I would strongly question the idea that he has "no structural abnormality".
It would be very interesting to see exactly what type of imaging they performed on him. Bear in mind, an abnormality in the hippocampus or other memory related structures could be sub-mm in size and result in a significant impairment.
If, for example, he did not have an MRI with diffusion weighted imaging with a sufficiently high B value (gradient value) they may be missing/have missed a very small stroke (this test is also time sensitive -only positive within the first few days of insult).
If they did not perform susceptibility weighted imaging, they may have missed a tiny micro-haemorrhage. Both of these scenarios can result in memory loss if critical structures are involved.
There are also several technical issues that may have resulted in a sub-optimal scan, precluding finding a tiny abnormality. There's also the question of whether the person reading the scan got it right or whether the strength of the magnet/technical parameters of the study were sufficient to resolve a tiny abnormality.
Either of these scenarios could have been a consequence of reduced blood flow (hypoperfusion), a small clot (embolus) or a tiny blood vessel injury (dissection) that could have occurred during the procedure - possibly related to the anaesthetic but not definitively so.
I suspect there is a definitive abnormality that the clinicians that saw him were unable to pick up. This seams a lot more likely than the idea that we need to revise our entire conceptualisation of memory formation to suit a psychological theory.
Not to deny what you're saying, because I believe a key tenet of biology is that structure follows function, but how would the structural abnormality be caused by the operation?
The doctors initially suspected that he’d reacted badly to the anaesthetic, causing a brain haemorrhage – yet they failed to find evidence of injury. So he was discharged with the mystery still hanging over him, and the family moved back to England, where he was referred to the office of Gerald Burgess, a clinical psychologist in Leicester.
Scouring the medical literature, he found five similar cases of mysterious memory loss without brain damage. Although none occurred during a trip to the dentist, they do seem to follow other periods of physiological stress during a medical emergency.
That doesn't prove that the anaesthetic isn't the root cause. The article title sounds link-baity.
Earlier this year I had a medical procedure and was given "twilight" anesthesia. I was explicitly told "you need to have your spouse or a friend here because we're going to give you instructions afterward and you probably won't remember it".
And, sure enough, my memory was pretty much wiped for the hour or so after the event. Later that evening I had a conversation with my wife that went like this:
"Um, did you help me with putting my clothes back on?"
"Um, no. You did that."
"Did I talk to you and the doctor?"
"Sure. Normal conversation."
I have no recollection of these events at all. It gave me an uneasy feeling for a day or so. Nothing traumatic but every time I tried to reach back and think about that post-op period I drew and continue to draw a complete blank.
This seems to be yet another case of HN users upvoting dubious link-bait scientific press-releases. This particular one has been posted 3 times this week.
Not only link-baity, but also blaming the doctor. Large percentage of the large percentage of people who won't read the article will move away with a inconsciouss (at least) fear of medical interventions.
Yeah, I've got a friend who had a brain haemorrhage with similar memory effects. It wouldn't surprise me if that had happened on a small scale and they just failed to detect the damage. I presume they use a brain scan and it can only pick up certain types / sizes of damage.
Oliver Sacks, in his wonderful essay collection "The Man Who Mistook His Wife For a Hat" [1], describes a similar case of a soldier, "Jimmy G.", who lost his ability to form memories after being wounded in 1945. Every half an hour or so his memory resets, and so 20 or 30 years later he still thinks that he's an 18 year-old man who just got wounded in the war. There's a particularly poignant moment in the story where his brother comes to visit the man in hospital in the 1970s, and how Jimmy is puzzled why his brother looks so old.
Another well-known case of retrograde amnesia is Clive Wearing, a British pianist who was the subject of a BBC documentary, "Man Without a Memory" [2]. I recommend watching the clip. He describes his "resets" rather terrifyingly as slowly emerging from a sleepless coma. Whenever he sees his wife after such a reset, he leaps up to greet her as if they have been apart for a long time, and his evident happiness and inability to recognize his situation is heartbreaking. (His wife, unbeknownst to him, of course, has since divorced him, which only adds to the poignancy of the scene.)
This is the condition that was described in Memento. Really fascinating stuff. It makes me want to keep notes on everything, because most people rely on their memory for a lot of things. When we forget something we are frustrated "Oh darn, I forgot it again!". Imagine not being able to remember anything at all...
In a talk that I attended, Steve Wozniak mentioned that he studied a lot of psychology when he returned to the university after leaving Apple. He thinks that he may have been the first person to have come up with idea that we lose our memories with our teeth, and that researchers later discovered a link between the loss of our early autobiographical memories and the loss of our baby teeth.
He says in his autobiography that he was in a plane crash. That was the reason for leaving apple. He suffered from memory loss, so probably that is the reason for his interest in psychology.
From wiki:
"Wozniak sustained severe face and head injuries, including losing a tooth, and also suffered for five weeks after the crash from anterograde amnesia, the inability to create new memories. He had no memory of the crash, and did not remember his name in the hospital or the things he did after he was released from the hospital."
A few comments in this thread mention "genera anaesthesia side effects" and long-term problems. I have never heard of this and a quick wikipedia/google search is not bringing up good source on the topic. Is this substantiated or another "vaccines cause autism" kind of thing?
General anaesthesia is actually somewhat dangerous.
Your chance of dying from anaesthesia is around 1 in 100,000 - 185,000. While it may seem like a safe number, it's orders of magnitude higher than winning a major lottery.
That number also doesn't include medical fuckups during anaesthesia, like overdose, airway obstruction. In that case the number shoots up to 1:2500 - 1:5000.
There was recent news on the detrimental effects of general anesthesia has on the very young and old. Apparently it can be neurotoxic but healthy adults don't seem to have long lasting problems.
It seems possible, due to what is used for general anesthesia. However, the person in the story was not given general anesthesia, only a local anesthetic.
>he wakes up every morning believing he is still in Germany in 2005, waiting to visit the dentist. Without a record of new experiences, the passing of time means nothing to him. Today, he only knows that there is a problem because he and his wife have written detailed notes on his smartphone, in a file labelled “First thing – read this”.
Much like the movie, yes, though in her case it was a daily, not an hourly, thing. It's nice that the film seems to be based on a real-life condition and portrays it fairly accurately.
If no link can be found between the dental surgery and the memory-forming loss, could it be that there is actually no link? Have any other hypotheses been researched besides the surgery?
Most people took a little bit of time to get familiar with smartphone UIs, especially for someone who's jumping from no smart phone at all to the latest version of iOS and Android. I wonder if he has been slowly learning how to use a smartphone like the other condition, or if he has to rediscover the UI every time.
I believe the memory used to retain skills is separate from other types of memory. There was a famous patient, Henry Molaison[0] who was the first person to suffer this condition and participated in some really amazing research. He was able to learn new skills, albeit slowly.
"His ability to form long-term procedural memories was intact; thus he could, for example, learn new motor skills, despite not being able to remember learning them."
Damaging my mind is my biggest fear. I had a simple surgery a year ago(shoulder arthroscopy), and I specifically said that I don't agree to general anesthesia or any kind of sedatives, because even a small probability of a small brain damage isn't worth it for me.
Doctors tried to push me into accepting the general anesthesia, saying that it's the only option(and that we lose brain cells every day really, so who cares). I went to a different clinic where a doctor agreed to do the surgery under local anesthetics and without sedation without any problems. Said someting along the lines "don't worry, man, your brain is gonna be fine."
He failed to mention that local anesthesia can also lead to neurotoxicity, and I was too ignorant to know about it(for some reason I assumed that local anesthetics are harmless, and didn't do my research).
During the surgery I felt the symptomps(dizziness, difficulty speaking), consistent with neurotoxicity caused by local anesthetics.
I don't notice any permanent damage, though I doubt that I'd be able to tell. 6 months after the surgery I have developed tinnitus, but I can't tell if it's connected to it or not.
Anyway, my point is that no way in hell would I agree to the surgery if I'd have known the risks.
Also, before that, doctors pushed me into unnecessarily taking general anesthesia for a routine procedure. They convinced me that it can't be harmful, and I was too young and socially awkward to ask more questions or argue.
I also fear dental anesthetics. There is research indicating that they can cause neurotoxocity. I can easily sit through filling regular cavities(with a dental laser it really isn't that painful), but I'm not sure what I would do if I have to get root canal. I would take any option over anesthesia, but I don't know of any alternative.
Some doctors say that it's just an irrational fear. But given that there's some research saying that even dental anesthesia can cause neurotixicity, I'm not sure what's so irrational about not wanting my brain cells to die. My brain is what matters to me the most in the world, far more than anything else, it has infinite value, because that's literally "me", so even small chance of small damage is worth avoiding at all cost(in my value system).
It's infuriating how casual doctors are about such risks, especially in cases when they can be avoided. I understand taking necessary risks when it's a life-saving surgery, but when you have alternatives, I think patient should be able to make an informed choice.
The "irrationality"[1] is the weight you put on the unknown risk of brain-harm from anaesthesia, while not appearing to assign much risk to how you get there.
How likely is it that you're going to suffer brain injury in your day to day life versus from anaesthetic?
[1] irrational is probably a not useful word here. You have real fear of real things.
He failed to mention that local anesthesia can also lead to neurotoxicity, and I was too ignorant to know about it(for some reason I assumed that local anesthetics are harmless, and didn't do my research).
You get that "neurotoxicity" in this case is almost exclusively referring to deleterious effects that local anesthetics can have on nerves at the site of injection, right? Subcutaneous injection of local anesthetics will have very little, if any, involvement with your brain.
You did the right thing finding a surgeon that would work with a block instead of GA if you were concerned about the (potentially real, if not that bad, effects of GA) but I think your fears of local anesthetics causing CNS damage are overblown and I wouldn't want others to refuse the use of them in themselves or their children based on your post.
Any chance he suffered a profound trauma being under surgery? I imagine an utter fear of surgery and this could have been triggered by something really insignificant like a small tingling or just the thought of surgery, of a foreign element cutting deep in your tooth canal. That, amplified over and over (he might even have lost conscience if his jaw was being held in place by a device -- the doctor wouldn't have known it this way) could have given birth of some kind of mechanism of memory wipe, sort of like the one victims of rape or horrible accidents develop as a self defence mechanism to (not?) cope with what just happened. Only in this case it went terribly wrong.
Local anesthetic is pretty much just a pain killer... it's not supposed to knock you out like GA (general anesthetic). I wonder if the article got the term right.
Is it necessarily the anaesthesia or a hemorrhage? Have they considered removing the root canal? Sometimes removing the materials from a root canal has improved a patient's health significantly.
Certainly one could understand why the dental industry would avoid the meme "root canal = bad!", but in this case the patient has little to lose, his future being lost already.
Claims that dental fillings are toxic, and that removing them will provide various health benefits, are a somewhat common medical scam. There is absolutely no evidence supporting these claims.
[+] [-] neuro_imager|10 years ago|reply
It would be very interesting to see exactly what type of imaging they performed on him. Bear in mind, an abnormality in the hippocampus or other memory related structures could be sub-mm in size and result in a significant impairment.
If, for example, he did not have an MRI with diffusion weighted imaging with a sufficiently high B value (gradient value) they may be missing/have missed a very small stroke (this test is also time sensitive -only positive within the first few days of insult).
If they did not perform susceptibility weighted imaging, they may have missed a tiny micro-haemorrhage. Both of these scenarios can result in memory loss if critical structures are involved.
There are also several technical issues that may have resulted in a sub-optimal scan, precluding finding a tiny abnormality. There's also the question of whether the person reading the scan got it right or whether the strength of the magnet/technical parameters of the study were sufficient to resolve a tiny abnormality.
Either of these scenarios could have been a consequence of reduced blood flow (hypoperfusion), a small clot (embolus) or a tiny blood vessel injury (dissection) that could have occurred during the procedure - possibly related to the anaesthetic but not definitively so.
I suspect there is a definitive abnormality that the clinicians that saw him were unable to pick up. This seams a lot more likely than the idea that we need to revise our entire conceptualisation of memory formation to suit a psychological theory.
[+] [-] jczhang|10 years ago|reply
[+] [-] csomar|10 years ago|reply
Scouring the medical literature, he found five similar cases of mysterious memory loss without brain damage. Although none occurred during a trip to the dentist, they do seem to follow other periods of physiological stress during a medical emergency.
That doesn't prove that the anaesthetic isn't the root cause. The article title sounds link-baity.
[+] [-] joezydeco|10 years ago|reply
And, sure enough, my memory was pretty much wiped for the hour or so after the event. Later that evening I had a conversation with my wife that went like this:
"Um, did you help me with putting my clothes back on?"
"Um, no. You did that."
"Did I talk to you and the doctor?"
"Sure. Normal conversation."
I have no recollection of these events at all. It gave me an uneasy feeling for a day or so. Nothing traumatic but every time I tried to reach back and think about that post-op period I drew and continue to draw a complete blank.
[+] [-] cpncrunch|10 years ago|reply
Agreed, and psychogenic causation seems more likely (see my comment at the previous discussion https://news.ycombinator.com/item?id=9810025).
This seems to be yet another case of HN users upvoting dubious link-bait scientific press-releases. This particular one has been posted 3 times this week.
[+] [-] cristianpascu|10 years ago|reply
[+] [-] tim333|10 years ago|reply
[+] [-] dang|10 years ago|reply
It does. We replaced it with the subtitle, which is more neutral.
[+] [-] iGoPro_HD|10 years ago|reply
(P.S. I will be using that word from now on.)
[+] [-] atombender|10 years ago|reply
Another well-known case of retrograde amnesia is Clive Wearing, a British pianist who was the subject of a BBC documentary, "Man Without a Memory" [2]. I recommend watching the clip. He describes his "resets" rather terrifyingly as slowly emerging from a sleepless coma. Whenever he sees his wife after such a reset, he leaps up to greet her as if they have been apart for a long time, and his evident happiness and inability to recognize his situation is heartbreaking. (His wife, unbeknownst to him, of course, has since divorced him, which only adds to the poignancy of the scene.)
[1] https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_f...
[2] https://www.youtube.com/watch?v=Vwigmktix2Y
[+] [-] iopq|10 years ago|reply
[+] [-] userbinator|10 years ago|reply
...including the fact that you can't remember anything? That would certainly be scary.
[+] [-] noblethrasher|10 years ago|reply
[+] [-] rayalez|10 years ago|reply
From wiki:
"Wozniak sustained severe face and head injuries, including losing a tooth, and also suffered for five weeks after the crash from anterograde amnesia, the inability to create new memories. He had no memory of the crash, and did not remember his name in the hospital or the things he did after he was released from the hospital."
[+] [-] realityking|10 years ago|reply
[+] [-] vvpan|10 years ago|reply
[+] [-] imaginenore|10 years ago|reply
Your chance of dying from anaesthesia is around 1 in 100,000 - 185,000. While it may seem like a safe number, it's orders of magnitude higher than winning a major lottery.
That number also doesn't include medical fuckups during anaesthesia, like overdose, airway obstruction. In that case the number shoots up to 1:2500 - 1:5000.
http://bja.oxfordjournals.org/content/95/1/95.long
1.5 people in 1000 wake up, so the pain shock alone can kill you.
Dental anaesthesia is known to kill, around 2 children per year.
http://www.huffingtonpost.com/2012/07/13/dental-sedation-chi...
[+] [-] VieElm|10 years ago|reply
[+] [-] jsprogrammer|10 years ago|reply
[+] [-] Foy|10 years ago|reply
Literally 50 First Dates...
[+] [-] TazeTSchnitzel|10 years ago|reply
[+] [-] RexRollman|10 years ago|reply
[+] [-] harryjo|10 years ago|reply
[+] [-] exizt88|10 years ago|reply
[+] [-] djfm|10 years ago|reply
[+] [-] imaginenore|10 years ago|reply
[+] [-] yoha|10 years ago|reply
[+] [-] HappyTypist|10 years ago|reply
[+] [-] bashinator|10 years ago|reply
"His ability to form long-term procedural memories was intact; thus he could, for example, learn new motor skills, despite not being able to remember learning them."
[0] https://en.wikipedia.org/wiki/Henry_Molaison
[+] [-] rayalez|10 years ago|reply
Doctors tried to push me into accepting the general anesthesia, saying that it's the only option(and that we lose brain cells every day really, so who cares). I went to a different clinic where a doctor agreed to do the surgery under local anesthetics and without sedation without any problems. Said someting along the lines "don't worry, man, your brain is gonna be fine."
He failed to mention that local anesthesia can also lead to neurotoxicity, and I was too ignorant to know about it(for some reason I assumed that local anesthetics are harmless, and didn't do my research).
During the surgery I felt the symptomps(dizziness, difficulty speaking), consistent with neurotoxicity caused by local anesthetics.
I don't notice any permanent damage, though I doubt that I'd be able to tell. 6 months after the surgery I have developed tinnitus, but I can't tell if it's connected to it or not.
Anyway, my point is that no way in hell would I agree to the surgery if I'd have known the risks.
Also, before that, doctors pushed me into unnecessarily taking general anesthesia for a routine procedure. They convinced me that it can't be harmful, and I was too young and socially awkward to ask more questions or argue.
I also fear dental anesthetics. There is research indicating that they can cause neurotoxocity. I can easily sit through filling regular cavities(with a dental laser it really isn't that painful), but I'm not sure what I would do if I have to get root canal. I would take any option over anesthesia, but I don't know of any alternative.
Some doctors say that it's just an irrational fear. But given that there's some research saying that even dental anesthesia can cause neurotixicity, I'm not sure what's so irrational about not wanting my brain cells to die. My brain is what matters to me the most in the world, far more than anything else, it has infinite value, because that's literally "me", so even small chance of small damage is worth avoiding at all cost(in my value system).
It's infuriating how casual doctors are about such risks, especially in cases when they can be avoided. I understand taking necessary risks when it's a life-saving surgery, but when you have alternatives, I think patient should be able to make an informed choice.
[+] [-] DanBC|10 years ago|reply
How likely is it that you're going to suffer brain injury in your day to day life versus from anaesthetic?
[1] irrational is probably a not useful word here. You have real fear of real things.
[+] [-] GoodOldNe|10 years ago|reply
You get that "neurotoxicity" in this case is almost exclusively referring to deleterious effects that local anesthetics can have on nerves at the site of injection, right? Subcutaneous injection of local anesthetics will have very little, if any, involvement with your brain.
You did the right thing finding a surgeon that would work with a block instead of GA if you were concerned about the (potentially real, if not that bad, effects of GA) but I think your fears of local anesthetics causing CNS damage are overblown and I wouldn't want others to refuse the use of them in themselves or their children based on your post.
[+] [-] Romme|10 years ago|reply
[+] [-] bite_victim|10 years ago|reply
[+] [-] atarian|10 years ago|reply
Local anesthetic is pretty much just a pain killer... it's not supposed to knock you out like GA (general anesthetic). I wonder if the article got the term right.
[+] [-] dbrgn|10 years ago|reply
[+] [-] dogmati|10 years ago|reply
[+] [-] ioquatix|10 years ago|reply
I highly recommend it, especially if you are a mathematician.
[+] [-] unknown|10 years ago|reply
[deleted]
[+] [-] jivardo_nucci|10 years ago|reply
Certainly one could understand why the dental industry would avoid the meme "root canal = bad!", but in this case the patient has little to lose, his future being lost already.
[+] [-] duskwuff|10 years ago|reply
http://www.quackwatch.com/01QuackeryRelatedTopics/mercury.ht...
[+] [-] curiousjorge|10 years ago|reply
[+] [-] __z|10 years ago|reply
[+] [-] sharon23758|10 years ago|reply
[deleted]