We Are Our Brains (34 page)

FIGURE 25.
The basal nuclei—the nucleus basalis of Meynert (NBM), the diagonal band of Broca (DBB), and the septum—are the source of the chemical messenger acetylcholine in the cortex and hippocampus. This chemical messenger is important for memory (see also
fig. 33
).

Gene therapy for disorders of the nervous system is most advanced in the field of ophthalmology. Children with Leber's disease—a hereditary condition caused by a genetic mutation—are born with poor sight and go completely blind in adulthood. Experimental gene therapy on dogs proved effective against this disease. A phase 1 study was then carried out on three young adult patients whose retinas were seriously affected to determine whether treatment involving insertion of a piece of DNA coding for the missing protein was safe. The new therapy caused no serious side effects. Moreover, one patient's sight improved remarkably; he regained the ability to detect and avoid objects in poor light. The next step will be to treat children with Leber's disease at a stage when their retinas are still reasonably intact. Monkeys with red-green color blindness have already been cured using gene therapy. Measurable results were achieved within five weeks, and within eighteen months they could distinguish all colors.

The first clinical studies involving gene therapy for the blind and for patients with dementia herald an entirely new era of potential treatment for human brain disorders. In its very early days, gene therapy sometimes proved shockingly disappointing. One young patient died, while others developed leukemia. But gene therapy is now reemerging as a promising form of treatment.

It was previously thought that brain tissue, once lost, could never be regenerated and that the functional improvements that can occur after a stroke are simply due to reduced swelling and, to a limited
extent, to functions being taken over by other regions of the brain. People who suffer trauma and go into a coma can come out of it within a matter of days or weeks or progress to a vegetative state also known as coma vigil, in which they are awake without being conscious. Coma vigil can herald improvement, but some patients remain in this state permanently without making any further progress (see
chapter 7
). After three months in a vegetative state a patient is thought to have no chance of recovery. Yet people occasionally do come out of a vegetative state after a very long period. An exceptional case is that of Terry Wallis, who went into a coma after a car accident and then progressed to a minimally conscious state from which he awoke nineteen years later. He had occasionally responded to external stimuli by nodding and grunting, but he couldn't communicate his thoughts and feelings. Yet nine years after the accident he started to speak the occasional word, and after nineteen years he fully regained the power of speech. He was also able to count and to move his limbs. However, he remained severely handicapped, unable to walk or to feed himself. He was also unaware of the passage of time; he didn't know that his daughter—a baby at the time of the accident—had become a stripper or that his wife had had three children by another man. You might wonder whether this constitutes a worthwhile existence and whether Terry, described by the media as “a modern Lazarus,” is himself happy about this “miracle,” but his case is truly special from a medical point of view. His recovery is attributed to the fact that new axons—nerve fibers that create connections between different brain regions—formed in his brain. Over a period of eighteen months, MRI scans showed an increase in the volume of nerve fibers at the rear of the cortex as well as in those connecting the various cortical regions. Increased activity was also detected in a part of the parietal lobe called the precuneus, which is important to our consciousness of our surroundings and of ourselves. This area, which doesn't function in patients in a vegetative state or coma or suffering from dementia—or during sleep, as a matter of fact—remains active when the brain is in a minimally conscious
state. It was during the period when these activity changes were registered that Wallis regained consciousness. An increase was subsequently measured in the fibers of his cerebellum, at a time when his motor functions had improved strikingly. What distinguishes the few patients who are able to emerge from a vegetative state or a minimally conscious state after such a long period is still a mystery. But their existence does overturn the long-held view that recovery is impossible in such cases.

The story of Jill Bolte Taylor caused a media sensation. She was a brain researcher at Harvard who, at the age of thirty-seven, suffered a massive stroke in her sleep. She woke up with a pounding pain behind her left eye, and when her left arm became paralyzed she realized what was happening. With huge difficulty she telephoned a colleague to try to ask for help. She thought she was speaking clearly but in fact could only utter unintelligible sounds. Luckily the colleague, realizing that something was terribly wrong, called 911. Trying to communicate at a moment like that must be nightmarish. A doctor friend of mine realized that he was having a stroke and called his GP. The GP listened briefly to the incomprehensible sounds at the other end of the line, decided that it must be a prank caller, and promptly hung up. At that moment my friend's wife came home with the groceries, and he called out to her. Annoyed, she yelled back, “How often do I have to tell you to wait until I'm in the same room before you talk to me! I can't hear a word you're saying out here!” and went on unpacking the groceries. Luckily he recovered spontaneously from the damage caused by his stroke and has fully regained the power of speech. The situation in which Jill Bolte Taylor found herself was very different. Two and a half weeks after the cerebral hemorrhage, surgeons removed a golf ball–sized blood clot from her brain. She was left unable to walk, talk, read, or write and could remember nothing of her former life. With her mother's help, she gradually learned how to function again. It took her eight years to recover fully. She has written a bestseller about that period in which she describes how she used her willpower and her knowledge
of the anatomy of the brain to consciously stimulate the damaged brain circuits and get them working again. This is pseudoscientific mumbo jumbo, but it proved immensely popular with the general public. “I truly believe that as a patient you're responsible for your own recovery,” she said with great conviction. Of course it's important to do your utmost to regain health after a cerebral hemorrhage or stroke. But the danger of Taylor's enthusiastic but unscientific pronouncements is that they can be used to reproach those unfortunate patients who don't recover from such injuries for failing to work sufficiently hard on their recovery. When I first began studying to be a doctor, my father placed the power of medicine in perspective. “There are two kinds of maladies,” he said. “One kind goes away by itself, and the other kind you can't do anything about anyway.”

Witnessing aggression sparks aggression. Measures have rightly been taken to restrict excessively violent computer games. So it doesn't make sense that certain forms of primitive aggression, like boxing, are still permitted. You can watch boxers inflicting permanent brain damage on one another on prime-time television, yet no one seems to get very upset about it. As the audience howls encouragement in the background, you see (repeatedly and in close-up) detailed footage of the onset of neurological damage: an unsteady gait, impaired speech, eyes flicking left and right, an occasional classic epileptic fit, reduced consciousness after being knocked down, unconsciousness after being knocked out, and occasionally coma and death. It's more or less a complete course in neurology, in fact. Since the Second World War, around four hundred boxers have died from injuries incurred under the supervision of the various boxing unions. It's incredible that the most revolting examples of this neuropornography
are shown on television, even at times when young children might still be watching.

In boxing, long-term brain damage from repeated blows to the head is much more common than acute damage. In 1928, the term
punch-drunk
was coined for boxers who stood unsteadily, moved slowly, and developed behavioral disorders, varying degrees of dementia, or Parkinson's disease. This was replaced by
dementia pugilistica
, and now the neutral term
chronic traumatic brain damage
is used to describe the condition suffered by 40 to 80 percent of professional boxers. Around 17 percent of professional boxers have Parkinson's. Muhammad Ali, formerly the world's greatest boxer and fastest talker, has become a shuffling Parkinson's patient with a mask-like face who struggles to form a sentence.

If boxing is character-forming, character can't be located in the brain, because there the only observable effect is deterioration. Many brain areas shrink as cells are lost, fibers are torn and lose their protecting myelin sheath, and the typical changes of Alzheimer's and Parkinson's can be seen under the microscope. If boxers die suddenly, it's usually because of cerebral hemorrhage. When someone is knocked out, their brain is slammed into the hole under the skull. This compresses the medulla, the lower half of the brain stem, which regulates vital functions like breathing, temperature regulation, and heart rhythm, with potentially devastating effect. Blows also destroy the hypothalamus and the pituitary gland, causing hormonal deficiencies in 50 percent of boxers. Their sense of smell is also impaired. Despite the use of protective helmets, one in eight amateur boxing matches leads to concussion. The current debate as to whether the brain damage incurred by boxers who are more genetically susceptible to brain trauma should be monitored more closely using psychometric tests is incomprehensible. By the time changes show up, it's too late. Professional boxing has already been banned for decades in Sweden, Norway, Iceland, North Korea, and Cuba. (Since 2001 Norway has in fact banned all martial sports that can lead to concussion,
including the popular and spectacular K-1 fights, a form of kickboxing.) In other countries, doctors have urged a ban on boxing. When you try this in my country, people counter by saying that boxers engage in this activity of their own free will, forgetting that the Netherlands outlawed dueling (in which people also partook of their own free will) centuries ago. You might wonder whether boxers are already showing the first signs of dementia when they elect to take up this barbarian form of “sport.” But that's yet another argument in favor of protecting them from themselves and finally banning this embarrassing remnant of our primitive evolutionary past.

In 1912, Baron Pierre de Coubertin, the founder of the International Olympic Committee (IOC), opposed the inclusion of women in the Games on the grounds that their participation would be “impractical, uninteresting, unaesthetic, and incorrect.” When women were allowed to take part, a distinction had to be made between the two sexes because of the biological advantage that testosterone gave men in terms of height and muscle power. At the time of the ancient Greeks, the distinction between men and women was easily made. Sports were performed naked, and if you didn't have a penis they didn't let you join in. But chromosomal gender, internal and external gender, and gender identity (feeling male or female) aren't always identical, and these discrepancies are sometimes linked to differences in testosterone levels. Women with too much testosterone can pose a threat to other sportswomen. Dora (Heinrich) Ratjen, a man who had been persuaded by the Nazis to pose as a woman high jumper, competed in the 1936 Olympics, though he came in only fourth. (The deception wasn't revealed until the 1950s.) It was at those
Olympics that the first serious gender controversy arose, when the American gold medal winner of the hundred-meter sprint, Helen Stephens, was accused of being a man, but turned out on inspection to be a woman. Ironically enough, Stella Walsh, the gold medal winner of 1930 whom Stephens beat in 1936, turned out, when she was murdered during a robbery, to be of indeterminate gender. In 1967, a number of Soviet athletes who had been asked to strip in front of a panel of gynecologists failed to turn up for the inspection. It was assumed that they had too much testosterone, either because of a disorder or injections.

The aim of testing for chromosomal gender is to prevent unfair competition in sports. Yet it hasn't led to any deserved bans, only to personal misery. The test involves screening cells scraped from the inside of a cheek. If someone has two X chromosomes (making them genetically female) a dark spot called a Barr body shows up inside the cell's nucleus. The first athlete to fail this test was the Polish sprinter Ewa Kłobukowska, who was banned from further participation and ordered to return her Olympic medals (Tokyo 1964). She turned out to have a deviant chromosome pattern of which she'd been unaware, and the affair caused her to become clinically depressed. This test has also been used—quite wrongly—to ban athletes with androgen insensitivity syndrome, like Maria Patino. People with this syndrome have a variation in the receptor for testosterone, which prevents testosterone from affecting their body or brain. Genetically male (XY) individuals with this syndrome therefore develop into heterosexual women. Despite having internal testicles (in the abdominal cavity), they don't possess an unfair advantage in sports. Quite the reverse, in fact, because they lack the effect produced on normal women by testosterone from the ovaries and adrenal glands. Paradoxically, girls with a mild form of congenital adrenal hyperplasia weren't banned as a result of chromosomal testing, even though their higher testosterone levels can generate more muscle tissue. SRY, a new genetic test introduced in the 1990s, didn't improve the situation. Patino was initially felled by the verdict from that test but subsequently fought
back and in 1988 was the first sportswoman to be reinstated. It's not known what test was used in 1950 to impose a lifetime ban on the runner Foekje Dillema, who, according to recent research by Anton Grootegoed, may well have been a woman but also possessed some testicular tissue as a result of a rare chromosomal abnormality. Whatever the case, it meant that top runner Fanny Blankers-Koen lost her main rival, and there are rumors that she or her husband had a hand in initiating a sex test by the Dutch National Athletics Federation. Foekje, too, was ultimately reinstated, albeit posthumously.