Sciatica - Frequently asked questions

 
   Sciatic Nerve
 

Sciatica

What Is Sciatic nerve?

Sciatic nerve is the largest single nerve in the body, it starts in the lower spine & runs down the back of each leg. It controls the muscles of the back of the knee and lower leg. It also provides sensation to the back of the thigh, part of lower leg & the sole of the foot. It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect. It is derived from spinal nerves L4 through S3. 

What is Sciatica?

Sciatica; Sciatic Neuritis; Sciatic Neuralgia

Sciatica, Sciatic neuritis, Sciatic neuralgia, or lumbar radiculopathy is a set of symptoms including pain caused by general compression or irritation of one of five spinal nerve roots (L4 to S3) of each sciatic nerve. Symptoms include lower back pain, buttock pain, and numbness, pain or weakness in various parts of the leg and foot. Other symptoms include a "pins and needles" sensation, or tingling and difficulty moving or controlling the leg. Typically, symptoms only manifest on one side of the body. The pain may radiate above the knee, but does not always. 

Sciatic nerve pain can be severe and persist for a prolonged period of time. If the cause of sciatic nerve dysfunction can be identified and treated successfully, full recovery is possible. The extent of recovery may vary  from no disability to complete loss of movement or sensation.


What are the common causes of Sciatica?

Common causes of sciatica include:

Spinal disc herniation

Spinal disc herniation pressing on one of the lumbar or sacral nerve roots is the primary cause of sciatica, being present in about 90% of cases. Sciatica is caused by pressure from a disc herniation and swelling of surrounding tissue.  

Spinal stenosis

Other compressive spinal causes include lumbar spinal stenosis, a condition in which the spinal canal (the spaces the spinal cord runs through) narrows and compresses the spinal cord, cauda equina, or sciatic nerve roots. This narrowing can be caused by bone spurs, spondylolisthesis, inflammation, or herniated disc, which decreases available space for the spinal cord, thus pinching and irritating nerves from the spinal cord that travel to the sciatic nerves.

Piriformis syndrome

Piriformis syndrome is a condition that may contribute up to 8% of low back or buttock pain. In a small number of the population, the sciatic nerve runs through, or under the piriformis muscle. When the muscle shortens or spasms due to trauma or overuse, it causes compression of the sciatic nerve. It has colloquially been referred to as "wallet sciatica" since a wallet carried in a rear hip pocket compresses the buttock muscles and sciatic nerve when the bearer sits down. Piriformis syndrome cause sciatica when the nerve root is normal.

Pregnancy

Sciatica may also occur during pregnancy as a result of the weight of the fetus pressing on the sciatic nerve during sitting or during leg spasms. While most cases do not directly harm the mother, indirect harm may come from the numbing effect on the legs, which can cause loss of balance and falling. There is no standard treatment for pregnancy induced sciatica.

Other

Sciatica can also be caused by tumours impinging on the spinal cord or the nerve roots. Severe back pain extending to the hips and feet, loss of bladder or bowel control, or muscle weakness may result from spinal tumours or cauda equina syndrome. Trauma to the spine, such as from a car accident, may also lead to sciatica.


What are the symptoms of Sciatica?

Symptoms can vary widely. You may feel mild tingling, dull ache, burning sensation, sharp pain or weakness. Usually the pain will be on one side in the lower back, the hip or the knee. 

The pain may get worse:  

  • On standing or sitting  
  • At night
  • On bending
  • On walking long distances
  • On coughing or sneezing

How do you diagnose Sciatica?

Sciatica Diagnosis

Medical history and physical examination can usually identify any serious conditions that may be causing the pain. During the exam, Dr. Goswami will ask about the onset, site, and severity of the pain; duration of symptoms and any limitations in movement; and history of previous episodes or any health conditions that might be related to the pain. Along with a thorough back examination, neurologic tests are conducted to determine the cause of pain and appropriate treatment. 

Imaging tests are not warranted in most cases. Under certain circumstances, however, imaging may be ordered to rule out specific causes of pain, including herniated disc or spinal stenosis. Imaging and other types of tests include:

X-ray 

It is often the first imaging technique used to look for broken bones or an injured vertebra. X-rays show the bony structures and any vertebral misalignment or fractures. Soft tissues such as muscles, ligaments, or bulging discs are not visible on conventional x-rays.

Computerized tomography (CT) & Magnetic resonance imaging (MRI) 

These imaging modalities are used to see spinal structures that cannot be seen on conventional x-rays, such as disc rupture, spinal stenosis, or tumors. Using a computer, the CT scan creates a three-dimensional image from a series of two dimensional pictures. MRI scans also produce images of soft tissues such as muscles, ligaments, tendons, and blood vessels.

Myelograms 

It enhance the diagnostic imaging of x-rays and CT scans. In this procedure, a contrast dye is injected into the spinal canal, allowing spinal cord and nerve compression caused by herniated discs or fractures to be seen on an x-ray or CT scans.

Discography 

It may be used when other diagnostic procedures fail to identify the cause of pain. This procedure involves the injection of a contrast dye into a spinal disc thought to be causing low back pain. The fluid’s pressure in the disc will reproduce the person’s symptoms if the disc is the cause. The dye helps to show the damaged areas on CT scans taken following the injection.

Electromyography (EMG), Nerve Conduction Studies (NCS), and Evoked Potential (EP) studies

These procedures are used to confirm whether a person has lumbar radiculopathy. EMG assesses the electrical activity in a muscle and can detect if muscle weakness results from a problem with the nerves that control the muscles. NCSs are often performed along with EMG to exclude conditions that can mimic radiculopathy. EP record the speed of nerve signal transmissions to the brain.

How do you treat Sciatica?

Sciatica may be very difficult to treat as it is a symptom of another medical condition. The underlying cause should be identified & treated. In some cases no treatment is required & recovery occurs on its own. Usually a combination of conservative therapy, physical therapy and interventional therapy might be needed.

Conservative treatment 

  • Applying heat or ice to the painful area
  • Taking over the counter pain relievers 
  • Sleeping in a curled up position with a pillow between your legs or sleeping on your back with pillow under your knees

The goal of our treatment is functional rehabilitation. While eliminating chronic back or neck pain is extremely hard, our functional rehabilitation program seeks to return patients to levels of activity that they were able to perform prior to suffering from back or neck pain. We have a multimodal approach to treatment, where we use many different approaches to treat pain. 

Our multimodal approach includes: 

Muscle strengthening regimen

We encourage our patients to begin stretching exercises and resume normal daily activities as soon as possible, while avoiding movements that aggravate pain. Strengthening exercises, beyond general daily activities, are not advised for acute low back pain, but may be an effective way to speed recovery from chronic or subacute low back pain. Physical therapy programs to strengthen core muscle groups that support the low back, improve mobility and flexibility, and promote proper positioning and posture are often used in combinations with other interventions.

Medications

The following are the main types of medications used for low back pain:

Analgesic medications are those specifically designed to relieve pain. They include over-the-counter acetaminophen and aspirin, as well as prescription opioids such as codeine, oxycodone, hydrocodone, and morphine. Opioids should be used only for a short period of time and under a physician’s supervision. People can develop a tolerance to opioids and require increasingly higher dosages to achieve the same effect. Opioids can also be addictive. Their side effects can include drowsiness, constipation, decreased reaction time, and impaired judgment. The use of opioids is heavily regulated by Drug Enforcement Agency (DEA). In our practice all patients who are being treated with opioids are required to sign an Opioid Agreement and periodically undergo urine and blood testing.
Anticonvulsants—drugs primarily used to treat seizures—may be useful in treating people with radiculopathy and radicular pain.
Antidepressants such as tricyclics and serotonin and norepinephrine reuptake inhibitors have been commonly prescribed for chronic low back pain, but their benefit for nonspecific low back pain is unproven, according to a review of studies assessing their benefit.
Counter-irritants such as creams or sprays applied topically stimulate the nerves in the skin to provide feelings of warmth or cold in order to dull the sensation of pain. Topical analgesics reduce inflammation and stimulate blood flow.

Minimally Invasive Treatment

Nerve block therapies aim to relieve chronic pain by blocking nerve conduction from specific areas of the body. Nerve block approaches range from injections of local anesthetics, botulinum toxin, or steroids into affected soft tissues or joints to more complex nerve root blocks and spinal cord stimulation. The success of a nerve block approach depends on the ability of a practitioner to locate and inject precisely the correct nerve. Some of the common treatment options include:

Epidural Steroid Injection

Epidural space is a potential space within the spinal canal. It surrounds the outermost covering of the spinal cord (dura mater). It contains nerve roots, blood vessels & fatty tissue. A relatively small amounts of corticosteroids together with a local anesthetic are injected into the epidural space around the spinal cord and spinal nerves. The anti-inflammatory effects of the corticosteroid is responsible for providing pain relief. Epidural Steroid Injections help patients suffering from disc herniation, disc bulges, degenartive disc disease, sciatica & spinal stenosis. It is considered to be an integral part of nonsurgical management of radicular pain from spinal disorders.

Facet Joint Injection or Medial Branch Block

The facet joints are formed by the superior and inferior articular processes of each vertebra. Every vertebrae in the spine has a left and right facet joint. Each joint gets its sensation from a tiny nerve called Medial Branch. These joints also allow the spine to bend and twist, and they keep the back from slipping too far forward or twisting without limits. Breakdown or degeneration of these joints can lead to pain in the back, arms or legs leading to a diagnosis of facet joint disease. For treatment of Facet Joint Disease, we initially perform Facet Joint Injection or Medial Branch Block with a local anesthetic or numbing medicine. This injection helps us identify the site of back or neck pain. This is usually followed by Radiofrequency Ablation (RFA)

Radiofrequency Ablation

Radiofrequency ablation is a procedure in which radiofrequency waves are used to produce heat on specifically identified nerves. Prior to Radiofrequency Ablation, the nerves to be ablated are identified through Facet Joint Injection or Medial Branch block. By generating heat around the nerve, the ability of the nerve to transmit pain signals to the brain is destroyed, thus ablating the nerve. Patients with back, neck or leg pain can get pain relief from these procedures. Pain relief can last anywhere from six months to two years.

Endoscopic Discectomy

Endoscopic Discectomy is a procedure used to remove damaged disc material in the spine. It is a minimally invasive technique that unlike the conventional procedure does not involve major tissue injury. Instead, a small metal tube, the size of a pencil, is inserted into the herniated disc space under x-ray guidance. The tube serves as a passage for the surgical tools and a tiny camera (endoscope). Under the guidance of real-time x-ray image (fluoroscopy) and a magnified live video feed, the fragment of the disc pinching the nerve is removed. You might benefit from discectomy if your presentation includes: Pain, numbness or weakness in arms or legs or imaging studies reveal disc problems such as disc annular tear, disc bulge, or disc herniation.

Platelet Rich Plasma Therapy

Our blood contains several types of cells such as red blood cells (RBCs), white blood cells (WBCs) and platelets. Platelets contain a number of growth factors, cytokines, proteins and other bioactive factors that initiate and regulate wound healing. Platelet rich plasma therapy uses patient's own blood components to stimulate a healing response in damaged tissues. Approximately 10 cc of patient’s blood is drawn and centrifuged with a machine. Platelet component of the blood is separated, concentrated and then injected in the patient. When Platelet Rich Plasma is injected into the damaged area it stimulates the tendon, ligament or muscle with a high concentration of growth factors that triggers the healing cascade. As a result new tissue begins to develop. As this tissue matures it begins to shrink causing the tightening and strengthening of the tendons, ligaments and muscle of the damaged area. Patients suffering from Arm, Shoulder, Leg or Hip Pain might benefit from this procedure.

Spinal Cord Stimulator (SCS) consists of stimulating electrodes, implanted in the epidural space, an electrical pulse generator, implanted in the lower abdominal area or gluteal region, conducting wires connecting the electrodes to the generator, and the generator remote control. SCS has notable analgesic properties and, at the present, is used mostly in the treatment of failed back surgery syndrome, complex regional pain syndrome and refractory pain due to ischemia.

Transcutaneous electrical nerve stimulation (TENS) involves wearing a battery-powered device consisting of electrodes placed on the skin over the painful area that generate electrical impulses designed to block incoming pain signals from the peripheral nerves. The theory is that stimulating the nervous system can modify the perception of pain. Early studies of TENS suggested that it elevated levels of endorphins, the body’s natural pain-numbing chemicals. More recent studies, however, have produced mixed results on its effectiveness for providing relief from low back pain.

Surgery

Surgery is usually reserved for very few patients with pain from structural anatomical problems that have not responded to medical or interventional therapy.