In a podcast released yesterday, Robert J. Marks, director of the Walter Bradley Center, interviewed Dr. Andrew Knox, a pediatric neurologist at the University of Wisconsin School of Medicine and Public Health, about “How the Brain Breaks Down.” #220, 5 January 2023).
The following reflects Part 2 of the discussion. Part 1 is below: How our brains are like computers (and aren’t they).
This part starts at approximately 10:50 minutes. A partial transcript and notes and additional resources follow.
Andrew Knox: All of these patients can lose the ability to move their arms on one side of the body if the stroke occurs in an area that has connections to motor pathways through the rest of the body, called the primary motor cortex. their feet, or their faces, or all three.
Robert J. Marks: Now some of the things I think people can recover from. Have you heard of the term neuroplasticity? It’s like if one part of your brain stops working, another part takes over. I think it may not be cured, but it may be cured. Does neuroplasticity play a role?
Andrew Knox: Yes, absolutely. In fact, if there is damage to that part of the brain, there aren’t many areas that other parts of the brain can’t take over.
Andrew Knox: There are some special areas. Areas associated with language are to some extent less plastic. Visual pathways are kind of hard-coded into your brain. [for] In the case of a stroke in the primary visual area, recovery of normal visual acuity cannot be expected thereafter. The same is true for the primary motor cortex. Long-term motor deficits are usually expected when there is a stroke in the primary motor cortex.
Robert J. Marks: motor area? Something that only affects how you move your arms and legs, or something like that?
Andrew Knox: yes. These are kind of the big three. There are similar sensory areas. If you have a stroke in your primary sensory cortex, you may always have trouble feeling things like your right hand or right leg. But again, these are specific exceptions to the more general rule that the brain is good at moving functions between different regions.
Robert J. Marks: It’s just amazing to me. For example, I’ve seen blind people who don’t use the neurons they’re supposed to use for vision. They developed the ability to hear echoes like bats by simply entering a room and clicking. And actually “see” — through Echo — their environment. I think some of the other things you’re talking about are a little more subtle. You’ll see some recovery, but not as much as you click.
Note: Dr. Marks mentions the human use of echolocation, a highly developed skill in bats, but largely ignored by sighted humans. Some blind humans have developed it as a skill. See, for example, “Batman is real, but not in the comics.”
Andrew Knox: It’s a different kind of coping. They have not regained their previous abilities, but have developed a different set of abilities. If you lose your sight, your hearing may become sharper and better. We may develop a way to use it instead of other functions. But I was actually talking more about restoring previous function. can recover to some extent — even if those neurons haven’t grown back. So those connections could be stronger and better usable.
Robert J. Marks: Is that so. Is there a difference between adapting to what you weren’t born with and adapting to what you’ve lost due to a stroke or something?
Andrew Knox: I see both adapting to loss of function by developing new functions that otherwise would not have developed, and adapting the brain to regain the function you lost, the same function. distinguish between
Heder: Neuroplasticity and Stroke, Childhood Dementia
Robert J. Marks: So what is the main cause of stroke in children? Is it genetic? Was it an accident that happened to them?
Andrew Knox: It’s a spectrum of things. Infection may actually be a common cause or an immune response to infection. A clotting disorder may be a common cause. There is a disease called sickle cell disease that can be a common cause of stroke in children.
In fact, there are many children today with significant heart deformities and congenital heart problems. prize. Now they can actually live a relatively full life. One consequence of their heart disease is that they are more likely to develop blood clots that can cause stroke.
Robert J. Marks: One of the causes of brain damage is dementia. I always associate dementia with old age, can a child get dementia?
Andrew Knox: Some children have dementia. Dementia is a little different than stroke. Stroke, the idea that a particular part of the brain is damaged and loses the functions associated with that particular area of the brain. I have a problem giving. So it’s not a specific area of the brain. It’s the whole brain. Not all neurons in the brain are lost at the same time, but neurons throughout the brain gradually begin to be damaged. It causes a different kind of change, and we see a loss of cognitive function over time.
Robert J. Marks: So can we say that dementia is decentralized whereas stroke is localized?
Andrew Knox: That’s right, out of focus.Now, there are exceptions to everything in neurology, but I think that’s a good way to think about dementia. [problems] Or problems with cellular processes that lead to things like dementia. In adults, it is much more likely to be part of the natural aging process.In children, it usually requires certain disorders that trigger early onset of dementia.
Note: One cause of childhood dementia is a rare genetic disorder called Batten’s disease.
Robert J. Marks: So is it gradual?
Andrew Knox: Gradually. Stroke effects can be seen over minutes to hours. Dementia usually affects people over months to years.
Again, adults don’t necessarily lose specific functions on one side of their bodies, but they do see such effects. Diffuse Neuron loss. With more global cognition, we see problems with paying attention, problems with memory, problems with understanding the world around us, and so on. Some of these symptoms can follow a very interesting progression and can give insight into how the brain works.
Next: How do stroke and dementia provide insight into how the brain works?
You may also want to read: Part 1: How our brains are like computers (and aren’t they). A pediatric neurologist, Andrew Knox, is a computer engineer and his engineer explores the topic with Robert J. Marks. The conversation drifts to a stroke. This is his one of the ways brains “break” even in children.
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