Last Updated on November 15, 2022
Sciatica is the term used to describe mild to intense radiating pain in the lower limb. The term does not denote any disease. It is, in fact, a vague expression for a set of symptoms.
An equivalent medical term is radiculopathy. It describes pain, numbness, tingling, and weakness in the arms or legs caused by a nerve root problem. If the nerve problem is in the neck, it is called cervical radiculopathy. Since sciatica affects the low back, it is called lumbar radiculopathy.
The pain is almost always caused by compression/or irritation of either nerve root(s) that form the sciatic nerve.
The pain can also occur due to compression of the sciatic nerve itself.
The pain of sciatica travels along the path of the sciatic nerve.
The sciatic nerve travels from the lower back through the hips and buttocks and down each leg.
The area where the pain is felt can include the back, buttock, leg, and foot.
The additional symptoms may include numbness, muscular weakness, pins, and needles, or tingling sensations. The symptoms are restricted to one limb in most cases.
The most common nerve roots involved are L4, L5, or sacral nerves.
As noted before, sciatica is just a set of symptoms. There can be various causes of sciatica and treatment of sciatica varies with the cause.
Relevant Anatomy
Sciatica is a pain in the regions supplied by the sciatic nerve. To understand the cause and distribution of this type of pain, we need to understand origin, travel and supply of sciatic nerve.
The sciatic nerve is the largest and longest nerve in the human body.
The sciatic nerve is formed by the contribution of motor and sensory fibers from spinal nerves L4 to S3 in the lumbosacral plexus.
This nerve runs along the back of the thigh and leg and terminates in the foot and supplies these very regions.
It is responsible for motor and sensory functions of the lower limb.
Causes of Sciatica
Impingement of the nerve fibers that constitute or contribute to the Sciatic nerve is the cause of Sciatica. Therefore any disease that either causes impingement of nerve roots that contribute to the sciatic nerve or the nerve fibers can lead to sciatica.
Because nerve roots from L4 to S3 contribute, any nerve root involvement may cause pain.
Common causes of sciatica are
- Spinal disc herniation
- Lumbar spinal stenosis
- Piriformis syndrome
- Trigger points
- Lumbar Spondylosis
- Spondylolisthesis
- A mass causing compression of nerve roots e.g. tumor
A herniated disc is the most common cause.
Diagnosis
The diagnosis is based on clinical history, physical examination and investigations wherever required. The diagnosis actually is of the underlying disease as sciatica is just a symptom or presentation.
Because of the many conditions which can compress nerve roots and cause sciatica, treatment, and symptoms often differ from patient to patient.
Often, there is a shooting pain that seems to go from the hip below. Some people describe it as coming from below to hip.
The pain may be accompanied by burning sensations, pins and needles or spasms of the muscle in the affected limb.
The symptoms may or may not be relieved by change in body posture. Prolonged sitting or standing may aggravate the symptoms.
The further course of workup depends on the likely causes and severity of the symptoms. Depending on the severity of the symptoms and patient profile, the investigation can be ordered right away or can be postponed while putting the patient on symptomatic treatment.
In later cases, the usual period of wait is six weeks. If no improvement in symptoms has occurred in six weeks, radiological investigations can be ordered.
[Read about sciatica bothersomeness index, a patient reported index that tells how sciatica is bothering the patient.]
Treatment
The actual treatment would depend on the underlying disease. There are different measures applied in general, for treating the symptoms.
These measures include:
- Pain control by use of drugs
- Anti-inflammatory medications
- Opioid drugs if severe pain
- Physical therapy / Stretching exercises
- Epidural steroid injections -Provides temporary relief
- Surgery in severe cases where the nerve requires decompression. Commonly performed surgeries are
- Discectomy
- Laminectomy
References
- Koes BW., Van Tulder MW, Peul, WC. Diagnosis and treatment of sciatica. BMJ: British Medical Journal, 2007 Jun. 334(7607), 1313-17
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1895638/ - Sabino J, Grauer, JN . Pregnancy and low back pain. Current Reviews In Musculoskeletal Medicine. 2008 1(2), 137-41
https://link.springer.com/article/10.1007%2Fs12178-008-9021-8
