In this episode, Dr. Blake Taylor leads a discussion focusing on sciatica, its causes, and treatment options.
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Sciatica and Herniated Discs
Blake Taylor, MD
Dr. Blake Taylor is a neurosurgeon who cares for patients with disorders or injuries of the spine and brain using minimally invasive and complex techniques. He specializes in treating patients with spinal disorders related to degenerative diseases, traumatic injuries or cancer; brain injuries or tumors; and bleeding in the brain; as well as patients in the hospital for neurointensive care. He has expertise in using computer-assisted navigation to treat certain spinal conditions, such as cervical myelopathy, cervical and lumbar disc herniations, degenerative disc disease, kyphosis, spinal stenosis and spondylolisthesis.
Sciatica and Herniated Discs
Dr. Rania Habib (Host): The National Institutes of Health estimates that 10 to 40% of Americans will experience some sort of sciatica in their lifetime. The most common cause of this pain is a herniated or bulging disc. Sciatica pain can be life-altering, so it's important to understand sciatica, its causes, and treatment.
Welcome to The Healing Podcast, brought to you by MarinHealth. I'm your host, Dr. Rania Habib. Joining me today is Dr. Blake Taylor, a UCSF neurosurgeon who sees patients at MarinHealth. Dr. Taylor is an expert in helping people improve pain and disability that can be caused from spine conditions. Today, he is going to talk about pain that radiates from the lower back down to the leg, also called sciatica. Welcome, Dr. Taylor, and thank you so much for joining me today.
Dr. Blake Taylor: Yes. Thank you, Dr. Habib, for inviting me.
Host: Dr. Taylor, let's begin with just the definition. Could you please describe sciatica and what causes it?
Dr. Blake Taylor: Yeah. So sciatica, it's a very common condition. It's often described as a shooting, sort of an electric shock-type pain. It travels from the low back, down the leg. There's often some numbness and tingling, there's often a little back pain, and there can even be some weakness in the leg or the foot. And it's often caused by compression of one or more of the nerves, which I'll discuss later on. It can be triggered by some heavy lifting, such as a heavy box or heavy weights in the gym, or repeated twisting or bending movements. Sometimes, frankly though, it's just a matter of bad luck.
And the good news is that it's a very common condition that I've treated many times. Most of the treatments are conservative, so meaning primarily medications, physical therapy, possibly some steroid injections. And the results or the outcomes as we call them are effective and they're very good in general. But sometimes surgery is required in some cases.
So, the thing is technically the term sciatica refers to the symptoms coming from a damaged or diseased sciatic nerve which is one of the nerves that runs down your legs and it controls the sensation, it controls your muscles, but it's somewhat of an inaccurate term that's used loosely to describe any sort of similar like pain, whether or not it's directly due to a problem with the sciatic nerve. So, it's important to know that in the lower part of your spine, which you've probably heard of, is called the lumbar spine, right? The nerves that control your legs and also your bowel and bladder function, they exit the spine. And, you know, you can think of it kind of like a highway intersection of the nerves. They crisscross, they connect with one another, and they form what are known as the peripheral nerves. And one of these nerves is the sciatic nerve and the sciatica, so to speak, can be due to nerve problems. Basically, anywhere up and down the roads that these nerves take from the spine to the feet.
Host: Dr. Taylor, you mentioned that sciatica is specifically from compression of that nerve. What are other common conditions that cause sciatica-type pain?
Dr. Blake Taylor: Right. So, most commonly sciatica-type pain is due to anything that causes the compression of one or more of the nerves as they leave the spine before they intersect with one another. So, if it's before the intersection, in that case, we call it a radiculopathy. And most of the time the compression is due to a herniated disc or it could be due to some changes that occur in the spine as we get older, which we call degenerative changes, right? And the herniated disc refers specifically to when a piece of the normal rubbery disc that separates the spinal bones, it sort of bulges outwards and it touches and it pushes on the nerves as they leave the spine. So, that sciatica-type pain, however, can be caused by compression anywhere along the root of that nerve, or it can be caused by diseases that affect our whole body, such as diabetes. And the nerve could be affected, as it goes through the hip area, or it could be affected in the legs further down after they've left the spine.
Host: Okay. Dr. Taylor, can you help us understand how you approach identifying the source of someone's sciatica?
Dr. Blake Taylor: So, the first step, and this is basically true in any sort of medical evaluation, you know, as you know, is doing a history and physical exam. That's where we sit you down. We ask you a lot of specific questions about your symptoms, and we do a thorough neurological exam. And basic questions include things like, How long have you had the pain? Where is it located? Does it move around? Does anything make it better? Does anything make it worse? You know, have you had any treatment for it? And are there other what we refer to as associated symptoms? So, like the numbness and tingling we mentioned, or the weakness, or the back pain. And what I often tell patients is thinking about your answers before you go to the doctor can often help move the process along more quickly.
So, once we do that, if we suspect a herniated disc based on what you tell us and kind of what our physical exam is, or if we suspect another significant spinal problem, we will often order imaging tests of your lower back. And so, those can be things most commonly an MRI. It can also be a CAT scan. It can also be x-rays. And each of these tests has different utilities. So, you know, an MRI is best at showing us the soft tissue, such as the spinal cord itself, such as the nerves and the discs and the ligaments around the spine, whereas a CAT scan is really good for looking at the actual bones. And the x-rays that we get can look at your spinal alignment. It can show if there's any abnormal motion between the bones of your spine as well.
Host: Okay. So once you've obtained the history and physical, and you've gotten imaging, and as you mentioned, you know, might be an x-ray, a CT, or an MRI, are there any other tests that might be ordered as well?
Dr. Blake Taylor: Right. So, sometimes the imaging that we show doesn't always pick up the disease process. And in those cases, we may order tests called nerve conduction tests and electromyogram. And that's basically when a neurologist will place small little short needles, they're not painful at all, they put them in the legs and then they measure the signal that the nerves generate as they travel from your back down your leg. And, you know, this can help look for problems in peripheral nerves, such as the sciatic nerve. And based on that, there may also be some other imaging tests that can be done in other parts of the body as well. We also may order certain laboratory studies from the blood and so on.
Host: Dr. Taylor, you've given us wonderful information about sciatica and how you work it up. Could you give us an example of a patient you've treated with sciatica-like pain?
Dr. Blake Taylor: Right. So, know, one of the ones that I remember that I think was pretty exemplary was a guy in his early 40s, otherwise, pretty healthy guy, came into the ER. And he said, "Look, doc, I have severe pain radiating from my lower back. It goes all the way down my left leg. It sort of went to the outside of his foot." He said it had started while he was lifting heavy weights. And when I got that call from the ER, even before seeing the patient, a herniated disc was high on my list of possible causes. And lifting heavy weights is a common trigger that can cause a disc to herniate, as we discussed.
So, just like I mentioned, I started by doing a history and physical exam. He said some other things, like his pain was worse with coughing and sneezing. It's better with straightening his lower back. That's often the case in patients who have herniated discs. And he also had mild to moderate low back pain, but what is also the case with herniated discs is that the leg pain usually is much worse than the low back pain. So, that was all consistent with that picture of a herniated disc. And then, when I did his neurological exam, if lifting his left leg straight in the air, which we call the straight leg raise test, it reproduced the pain that he had, and that can suggest a herniated disc problem.
And I also found that he was unable to move his foot or his toes in an upward direction, and that's a weakness problem. That's known as a foot drop. That's one of the red flags that can occur in patients that have herniated discs. So, you can have both the symptoms, the pain, and the numbness and tingling. But when there's weakness, that's considered a red flag.
Some other red flags that we look for are changes in bowel or bladder habits, such as incontinence. And that's because the nerves that control that in part run through the spine. The other thing is if there's numbness or tingling in the groin area, that can suggest something very dangerous. And then, some other red flags are if you've had a recent trauma, you know, if you had a fall or a car accident, because there could be certain fractures, for example, there could be dislocations, there could be bleeding. And then, some other things that you may have in your medical history like major infections or even cancer which, you know, there's always the possibility it can spread to the spine So, you know in his case the main red flag for him was the weakness, was the foot drop, and so that was the most concerning thing
Host: So, based on what you said earlier, Dr. Taylor, this patient with these red flags would likely need an urgent MRI, am I right?
Dr. Blake Taylor: Oh, absolutely. So, the issue in his case was the pain and the weakness. So, the weakness is basically what we refer to as a motor deficit. There's a problem with the motor function of your muscles, which are controlled by the nerve. And, you know, in general, when you have a problem with weakness that's one-sided and specific to a certain body region, the medical team should be very proactive about diagnosing the problem as quickly as possible. And in this case, once there is significant weakness from the compression on the nerve, that indicates that the nerve function is almost gone. And if you don't do anything about it in a time frame that's short, then there can be irreversible damage.
Host: We definitely want to catch that as soon as possible. So, in this case, Dr. Taylor, what did the MRI show?
Dr. Blake Taylor: Right. So when you get an MRI of your lower back, that always includes the five bones of the lumbar spine. So, if you think of someone standing upright, they're labeled from one to five, going from higher in the lower back to lower in the lower back, so L1, 2, 3, 4, 5. So, the bones which are known as vertebrae, they're stacked on top of each other. In between those are where the discs are. And then, behind those bones, it's where the spine is, in the spinal nerve. And then, the the vertebrae also surround the spine kind of like a ring. So, we have both bones in front and also behind the spine, which kind of helps protect the spine.
So, in this man, we basically found that there was a herniated disc between the L4 and the L5 vertebrae. And the interesting thing is this in particular is very common. It's responsible for about half of all the lumbar disc herniations. And a lot of it is just thought to be due to physics, because the bottom of the lumbar spine is supporting most of your body weight. So therefore, it's more susceptible to injury. And it so happens that when a disc herniates here, it usually affects the nerve, which is known as L5, which takes the name of the lower bone. And that nerve in particular is in part responsible for moving your foot upright, so kind of moving your toes to your nose. So when that nerve is affected, you're not able to do that.
Host: Now, you mentioned in this particular example that the patient had muscle weakness and was noted to have foot drop. Dr. Taylor, can anything else cause foot drop?
Dr. Blake Taylor: Yes, absolutely. The most common cause of foot drop is due to a herniated disc in these circumstances, but it can really be due to a nervous system problem anywhere along the nerve pathways, and that includes anywhere all the way up to the brain in some rare cases.
Host: So, what did you do for this patient? It's a really interesting case. Did he need surgery? And how do you decide who needs surgery, Dr. Taylor?
Dr. Blake Taylor: Right,. So, for patients like him who have a herniated disc, the indications for urgent surgery are similar to the red flags that we had discussed. So, in his case, because there was severe weakness of the foot, that was a textbook reason to do urgent surgery that day. And that's because waiting too long to do the surgery, it reduces the likelihood that he'll recover strength from that foot.
Host: Okay. And how do you decide who needs surgery?
Dr. Blake Taylor: Yeah. So, basically, the important thing to remember, as I mentioned in the beginning, is that most of the patients with herniated discs don't need surgery. So, if you're a patient and you don't have any of the red flags, you don't have significant weakness, you don't have any incontinence, you don't have any scary things in your medical history, like trauma or cancer or something like that, in those patients, the symptoms from most herniated discs resolve with time, about two-thirds of patients or so we would think.
And basically, the logic behind that is there's essentially a herniated piece of that disc that's pushing on the nerves that we discussed. And over time, it's thought that that tends to dry up. And as it does, the compression on the nerve is gradually relieved. I'll also mention that there's often a lot of herniated discs that don't cause symptoms. And if you do an MRI on someone who is of an older age, most likely you're going to find some evidence of that. So, they're very common and they often very commonly don't cause symptoms. And if it doesn't cause symptoms, we often won't offer surgery in those cases.
So, you know, if there's no need for urgent surgery, basically, what we do, the standard of care actually is to initially manage this conservatively. So, when you first have the symptoms, most patients will get a short course of oral steroids, such as a Medrol Dosepak. And the logic behind that is it reduces the inflammation around the compressed nerve and that can help in turn relieve the pain. Then later on, we'll recommend physical therapy, usually about six weeks, and then also a good pain medication regimen. So, that could be medications like gabapentin, which helps with nerve pain, certain NSAIDs such as ibuprofen, Tylenol, certain muscle relaxants. And some patients do need a judicious use of opioids as well.
It's also important to remember that there are certain activity limitations such as no heavy lifting so that the disc doesn't herniate to a greater extent that doesn't get bigger and push on that nerve more. And then if the medications and the physical therapy don't work, then we usually will send patients to one of our Pain Management physicians. And then, at that point, they could potentially give steroid injections that target the nerve that's being compressed to help relieve the symptoms. And, basically, the idea behind that is to bide time until hopefully the disc dries up and then the symptoms get a lot better.
Host: Okay. Now, what happens, Dr. Taylor, if the conservative therapy that you described in detail doesn't work?
Dr. Blake Taylor: So, this does happen in about, you know, a third of patients and if you don't have any improvement for about six weeks and the symptoms are still pretty bad or if, more importantly, if you worsen, if you get some of the red flags, then surgery can be considered. And this is often the point where primary care doctors will refer to a neurosurgeon. So, this is usually the point at which I would see the patient in my office.
So, I will mention, overall, the studies that were done that basically compare the conservative treatment to surgery for these types of discs and the lumbar spine, they didn't find many differences in terms of function such as going back to work or pain at a long-term followup. But, you know, what was interesting is that the patients who were treated surgically basically had symptom relief sooner and returned to function sooner. But there also may have been, for example, less of a reliance on long-term pain medication, such as opioids in the patients who got surgery, because they didn't need such long-term pain medication care. On the other hand, it's important to remember surgery isn't without risks, and the risks and benefit of both treatment options have to be carefully weighed. They have to be individualized for each patient.
Host: Okay. Now, let's go back to the patient that you described who ended up needing surgery. Dr. Taylor, could you tell us about the surgery?
Dr. Blake Taylor: Right. So, I offered him what we call a microdiscectomy, which is kind of a fancy term. It just means we use the microscope, that's the micro portion, to operate on and remove the disc, which is the discectomy. So, I often do this surgery in a way that's minimally invasive. And I make a small skin incision, an opening that's about a few centimeters in the middle of your lower back. And then, I insert a hollow metal tube, it's about the width of your thumb. And I do it under x-ray guidance. And then, what we do is we drill off some of the back part of the bone known as the lamina, which is part of that ring that we talked about that goes behind the spine. And then, after that is where I look for the piece of the disc that's herniated, and then I remove it. Most of the time, we actually leave the rest of the normal part of the disc intact, and we don't touch it.
After we remove the disc, we then look at the nerve that was affected and kind of make sure the nerve looks all free and floating and not compressed. And after that, we close up the wound with some absorbable stitches. And, you know, I would say it usually takes an hour and a half, two hours, something like that.
Host: Oh, that's great. So, it's a very short procedure.
Dr. Blake Taylor: Yes, yeah, fairly short.
Host: Now, Dr. Taylor, some of our listeners might not understand what minimally invasive actually means. So, could you describe that to us and also highlight who is a candidate for that specific type of surgery?
Dr. Blake Taylor: Of course. So, basically, minimally invasive means we're doing the surgery with less exposure of and less trauma to the tissues that are in the way of where the target for surgery is, which is, in this case the herniated disc. And that's opposed to a more invasive, more traditional, and open procedure, as we would say.
So with minimally invasive, there's basically less disruption of the soft tissue, such as smaller wounds, and less of the muscle is damaged on the way in. There's usually less pain in the area where the surgery was. The patients often need fewer postoperative pain medications. There's less bleeding in surgery. There's lower hospitalizatio-related costs. And usually, patients are in the hospital for a shorter period of time. And you know, overall, this is what is often referred to as the Enhanced Recovery After Surgery or ERAS protocol, which is very common in many hospitals. And here at MarinHealth, we routinely do minimally invasive procedures for patients many types of spinal surgeries. I will say the caveat to that though is that it's important to remember that minimally invasive surgery has some great benefits, but it's not for everybody. And sometimes the traditional open approach is actually the best for you.
Host: You've described a microdiscectomy in great detail. How safe is a microdiscectomy and what are some of the short and lon-term complications, Dr. Taylor?
Dr. Blake Taylor: So, overall, microdiscectomy is a very safe procedure. It's one of the most common ones that we do. It's one of the most common ones that neurosurgeons do across the country, actually. But every surgery does have risk, and some of the short-term complications that can happen are bleeding and infection. These are very low and frankly can happen in any type of surgery. There can also be incomplete removal of the problematic portion of the disc. So in other words, leaving some of that disc in there and not knowing that it's there, which means that the nerve would still be under compression.
There could also be leaking of the fluid that surrounds our brain and spine, which is known as cerebrospinal fluid. I would say those are some of the shorter term issues in the, longer term. There's some other issues. And, you know, I'm talking about weeks to months later, there's always a risk of the disc herniating again as we refer to as re-herniation, which is basically where there can be recurrence of the symptoms after an initial period of the symptoms improving. And in general, what I tell patients is that in the first three months, this is when the risk is highest. And it occurs in about 4 percent of patients by that time point. If you go up to 4 years, it's about 12%. But it's important to note that patients can reduce their risk by reducing a high BMI if they have that, by losing weight, because that puts less pressure on the discs, and also doing things such as controlling diabetes, if they have it. And it's also why physical therapy is important. It's why certain activity restrictions, such as no heavy weight lifting, is important. And it's important to have close contact with your surgeon.
And I'll also mention that years after the microdiscectomy, there is a slight, but present risk, about 5-10% of patients at 4 years, who actually may need a lumbar fusion. And that's basically where we put hardware in to support the spine. And if you have a re-herniation of the disc, that chance of needing the fusion is higher. But as I said, discectomy is very safe. It has a very high success rate, in terms of pain relief; improvement and weakness and return to function such as going back to work and doing the fun activities that you like to do.
Host: Yeah. That's fantastic. Now, I'm sure a lot of our listeners are very curious. How did your patient do after surgery, Dr. Taylor? And could you also describe the recovery after a microdiscectomy?
Dr. Blake Taylor: Right. So, fortunately, he did great. You know, I saw him not too long ago actually and he's playing golf again, swimming. He's running up and down the hills here in Marin County. So, he's doing great. His pain actually significantly improved within the first week or so. Most patients, they get better in terms of their pain fairly quickly after surgery. So, the initial part of the recovery, I'd say for the first two weeks or so, it's geared more towards wound healing and pain control, because, you know, there is some pain just from doing the actual surgery. And these sorts of things include not scrubbing the wound in the shower, not submerging it in water such as a bath and having it checked in the office about two weeks after surgery.
And then, for the first three months or so, the main goal is to continue improving the symptoms that you had before surgery, but also being careful to reduce the risk of that re-herniation happening, which, as we discussed, is highest in those first three months or so. So for this reason, we recommend sort of measured, less intense physical therapy. We advise patients to avoid things that can disturb the physics of the discs and the bones in the spine. So, that could be things like significant bending or twisting or heavy lifting, you know, again for about three months.
So once we get to that three month time point, if the symptoms have resolved, if the neurological exam is normal, such as in this guy's case, if there was no more foot drop, then usually patients can return to more intense activities such as weightlifting and other things that they love to do.
Host: Dr. Taylor, you've provided us with wonderful information today. What is your final take-home message for our audience?
Dr. Blake Taylor: Yes. I would say, if you have sciatica, it's very important to seek medical treatment, because although most of the time these can be treated conservatively and most patients get better, there is a chance that you might benefit from surgery. And it's very important to see your primary care doctor. But if the symptoms are bad, or if you have some of the red flags that we discussed, don't hesitate to go to the ER, because you might need a neurosurgeon at some point, and that's where I would come in.
Host: Well, thank you so much for your time and for your detailed explanation today, Dr. Taylor.
Dr. Blake Taylor: Yes, thank you very much, Dr. Habib. It was a pleasure speaking with you.
Host: Once again, that was Dr. Blake Taylor, a UCSF neurosurgeon who works at MarinHealth. If you would like to learn more, please visit www.mymarinhealth.org. If you found this podcast helpful, please share it on all your social channels and check out the full podcast library for topics of interest to you. I'm your host, Dr. Rania Habib, wishing you well. Thank you for listening to The Healing Podcast brought to you by MarinHealth.