Dentist After simple dental surgery, William lost his
ability to form new memories. What happened?
This real-life medical mystery should change
the way we think about the brain, says David
William’s internal clock is eternally jammed at
13:40 on 14 March 2005 – right in the middle of
a dentist appointment.
A member of the British Armed Forces, he had
returned to his post in Germany the night before
after attending his grandfather’s funeral. He had
gym in the morning, where he played volleyball
for 45 minutes. He then entered his office to
clear a backlog of emails, before heading to the
dentist’s for root-canal surgery.
“I remember getting into the chair and the
dentist inserting the local anaesthetic,” he tells
me. After that? A complete blank.
It is as if all new memories are being
written in invisible ink that slowly
Since then, he has been unable to remember
almost anything for longer than 90 minutes. So
while he can still tell me about the first time he
met the Duke of York for a briefing at the
Ministry of Defence, he can’t even remember
where he’s living now; 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”.
It is as if all new memories are being written in
invisible ink that slowly disappears. How could
minor dental work have affected his brain in
such a profound way? This real-life medical
mystery offers a rare glimpse at the hidden
depths of the brain’s workings.
Even the events leading up to William’s amnesia
are highly puzzling. At the time of the surgery,
the dentist didn’t realise that anything was
wrong; it was only after they asked him to take
off his protective dark glasses that they saw he
was pale, and struggled to stand up. They
called his wife. “He was lying on a couch,”
Samantha recalls. (Both their names have been
altered to preserve the family’s privacy). “His
eyes were staring; he looked surprised to see
me – he had no clue what was going on.” By
5pm he was removed to hospital, where he
stayed for three days. Even after some of the
mental fog dissipated, he was still unable to
recall anything for more than a few minutes.
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.
The brain’s printing press
The obvious explanation would have been that
William had a form of “anterograde amnesia”,
like Henry Molaison, whose experiences have
informed much of what we know about memory.
During brain surgery to treat his epilepsy,
surgeons sliced out a large chunk of Molaison’s
grey matter, including his hippocampi –
seahorse-shaped regions at the centre of the
brain. They act as our memory’s printing press,
stamping the “episodic memories” of events into
long-term storage – and without them,
Molaison was unable to hold on to anything
that occurred after the surgery.
William could work out how to solve a
complex maze, only to completely forget
the skill three days later.
Yet as William’s first doctors had noted, brain
scans seemed to show that these crucial areas
were still intact. Nor did his symptoms exactly
match those of other anterograde amnesiacs.
While Molaison couldn’t remember details of
personal events, for instance, he could learn new
“procedural” skills since they are processed in
different parts of the brain. When Burgess asked
William to work out how to solve a complex
maze, however, he had completely forgotten the
skill three days later. “It was like a déjà vu
replica of the same errors – he took the same
time to relearn the task once more,” says
One possibility is that William’s amnesia is a
“psychogenic illness”. Some patients report
memory loss after a traumatic event – but that
tends to be a coping mechanism to avoid
thinking about painful past events; it doesn’t
normally affect your ability to remember the
present. Samantha says that William had
suffered no trauma, and according to Burgess’s
detailed psychiatric assessments, he is
otherwise emotionally healthy. “He was a
successful father and military officer with good
job evaluations,” says Burgess. “There was no
reason to think that there was anything wrong
Given the evidence, Burgess instead suspects
the answer may be hiding in the thicket of tiny
neural connections we call “synapses”. Once we
have experienced an event, the memories are
slowly cemented in the long term by altering
these richly woven networks. That process of
“consolidation” involves the production of new
proteins to rebuild the synapses in their new
shape; without it, the memory remains fragile
and is easily eroded with time. Block that
protein synthesis in rats, and they soon forget
anything they have just learnt. Crucially, 90
minutes would be about the right time for this
consolidation to take place – just as William
starts to forget the details of the event. Rather
than losing its printing press, like Molaison,
William’s brain seems to have simply run out of
Even so, it’s not clear why root canal surgery
should have made his brain run dry in this way.
“That’s the million-pound question”, says
Burgess, “and I don’t have an answer.” 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. “It could be a genetic predisposition
that needs a catalyst event to start the
process,” says Burgess.
Burgess hopes that his new paper, which
appears in Neurocase journal , will encourage
other psychologists to share similar stories and
perhaps spark other theories. They are already
intrigued. “It is a bit of a head scratcher,”
admits John Aggleton, at Cardiff University in
the UK. He would like to see more detailed
tests, looking more specifically at the long-
distance connectivity of the brain. Even if
there’s no damage to the brain cells
themselves, William may be missing some of the
necessary wiring around the hippocampi and
other parts of the memory processing pipeline,
he thinks.
For the time being, William helps to remind us
just how little we know about our own minds.
Mesmerised by colourful MRI scans, many now
think of the brain as a kind of computer, with
separate chips devoted “memory”, “fear” or
“sex”. Yet William perfectly demonstrates why
this modular view of the mind is over-simplistic.
Even when all that machinery is apparently
intact, you can still find yourself lost in the
present, with no way of bridging the past and
the future. Clearly, the brain has many more
layers to be peeled away before we can get to
the heart of what makes us who we are.
In the last 10 years, William has been
able to cling to one new fact – his
father’s death.
William also demonstrates just how the
powerfully our emotions shape our minds. In the
last 10 years, he has been able to cling to one
new fact – his father’s death. Somehow, the
force of his grief helped him to forge new tracks
in the brain and grasp on to that fact, when
everything else has slipped away. Even then, he
is unable to remember the events surrounding it,
nor the bedside vigil in his last few days.
When I speak to him, he has just relearnt – for
the thousandth time – that his daughter and
son are now 21 and 18, not the young children
he remembers. He hopes the rest of their lives
will not be lost to him. “I want to walk my
daughter down the aisle and remember it.
Should they become parents, I would like to
remember that I have grandchildren, and who
they are.”