
After simple dental surgery, William lost his ability to form new memories - tchalla
http://www.bbc.com/future/story/20150630-my-dentist-saved-my-tooth-but-stole-my-memory
======
neuro_imager
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.

~~~
jczhang
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?

------
csomar
_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.

~~~
joezydeco
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.

~~~
tptacek
The fact that anesthesiologists apparently deliberately induce amnesia with
benzos scares the shit out of me, much more so than full general anesthesia
does (which seems backwards, right, because general anesthesia is actually
dangerous). Why do they want me not to remember anything? Is it that horrible?

~~~
jandrewrogers
The use of amnesiacs like midazolam in conjunction with unpleasant surgery has
become common practice because it has been shown to significantly reduce the
psychological trauma associated with surgical procedures and related changes
in behavior as a result. You will still experience the trauma at the time
whether you remember it or not, but the experience is not persistently encoded
into your brain.

This is important because the psychological trauma of a surgical procedure
will often cause people to avoid future procedures even when procedures are
medically advisable. These drugs temporarily prevent strongly negative
experiences from becoming a part of who you are mentally, subconscious or
otherwise.

~~~
tptacek
And that makes intuitive sense. I'm still left with the question: is the
experience of surgery really that bad?

~~~
carbocation
I'll say yes. For example, sometimes we have to run electrical current through
someone's chest to correct an arrhythmia. Depending on the urgency, we will
give a medication such as midazolam. Ideally you want the sedation to have
taken effect, but you don't always have the time to wait for that before your
hand is forced and you have to cardiovert. The amnestic properties will help
reduce some of the traumatic memories.

~~~
tptacek
Sure. That makes sense. You gave me enough keywords with that comment to look
up electrical cardioversion and pain, and so now there's something new that
I'm scared of (kale for dinner tonight!) (thanks!).

But that's actually something different than what I'm asking. I have no
trouble understanding why I wouldn't want to remember a pain "similar to that
of surgical incision". Similarly: I wouldn't want to remember an
unanesthetized incision!

But before learning that surgical patients were routinely given midazolam to
zap their memory, my impression was that surgical patients were completely
zonked out by general anesthesia, and so there'd be no need to zap their
memory, because they weren't going to consciously experience the incision in
the first place.

Now I'm like, is all of general anesthesia a scam, and we're all enduring
horrible pain, and we just don't remember it? J/K ONLY SERIOUS.

~~~
carbocation
Midaz can be used as premedication before induction of general anesthesia, but
it's not an induction agent itself. If you're getting general (as opposed to
"twilight") anesthesia, once you're induced, you should be unconscious (to the
best of our ability to understand consciousness).

I'm medicine, not anesthesia, so I don't use these agents all day and
therefore referred to cardioversion which is more in my domain. Cheers!

~~~
tptacek
I am noting with interest and a small amount of alarm the abruptness with
which you've ejected yourself from this thread after my suggestion that all of
anesthesia is a huge scam. :)

~~~
Anderkent
FWIW, unlikely. I specifically remember being asked to count down from 10,
going like 8 7 6 ... 5 wait I feel weird and sleepy. That is, my first thought
after being woken up was the next number in sequence.

It seems unlikely that would be the case if the time inbetween was spent
thinking 'oh my god this hurts so much' rather than just blacked out.

~~~
tptacek
Were you given a benzo specifically to erase your memory of the events?
Because this thread is about the fact that many (maybe most) surgical patients
are.

(Let me clear, I'm being deliberately silly about all this. I do not think
there is a huge anesthesia conspiracy. I am, at the same time, seriously
skeeved out by having my memory deliberately tampered with.)

~~~
Anderkent
> Were you given a benzo specifically to erase your memory of the events?

I don't remember! :P

------
lobster_johnson
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.)

[1]
[https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_f...](https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_for_a_Hat)

[2]
[https://www.youtube.com/watch?v=Vwigmktix2Y](https://www.youtube.com/watch?v=Vwigmktix2Y)

------
iopq
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...

~~~
userbinator
_Imagine not being able to remember anything at all..._

...including the fact that you can't remember anything? That would certainly
be scary.

~~~
rusabd
I once lost a memory for couple hours - I was fully aware that I don't
remember anything

------
noblethrasher
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.

~~~
realityking
My Mom's got only three teeth left. Going by this theory, she should remember
barely anything. But she does remember a lot.

~~~
ams6110
Well Woz is a brilliant guy in many respects, but even highly intelligent
people get the occasional wacky idea.

------
vvpan
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?

~~~
imaginenore
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.

[http://bja.oxfordjournals.org/content/95/1/95.long](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...](http://www.huffingtonpost.com/2012/07/13/dental-sedation-child-
deaths_n_1671604.html)

~~~
jwdunne
When having staples inserted (and also removed a year later) into the growth
plates in my knees, I was given the option of having my legs numbed too for
pain relief. I'm glad I took that option now - unless it was post-op only.

From the second op, I had a huge black bruise on my thigh in the shape of a
hand print. I couldn't imagine the pain if I'd have woken during the cause of
that.

------
Foy
>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”.

Literally 50 First Dates...

~~~
TazeTSchnitzel
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.

~~~
jedberg
I mentioned this to a psychologist and she laughed at me very hard. She was a
professor and said that she uses the movie 50 First Dates in her class -- by
having them write down everything that is wrong. She says it's so horribly
inaccurate that it makes for a good long discussion.

~~~
Foy
Out of curiosity what are some of the things wrong with it?

~~~
DanBC
This page doesn't like the film, and lists some mistakes, but also lists some
of the accurate bits.

[https://www.psychologytoday.com/blog/psychologist-the-
movies...](https://www.psychologytoday.com/blog/psychologist-the-
movies/201212/amnesia-in-50-first-dates)

~~~
Foy
The only real "issue" that article seems to take with the movies was that (A)
it used a term that doesn't exist to describe a condition that does have an
actual name and (B) it was a cheesy romcom. But I mean, do you really expect
any Adam Sandler movie to get to the real grit of living with a terrible
disease?

------
exizt88
A comparably horrifying experience:
[https://en.wikipedia.org/wiki/Clive_Wearing](https://en.wikipedia.org/wiki/Clive_Wearing)

------
djfm
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?

~~~
imaginenore
Exactly. It can be just a coincidence. A blood clot, undetected cancer,
genetic disorder, or a million other things.

~~~
cpncrunch
Or more likely psychogenic, given the recent death of his father.

------
yoha
Previous discussion:
[https://news.ycombinator.com/item?id=9810025](https://news.ycombinator.com/item?id=9810025)

------
HappyTypist
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.

~~~
bashinator
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."

[0]
[https://en.wikipedia.org/wiki/Henry_Molaison](https://en.wikipedia.org/wiki/Henry_Molaison)

~~~
timcederman
If you read the article, it says the patient mentioned can't form procedural
memories.

------
rayalez
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.

~~~
DanBC
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.

~~~
rayalez

        > while not appearing to assign much risk to how you get there.
    

I'm not sure what you mean by this, can you rephrase it?

If you are saying that I'm not putting enough weight on the risks of avoiding
the procedure - let me be clear, I'm talking about cases where anesthesia is
optional, and is a matter of pain vs comfort.

I know that avoiding root canal puts me at risk of dying from infection, so of
course I wouldn't avoid doing it, and it makes sense to prefer "treating tooth
with anesthesia" over "not trating a tooth." But I _could_ have avoided that
surgery(it was about quality of life, not survival), and I _could 've_ avoided
anesthesia if I was willing to suffer some pain/discomfort. And _that_ should
be my choice to make.

I think that it is rational to take short term pain over (even small)
probability of long term brain damage. If I could take some reasonable amount
of pain over brain damage risk, I would take it any time, and it would be the
_right_ choice. My problem with root canal is that I don't think I could
handle the pain without anesthetics. So I fear that when faced with choice "a
lot of pain" vs "safety for my brain" I will fear the pain, take anesthetics,
and betray my values.

Do you see my problem here? If brain has literally "infinite" value, then no
matter how infinitesimal risks are, it is rational to minimize them at all
cost. If doing the procedure minimizes them, it is rational to do it, if it
doesn't - the right thing is to avoid it.

Correct me if I misunderstood what you're saying.

    
    
        > How likely is it that you're going to suffer brain injury 
        > in your day to day life versus from anaesthetic?
    

Ehm... Less likely? Possible, but less likely.

~~~
DanBC
Having an anasthetic carries some risk. How much? How many people per million
suffer the adverse outcome you fear?

Now compare that to the risk of day to day life. How much has the risk
increased?

There's a bunch of stuff you do that you don't need to do that carries more
risk than anaesthetic.

It's fine for you to chose your medical care. You might want to investigate an
"advance health care directive". Having one should persuade doctors that you
have spent time thinking about this and it is your sincere and considered
desire to ignore their advice to have anasthesia.

[https://en.wikipedia.org/wiki/Advance_health_care_directive](https://en.wikipedia.org/wiki/Advance_health_care_directive)

~~~
__z
>There's a bunch of stuff you do that you don't need to do that carries more
risk than anaesthetic.

I don't have any evidence for this but I suspect that the majority of brain
injuries in otherwise healthy people come from trauma due to accidents. If my
suspicion is true then wearing a helmet all the time might be the most
effective way to avoid brain injury.

~~~
ams6110
Helmets protect your skull. They are not as effective at preventing brain
injury.

------
bite_victim
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.

------
atarian
>local anesthetic

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
There's a great movie by Christopher Nolan about exactly this condition:
[https://en.wikipedia.org/wiki/Memento_%28film%29](https://en.wikipedia.org/wiki/Memento_%28film%29)
[http://letterboxd.com/film/memento/](http://letterboxd.com/film/memento/)
Highly recommended.

~~~
dogmati
There is also a mediocre but surprisingly endearing Adam Sandler movie about
this condition.

------
ioquatix
There is a Japanese movie about this:
[https://en.wikipedia.org/wiki/The_Housekeeper_and_the_Profes...](https://en.wikipedia.org/wiki/The_Housekeeper_and_the_Professor)

I highly recommend it, especially if you are a mathematician.

------
jivardo_nucci
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.

~~~
duskwuff
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.

[http://www.quackwatch.com/01QuackeryRelatedTopics/mercury.ht...](http://www.quackwatch.com/01QuackeryRelatedTopics/mercury.html)

~~~
jivardo_nucci
We're talking about _root_ _canals_, not dental fillings! Other than the
anaesthetic, the materials used in root canals are are entirely different from
those used in a dental filling.

Furthermore, root canals require different training and are (usually) done by
endodontists. Dentists usually handle the more mundane and more tested
procedure of dental fillings.

My point is, root canals are much more invasive and have their own
problems(not associated with dental fillings).

------
curiousjorge
so is root canal dangerous??

~~~
__z
All medical interventions have the risk of adverse outcomes. Treating a
patient is a risk-benefits analysis.

