GREAT STRIDES
How one boy changed a doctor’s thinking about the brain. Excerpt,
I first saw Daniel as a premature infant when I was a neonatology fellow at the Hospital for Sick Children in Toronto. Daniel was born at 26 weeks. In the first week of his life, he developed a major bleed into the right side of his brain, damaging the areas that would normally control the left side of his body.
A 26-week infant is tiny. Daniel at birth weighed 750 grams, about a pound and a half. When I started in neonatology in the 1970s, he would have had, at best, about a 50-50 chance of surviving. Daniel survived, but the common wisdom at the time was that the damage to his brain was permanent and would lead to disability. The expectation was that he would have difficulty with both gross and fine motor skills. We knew he had a brain lesion, so he was started in therapy fairly early.
To my surprise, the disabilities that developed in Daniel as he grew from infancy to childhood, as measured on a standardized scale of function, were not too bad. As I expected, he limped on the left side, landing on the front half of his foot, not his heel. His left arm hung at his side and did not swing normally when he walked. His right side was unaffected and his speech and cognition were normal. I diagnosed him with a left-sided hemiplegia, a type of cerebral palsy that affects the motor functions just on one side of the body. Hemiplegia is found in roughly 40 per cent of all children with cerebral palsy, and, like Daniel, 99 per cent of these children are able to walk.
The Neonatal Follow-Up Clinic, where I worked, tracked patients for only the first three to four years. Daniel had been discharged for several years when his mother phoned me with news. She told me he was now playing soccer, not just in a league that accepted children of diverse ability, but in a league for competitive, able-bodied children.
The hell he is, I thought. What I said was, “Oh?”
I didn’t believe her. Daniel being able to play competitive soccer was outside my understanding of hemiplegia. I assumed, as many doctors would have, that an overly optimistic mother was seeing a degree of recovery that just wasn’t there. Still, I arranged for her to come in with Daniel so I could see for myself. When they came, I had him walk up and down the hallway to confirm that he still had the typical gait of a child with mild spastic hemiplegia. He did. Then I asked him to run. And, to my astonishment, he ran like a normal little boy, with an easy, balanced stride and reciprocal arm movements. He performed tight pivot turns, at speed, on both legs. Even the left leg, which had a limp when he walked, performed perfectly when he was running.
For a moment I was speechless. (Anyone who knows me knows this rarely happens.) Then I said, “You can’t do that!” And I meant it. I could not, for the life of me, figure out what was going on. We all know children learn to walk before they run. It’s a phrase embedded in folk wisdom. And yet, here was a child who had turned conventional wisdom upside down.
My first instinct was to think of Daniel as an outlier, an exception who somehow defied the rules. The natural history of cerebral palsy has been studied and described over a period of decades, and Daniel’s ability to run so well didn’t fit the description. It was incomprehensible in terms of the accepted theory of permanent brain damage that my fellow physicians and I understood. Which is why I said, “You can’t do that!” What he was doing was impossible. Daniel’s ability to run was great for him but it posed a problem for me and, indeed, for anyone treating children with cerebral palsy. We walk and run using the same parts of our brain. Daniel’s brain — specifically the corticospinal system on the left side of his brain that controls movement — was injured, so I thought there was no way he could run. But he could run really well. (He could also turn at speed and kick a soccer ball accurately with either leg, but, frankly, his running was enough of an issue without my having to take these added abilities into account.)
It took many years for me to realize that our assumptions of permanent brain damage were wrong and his normal run meant that his brain had recovered from the early injury. The damage had been repaired. Or the brain had grown and its capacity had grown with it. Or new neural pathways had been forged in his brain to get around the original damage. In the late 1970s, these were all new ideas when it came to thinking about the outcome of brain injury in newborns. The idea that the brain can grow, adapt and recover from damage has been the subject of research and debate for many years, but the majority of research into neuroplasticity had been in animal studies or adult human diseases and injuries. As far as I knew, very few people had speculated that an infant’s brain could heal itself as the child grew up. It didn’t occur to me then either. All I had when I saw Daniel run were questions.
What is going on? How is this possible?
Once I had noticed the discrepancy between Daniel’s poor walking skills and his superior running skills, I started to see more examples. Most experienced therapists can help a child with mild cerebral palsy produce, in as little as a one-hour session, a short-distance walk with a perfectly acceptable, heel-to-toe reciprocal gait. In North America, this is frequently called a “therapy walk.” To the endless frustration of both therapists and parents, the child who has laboriously acquired a new way of walking in the therapy session loses it on the way to the parking lot for the trip home. The more familiar unsteady gait of the child with hemiplegia reasserts itself.
Even the children know the difference between their therapy walk and their habitual walk. When asked to demonstrate their “best walk,” most children with mild cerebral palsy will straighten up and walk normally. They have been drilled by their therapists and have practised these correct movements many times. When asked to demonstrate their regular walk, they happily go back to the abnormal gait that is their comfortable habit. If you ask why they do not keep walking as they have been taught, they say it doesn’t feel normal to them. They can do it, but it doesn’t feel comfortable. For Daniel, his limping gait was his normal. What the therapist taught him felt weird.
Over years of clinical practice, I have found that most children with mild to moderate cerebral palsy run better than they walk. This fact is known by most experienced therapists, orthopedic surgeons and physicians, but they, like me, did not stop to think it through. If the run is normal, if the therapy walk is ever normal, even briefly, then the corticospinal system must have recovered.
Thirty-five years after treating Daniel, it is now obvious to me that children with early neurologic damage can have two or more completely different skill levels all originating from the same area of the brain. There are thousands of children just like him.
A mother sent me a soccer card of her son, the kind of imitation bubblegum card that professional photographers make when they take pictures of children in organized sports. It showed that her boy, diagnosed with the same kind of CP as Daniel, was playing soccer, too. I saw children with cerebral palsy who rode bicycles, who skateboarded and iceskated.
Even rollerblading, a skill I would not even attempt, was not beyond the reach of a young boy from California who did not let the diagnosis of spastic cerebral palsy hold him back. This young boy could walk only with an unsteady, lurching gait that is characteristic of diplegia, affecting the motor control of both legs, yet he was able to rollerblade with skill. I met another boy with hemiplegia who was playing on his high school basketball team. He could run, turn, jump and pivot and even throw the ball accurately using both hands. I learned later that he went on to coach the sport.
Probably the biggest shock was a teenager with mild athetoid quadriplegia (meaning all four limbs were involved, with significant co-ordination and balance problems) who won a gold medal at a swim meet in the butterfly event. For those who are not swimmers, this is a stroke that defeats many an able-bodied swimmer. Her parents showed me videos of her competing. She would walk up to the starting block with all the awkwardness associated with her condition and then swim like a dolphin. In a variety of ways, children with CP were showing me that their hemiplegia, diplegia and even mild quadriplegia, obvious when they walked, disappeared when they took part in challenging higher-order activities.
I got another surprise when the mother of a little girl made an unexpected observation. We were watching her daughter walk in the hall of the clinic. By this time I had made walking and running in the hallway a routine part of my initial examination of every patient who was able to walk. She had spastic hemiplegia: she could bring the affected leg only about half as far forward as the un- affected leg. The medical term for this is a shortened stride length.
“She walks better backwards,” said her mother.
What? It’s not something you think of ordinarily. How often do we walk backwards?
I said, “Show me.” The child backed up as easily as an able-bodied person would, with no sign of spasticity, perfectly balanced. She had a normal stride length on both sides.
We walk and run with the same parts of the brain. This means that the highest-order or “best” skill reflects the degree to which the brain has recovered from the early injury. The lower skill level is the habit acquired when the brain was still damaged.
When I saw Daniel run, what I was seeing was definite evidence of brain recovery. And when I saw him walk, I was witnessing a well-established habit that is not easily shed. I now understand that many of the earlylearned movements of a child with cerebral palsy are habits. And habits can only be replaced with new ones with difficulty. But they can be replaced.
Excerpted with permission from The Boy Who Could Run But Not Walk: Understanding Neuroplasticity in the Child’s Brain, by Karen Pape, MD (Barlow Books).