The Woman with the Mysterious Brain
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.
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'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.
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.
|Hydrocephalus: A Guide for Patients - Chuck Toporek|
|Pediatric Hydrocephalus - Guiseppe Cinalli|