap it down to make sure they can you know move their foot through and get it onto the floor. Weakness, hand weakness, muscle cramps, difficulty swallowing, difficulty speaking because of difficulty moving the tongue. So any of those motor manifestations. Myasthenia gravis is this really odd autoimmune condition that attacks what are known as acetylcholine receptors. Now I'm not going to get too much into neurotransmitters because that's a whole other lecture, but acetylcholine is a neurotransmitter that goes to voluntary muscles and the receptor that accepts acetylcholine on the muscles in patients with myasthenia gravis gets damaged or destroyed or they get fewer of them okay so they have a few you know suppose you're supposed to have a million on your muscles they only have 500,000 or whatever it means I don't know the exact number numbers but so those receptors for acetylcholine get destroyed so the muscles can't be fully stimulated so they tend to feel weak and not want to be very active So this will affect voluntary skeletal muscles. 50% will develop ptosis, or I shouldn't say ptosis, it's ptosis, sorry. You're not supposed to say the P, it's a very big no-no, which is drooping of the eyelid. Okay, so muscle weakness typically increases during periods of activity, improves after periods of rest, and they can build up some acetylcholine again. So. muscles, any of those voluntary muscles can be affected. Okay. And this actually can progress to myasthenic crisis, which is when the muscles become too weak to maintain respiration. Okay. And we'll take a look at that in a little bit. Huntington's disease, also known as Huntington's chorea. And chorea is an involuntary, unpredictable movement in a patient. You can have chorea and other conditions and almost like this slow writhing kind of movements. I know there's some medicine, it's an antipsychotic that they used to give in the 70s, maybe the 80s that presented them that actually created a permanent chorea in patients. And they have the kind of this, I'm sure you've probably seen some writhing movements of the mouth. So there's a genetic link with this. This is autosomal dominant disorder which has a defect on chromosome four so this causes degeneration of the nerves in the brain particularly in the i cannot talk today okay particularly in that basal ganglia and the frontal cortex which will cause difficulty once again with the control of their voluntary motor reactions and movements So usually slow, there's such a strong genetic link that usually if a parent has it, the child will get it. So mood swings, obviously they can become irritable if it's attacking that frontal lobe, that's where their personality is. And you start to get those uncontrolled rapid jerky movements in the fingers, feet, hands or trunk can also lead to dimension, other cognitive dysfunctions. So let's practice some of these. What two conditions do you think we're comparing below, left to right? If you need to pause the tape, go ahead. Otherwise, I'm going to uncover the answer. So these two conditions are your upper motor neuron, which gives you that spasticity or the tightness in the hands, arms, legs, feet, versus the lower motor neuron, which will give you that flasticity and hypotonia, which would be... muscles that are becoming atrophied and weak and what condition might you think this is here's probably your best clinical okay right that's going to be ptosis if you need a positive go ahead and do so and these are the acetylcholine receptors that i spoke about and what happens with our condition is antibodies attack those receptors and destroy them or make them inefficient. So what do you think this is? Yep, this is going to be myasthenia scrabus, this condition. So just to get you oriented, this would be normal. This would be abnormal. This is a basal ganglia that we spoke about previously. We looked at from a different view. This is a slice of the brain, so I just wanted to get you oriented. If we look at the other side, we can see it's completely missing. There's just, not completely, there's a little segment left, and you're also getting some thinning of the cerebral cortex here. So this condition, if you need another second, go ahead and pause it. This is going to be Huntington's and the damage that happens in the brain. This final thing, what do you think this might be? So there's normal on the left, abnormal on the right. That lower motor neuron is becoming damaged. The muscle cell is becoming weakened and atrophied. So it's not going to work effectively. If you need to pause it, go ahead and do so. But this is going to be ALS. All right, so dementia. I think you're pretty familiar with this. a group of conditions in which cortical functions decreased, issues with memory, behavioral, can lead to other conditions as well. This is probably things you see a lot. So could be vascular, could be an infection, could be genetic. The only one we're going to talk about is Alzheimer's. This chapter was so huge, I tried to just narrow it down. There's going to be more information if you want to look at the other dementia complexes, but we're just going to zip through Alzheimer's because it's the most common form. and a lot of people end up getting this unfortunately that brain tissue can degenerate and it'll actually decrease in size and it'll cause a decline in memory and mental abilities so the etiologies or the causes are not super well known but there are manifestations that happen with the brain that are very stereotypical stereotypical alzheimer's so you can get these plaques these amyloid plaques which which actually will deposit into and around the nerves which will decrease the functioning of the nerves in the brain you can get also neuro fibrillary tangles which actually has a protein called tau which will wrap around axons and dendrites and sort of clump them together almost like a scar tissue and pull them inwards so they can't function normally once again nerves don't like pressure So if you're putting pressure on them, they're not going to function properly. The connections between neurons are actually, I don't think they're necessary. Your book says they're lost, but I think sometimes the pathways aren't as efficient as they could be in somebody without Alzheimer's. Okay. So I would never ask you that on an exam. So kind of an insidious low onset can go on for years. I kept all of the manifestations here because, you know, those I think that are mentally affiliated make sense. You know, they lose their memories. They have difficulty following conversations, difficulty reading, writing, disorientation, loss of judgment, personality changes, hallucinations, incontinence of bowel and bladder are additional things that I never really thought to tie in together. But those are other. manifestations of people with Alzheimer's. So sometimes it's difficult. I've seen people progress with this and they just seem really cranky. And then a year later, they're put in the hospital for Alzheimer's. You know, some of the manifestations aren't really obvious at first, but as time goes on, it becomes more and more obvious. And then they really start to lose their memory. It's so sad. So I want you to practice just this quick little one. And this is so easy. But look at the difference. Okay, from left to right. Right is going to be normal. Left is going to be abnormal. If you need another second to pause it, go ahead and do so. But otherwise, what do you think this might be? This is going to be Alzheimer's on the left compared to the right. And see how shrunken that's become. Interesting. And so sad. All right, so brain tumors. So here's the thing. Because nerves don't like pressure, malignant or benign tumors can cause a problem. Either one can increase the intracranial pressure which can push on the surrounding tissues and cause damage. So you can have a primary malignant which will start in the brain itself or secondary due to malignancy from somewhere else. Primary tumors are thought to arise from genetic mutations. They'll usually be in the supporting glial cells or the surrounding cells. So for example, glioma glial cells these are glial cells that become cancerous meningioma is going to be from the meninges pituitary at pituitary adenoma is from the anterior pituitary usually this will be where it manifests because the posterior pituitary is nerves and we generally don't get cancer in the nerves itself acoustic neuromas i put down two because that's going to be vestibular cochlear nerve of the ear and we have that affiliated with some other conditions that we've studied previously. So you could get anything that will be affiliated with neurological deficits eventually leading to death if it's progressed enough. So it varies on, you know, the manifestations will vary depending on size and location, and it will reflect the area of the brain involved. Once again, if you have that basic understanding of the functions of the brain, you can almost localize where that. tumorous according to the manifestations so here we're looking at a pretty large tumor and this is the brain's been cut in half when we're looking at both sides i can't believe it got that big to be honest with you for example if that is in the occipital lobe and i can't tell what level that is but i'm pretty sure that's occipital and parietal you could have loss of vision with this tumor now as a sidebar i didn't really fill this in previously But I want to talk about decorticate and decerabate posturing. And if there, and the reason I didn't tie this in with anything is because it could be due to any damage to the brain and the spinal cord. It could be a tumor. It could be hemorrhage. It could be bleeding. It could be trauma. Okay. So it kind of ended up just lumping it at the end here. And we're almost at the end. You only have one more slide and then a question and you're done. But It's a little difficult to remember. So I put this in, I think this is helpful. So this is a posturing that will happen if there is damage to the brain and or the spinal cord. Decorticate. They start to form the arms like a C that moves into their core is how you remember that posturing. Usually the feet will point down as well. Sometimes the back might arch. Okay. So not only is this a C-shaped arm for decorticate, it usually will be with the cortex or cerebral hemispheres or the cervical spine. So a lot of C's there. Decorticate, arms like a C, cortex, cerebral hemispheres, cervical. Okay, and it moves you into that flexure posture. Discerabrite, okay, so you have a B in discerabrite. This is going to be somewhere in your brain stem, okay? So brain stem, discerabrite brain stem. So it could be midbrain or pods. And look at all the E's. it moves into an ex let me clear that out extensure extensor posture the arms extend the legs extend the feet point down or plantar flex okay so hopefully those little keys will help you to remember so hopefully you get that question on your boards if you get it okay so postures that happen with brain or spinal cord trauma or damage know the posturing the names and whether it's flexor extensor where it's damaged to that brings us my friends to the end of nervous system yay that was a big one so as always if you have any questions let me know let's finish up this question and then I will see you in the next set of videos so question time when dealing with brain issues this patient's symptoms will reflect the area damage which of the following is correctly paired when regarding this occipital lobe will be damaged damage will affect hearing Temporal will affect voluntary movement. Basal ganglia will affect balance and coordination. Cerebellum will affect vision. You picked the best answer, hopefully the correct one. I'll see you in the next video. This is Dr. De Chavo. If you have any questions, feel free to shoot me an email and have a great day.

burst of abnormal electrical activity in the brain. And we know that ions are going to be the substances which cross over those cell membranes in order to create an action potential. And with seizures, these action potentials happen abnormally in the brain, causing abnormal electrical activity going through circuits in the brain that don't normally get stimulated in that way.

And they could present with that loss of cognition. and the tensing and relaxing of the body but it's just interesting that we can't quite figure these out to me um now you can have us anybody could have a seizure god forbid if there's some sort of complication in your physiology but there are certain conditions that are more prone to seizures which we're going to talk about epilepsy is going to be a disorder resulting from that spontaneous abnormal firing of the neurons and they have recurrent seizures where there's no underlying or correctable cause. The one interesting thing that I've learned about this in researching and looking into seizures is there are dogs that they can train that can actually sense before a seizure happens.

So people who have seizures repeatedly will actually have one of these specially trained dogs and the dog has a signal. I think it's the dog lays down and puts her head down. It means they're going to have a seizure so that patient knows they could get to a safe place before they have their seizure. That's so amazing to me. So complications with this could be brain damage over a prolonged period of time, TBI if they fall down and they hit their head, aspiration if they vomit a little bit or even just from their saliva, and status epilepticus, which would be seizures that last longer than, 20 minutes or continual seizures can be dangerous for that patient because normal brain activity will be taken over by the seizures.

So generalized seizures, same abnormal neuronal activity, can lead to loss of consciousness, falls, or massive muscle spasms. And I'm kind of zipping through this because I'm assuming that you know most of this. So the three type that we will talk about. and I guess they have renamed them but I'm going to give you the new and the old names.

Febrile seizures are the same. They're in children usually due to a spike in fever. It's very scary I'm sure for the parents but they actually don't get any damage from it unless they have some sort of injury from falling and children usually do grow out of them.

It's probably very bread and butter stuff for you guys. Now there used to be what was called petite mal versus grand mal and the teat means small in french so this would be a teeny tiny seizure i actually had a friend who would get these absent seizures and you would have no idea she was having one she would literally just pause her eyes would get a little vacant and then she'd continue talking after a couple of seconds so they're brief they really don't cause a lot of problems other than that person you know kind of being out of it for a little bit I'm sure this could be a problem while they're driving. I don't know what the complications really are because I've never treated anybody with that. But if you're driving and have one, I'm sure that's a complication.

Now, what used to be known as grand mal are those tonic-clonic seizures where they'll have this stiffening of the body and then the repeated jerks of the arms and legs, as well as that loss of consciousness. They obviously don't have control over their bodies, so they will fall down. and it's much, much more intense than those absence seizures. We can test for these, I think, best with an EEG and see the activity of the brain.

They'll also go through and do CAT scans or maybe a contrast MRI to make sure that there is nothing, such as a tumor in the brain, complicating the situation. And I do have some pictures of these seizures disorders when we start to do a little less practice in a few slides. So MS or multiple sclerosis is an autoimmune condition. Interestingly enough, there are some links with a lack of sunlight. So it says down a little bit further, you can see most common in women, Caucasians and those living in temperate climates.

They mean people that are away from areas with a lot of sun. such as New York State where we live, unfortunately. But there is some correlation with a lack of sunlight. Maybe some vitamin D deficiencies is a possibility. They don't quite know, but they do see those correlations.

This usually happens in younger females. You can have this. We have a friend who's an older male and he has it.

So, you know, it can vary from person to person. So this is autoimmune. Somehow their immune system is going to start attacking the brain and the spinal cord and potentially the cranial nerves.

And what happens is the oligodendrocytes, which produce myelin in the central nervous system. Remember, we have Schwann cells created in the peripheral, oligodendrocytes created in the central nervous system, brain and spinal cord. The oligodendrocytes stop producing adequate myelin around the axons. And what will happen is because you don't have proper myelin there, you will also get damage to this area, which can turn into hardened sclerotic plaques.

And this is why it's called multiple sclerosis because of those plaques that take over the area where the myelin should be. So it could be diffuse patches throughout the system. There could be some that don't progress. This disease has very varying degrees of intensity. So symptoms usually between 20 and 40 years of age can also be in older people as well.

So epilepsy, paralysis, depression are all complications from this disease. So manifestations, the manifestations with this will vary depending on how much of the central nervous system is affected. but they also have remissions and exacerbations so and once again this is super variable from person to person one thing that i didn't put in there that i really would like to is that vision is usually is one of the first things to be affected it can be very insidious You know, a patient might say, I'm looking somewhere and it goes in and out of focus.

You know, it's as simple and as short as that. Okay. Also, fine motor skills.

They'll say, yeah, I pick up my coffee and I drop it. Or I pick up my brush and I drop that. You know, fine motor skills are one of the first things to go.

Okay. So fever, hot mass, sun exposure, stress can trigger or worsen episodes, may progress without remissions, may totally remit and then not come back. So the degree of variation is huge with MS. Parkinson's disease is a progressive involvement with what is called the substantia nigra in the midbrain. And the substantia nigra in the midbrain. I thought I had put in a picture here of this, the substantia nigra in the midbrain.

Okay, so I'm going to pause the tape here. I'm going to get you that picture of substantia nigra. I think it may have not saved.

I'll be back in just a second. I am back, and I got a picture of the substantia nigra. So the substantia nigra is part of that basal ganglia, also known as basal nuclei, that help to coordinate our movements.

It helps with some emotional responses as well. And the substantia nigra actually is in the midbrain. So this is a little tough to understand this, but this is the bottom of the brain.

Okay. And what they've done is they've sectioned right at the midbrain. So we're just above the pons, right in the midbrain. And this right here, these two dark areas are the substantia nigra. And this is what releases dopamine.

And dopamine is a neurotransmitter, which is very important to help with the correlation and coordination of voluntary movements. People with Parkinson's you can see the reduced substantia nigra and so if we have less substantia nigra we don't produce as much dopamine okay so just to give you a visual of where that happens and that's deep in the brain and that gray matter deep in the brain which we had learned about previously okay so they have a lack or a decrease in the amount of dopamine when approximately 80% of the dopamine producing cells are destroyed movements and issues including tremors of the hands and head develop so the head moves and the hands move unless they're intentionally moving if they stimulate that voluntary motor pathway what will happen is they will actually stop those tremors it's very interesting okay so there's that picture of substantia nigra those two little bands of gray matter part of the basal nuclei or ganglia. So manifestations are very obvious. They may not be initially, but as it progresses, they will start to present with slowing or stopping of automatic movement, such as blinking.

They'll have difficulty swallowing, so therefore they may drool a little bit. They have a very unsteady gait or a shuffling gait. And they may actually slap their foot down a little bit because they know that they're having difficulty with that gait and it helps them to feel the floor a little bit better. With that, I'm also going to add stooped posture.

Okay, so they usually tend to build bend forward because once it. they're having difficulty with that walking so they're trying to balance themselves out okay they'll also have a pill rolling or resting tremors and their head may shake back and forth but as they intentionally start to move those tremors go away so they are known as resting tremors they also have a mask like appearance in their face which means they don't respond Usually in conversation, somebody says something, you're like, oh, all right. You know, you have a response.

They don't. And they may be feeling those emotions, but they're not showing it on their face. All right.

So let's practice. I put some pictures together. Which is which?

So out of those diseases that we just spoke about, this one. So think about what we've talked about, what manifests in here. This may be a little tough at first. If you need to pause the tape, go ahead and do so.

But what we're seeing there is those plaques that we'll see with multiple sclerosis. And where all four arrows are, they start to show a brighter appearance because of that scarring or plaquing. That happens, it starts to replace the myelin location on the axons.

It shows up whiter on an MRI. What do you think this condition might be? And I left the words in there because it might be a little hard to understand what he's doing. But this petite mal or absence seizure is just as simple as that. It's almost like somebody is pausing to think for a minute and then they continue on with their normal conversation.

What condition do you think this might be? So you can't see it, but mask-like faces is written there, that stooped posture. Rigidity, short shuffling steps, tremor at rest, might be forward flex, okay, tremor of head and hands. And this indeed is Parkinson's disease.

This one you're going to be like, got this, okay. So these are going to be seizures, okay, tonic-clonic seizures. So tonic phase is that tightening where they hold.

And then clonic is when they start to go into that jerking of the limbs. And they have other things listed there. I want you to know that tonic is that held contraction, and clonic is when they alternate their contractions back and forth. So that would be what used to be known as grand mal.

All right. Now, before we move into the next set of notes, I wanted to go over an important concept. and this applies to the next condition called upper motor neuron versus lower motor neuron okay so don't let this blow your brain too much it's actually pretty simple but it's an important concept clinically that we need to speak about hmm So an upper motor neuron is just that. It is the motor nerve that comes from the primary motor cortex in the frontal lobe. And it's going to come down the cord to the front of the cord at whatever level it's going out to.

And remember, you have these coming out at each vertebral level. So don't worry about the vertebral level. It just is going to come to the cord at whatever level it's going to go out to. That is the upper motor neuron. Okay.

There's a second nerve in this pathway. There's just two with motor. The second one comes from the front part of the cord out to whatever muscle it's going to.

This is, you got it, lower motor neuron. Okay. With upper motor neuron.

If this gets damaged, so you have some sort of cord trauma, you could even have a stroke that damages the motor cortex, whatever it may be along that upper motor neuron pathway, if that nerve gets damaged, your patient's going to have spastic paralysis because basically this upper motor neuron will either turn motions on or off. so if it can't turn your motions on or off you get paralysis but you can get involuntary spasticity just as if somebody starts to move back into that fetal position excuse me now this is compared to lower motor neuron which gives us flaccid paralysis this lower motor neuron simply turns the muscle on so if this gets damaged what will happen is you can't send any signal out and you get flaccid paralysis where a patient has a limp extremity that they have no control over okay so upper motor neuron versus lower motor neuron and that's what differentiates plastic versus spastic versus flaccid the reason i wanted to go over that is because now we're going to go into als this is also known as lugeric's disease lugeric's disease can affect either that upper motor neuron the lower motor neurons so they might have spasticity or they might have flaccid paralysis either way it only affects the motor portion so it'll be from the motor cortex down to the front of the cord because once again the front of the cord is motor excuse me so nerves continue to lose their ability to trigger muscle movement which will eventually lead into weakness and possibly death this can lead to paralysis the diaphragm too And intercostal muscles so they are not able to breathe without help This also can increase the risk of dementia. Okay unknown disease, but we're thinking once again, it's probably autoimmune So the way that it manifests is it'll begin and then slowly progress over time You'll lose upper motor neurons which will cause that spastic paralysis. And also hyperreflexia is a good thing to remember with upper motor neurons as well. There's also superficial reflexes.

You'll probably learn an orthoneural that can present with upper motor neuron lesion. And then that flaccid paralysis with the lower motor neurons. So you could have foot drop, which simply means when they're walking, instead of...

bringing their toes up to their shin, which is what we all do when we're walking, it drops down. So they actually get kind of a slapping gait where they bring their foot up and slap it down to make sure they can you know move their foot through and get it onto the floor. Weakness, hand weakness, muscle cramps, difficulty swallowing, difficulty speaking because of difficulty moving the tongue.

So any of those motor manifestations. Myasthenia gravis is this really odd autoimmune condition that attacks what are known as acetylcholine receptors. Now I'm not going to get too much into neurotransmitters because that's a whole other lecture, but acetylcholine is a neurotransmitter that goes to voluntary muscles and the receptor that accepts acetylcholine on the muscles in patients with myasthenia gravis gets damaged or destroyed or they get fewer of them okay so they have a few you know suppose you're supposed to have a million on your muscles they only have 500,000 or whatever it means I don't know the exact number numbers but so those receptors for acetylcholine get destroyed so the muscles can't be fully stimulated so they tend to feel weak and not want to be very active So this will affect voluntary skeletal muscles.

50% will develop ptosis, or I shouldn't say ptosis, it's ptosis, sorry. You're not supposed to say the P, it's a very big no-no, which is drooping of the eyelid. Okay, so muscle weakness typically increases during periods of activity, improves after periods of rest, and they can build up some acetylcholine again.

So. muscles, any of those voluntary muscles can be affected. Okay.

And this actually can progress to myasthenic crisis, which is when the muscles become too weak to maintain respiration. Okay. And we'll take a look at that in a little bit.

Huntington's disease, also known as Huntington's chorea. And chorea is an involuntary, unpredictable movement in a patient. You can have chorea and other conditions and almost like this slow writhing kind of movements. I know there's some medicine, it's an antipsychotic that they used to give in the 70s, maybe the 80s that presented them that actually created a permanent chorea in patients.

And they have the kind of this, I'm sure you've probably seen some writhing movements of the mouth. So there's a genetic link with this. This is autosomal dominant disorder which has a defect on chromosome four so this causes degeneration of the nerves in the brain particularly in the i cannot talk today okay particularly in that basal ganglia and the frontal cortex which will cause difficulty once again with the control of their voluntary motor reactions and movements So usually slow, there's such a strong genetic link that usually if a parent has it, the child will get it. So mood swings, obviously they can become irritable if it's attacking that frontal lobe, that's where their personality is. And you start to get those uncontrolled rapid jerky movements in the fingers, feet, hands or trunk can also lead to dimension, other cognitive dysfunctions.

So let's practice some of these. What two conditions do you think we're comparing below, left to right? If you need to pause the tape, go ahead.

Otherwise, I'm going to uncover the answer. So these two conditions are your upper motor neuron, which gives you that spasticity or the tightness in the hands, arms, legs, feet, versus the lower motor neuron, which will give you that flasticity and hypotonia, which would be... muscles that are becoming atrophied and weak and what condition might you think this is here's probably your best clinical okay right that's going to be ptosis if you need a positive go ahead and do so and these are the acetylcholine receptors that i spoke about and what happens with our condition is antibodies attack those receptors and destroy them or make them inefficient.

So what do you think this is? Yep, this is going to be myasthenia scrabus, this condition. So just to get you oriented, this would be normal.

This would be abnormal. This is a basal ganglia that we spoke about previously. We looked at from a different view.

This is a slice of the brain, so I just wanted to get you oriented. If we look at the other side, we can see it's completely missing. There's just, not completely, there's a little segment left, and you're also getting some thinning of the cerebral cortex here. So this condition, if you need another second, go ahead and pause it. This is going to be Huntington's and the damage that happens in the brain.

This final thing, what do you think this might be? So there's normal on the left, abnormal on the right. That lower motor neuron is becoming damaged.

The muscle cell is becoming weakened and atrophied. So it's not going to work effectively. If you need to pause it, go ahead and do so. But this is going to be ALS.

All right, so dementia. I think you're pretty familiar with this. a group of conditions in which cortical functions decreased, issues with memory, behavioral, can lead to other conditions as well.

This is probably things you see a lot. So could be vascular, could be an infection, could be genetic. The only one we're going to talk about is Alzheimer's. This chapter was so huge, I tried to just narrow it down.

There's going to be more information if you want to look at the other dementia complexes, but we're just going to zip through Alzheimer's because it's the most common form. and a lot of people end up getting this unfortunately that brain tissue can degenerate and it'll actually decrease in size and it'll cause a decline in memory and mental abilities so the etiologies or the causes are not super well known but there are manifestations that happen with the brain that are very stereotypical stereotypical alzheimer's so you can get these plaques these amyloid plaques which which actually will deposit into and around the nerves which will decrease the functioning of the nerves in the brain you can get also neuro fibrillary tangles which actually has a protein called tau which will wrap around axons and dendrites and sort of clump them together almost like a scar tissue and pull them inwards so they can't function normally once again nerves don't like pressure So if you're putting pressure on them, they're not going to function properly. The connections between neurons are actually, I don't think they're necessary. Your book says they're lost, but I think sometimes the pathways aren't as efficient as they could be in somebody without Alzheimer's.

Okay. So I would never ask you that on an exam. So kind of an insidious low onset can go on for years.

I kept all of the manifestations here because, you know, those I think that are mentally affiliated make sense. You know, they lose their memories. They have difficulty following conversations, difficulty reading, writing, disorientation, loss of judgment, personality changes, hallucinations, incontinence of bowel and bladder are additional things that I never really thought to tie in together. But those are other.

manifestations of people with Alzheimer's. So sometimes it's difficult. I've seen people progress with this and they just seem really cranky. And then a year later, they're put in the hospital for Alzheimer's. You know, some of the manifestations aren't really obvious at first, but as time goes on, it becomes more and more obvious.

And then they really start to lose their memory. It's so sad. So I want you to practice just this quick little one. And this is so easy. But look at the difference.

Okay, from left to right. Right is going to be normal. Left is going to be abnormal.

If you need another second to pause it, go ahead and do so. But otherwise, what do you think this might be? This is going to be Alzheimer's on the left compared to the right.

And see how shrunken that's become. Interesting. And so sad.

All right, so brain tumors. So here's the thing. Because nerves don't like pressure, malignant or benign tumors can cause a problem.

Either one can increase the intracranial pressure which can push on the surrounding tissues and cause damage. So you can have a primary malignant which will start in the brain itself or secondary due to malignancy from somewhere else. Primary tumors are thought to arise from genetic mutations.

They'll usually be in the supporting glial cells or the surrounding cells. So for example, glioma glial cells these are glial cells that become cancerous meningioma is going to be from the meninges pituitary at pituitary adenoma is from the anterior pituitary usually this will be where it manifests because the posterior pituitary is nerves and we generally don't get cancer in the nerves itself acoustic neuromas i put down two because that's going to be vestibular cochlear nerve of the ear and we have that affiliated with some other conditions that we've studied previously. So you could get anything that will be affiliated with neurological deficits eventually leading to death if it's progressed enough.

So it varies on, you know, the manifestations will vary depending on size and location, and it will reflect the area of the brain involved. Once again, if you have that basic understanding of the functions of the brain, you can almost localize where that. tumorous according to the manifestations so here we're looking at a pretty large tumor and this is the brain's been cut in half when we're looking at both sides i can't believe it got that big to be honest with you for example if that is in the occipital lobe and i can't tell what level that is but i'm pretty sure that's occipital and parietal you could have loss of vision with this tumor now as a sidebar i didn't really fill this in previously But I want to talk about decorticate and decerabate posturing. And if there, and the reason I didn't tie this in with anything is because it could be due to any damage to the brain and the spinal cord. It could be a tumor.

It could be hemorrhage. It could be bleeding. It could be trauma. Okay. So it kind of ended up just lumping it at the end here.

And we're almost at the end. You only have one more slide and then a question and you're done. But It's a little difficult to remember.

So I put this in, I think this is helpful. So this is a posturing that will happen if there is damage to the brain and or the spinal cord. Decorticate. They start to form the arms like a C that moves into their core is how you remember that posturing. Usually the feet will point down as well.

Sometimes the back might arch. Okay. So not only is this a C-shaped arm for decorticate, it usually will be with the cortex or cerebral hemispheres or the cervical spine.

So a lot of C's there. Decorticate, arms like a C, cortex, cerebral hemispheres, cervical. Okay, and it moves you into that flexure posture.

Discerabrite, okay, so you have a B in discerabrite. This is going to be somewhere in your brain stem, okay? So brain stem, discerabrite brain stem. So it could be midbrain or pods. And look at all the E's.

it moves into an ex let me clear that out extensure extensor posture the arms extend the legs extend the feet point down or plantar flex okay so hopefully those little keys will help you to remember so hopefully you get that question on your boards if you get it okay so postures that happen with brain or spinal cord trauma or damage know the posturing the names and whether it's flexor extensor where it's damaged to that brings us my friends to the end of nervous system yay that was a big one so as always if you have any questions let me know let's finish up this question and then I will see you in the next set of videos so question time when dealing with brain issues this patient's symptoms will reflect the area damage which of the following is correctly paired when regarding this occipital lobe will be damaged damage will affect hearing Temporal will affect voluntary movement. Basal ganglia will affect balance and coordination. Cerebellum will affect vision. You picked the best answer, hopefully the correct one.

I'll see you in the next video. This is Dr. De Chavo. If you have any questions, feel free to shoot me an email and have a great day.

Transcript for:Seizure Disorders and Neurological Conditions Overview

Transcript for:
Seizure Disorders and Neurological Conditions Overview