San Diego Reader

Most stories begin with a person or an event. This one begins with a book.

Last summer I read The Brain That Changes Itself by research psychiatrist and psychologist Norman Doidge, M.D., which discusses developments in neuroscience, especially in the area of neuroplasticity. Now, if I were in a bar and the guy on the next stool leaned over and said to me what I’ve just written here, I’d give a wave to the bouncer. But hang on.

When I was in school, I was given two pieces of information about the brain that, well, stuck in my brain. The first was that the brain was hardwired, meaning that each bit of the brain had a specific function and if that bit were damaged then that particular function was lost forever. The second piece of information was that even though the brain consisted of billions of nerve cells called neurons, I was constantly losing them and I would never get them back.

As a kid, it seemed I was so rich in neurons that the loss caused by a few six-packs during the week or a rough pickup football game without a helmet meant nothing. After all, I was a billionaire.

But as I moved into old age, it seemed I could feel windy places between my ears where megalopolises of neurons used to be situated, dank caverns inhabited by gloomy question marks bent over smoking piles of dead synapses. Some days it seemed as if I only had about 475 neurons left. Some people hear a ringing in their ears? I heard creaking.

Then I read Doidge’s book and learned that all that was a lot of baloney. If one part of the brain is damaged, its function can often be picked up by another part through the creation of new neural pathways. This has resulted in vast improvements and even cures in a number of conditions, from stroke to irrational compulsions, worries, and obsessions. It has also led to new ways of fixing learning problems and sharpening perception and memory. And this is only the beginning of the list.

Those lost neurons? If you don’t watch too much TV and continue to read books, a sizeable number can be replaced.

When I finished the book, I read a few others on the topic and it turned out that one of the top neuroplasticity guys was at University of California, San Diego: Dr. V.S. Ramachandran, who is director of the Center for Brain and Cognition and professor of psychology and neuroscience. His most recent book, The Man with the Phantom Twin, came out in January, and he has published a handful of other books and well over 150 articles and has enough medals, awards, and certificates of merit to fill a large living room. Newsweek has named him one of the hundred most important people to watch in the 21st Century.

One of Ramachandran’s books, Phantoms in the Brain (1998), has a section about phantom-limb syndrome, a condition found in nearly all amputees that makes them experience feeling in the missing limb, as well as feeling that they can move the limbs, as in waving goodbye or kicking a ball. Many people whose bladders have been removed (or genitals or rectums or uteruses or ulcers) can also feel phantom sensations — but that is another story.

Many of those who lost a limb have also experienced intense pain in the phantom limb, pain that might keep them awake night after night and continue for years. Well, Ramachandran invented a device that cured or substantially helped a majority of the amputees he worked with who suffered from this pain. And what struck me most was that the device only cost a few bucks.

Before I describe this gadget, let me describe my friend Glenn, who cracked up his motorcycle in 1991 when he was in his 20s. Swerving to the left to avoid an oncoming car, he hit the curb, and the motorcycle toppled over and mushed his left leg. When he woke up in the hospital, his leg, below the knee, was gone. About 4500 men and women are killed on motorcycles each year, and about 85,000 are injured. A fair number of those are part of the approximately two million amputees in the U.S.

What Glenn soon discovered was that the leg didn’t feel gone. He could move his phantom toes, waggle his phantom ankle. At times it tingled as if it had gone to sleep. Most disturbing, at times it felt as if a knife were being driven into it. The pain would often occur when he got home from work and was trying to relax. Or it would occur at night: a phantom knife blade through the phantom foot to make him jump out of bed.

The tingling sensations and waggling of the phantom toes can occur every day. The pain has become less frequent over time; it happens now perhaps once a month. Still, it has never gone away. Glenn is a tall, handsome guy, over six feet, with jet-black hair and a neatly trimmed beard. Mostly, you wouldn’t notice that he has a fake leg, but if he’s tired he’ll limp a little. “They’re heavy,” he told me, “even the expensive ones. They’re always dragging at you.”

The number of amputees who suffer from phantom pain ranges from 50 to 95 percent, depending on which specialist is asked, but the most agreed upon number is around 75 percent. Usually it develops soon after amputation, but it can also begin after a few months or even years. For some people it might get better after a year or two, for others it never stops. Often the pain comes in bursts several times a day, but some experience it less than once a month. A much smaller percentage have it constantly. With missing limbs, the pain often occurs at the end of the limb, or it feels as if the limb is shorter or twisted into a painful position, or as if something is being jabbed into it, or as if it’s on fire. Stress and anxiety can affect the pain, even changes in the weather.

Aspirin gives no relief, but anticonvulsant drugs and heavy painkillers like morphine have helped some amputees. Others have been helped by a transcutaneous electrical nerve stimulator, or TENS, a battery-driven device about the size of an iPod that delivers electrical impulses to stimulate nerves in the painful area. Somewhat more effective has been a spinal cord stimulator, an electric impulse-generating device implanted near the spinal cord. Hypnosis, acupuncture, biofeedback, vibration therapy, massage, yoga, ice packs, heating pads, and even steroid shots have also been useful. But what seems most significant is that nothing helps very much. The pain is often most severe when the prosthesis is removed, and so patients are encouraged to use the prosthesis as much as possible.

According to Doidge’s book, Ramachandran’s research led him to think that the absence of feedback from the missing limb to the brain leads not only to the phantoms but to phantom pain. “The brain’s motor center might send commands for the hand muscles to contract but, getting no feedback that the hand has moved, it escalates its command” until, for instance, it feels as if the fingernails are digging into the palm. This oversimplifies Ramachandran’s findings, but he felt that the phantoms were a result of the brain’s mistaken body image. If the image were reinforced, he reasoned, the pain might vanish.

Advances in prosthetic technology have been hugely affected by the Iraq War, and by 2004 new prosthetics were coming onto the market that seemed more products of science fiction than medical technology. The Otto Bock C-leg has a battery-powered “onboard” microprocessor that controls knee movement and communicates with a computer through Bluetooth technology. It can switch between two modes of activity with several taps of the toe.

The C-leg, however, is receiving serious competition from the Ossur Bionic Power Knee, which can synchronize movement with the sound leg to “lift the user to standing from a seated position; support the user while ascending inclines; and power them upstairs.” When the user is walking, the knee’s pendulum motion swings it forward, senses the changing terrain, and “actively lifts the heel off the ground,” according to Ossur’s website. By means of “artificial proprioception,” which is a person’s awareness of his or her posture, movement, balance, and location, the knee “anticipates and responds to the appropriate function required for the next prosthetic step.” There are also power heels to give the walker a boost so the prosthesis won’t, in Glenn’s words, “always [be] dragging at you.”

Yet these bionic prosthetics are nothing compared to what is currently in development. In February, the Defense Advanced Research Projects Agency (DARPA) awarded a contract to the Applied Physics Laboratory at Johns Hopkins University to finish work on a mechanical arm “that will look, feel and perform like a normal limb,” according to the online magazine Gizmag. The Johns Hopkins laboratory, leading a team drawn from about 30 organizations, had already developed two prototypes of prosthetic arms. The first is an arm that “can be controlled naturally, provide sensory feedback and allow for eight degrees of freedom.” The best prosthetic arms now on the market provide for only three degrees of movement. The second prototype uses 25 individual joints “that approach the natural speed and range of motions of the human limb…[and] are complemented by a range of emerging neural integration strategies,” meaning they can be wired to the brain through the nervous system. You think your hand into motion and it moves. The arm should be ready for regulatory clearance in under two years.

< PREVIOUS | NEXT >