Patrick Wall, a pioneer in the field of pain, commented on CIP:
Let us pause here to consider the fact that, very, very rarely, children are born who grow up with no sensation of pain. [They] have been the subject of intense study because they are so fascinating and test all our ideas about the meaning and usefulness of our normal ability to perceive pain.
In an interview with Wall, a Canadian student at McGill University with CIP reported a strong pinch felt merely like a “strong pressure.” Wall continued:
All her other body sensations—touch, pressure, warm, cold, and movement—appeared completely normal. How had she grown up without the massive protection supposedly provided by the withdrawal reflex? She had continuous monitoring by her doctor father, mother, and siblings, who were all aware of her problem. Gross damage such as a cut, burn, or fracture does not need pain to be rapidly detected by the victim. Appendicitis had been diagnosed in her by the signs of fever, inflammation, and gut motility, even though she had no pain. Unusual accidents do occur in such people in novel situations. For example, as a child in the deep Canadian winter, she climbed up to look out of the window and knelt on a hot radiator. One could still see the line scars on her knees as an adult.
The Canadian student died at the age of 22 from osteomyelitis, the same bone infection contracted by the infant described in the Journal of Orthopedic Surgery. Why? Remember what I said earlier about the constant presence of low-level discomfort in our lives, how even as we jog, our stride adjusts to give breaks to parts of the body taking more than normal stress, so they can recover?
Whenever the student was injured in a minor way, this automatic recovery phase did not occur. The surfaces of her joints and ligaments were never given the time to fully recover from stress. This left them in a perpetually weakened state, ill-equipped to face future trivial injuries.
Counterintuitively, severe injuries such as fractures do not have such severe consequences for CIP sufferers. When a limb is severely damaged, it is simply put in a cast and held stationary until the healing is complete. Repetitive minor injuries, on the other hand, demolish the joints of those with CIP over time, particularly the ankles, knees, and wrists. The dead and damaged tissue in the joints then becomes a haven where bacteria can flourish, eating their way through the bone and into the marrow. This explosive invasion, osteomyelitis, is still extremely difficult to treat, even with antibiotics, because the medicine cannot easily penetrate this deeply into the body.
Learning about CIP brought me back to my work in anesthesiology. While under anesthesia, patients have to be cared for with vigilance. Nerve injury can occur if, for example, the patient’s body moves into the wrong position. Even when we’re asleep at home, our bodies feel pain and will adjust to anatomically comfortable positions. Under anesthesia, it falls on the anesthesiologist to vigilantly guard the patient while pain is turned off. Life without pain subjects you to the same need for constant attention.
Golnar Jahanmir, a pediatric dentist at Children’s Hospital in Washington, D.C., works with patients with CIP. In some cases, she and her colleagues have had to remove teeth because a child was continuously biting and producing skin erosions in the mouth. For some children with CIP, what should be pain is actually felt as a tingling that actually drives them to physically harm themselves because they find the sensation stimulating. This brings me back to my childhood. When I’d have a numb lip after a dental procedure, all I wanted to do was to keep biting it. Thankfully for me, that numbness was only temporary.
CIP isn’t the only way our capacity for pain can be lost. Diabetes, a chronic inability to correctly regulate blood sugar, can damage nerves when blood sugar levels are too high for too long. This nerve damage, called neuropathy, can cause patients to lose sensation in their feet and ankles. As with CIP, diabetic neuropathy makes the feet vulnerable to constant, repetitive stress due to walking or running. Because of the patient’s inability to sense the injury, ulcers can eventually occur. Decreased blood flow, also due to diabetes, combined with additional, unremitting pressure on the ulcer can result in infection. By the time these infections are detected, there is often erosion into the bones of the feet, culminating in osteomyelitis. This can result in the loss of the limb or the spread of the infection to other parts of the body.
Another threat to our protective pain response is leprosy. For most of human history, people believed that the disease of leprosy, widespread enough to be mentioned multiple times in the Bible, caused the body’s extremities to rot and fall off. But, as first discovered by the English physician Paul Brand, leprosy’s true effect is to damage the nerves that transmit pain.
After completing extensive work with leprosy patients in India, Brand noticed how patients with the disease would constantly injure themselves without realizing it, resulting in skin ulcers and trauma. One experience at the leprosarium opened his eyes to the effects of the disease, as he later related in his book, The Gift of Pain:
A woman…was roasting yams over a charcoal brazier…The yam fell off the stick, however, and I watched as she tried unsuccessfully to spear it, each jab driving the yam farther underneath the hot red coals. Finally, she shrugged and looked over to an old man squatting a few feet away. At her gesture, obviously knowing what was expected of him, he shambled over to the fire, reached in, pushed aside the hot coals to retrieve the yam, and then returned to his seat.
Aghast, Brand rushed over to examine the old man’s hands. He had no fingers left, only stubs covered in blisters and scars, the pain of which he seemed to be blissfully unaware. This experience led Brand to focus his efforts with leprosy patients on teaching them self-monitoring and constant vigilance. Without pain to warn them of damage to their bodies, they would have to rely on using their eyes. Once he’d successfully taught patients how to do this, the “rotting” effect of leprosy disappeared. Brand’s experiences with leprosy led him to dub pain “God’s greatest gift to mankind.”
Pain as Protector
In medicine, when we treat pain without deciphering the underlying cause, we are making a grievous error. It’s like shutting off the power to a burning building because the sound of the fire alarm is bothering you. You have to put the fire out. If the body heals on its own from injury, medical intervention isn’t necessarily needed, but when pain persists, the underlying cause must be resolved to restore balance. Once the problem is addressed, the pain has served its purpose, which is to get the person to identify the damage and deal with it.
When you get a small cut on your skin, you heal quickly and often with no visible mark. There may be a lesson to learn from this injury, such as avoid sharp objects. A deep wound, on the other hand, usually stays with you as a scar, a visible reminder of an injury in addition to the memory of the pain to remind you of what not to do next time. Pain teaches you to avoid a similar injury in the future by adjusting your actions and behavior.
“But why am I in so much pain for months after my injury?” Patients often ask me why their pain persists so strongly and for so long after an injury. They are frustrated at the slow healing process that limits their activity for weeks to months. I remind them that the pain remains to ensure that they are particularly careful around that part of the body so that it can heal completely.
When we see someone with a lot of scars, we infer that they have endured a lot of pain in their lives and that they are wiser and more experienced as a result. Scar tissue is used as a metaphor for physical or psychological trauma. When we learn from pain, we call it adaptive—it helps us adapt ourselves to the world.
Instead of looking at pain as a discrete, traumatic event, let’s try another perspective. Let’s say you’ve decided to start playing tennis. When you start practicing a new sport in earnest, it’ll hurt. Beyond general muscle soreness, your hands
