3 ms·

Wow.. Wow wow wow. I had no idea this was even remotely possible... I would never have imagine that the nervous system alone would be able to adjust. This is i

Wow.. Wow wow wow. I had no idea this was even remotely possible... I would never have imagine that the nervous system alone would be able to adjust. This is incredible. I'm really curious now if there have been other transplants like this before with similar results? > The nerve begins to send signals, it is called reinnervation, and the muscles function according to body needs. Also, is this just letting the body 're-connect' or is this some specific medical process to achieve ? Either way this is incredible!

hinkley 7y ago
Are you talking about the general case of attaching nerves or the specific case of the physiological changes here? From the article they seemed to be describing well known phenomena regarding peripheral nerves. The myelin sheath can survive detachment, the nerve does not. With finger re-attachment, a very talented surgeon reattaches the sheathes, and new nerves grow down the channel, at a rate of about an inch a month (mentioned in passing in the article). So for a finger, with some luck you should be able to feel your fingertips in a few months. The arms would have taken a year or more. (I can't imagine what that feels like, emotionally). There's also a lot of plasticity in the brain. I'd heard of cases where a badly seared finger has a patch of skin grafted from the side of another finger to restore tactile function. They move the skin patch with the nerves still attached, and at first your brain tells you that the side of your finger is being touched. With rehab your brain eventually believes that the sensation now happening to your thumb actually occured on your thumb. But she would have had to do this for the whole lower arm, twice.
- bilekas 7y ago
  Again.. I am blown away. > well known phenomena regarding peripheral nerves. This for starters has my mind blown, but I was curious if they were using techniques that were enhancing that. > new nerves grow down the channel, at a rate of about an inch a month Again, amazing! I guess I just never appreciated how amazing the body really is. I always take it for granted of course, but the nervous system for me was always like a webbing, that if broken could never grow back. Insane, thank you for the info! And again, credit to her and her physicians, nurses and donor. Amazing!
  - liveoneggs 7y ago
    https://youtu.be/Nlreep7UDIc?t=171 https://youtu.be/Nlreep7UDIc?t=171
    - bilekas 7y ago
      We need more Simpsons & Futurama references in the world! Thanks for bringing a smile!
- tempestn 7y ago
  Does this same process not work for a severed spinal cord? Or would it just take a prohibitively long time? Or.. can severed spinal cords be repaired now?
  - hinkley 7y ago
    I never quite understood this. I mostly remember that it was important to some people to distinguish between the peripheral and central nervous system when discussing how it behaves https://en.m.wikipedia.org/wiki/Neuroregeneration https://en.m.wikipedia.org/wiki/Neuroregeneration has a bit, about the central nervous system being actively hostile to regrowth. It also says I was off about the myelin sheath - it’s the next layer of tissue that surrounds the myelin sheath that survives. The sheath itself also begins to break down post-trauma, apparently.
  - isaacgreyed 7y ago
    Not the most credible evidence, but from some reading long ago I can't find. I think it has to do with the way spines break it damages the nerve endings. If you were to slice the spine with a sufficiently sharp blade I believe they would regrow.
- webmobdev 7y ago
  I came to ask about this too - the nerves. The article briefly explains how the doctors did the surgery - The hand of the donor was first attached by bone, then arteries, veins and tendon muscles before the skin was stitched to Shreya’s upper limb. But says nothing about the nerves. I had read that nerve damage is irreparable. Then there is the fact that that the human body also attacks transplanted organs. So I am really curious what happens in such cases - will she ever have full nerve functions in the transplanted hand and will her body start rejecting her hand?
  - hinkley 7y ago
    That is a curious omission. I think the wiki page I linked below or another doc I tried to find something more accurate (than my recollection of fifteen year old medical documentaries) said that the regrown nerves are often weaker. Something is better than nothing. Now that you mention it, something about the article bothered me regarding rejection too. She said that they told her they had a blood type match to a donor. I was under the impression that there were much more precise tissue matching criteria that reduce the rate and chance of rejection. But second or third hand medical info can be pretty awful. She was likely much more focused on “I get to feed myself again” than medical accuracy. That guy who got the first hand transplant, I hear they were removed again. I believe he said that they started to itch so bad when rejection started that he took the doctors’ advice.
jussij 7y ago
> I'm really curious now if there have been other transplants like this before with similar results? Sometimes the results are not so good: https://time.com/4419959/double-hand-transplant-surgery/ https://time.com/4419959/double-hand-transplant-surgery/ This link describes a transplant patient who did not achieve a similar level of success. However since his surgery dates back to the very early days of this medical procedure, I suspect over time the process has improved and current surgery patients end up with better outcomes.
- hinkley 7y ago
  For a moment I thought this was the guy I was thinking of, and was shocked I never heard he couldn’t use them. But the guy I’m thinking of had a drunken encounter with fireworks, not sepsis. I recall being mad that the first recipient was just some random fool instead of a wounded hero. But a fool is probably easier to talk into a crazily experimental procedure...

hinkley 7y ago

Are you talking about the general case of attaching nerves or the specific case of the physiological changes here? From the article they seemed to be describing well known phenomena regarding peripheral nerves. The myelin sheath can survive detachment, the nerve does not. With finger re-attachment, a very talented surgeon reattaches the sheathes, and new nerves grow down the channel, at a rate of about an inch a month (mentioned in passing in the article). So for a finger, with some luck you should be able to feel your fingertips in a few months. The arms would have taken a year or more. (I can't imagine what that feels like, emotionally). There's also a lot of plasticity in the brain. I'd heard of cases where a badly seared finger has a patch of skin grafted from the side of another finger to restore tactile function. They move the skin patch with the nerves still attached, and at first your brain tells you that the side of your finger is being touched. With rehab your brain eventually believes that the sensation now happening to your thumb actually occured on your thumb. But she would have had to do this for the whole lower arm, twice.

bilekas 7y ago
Again.. I am blown away. > well known phenomena regarding peripheral nerves. This for starters has my mind blown, but I was curious if they were using techniques that were enhancing that. > new nerves grow down the channel, at a rate of about an inch a month Again, amazing! I guess I just never appreciated how amazing the body really is. I always take it for granted of course, but the nervous system for me was always like a webbing, that if broken could never grow back. Insane, thank you for the info! And again, credit to her and her physicians, nurses and donor. Amazing!
- liveoneggs 7y ago
  https://youtu.be/Nlreep7UDIc?t=171 https://youtu.be/Nlreep7UDIc?t=171
  - bilekas 7y ago
    We need more Simpsons & Futurama references in the world! Thanks for bringing a smile!
tempestn 7y ago
Does this same process not work for a severed spinal cord? Or would it just take a prohibitively long time? Or.. can severed spinal cords be repaired now?
- hinkley 7y ago
  I never quite understood this. I mostly remember that it was important to some people to distinguish between the peripheral and central nervous system when discussing how it behaves https://en.m.wikipedia.org/wiki/Neuroregeneration https://en.m.wikipedia.org/wiki/Neuroregeneration has a bit, about the central nervous system being actively hostile to regrowth. It also says I was off about the myelin sheath - it’s the next layer of tissue that surrounds the myelin sheath that survives. The sheath itself also begins to break down post-trauma, apparently.
- isaacgreyed 7y ago
  Not the most credible evidence, but from some reading long ago I can't find. I think it has to do with the way spines break it damages the nerve endings. If you were to slice the spine with a sufficiently sharp blade I believe they would regrow.
webmobdev 7y ago
I came to ask about this too - the nerves. The article briefly explains how the doctors did the surgery - The hand of the donor was first attached by bone, then arteries, veins and tendon muscles before the skin was stitched to Shreya’s upper limb. But says nothing about the nerves. I had read that nerve damage is irreparable. Then there is the fact that that the human body also attacks transplanted organs. So I am really curious what happens in such cases - will she ever have full nerve functions in the transplanted hand and will her body start rejecting her hand?
- hinkley 7y ago
  That is a curious omission. I think the wiki page I linked below or another doc I tried to find something more accurate (than my recollection of fifteen year old medical documentaries) said that the regrown nerves are often weaker. Something is better than nothing. Now that you mention it, something about the article bothered me regarding rejection too. She said that they told her they had a blood type match to a donor. I was under the impression that there were much more precise tissue matching criteria that reduce the rate and chance of rejection. But second or third hand medical info can be pretty awful. She was likely much more focused on “I get to feed myself again” than medical accuracy. That guy who got the first hand transplant, I hear they were removed again. I believe he said that they started to itch so bad when rejection started that he took the doctors’ advice.

jussij 7y ago

> I'm really curious now if there have been other transplants like this before with similar results? Sometimes the results are not so good: https://time.com/4419959/double-hand-transplant-surgery/ https://time.com/4419959/double-hand-transplant-surgery/ This link describes a transplant patient who did not achieve a similar level of success. However since his surgery dates back to the very early days of this medical procedure, I suspect over time the process has improved and current surgery patients end up with better outcomes.

hinkley 7y ago
For a moment I thought this was the guy I was thinking of, and was shocked I never heard he couldn’t use them. But the guy I’m thinking of had a drunken encounter with fireworks, not sepsis. I recall being mad that the first recipient was just some random fool instead of a wounded hero. But a fool is probably easier to talk into a crazily experimental procedure...