Whether it's a dull, underlying ache in your spine or a piercing stab, chronic back pain affects roughly 1 in 4 Americans. UC San Francisco's Prasad Shirvalkar, MD, Ph.D , neurologist and pain medicine specialist, studies the multitude of nerve-to-brain connections that could impact how we treat debilitating back pain.
We asked Shirvalkar about his research on pain and what makes chronic back pain so difficult to treat.
What is chronic back pain?
Chronic back pain lasts more than three months and can be caused by multiple factors, including degenerative disc disease, arthritis, spinal stenosis, nerve compression, muscular irritation, and a combination of these and others.
Sometimes, physicians cannot identify any clear cause at all, but the pain is definitely real.
How does chronic pain compare to "everyday" back pain?
What some people might call "everyday" back pain is acute and lasts a few days to many weeks. This back pain usually comes from muscular strain or arthritis and is treated with conservative measures. Sometimes even a slipped or degenerated disc can cause "everyday" back pain, which sometimes heals itself in some people with physical therapy or exercise.
The mystery is why some people with such back pain have symptoms that resolve completely, while other people go on to develop chronic symptoms that do not go away with time.
Why is treating chronic back pain so complex?
Chronic pain becomes built into the nervous system, and the brain's wiring can actually change. Over time, chronic pain also starts to affect parts of the brain that control mood and thinking.
Understanding how this kind of maladaptive rewiring happens will help us to undo it, try to reverse it, and ideally prevent it from happening in the first place. Pain is transmitted by the nerves in our skin, our muscles, our bones, and, ultimately, is perceived by the brain. If we could understand what's happening in our nerves during the shift from acute to chronic pain, it would be the holy grail for treating pain and preventing it.
What are the standard treatments for chronic back pain?
Chronic back pain is difficult to treat, mainly because there are multiple causes for the pain and no one solution that works for everyone. Certain drugs work well for some people, but most of the drugs we have don't work very well for everybody. Right now, the state-of-the-art is trial and error, and we don't know up front who is going to benefit from a drug that targets an inflammation or nerve dysfunction versus a muscle relaxer to address a spasm.
Are there ways to treat back pain without drugs?
When we approach any kind of pain, especially chronic pain, we first try non-invasive, conservative approaches like physical therapy. We then add acupuncture with oral medications and finally consider procedures like epidural injections or nerve blocks.
The last resort is for more invasive procedures like spinal cord stimulation, which is a medical procedure in which a device called a neurostimulator is implanted to target the spinal cord or peripheral nerves that provide electric impulses to modulate nerves and relieve chronic pain.
What does your research show about how to treat chronic back pain?
In our lab, we used special brain recordings to show, for the first time in humans, that we can predict how bad a person's chronic pain is by looking at signals in their brain. Brain signals for long-term, chronic, pain were different from the ones we saw for short-term, temporary, pain in the lab.
Recently, we took this a step further. We used these brain signals to create the first personalized brain stimulation treatment for chronic pain in humans. We tested this in a careful, double-blind study - meaning neither the patients nor the researchers knew who was getting real treatment and who was getting a fake version.
We used brain surgery to place tiny wires into specific parts of the brain and tested different areas to see where electrical stimulation worked best. Unlike past treatments that used constant stimulation all day and night, we only turned on the stimulation when the patient's brain showed signs of high pain.
Because we only stimulated the brain when needed, we used less energy and reduced possible side effects. This was all possible thanks to new brain-computer technology that lets us both read and change brain activity at the same time.
We hope to translate these insights to a noninvasive brain stimulation, which would be more scalable for chronic back pain. Managing this pain would greatly improve the patient's quality of life.
How can we prevent back pain?
There's no silver bullet, but the best answer is the age-old prescription of exercise. Exercise helps to build muscle, specifically with strength training and balance training, which stabilizes the spine. While daily exercise is critical in helping the body to heal, it also encourages the brain to become more plastic and form new connections that can relieve pain.
What are the best exercises for back pain?
I think the best overall exercises are running and aerobic exercises for stimulating bone growth and keeping the cartilage and tendons healthy. Moderate exercise is best.
Another important group of exercises includes those focused on the core, like planks, sit-ups, and even back arches. Intense yoga or Pilates are great exercises that help focus on the core.
