Dec 17, 2017 by spinalcare
“Doc, I have Sciatica!”
Not so fast……
We live in a world where the information is at our fingertips. When we need directions, we Google. When we want to know the weather, we Google. When we want to find out what movie won Best Screenplay in 1975, we Google. Turning to Dr. Google is no different when researching pain. While the convenience of the internet is beneficial, it has its downfall when self-diagnosing. Often patients come into the office thinking they have “sciatica” (or tumors, or rare-infections), and that is not often case (even less with tumors and rare-infections). It is always best to be examined by a healthcare professional; it will save you the anxiety from the often life- threatening diagnoses Dr. Google provides. Here in this post we will explain the symptoms, causes, and treatments of true sciatic pain, while also explaining other conditions that often mimic sciatica.
What is Sciatica?
The sciatic nerve is one large nerve that is comprised of a group of smaller nerves from the lower part of the spinal cord that come together and pass through the back side of each hip to supply muscles and skin in the back part of the leg (see figure above). It is the largest nerve in the human body, which is why it can cause a great deal of pain in a widespread area when irritated. Sciatica is a term that describes pain into the buttock, leg and foot due to irritation of any part of that sciatic nerve.
Symptoms of Sciatica
Pain associated with sciatica include: continuous burning, sharp and/or tingling pain from the buttock into the back part of the leg, weakness in the leg, foot, and/or toes. Sciatic pain into the buttock and leg often makes it difficult to sit, especially for a prolonged period. Someone with sciatic pain will have difficulty standing up from the seated position and walking due to the pain. While sciatica is not limited to one side of the lower body, it is rarely present in both legs.
Causes of Sciatica
While there are many causes of sciatica, we will dive into a couple of the most common causes. A herniated disc is a common cause of sciatica symptoms. If you are unsure what a herniated disc is, please refer to May and June’s blog posts. When a disc is herniated, it presses onto the nerves exiting the spine that comprise the sciatic nerve; this will cause true sciatica. Establishing motion within the low back joints and treating muscles that connect directly onto the low back discs will help reduce inflammation surrounding the herniated disc. Often inflammation surrounding the herniation is the cause of sciatica; therefore, diminishing inflammation will alleviate sciatica pain.
The sciatic nerve travels through narrow passageways in the bone and muscles, which allows for the potential for the nerve to become entrapped or impinged. Most of the time the sciatic nerve runs beneath a muscle in the buttock region, the piriformis. In some people, the nerve may run through the muscle. A study was published in Muscles, Ligaments and Tendons Journal that looked at 130 dissected cadavers and showed the sciatic nerve passed beneath the piriformis muscle in 78% of the dissections [Figure 1], while in 21% of the dissections part of the sciatic nerve passed through the piriformis muscle1 [Figure 2]. When the piriformis muscle is spasmed, tight, swollen, or injured it can compress or irritate the sciatic nerve. However, if the sciatic nerve penetrates through the tight piriformis muscle, the patient is more likely to have sciatic-type pain. This is called piriformis syndrome, which is not true sciatica. In piriformis syndrome, the problem lies outside the spine and in the hip region, whereas in true sciatica the pain is originated at the spine. By addressing the piriformis muscle, pain can be alleviated.
Figure 2: The sciatic nerve passes through the piriformis muscle.
Pain into the buttock and leg can also be caused by sclerotogenous pain. The cause of sclerotogenous pain is due to irritation to a structure that has the same nerve innervation from embryonic development. Essentially, because two tissues developed from the same origin in utero, the brain has a hard time telling them apart and often tells the body one area is in pain, when the pain is really coming from somewhere else. This is also known as “referred pain”. Sclerotogenous or referred pain, for example, is thought to be the cause of arm and neck pain in a patient experiencing a heart attack. Many structures such as the kidneys, gallbladder and the psoas muscle can refer pain into the low back and hips. Structures of the low back and abdomen have similar embryonic origin as the skin and leg, which explains when structures of the low back are irritated the patient may experience pain into the leg. This is not true sciatica. Referred pain will not cause weakness, whereas that is a symptom in true sciatica.
While it is clear there are many causes of pain into the leg, it may not be true sciatica. Sciatica needs to be properly treated because it can lead to irreversible weakness, or weakness that is prolonged. Incidentally, true sciatic pain is not often surgical as most people think. It can often be resolved with conservative care and rehab. Generally, the earlier you are evaluated and treated for any injury and onset of pain the better the prognosis. Please do yourself a favor and if you are experiencing pain into the buttock and leg come see us at Spinal Care and avoid that temptation to refer to Dr. Google! A thorough exam will show the cause of pain and lead to a proper diagnosis. We are here to help!
1Carro, Luis Perez et al. “Deep Gluteal Space Problems: Piriformis Syndrome, Ischiofemoral Impingement and Sciatic Nerve Release.” Muscles, Ligaments and Tendons Journal 6.3 (2016): 384–396. PMC. Web. 13 Nov. 2017