Sciatica Causes: Genetics, Low Back Problems, Piriformis, Arthritis

Sciatica Causes: The sciatic nerve forms by the union of Lumbar4 to Sacral31 nerve roots and exits the pelvis through the greater sciatic foramen, below the piriformis muscle located deep in the buttocks. The nerve runs down the back of the thigh, into the leg, and ends in the foot. The sciatic nerve becomes inflamed, irritated, and/or mechanically compressed. Any type of pain and/or neurological symptom/s from the sciatic nerve is referred to as sciatica. Sciatica is a type of lumbar radiculopathy, which means that the pain originates from the low back and/or sacral nerve roots.

Sciatica Causes

Physical forces on the nerve can cause mechanical compression due to the following conditions:

Herniated Discs

• A disc in the lower back can bulge or herniate, causing irritation and/or compression of a sciatic nerve root.

Foraminal Stenosis

• Stenosis, the intervertebral opening through which the nerve roots travel, begins to narrow/close in, can compress or irritate the sciatic nerve.

Degeneration

• Degenerative changes in the spine like the thickening of facet joint capsules and/or ligaments can compress the sciatic nerve.

Segmental Instability

• Instability of a spinal vertebral segment that happens if one vertebra slips over the one beneath it – spondylolisthesis
• Vertebral defects – spondylolysis
• Complete dislocation of one or more vertebrae can compress the nerve root/s of the nerve.

Other Sciatica Causes

• Tumors, cysts, infections, or abscesses in the lower spine or pelvic region can also cause sciatic nerve compression.

Chemical Inflammation

• Chemical irritants can include hyaluronic acid and/or fibronectin/protein fragments that leak out of degenerated or herniated discs. These irritants can cause inflammation and/or irritation of the sciatic nerve.
• Degenerated discs can cause nerve tissues to grow into the disc, penetrating the outer and inner layers of the disc, causing sciatica. Immune system responses can contribute to pain when exposed to disc fluid.
• Substances such as glycosphingolipids/fats and neurofilaments /protein polymers secreted by the immune system are increased in individuals with sciatica. These substances are released from the reaction between nerve roots and exposed disc material, causing inflammation.

Job Occupation

Individuals with specific jobs have an increased risk of developing sciatica. Examples include:

• Truck drivers
• Desk workers
• Teachers
• Warehouse workers
• Machine workers
• Plumbers
• Electricians
• Carpenters
• Fitness trainers

Sitting and standing for long periods, using improper posture, constantly bending, twisting, reaching, and regularly lifting are risk factors for sciatica.

Piriformis Syndrome

Piriformis syndrome is a condition where the piriformis muscle swells and spasms from overuse or inflammation irritating the sciatic nerve that is right underneath. The nerve can get trapped in the muscle causing sciatica-like symptoms that include:

• Pain follows the same pattern in the leg as a compressed sciatic nerve root.
• Tingling
• Numbness

Discomfort from piriformis syndrome feels similar to sciatica, but it is not caused by compressed sciatic nerve root. Piriformis pain comes from compression of the sciatic nerve near the piriformis muscle.

Genetic Sciatica Causes

Sciatica caused by degenerated and/or herniated discs can be genetic. Research has shown that certain genetic factors are more prevalent in individuals with back and spinal problems. These congenital disabilities can cause the discs to become weak and susceptible to external stress. With time the proteins in the disc break down, compromising the integrity and function.

Arthritis and Joint Issues

Arthritis or other inflammatory conditions around the hip joint can cause pain down the leg, similar to sciatica. This is referred pain that spreads out from the source and is not radicular nerve pain that originates in the nerve roots.

• Conditions like sacroiliac joint dysfunction or sacroiliitis can cause sciatica-like pain that runs down the back of the thigh but usually ends before or at the knee.
• The pain can be acute and debilitating, like sciatica but is caused by an abnormal motion or malalignment of the sacroiliac joint.

Body Composition

Normal Cholesterol Ranges

High cholesterol can lead to severe consequences when left untreated, but it can be difficult to spot with no noticeable warning signs. This is why it’s essential to monitor cholesterol levels with blood tests, especially if there is an increased risk. Example of normal cholesterol levels for adults 20 years of age or older:

• Total cholesterol 125-200 mg/dL
• LDL <100 mg/dL
• HDL >40 mg/dL men, >50 mg/dL women

Lifestyle

• Lack of physical activity contributes to high cholesterol levels.
• Diets that mainly consist of processed foods and saturated fats increase the risk of high LDL levels.
• Smoking can lower HDL levels.

Aging

• Individual risk for developing high cholesterol tends to increase as the body advances in age. This is why it is recommended to have regular physicals and blood tests.

Genetics

• Some individuals are more genetically predisposed to developing high cholesterol and heart disease.
• Knowing family medical history can help predict whether it may become a problem.

References

Davis D, Maini K, Vasudevan A. Sciatica. [Updated 2021 Sep 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: www.ncbi.nlm.nih.gov/books/NBK507908/

Giuffre BA, Jeanmonod R. Anatomy, Sciatic Nerve. [Updated 2021 Jul 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: www.ncbi.nlm.nih.gov/books/NBK482431/

Hicks BL, Lam JC, Varacallo M. Piriformis Syndrome. [Updated 2021 Jul 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: www.ncbi.nlm.nih.gov/books/NBK448172/

Raj MA, Ampat G, Varacallo M. Sacroiliac Joint Pain. [Updated 2021 Aug 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: www.ncbi.nlm.nih.gov/books/NBK470299/