What is Sciatica or Sciatic Nerve Pain?
Sciatica refers to pain, numbness, or tingling in the posterior (back) aspect of the leg. At times, sciatica pain can even radiate into the foot and toes. The sciatic nerve is a large nerve that originates in the buttock region and travels along the posterior aspect of the leg. Interestingly, sciatica does not specifically refer to a problem with the sciatic nerve itself. The overwhelming majority of cases of sciatica stem from the lower lumbar spine (the L4-L5 and L5-S1 segments). The L4, L5, S1, S2, and S3 nerve roots originate in the spine and come together to form the sciatic nerve. When these nerve roots (most commonly the L5 or S1 nerve roots) are impinged, patients experience “sciatica.” As simple metaphor for the spinal nerve roots as they relate to the sciatic nerve, is that the spinal nerve roots are small tributaries, and the sciatic nerve is a river that is fed by multiple small tributaries.
Causes of Sciatic Nerve Pain
Disc pathology: The discs are are cushions between the vertebrae and allow for movement. When a disc bulges or herniates, a piece of the disc may come in contact with a nerve root, which can cause sciatica.
Facet joint pathology: The facet joints are the joints in the lumbar spine. They are what “crack” and “pop” when someone stretches or goes to a chiropractor. Arthritic joints can become large and come in contact with a nerve root. Sometimes, arthritic joints can form fluid-filled cysts, which also can come in contact with a nerve root and cause sciatica.
Spondylolisthesis: A spondylolisthesis is when a vertebra is slipped forward or backwards over another vertebra. This process is typically degenerative but can be traumatic. When the vertebrae are not properly aligned, the space in which the nerve roots travel can be compromised, which can result in nerve impingement and sciatic pain.
Ligamentum flavum hypertrophy: The ligamentum flavum is a ligament in the spinal canal that can become thick as patients age. This thickened ligament can put pressure on the nerve roots and cause sciatica.
Tumor, Cancer, Infection: Any “space-occupying lesion” that is located along the spinal nerve roots can cause pain. The most concerning and life-threatening are cancer and infection (abscess). Non-malignant tumors can also cause sciatica pain.
Non-surgical Sciatica Treatment
Observation/Time: Many causes of sciatica will resolve with relative rest over the course of several weeks. Complete inactivity is not recommended, though, and patients should gradually resume regular activities, as tolerated. Often sitting can be very uncomfortable if the cause of sciatica is a disc herniation, in which case standing or at least sitting with a good lumbar support is recommended.
Self-care: Weight loss has been shown to help low back issues, as decreased upper body weight results in less pressure being placed on the lumbar spine. Anti-inflammatory diets can also be helpful, as can exercise. Patients are always encouraged to “listen to their bodies” when exercising and avoid painful activities.
Physical Therapy: Physical Therapy focuses on stretches and exercises in a controlled environment. Most lumbar PT is centered around core strengthening & stabilization (to reduce the amount of pressure being transmitted to the lumbar spine), and stretching (to reduce secondary muscle spasm/tightness). Physical Therapy can be helpful for both treating and preventing sciatica. The goal of any Physical Therapy program is to eventually “graduate” from in-person Physical Therapy and then to maintain a home exercise program going forward.
Chiropractic care: Chiropractic care focuses on spinal manipulation and decompression in order to alleviate pain. Additionally, chiropractors often use a variety of other modalities that can provide transient relief.
Acupuncture: Acupuncture is the placement of very thin needles into specific locations on the body, which may relieve pain. Its mechanism of action is likely multifactorial. Some studies indicate that acupuncture results in a release of pain-relieving neurotransmitters into the bloodstream.
Medications: The most commonly prescribed medications for sciatica are Tylenol, anti-inflammatories (nonsteroidals – ibuprofen and Naprosyn, steroid tapers – prednisone and methylprednisolone), muscle relaxants, and neuropathic pain agents. Each of these medications have varied evidence for sciatica. Opioids have been shown to be no more effective than other medications, but they have a much worse side effect profile.
Injections: Epidural steroids injections (ESI) are fluoroscopic- (x-ray) guided injections. The goal of an ESI is to deliver a steroid (anti-inflammatory medication) to the area of the spine that is causing sciatic pain. ESIs have been shown to be safe and effective for sciatica. These injections are well-tolerated and typically take less than 5 minutes to perform, with the most painful part of the injection being the local anesthetic (the numbing medication, similar to a dental procedure), which causes a burning/stinging pain for about 5 seconds. It is recommended that patients avoid strenuous activities on the day of the injection, but typically no specific restrictions are needed the day after. Steroid injections typically take between 3 and 7 days to take effect, though sometimes they can take up to 14 days.
History and Physical Examination: The history and physical examination are critical to determine which part of the spine is most likely to be causing pain. Some of the most important aspects of a neurological examination for sciatica are reflexes, sensation, and strength in the legs.
Imaging: X-ray imaging and magnetic resonance imaging (MRI) are the most valuable diagnostic tests for sciatica. These images are complementary and are often both needed in order to make a correct diagnosis. When patients cannot have an MRI due to implanted medical devices, a cat scan may sometimes be used in place of an MRI.
Electrodiagnostics: While electromyography (EMG) and nerve conduction studies (NCS) are often very helpful in diagnosing nerve issues such as carpal tunnel syndrome peripheral neuropathy, they typically are not needed for the diagnosis of sciatica. History, physical examination, and x-rays/MRI are typically sufficient, and EMG/NCS rarely adds value to the diagnostic workup.
When to see a doctor about sciatica
Most cases of sciatica resolve on their own. Patients should seek medical attention if pain has not started to improve even slightly after the first few days or if over-the-counter remedies that typically help with pain have not helped.
Patient should seek urgent medical attention (go to the emergency department) if they notice progressive weakness in one or both legs (tripping or falling), new or progressive bowel or bladder dysfunction (incontinence), or saddle anesthesia (numbness or tingling in the genital and/or anal regions), as these symptoms are indicative that urgent surgical intervention may be warranted.
When to consider surgery for sciatica
Surgery is typically indicated when symptoms do not resolve on their own or with conservative treatment (medications, therapy, epidural steroid injections and time). The goal of surgery is to remove the compression or “pinching” of the nerve that is causing pain. In some instances, patients may develop weakness in some of the muscles of their leg(s). One example of this is the development of a foot drop, or the inability to lift your foot up when trying to walk. When this occurs, surgery may be indicated sooner to help improve the likelihood of regaining strength in that muscle group.
Types of surgery for sciatica
Surgical options for treating sciatica are centered around removing the compression or pressure on the nerve or nerves that are causing symptoms. Each surgery is based on each individual patient’s pathology. Some patients may develop symptoms from a herniated disc where the nerve is getting pinched by the disc material. A common treatment for this this type of problem would be a microdiscectomy which involves removing a small amount of ligament and bone in the back of the spine in order to remove the disc material that is causing symptoms. This is commonly performed as an outpatient procedure and patients are able to start walking the same day as surgery. Other patients may develop arthritis of the bones or overgrowth of the ligaments in the back of the spine which causes stenosis or compression of one or more of the nerves. Treatment for this type of pathology is typically a laminectomy which involves removal of the lamina, or the bone in the back of the spine and excess ligament to relieve pressure on the nerves and help alleviate symptoms. Lastly, another common type of surgery is a lumbar spinal fusion. This is typically reserved for patients that develop abnormal alignment or motion between the bones of the low back. We commonly refer to this as a spondylolisthesis. The fusion aspect of the procedure is aimed at stopping the abnormal motion, correcting alignment and preventing additional abnormal motion from occurring. Surgery provides substantial improvement in pain and function for most patients.
Recovery after sciatica surgery
The goal of surgery is to relieve symptoms and restore function. We typically employ a combination of medications after surgery to help alleviate pain and get people back to feeling like themselves. In most cases we try to get patients up and walking on the same day as surgery. Walking is encouraged after surgery as it helps with pain as well as the rehabilitation process. The recovery of surgery varies depending on the type of procedure performed. Typically, patients are temporarily limited postoperatively in the amount they can bend, lift and twist as the back heals. Most patient start to feel like themselves within a few weeks after surgery but patients can see continued improvement for several months after the procedure.