What is SDR?
SDR stands for selective dorsal rhizotomy. It’s a spinal cord surgery for people with cerebral palsy (CP) or hereditary spastic paraplegia (HSP) who have spasticity, which is muscle tightness resulting from mixed-up messages between the brain and spinal nerves. During SDR, the surgeon divides the spinal cord’s sensory nerves into their smaller branches, called rootlets, and then cuts the rootlets that are most overactive, thereby getting rid of spasticity in the lower body. Currently, SDR is the only treatment that can eliminate or permanently reduce spasticity.
Is this website for Dr. Park’s patients only?
No! I want this site to be a resource for all SDR patients and their families. That said, you’ll notice that much of the information on this site is geared toward Dr. Park’s SDR and St. Louis. I’m not affiliated with the St. Louis hospitals or Dr. Park (except as patient). But here’s why this site focuses a lot on St. Louis:
- Dr. Park is considered the world expert on SDR. SDR can be (and is often) successful with other surgeons, but the technique (and therefore, the outcomes) vary so much from surgeon to surgeon. It’s not fair to compare Dr. Park’s SDR with an SDR done by an inexperienced surgeon or a surgeon who only cuts 20 percent of the nerve rootlets. Even surgeons who say they use “Dr. Park’s technique” can’t possibly perform SDR in the exact same way because it’s such a nuanced surgery. Again, that doesn’t mean that SDR is only successful when people go to Dr. Park. But you need to be careful in your selection. I trust Dr. Park, and while other great SDR surgeons are out there, I can’t in good conscience recommend SDR done by any random neurosurgeon.
- Dr. Park has done SDR on more than 4,200 patients over the past 30+ years, and he has published a wide body of research and statistics about his specific version of the procedure. He is also very active in the SDR community. To my knowledge, no other surgeon in the world has published as much SDR research or has done nearly as many SDRs, so it’s much more difficult to find detailed information about other centers.
- Dr. Park did my SDR, and he was the SDR surgeon for the majority of the SDR families/patients I’m familiar with. As a result, I have the most information about his center. Furthermore, more families go to St. Louis for SDR than any other city, so I thought gearing this site toward St. Louis would maximize the number of people I could help.
How do I know if I’m a candidate for SDR? If I’m an adult, am I out of luck?
Please see the How to Apply tab. As of 2020, Dr. Park has operated on over 150 adults ages 18 to 50 with cerebral palsy and its genetic equivalent, hereditary spastic paraplegia (as well as 4,000+ patients overall). Other surgeons throughout the country and the world have also started doing SDR on adults. Note that the recovery tends to be more difficult for adults, and there are more risks, especially for adults toward the end of that age range (some experience long-term nerve issues, for example). You need to do your research and decide if SDR is best for you, and it is important to manage expectations according to your individual situation. But I encourage you to explore your options and seriously consider SDR even if you’re an adult with CP. SDR was life-changing for me and many others!
Also, if you’re an adult (18+) who is seriously considering SDR, feel free to contact me about joining a private SDR adult support group.
Does it matter which surgeon I choose?
Yes—it matters completely!!! SDR is a very nuanced surgery and no surgeon performs it exactly like another.
Some surgeons cut a lower percentage of nerves—I’ve seen as low as 20 percent—aiming to leave some spasticity behind. (In my opinion, this is problematic, because spasticity can cause physical deterioration over time, and SDR cannot be repeated to cut additional nerve rootlets if needed.)
Another difference is the type of SDR procedure that surgeons perform. Some surgeons perform an older version of the procedure called a multi-level laminectomy. This version of SDR is much more invasive because it requires removing many pieces of vertebrae from the back; the recovery process is longer for multi-level SDR, and studies have found that it can lead to a higher risk of back deformities like spinal curvature (scoliosis).
Many people opt to go to Dr. Park in St. Louis, Missouri, USA, because he is considered to be the world’s expert on SDR. Dr. Park pioneered the single-level, minimally invasive form of SDR, which only requires removing one piece of bone and has not been shown to increase the risk of spinal deformities. His success rate is extremely high, and he has performed more than 4,000 SDR surgeries since the 1980s. Dr. Park aims to eliminate spasticity and typically cuts about two-thirds (66 percent) of the sensory nerve rootlets leading to the lower body.
Some families choose to pursue SDR with a different surgeon, frequently due to financial/insurance constraints (although SDR at St. Louis is often covered by insurance even for people who are out of state; mine was). Many are happy with their results. But done incorrectly, SDR can have very serious consequences, including paralysis, incontinence, significant residual spasticity, and other side effects. You must choose your SDR surgeon carefully and remember that all SDR surgeries are not created equal! The surgeon you select can have a tremendous impact on your overall outcome, for better or for worse. Take a look at this page for questions you can ask your surgeon.
Does anybody regret SDR?
Yes. All surgery has risks. The research indicates that the overwhelming majority of patients *do not* regret their SDR (especially when it is performed by an experienced, reputable surgeon), but the satisfaction rate is not 100 percent, particularly among adults. Those with negative experiences tend to be quieter about their situation; often, they feel more comfortable sharing their stories in private groups. People who pursue SDR as adults are at risk of developing chronic nerve pain, especially if they have SDR in their 40s. Adults in their 40s are also at the highest risk of experiencing sensation loss, although in my experience, people with this side effect tend to still report that SDR was worth it for them. Other risks include paralysis, incontinence, and chronic back pain (particularly with multi-level SDR), although these risks are rare as well and are minimized if you pursue SDR with an experienced, reputable surgeon.
Adults with significant pre-existing orthopedic issues also tend to struggle a lot after SDR. These patients may not necessarily regret their SDR, but they may find that it doesn’t solve their pain in the way that they had hoped, and their rehab process tends to be harder.
In addition, even in the absence of complications, patients must be willing to fully commit to the post-op rehab in order to get the most out of surgery.
With that said, many patients and families seem to say that their only regret is that they didn’t know about SDR sooner. That’s my only regret as well; I wish I had the opportunity to receive SDR when I was younger … and that’s why this site is here.
Is SDR just for people with cerebral palsy (CP)?
No, it isn’t just for people with cerebral palsy! The main other group of people who have pursued SDR are those with a genetic neurological condition called hereditary spastic paraplegia (HSP) that can sometimes mimic spastic diplegia CP. Dr. Park in St. Louis operated on his first patient with HSP over 30 years ago, and she is still spasticity-free. (This patient had gone her whole life being told she had CP, but years later, her child was born with similar issues. That’s when her diagnosis changed to HSP instead.) Since then, he has operated on about 30 others with HSP.
More rarely, other surgeons have performed SDR on people with other neurological conditions that involve spasticity, including multiple sclerosis (MS), spinal cord injury, ALS, and adulthood stroke (see Gump, Mutchnick, and Moriarty 2013). According to this review, although there weren’t very many cases to evaluate, the results were generally satisfactory. However, it would probably be pretty difficult to find a surgeon willing to perform SDR for people with these conditions.
What are the benefits of SDR?
When someone is a candidate for SDR and they pursue it with a reputable, experienced neurosurgeon, the benefits can be tremendous. SDR has allowed me to move more freely and more comfortably, strengthen my muscles more effectively, and develop so many new skills. I love the feeling of being able to relax my body more. It has also helped my startle; I still jump more easily than most people (this is part of CP, because the brain doesn’t inhibit that reflex as well), but my muscles don’t tense up as much when I do, so it’s much more comfortable. Also, people with spasticity tend to experience early aging of their muscles and joints because their constant tightness puts a lot of stress on their bodies. SDR can slow or reverse that early aging process to help prevent the effects of CP from becoming more pronounced over time. (With all this being said, do keep in mind that the results may vary, and that SDR isn’t a magic solution, cure, or “easy fix.” Patients must be willing to commit to intense rehab after surgery, and benefits also depend on age, pre-existing orthopedic issues, the surgeon you choose, etc.)
What are some of the challenges I may face if I have SDR as a teenager or adult?
As a general rule, SDR recovery is more difficult for teens and adults compared to children, for older adults especially. Here are some of the longer-term challenges that teens and adult patients have reported:
- The brain tends to be less neuroplastic (adaptable) with age, so it’s harder for the brain to rewire itself and to break old habits that were developed in the presence of spasticity. SDR is often a journey of patience … especially for adults. ♥
- Some post-SDR teens and adults experience “nerve zaps” in their legs: little needle-pricks of pain in their legs that last for a second or two and come every now and then. Oftentimes there’s no trigger for these needle-pricks, but sometimes people experience increased increased zaps and tingling in their legs after intense exercise. This has been my experience too; I’ve found that when I *really* overdo it at the gym I sometimes get these zaps intermittently for a few hours later on, as my muscles recover. They aren’t fun, but many of us have found that resting, stretching, and magnesium supplements are helpful until they subside.
- Some people have increased sensitivity in their feet. (For some patients, the opposite is true: pre-SDR, some people say they jumped whenever someone touched their feet, and now that they’re more relaxed, their feet aren’t as jumpy. This is my experience too, although my feet and legs were definitely hypersensitive in the beginning of my recovery; the hypersensitivity resolved gradually for me over the course of a year and a half.)
- Some people have patches of reduced sensation on their legs or feet, especially older adults.
Note that the hospital stay and early recovery process may be more difficult for teens and adults as well. See the Hospital Stay tab for some tips and information to help guide you through.
Can SDR be done more than once?
No. That’s why, if you’re considering SDR, it’s really important to choose a reputable, experienced surgeon. SDR cannot be undone or redone.
Is SDR a cure for cerebral palsy?
No, SDR is not a cure. I like to think of it as a surgery that can unlock potential: It may allow you to move more freely, gain new skills, and strengthen your muscles more effectively, but you must be willing to put in the work afterward. The results also depend on many other factors, including the severity of CP, age, and existing orthopedic issues. I don’t want this website to give false hope.
Also, while it is an excellent treatment option for many patients, there are limitations. It does not address upper body spasticity; some patients report improvements in their upper body after SDR (see a possible explanation in the Science FAQ), but this should be considered a happy side effect—it’s not something that you should necessarily expect to gain from surgery. In addition, it does not fix muscle contractures (permanent shortening of the muscle itself), so you may still have some muscle tightness even after your spasticity has been eliminated. That’s why many people have PERCS afterward.
Also, while balance, flexibility, gait, etc. may improve after SDR, most patients still have issues in these areas. SDR addresses spasticity, but it does not fix the actual brain injury that causes CP, so your brain will still have trouble sending signals to your legs, and habits + long-term buildup of orthopedic issues can be tough to deal with even after SDR.
Will spasticity return after surgery?
The rate of spasticity recurrence may depend on the individual surgeon, but for Dr. Park’s patients, return of spasticity after SDR is pretty rare, occurring in a very small percentage of patients, and if it does come back, it tends to be less severe than before SDR.
People with quadriplegic (whole-body) CP are at greatest risk for recurrent spasticity, but it can happen in diplegics too (particularly diplegics who were born full-term with no brain abnormalities on their MRI; I read somewhere that the risk of recurrence in this subgroup is around 1 percent, although I don’t know if this statistic is still accurate.). Recurrence can also happen in a minority of people who had SDR as adults, and no one knows exactly why in any of these cases. If it does happen, I was told it typically occurs within 6 months of surgery, and that even if it does recur, it tends to be less severe than before surgery if the person was able to walk independently or with assistance. Sometimes, people with severe quadriplegic CP who cannot walk with assistance have SDR purely for palliative (comfort and hygiene) reasons; these patients are at risk of full return of their spasticity. The risk of recurrent spasticity appears to be highest in people who are completely non-ambulatory or cannot walk much even with a lot of assistance.
Can I expect SDR to fix my pain?
I wish I could give a definite “yes” to this question, but it really depends on your situation. This would be a question to ask your SDR surgeon and other doctors. Some people pursue SDR with the expectation that it will fix their pain and are then disappointed—often teens and adults with pain related to orthopedic issues, not spasticity, and it’s not always easy to tell where that pain is coming from until after SDR. So with that in mind, I don’t want to give false hope.
I definitely had pain relief after surgery, because much of my pain and discomfort was related to my spasticity. I still have CP-related pain some days (sometimes a knee will bother me, sometimes an ankle, etc.) but it tends to resolve more quickly and is much less of a burden compared to before SDR! I’m also hopeful that I’ll have less pain in the future now that I’m living without spasticity; that was a major reason I pursued SDR, and so far, it seems to be the case for me.
What are some of the possible consequences of spasticity?
- Early aging (including early onset arthritis; a significant proportion of people with spastic CP develop arthritis even in their 20s and 30s)
- Contractures/permanent cellular changes in muscles and tendons
- Bone deformities
- Inability to fully strengthen and stretch muscles
- Chronic pain and discomfort
- Negative changes alignment and posture
In addition, spasticity often negatively affects concentration and sleep—and for me, it seemed to cause anxiety as well. Studies have shown that tension in the body often translates to tension in the mind, and vice versa. Now that my spasticity is gone and my legs can relax, my mind is more relaxed too.
St. Louis Children’s Hospital has a helpful informational page here: https://www.stlouischildrens.org/conditions-treatments/center-for-cerebral-palsy-spasticity/about-selective-dorsal-rhizotomy