Strokes and brain diseases can radically change our personalities. But with more understanding of how brains work, a leading neurologist says sometimes, our old selves can be restored.
What makes the self? Is it simply manifestations of the brain? If that’s the case, what happens when the brain is injured or affected by illness? Are we still ourselves?
Masud Husain, a professor of neurology and cognitive neuroscience at Oxford, says brain ailments can not only alter our personal identities but our social identities – how we interact with others. In a new book, he introduces us to patients who illustrate how radical changes in our brain can cause radical changes in our selves – from the extroverted, ambitious young man who completely lost all motivation after a stroke; to the woman whose hands appeared to have an embarrassing mind of their own; to a father whose community standing began to crumble because he suffered hallucinations; to a woman who thought her husband had been replaced.
“Modern neuroscientists would think, I would think, that the self is really something which emerges from the activity of the brain, a constellation of different kinds of capacities, or, if you like, cognitive modules – language, attention, perception, these kinds of things,” Husain told the Listener. “And those modules which created that society of mind can be changed if you take one of those modules away or it becomes dysfunctional.”
It’s not like you’ve lost yourself, he says, but you’ve become a different self. “Your relationships with other people are in a way what defines a self. And if you change in the way you interact with other people, that really alters the way people think about you.”
In an increasing number of cases, modern neuroscience can help those whose brains have become dysfunctional to regain their sense of self. These developments are explored in Our Brains, Our Selves: What a Neurologist’s Patients Taught Him About the Brain, which follows seven of Husain’s former patients at London’s National Hospital for Neurology and Neurosurgery.
Take David (not his real name), the stroke victim who became pathologically apathetic. David had previously been an outgoing, highly motivated extrovert, centre of his social group. He worked as a financial consultant. Unusually, he had his stroke in his 30s, and though he made an excellent physical recovery, overnight his enthusiasm for everything vanished. He lost his job, but couldn’t be bothered even to claim an unemployment benefit. Close friends he moved in with quickly became irritated with him. He didn’t clean or cook, just waited for them to come home and entertain him. “He’d become a stranger to his closest acquaintances,” says Husain.
David’s doctor put him on an antidepressant, but it did nothing. Checking his MRI brain scans, Husain saw he’d actually suffered not one but two strokes. There were two small holes, one on each side, in the basal ganglia deep in his brain. Strokes usually affect only one side of the brain, either through a blockage – ischaemic – or the bursting of a blood vessel – haemorrhage. To have affected both sides of David’s brain, a clot may have originated elsewhere, such as his heart.
David missed his first appointment at the National Hospital. “It just seemed like a long way to go,” he said on the phone later. The next morning, 40 minutes late, a short, wiry man with greasy brown hair and rusty facial hair turned up, wearing a crumpled, stained shirt and glasses. Upon examination, David wasn’t unhappy; he just couldn’t be bothered doing anything. This included spending five minutes reassembling his hi-fi to play the music he used to love.
Motivational keys
The basal ganglia are like “the dark basement of the brain”, as one famous neurologist put it, present in the earliest vertebrates. But in humans, they are closely connected to the cerebral cortex that lies above them. The connections have been found to be critical for many functions, including why and how we move. When the basal ganglia are damaged, as in Parkinson’s, Huntington’s or Wilson’s disease, abnormal movement is often noted. A slowing or rigidity, unwanted thrusts of the head or limbs, or awkward posture of the limbs known as dystonia. But it’s become clear they do far more.
Humans, like all creatures, need a reason to move: to eat or drink, go to safety, reproduce. What is hunger but a motivation to find food? Some neurologists think the basal ganglia act as a crucial bridge between motivation and the initiation to action. In David, one of the parts of the basal ganglia, the nucleus accumbens, was intact, but the ventral pallidum had been damaged. Both these regions appear to be necessary for motivated behaviour.
Within a few months, David had gone from “in-group” to “out-group”.
“Motivation to behave in the way that is expected of a group member is a key part of belonging,” says Husain.
The evolutionary psychologist Robin Dunbar notes that “free-riders” challenge the mutual trust within a group. Social groups probably originally evolved because of benefits such as mutual protection and the ability to hunt, share food and knowledge. But this involves unwritten contracts, such as honouring social obligations and contributing without expectations of return. For many people with a brain disorder it is not possible to meet social expectations, and ostracisation may result.
David easily passed perception, attention, memory, language and visuospatial tests. Husain’s research group had developed a new test to measure risky decision-making for rewards. To make the most money, participants have to take a risk of a small penalty by anticipating the change of a traffic light. David never anticipated. In the jargon, he had “blunted sensitivity to reward”. He couldn’t be bothered because the outcomes didn’t matter to him.
Dopamine is generally regarded as the “pleasure” chemical. But most researchers now believe it acts as a key chemical to motivate us to seek pleasure or reward, says Husain. Dopamine is also a key brain chemical for the basal ganglia. When parts of it are depleted of dopamine, people can develop the motor features of Parkinson’s. This was untreatable until researchers found a way to boost the levels of dopamine in the brain. Oliver Sacks records some early studies in his book Awakenings. Neurologists such as Sacks used the precursor of dopamine, levodopa, combined with a drug that stopped its breakdown in the blood if taken by mouth, to amazing effect in Parkinson’s patients. But David had no problem moving, only being motivated to move.
Over several weeks, David’s dose of levodopa was increased. But it made no difference. Husain had an idea. Many Parkinson’s patients are now treated with levodopa and drugs that mimic dopamine by locking on to nerve cell receptors that bind the neurotransmitter. One problem is that such dopamine agonists can make some patients too incentivised to seek rewarding outcomes, leading to excessive gambling, going on rash shopping sprees or becoming hyper-sexual. David was put on a dopamine agonist called ropinirole. Three months later, he was a changed man. In the waiting room was a clean-shaven guy with a sharp haircut in an immaculate navy blue suit. David had got a job, moved out of his friends’ flat and even met someone. “I’m really happy,” he said. This time he aced the traffic-light test. Thanks to ropinirole, David had become a highly motivated individual.
David proved a turning point in Husain’s life and research. It was possible to turn a pathologically apathetic individual into a motivated and independent one.
“Motivation is a key attribute of human brains and of being human. It’s a brain ‘function’ we usually take for granted, but it shapes our identities.”
David suffered a rare brain injury, but about a third of patients with Alzheimer’s, vascular dementia or Parkinson’s develop pathological apathy, says Husain, and this is something that can grate on partners more than loss of cognitive function. Brain scanning has found that the circuit that was dysfunctional in David is also disrupted in apathetic people who have vascular dementia.
History matters
Modern science can increasingly help people suffering neurological problems. Such as Anna, whose wandering-hands problem went away after corrective surgery on her brain. Or Wahid, who saw hallucinations due to a form of dementia and was helped by rivastigmine, a drug that boosts the levels of acetylcholine, another neurotransmitter, in the brain.
Often, the difficulty for the neurologist is to tease apart what is reversible from what looks like a structural neurodegenerative condition. Poor sleep, anxiety, stress or depression can powerfully affect cognitive function. Then there are those who have neurodegenerative diseases and naturally develop anxiety. “More than the brain scans, it’s actually necessary to get the history from the patient.”
But neurologists can’t always give people the help they’d like. Such as Husain’s patient Michael, an immaculately dressed, well-spoken, ex-finance fellow who, despite having a good memory and awareness, had begun to lose his words and concepts – his “semantic memory” – because of brain disease. He lost his ability to tell and understand jokes. “He always made me laugh,” said his wife. “The fun has gone.”
Jokes demand sophisticated comprehension of language and concepts, and, like memories and perceptions, are vital to people’s social identity. Although Michael’s condition was irreversible, a diagnosis often provides comfort that symptoms are not imagined.
Easing the burden
Cases that are absolutely successful, like David or Anna, are rare, Husain says. “Of course, in Alzheimer’s disease the successes are small. But it’s a huge burden for families and partners. So many of the partners say, ‘I was really looking forward to retirement and I’ve lost the man I married.’ If you can even lighten that burden a little bit I think it’s important.”
Even if we are still a long way from having a perfect description of how the brain works, things have improved markedly for neurological ailments in recent years, he says. Tests and scans are more able to diagnose what is going wrong. More drugs are available to treat symptoms such as a deficit of dopamine or acetylcholine. Electrical stimulation of parts of the brain is being further investigated, as are brain implants. Sometimes, surgery can help, as with Anna.
Hallucinations caused by dementia were helped by a drug that boosts a neurotransmitter.
Twenty years ago, says Husain, the National Hospital for Neurology and Neurosurgery had one consultant looking after dementia patients. Nothing could be done for them, and it was an unfashionable thing to be studying. Now, there’s an entire building working on neurodegeneration.
“That’s because of the advances that have occurred. The money in the last 30 years has gone to cancer and cardiovascular disease. Suddenly, people are switching to thinking about whether we can do something about these conditions. And it’s not just what we call disease-modifying drugs, which can slow the progress, but drugs that treat the symptoms and make patients’ lives and carers’ lives better on a day-to-day basis have also emerged in that time.”
A major change came last year, says Husain. “The Food and Drug Administration in the US approved two new drugs which appeared to slow down the progress of Alzheimer’s disease by mopping up the amyloid proteins.
“This is still a very controversial area because even those effects are small. But if we think about how we reduced the incidence of heart attacks, those effects were also small. But over a population level, it’s made a huge difference.
“Statins don’t cure heart disease, but they have prevented so many [heart attacks]. Aspirin has added on another layer. So these small increments have made a huge difference, such that now the kinds of people who you used to see in their 50s who’d be having heart attacks are really quite rare.”
Early detection
Treatment of brain disorders is a young game, he says, and with new research and funding even small gains might be the beginning of something better.
“Now that two drug companies have succeeded, the others are looking at compounds on their shelves and thinking, ‘Maybe we should try these out.’
“But it’s a very costly affair: each drug, to take to a clinical trial and look at the outcome, is billions of pounds.”
Husain accepts there is now debate about amyloid and tau proteins in the brain being not the cause but the result of disease. “But what I would say is the state of the art is that the deposition of amyloids probably triggered something [that led to the neurodegeneration]. And it triggered something, perhaps 10 years, even more, before the patient comes to see us. So, mopping up the amyloid 10 or 15 years later might make a little difference.”
As much as the new drugs, he’s optimistic about screening. “We now have cognitive tests that we can do online with people. We also have blood tests which, in the last two years, have really shown you can detect Alzheimer’s disease just as well as if you’d had a fancy PET scan.
“And if you could imagine doing that on a national scale – sending a link out every year to people in their 50s [to] do the cognitive test – [and] if there’s something not quite right on that test we send you a pinprick blood test device. You put it in the post, we analyse it, and if we’ve picked up something that isn’t right, say, a marker for Alzheimer’s disease, we can bring you in and think about what else we can do at that stage.
“That’s the problem – we’re seeing people 10, 15 years after the pathology starts.
“There’s also vascular risk factors: making sure people’s blood pressure is okay, their glucose isn’t too high, they’re not smoking – that would make a huge difference if we started that in middle age.
“We now know that most people with Alzheimer’s disease probably have some degree of co-existing vascular disease. On a population level that could be a huge change.”
