Sharon Parker
The Woman with the Mysterious Brain
Hydrocephalus
Sharon Parker was born and bred in Barnsley, Yorkshire. She's married
with three children and is a qualified staff nurse. But, Sharon has
almost no observable brain. Since she was a child, doctors have told her
that she has no more than 10-15% of a normal brain.
Historically, it was a popular assumption that the size of the brain
determined the level of a person's intelligence. By that reckoning,
Sharon should be a gibbering idiot.
Jonathan Cole
Dr Jonathan Cole, Consultant Neurophysiologist explains further: "For
a long time, people have measured the size of the brain, in post mortem,
and and they've measured the size of of heads in people and tried to
relate the size of the brain to how bright the person is. There are some
people who are severely micro cephalic, with very small brains, and they
have severe learning difficulties. But, on the whole, it's very
difficult to relate the size of the brain to how it functions. The
function of the brain is not something that is related to how big the
brain is or to it's volume. Rather it's how well the nerve cells
function within that brain. In particular, how well they connect with
other brain cells".
Sharon's mother Pat recalls: "We were told, so many times, that
Sharon wasn't going to live to adulthood".
Sharon and Dave have been married for fifteen years. Dave has his own
construction business. No master of new technology; he still writes his
invoices out by hand. Sharon is the one who works them out and puts them
on the computer.
Sharon is clearly competent, but just how intelligent is she? She was
asked to take an IQ test marked by an educational psychologist. How does
she compare with the rest of the population? Dave thinks that Sharon is
normal, except for her untidiness. Sharon claims she sees past the
untidiness and maybe that part of her brain is missing.
If Sharon has a hole where most people have brain, has she noticed
anything else she has difficulty with? She tells us: "Sequences of
numbers, telephone numbers, I find hard to remember". The IQ test
results that Sharon, far from being an idiot, has an IQ of 113 making
her above average. 80% of the population would have a lower score.
So, how did Sharon come to have such an extraordinary brain? When she
was eight months old, her parents were worried that her head was
unusually large. They took her to see a specialist who diagnosed water
on the brain. At nine months they found out she was hydrocephalic and
needed surgery.
Traditionally, hydrocephalus or water on the brain was a killer.
Occasionally, children survived, but as their heads swelled they became
little more than monsters at a freak show.
Mr Cole explains "Hydrocephalus is a build up of fluid within the
brain. We all have fluid in the brain, in areas called ventricles and
that flows out to bathe the outside of the brain. If that fluid builds
up within the ventricles it tends to expand and the brain is pushed out
against the skull. In children the skull is not set and the squashing of
the brain and th slightly raised pressure can actually lead to an
enlargement of the skull itself".
Sharon Parker
Sharon's life was saved by a pioneering operation in which a valve
was put into her brain to control the fluid. By the time her
hydrocephalus was detected, the fluid had been building up for nine
months, creating an enormous hole in the middle o her brain.
Brains that have developed abnormally are intriguing subjects of
research for neuro specialists. Leading American Neurosurgeon Dr Mark
Luciano believes there is much that such a brain can tell us.
Dr Luciano says: "For me, Sharon is most interesting because the
hydrocephalus has developed so slowly that her brain has adapted very
well to allow her to function to a high level. We want to know how the
brain can do that". So, Sharon and her family fly to Cleveland,
Ohio to meet Dr Luciano, to find out more about what her brain is really
like.
Armed with the latest technology and with new tests available, Dr
Luciano is hopeful of finding out much more about Sharon's brain than
she ever knew before.
First, Sharon goes for an MRI scan, but this is no ordinary scanner.
Dr Luciano explains "It is considered one of the fastest scanners
in the world. It has a lot of channels and takes lots of pictures at one
time. What it can do is not only a standard picture of the brain, it can
also get a picture of the blood vessels and blood flow. Sharon's brain
scan takes over two hours. Doctors are looking at her brain from every
angle, pinpointing functions and checking blood flow. It emerges that
Sharon has had a lucky escape. As her brain pressed against her skull,
it became dangerously thinned in the crucial frontal lobe.
The outer surface of the normal brain is ridged to give it more
surface area, whereas Sharon's brain has been stretched and the surface
flattened, especially in the frontal lobe where functions like memory
are located.
Hydrocephalic Skull
Back in the 18th century, there was a fashion for something called
phrenology. It was believed that bumps on the skull were a guide to a
person's abilities. Phrenologists even mapped the skull to show where
different human characteristics were, supposedly, located. These
theories have long since been discredited but, in one respect, the
phrenologists were not so far from the truth. We now know that different
functions are located in specific areas of the brain.
It was only with memory that Sharon showed signs of a problem but,
even there the doctors discovered that her brain had made every effort
to compensate. Tests showed that she scored well above average on her
long-term memory but, below average on her short-term memory. The
amazing thing is that she seems, somehow, to combine the two in order to
overcome some of her memory problems.
Dr Luciano summarises "Overall, I'm surprised that each test
showed so much normalcy. I think she's a very good example of how the
brain can adapt to a very unusual situation and that if the forces
against the brain occur slowly enough and early enough the brain can be
extremely flexible".
For Sharon, the most important discovery the American doctors made
concerned the size of her brain. Something that only the very latest
technology allowed them to measure. Having been told, all her life, that
she has only 10-15% of a normal brain the result came as a welcome
surprise, but it was something of a shock for Dave. While the volume of
Dave's brain was 1300cc Sharon took great delight in telling him that
hers was 2300cc.
The American doctors had discovered that although Sharon's ventricles
expanded hugely because of her hydrocephalus, it was not at the expense
of brain size. Part of the brain mass was pushed to the bottom rear of
her skull and because her infant head swelled slightly her brain is
actually occupying a larger space.
Further Reading:
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Hydrocephalus: A
Guide for Patients - Chuck Toporek |
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Pediatric
Hydrocephalus - Guiseppe Cinalli |
