Anita Chandrasekaran, MD, MPH, is board-certified in internal medicine and rheumatology and currently works as a rheumatologist at Hartford Healthcare Medical Group in Connecticut.
Although both multiple sclerosis (MS) and sacroiliitis can cause lower back or hip pain, they are otherwise unrelated conditions that differ significantly in biology, diagnosis, and treatment.
MS is an autoimmune disease of the brain and spinal cord. Pain in MS is related to either nerve damage or muscle/soft tissue damage that occurs as people with MS try to manage certain MS symptoms like spasticity (muscle stiffness and tightness), numbness, or imbalance.
Sacroiliitis is inflammation of one or both of the sacroiliac (SI) joints. These large joints are located on each side of the body and connect the lower spine to the hip bone. Various health conditions or issues may cause sacroiliitis, including arthritis, pregnancy, trauma, and infection.
This article will provide a general overview of MS and sacroiliitis and highlight key differences between the two conditions.
Pain in the lower back or hip is a hallmark symptom of sacroiliitis. In MS, lower back/hip pain is not a direct result of the disease but rather a secondary effect of people with MS trying to adapt to their symptoms.
MS symptoms arise from interrupted nerve signaling between the brain and spinal cord and the rest of the body.
Pain is a common symptom of MS, and there are two types, which are:
Other common symptoms of MS include:
The main symptom of sacroiliitis is a sharp or aching pain felt in the lower back, hip, and/or buttock. The severity of sacroiliitis pain depends on the degree of inflammation or injury to the joint.
Besides pain, other symptoms of sacroiliitis may include:
Stems from inflammation of the sacroiliac (SI) joint
May be accompanied by stiffness or whole-body symptoms like fever or weight loss
Stems directly from nerve damage or indirectly from muscle/soft tissue damage
Usually accompanied by other MS symptoms, such as fatigue, spasticity (muscle stiffness), or weakness
MS is an autoimmune condition, and sacroiliitis may be caused by or associated with certain autoimmune conditions. Apart from this general similarity, MS and sacroiliitis are vastly distinct conditions.
MS occurs when the immune system malfunctions and attacks nerve fibers and their protective myelin covering in the brain and spinal cord.
Experts do not know why the immune system launches such misguided attacks in MS. It's likely that a combination of factors, both genetic and environmental, are involved.
Some environmental factors potentially linked to MS development include:
The purpose of your SI joints is to facilitate absorption and transmission of any impact from your spine to the lower part of your body.
Inflammation of the sacroiliac joint may be caused by a variety of health conditions or factors.
Some of these conditions and factors are:
The estimated prevalence of sacroiliitis is around 0.3%–0.7% of the U.S. population. MS is seen in around 0.36% of the U.S. population.
There is no single test that can diagnose MS or sacroiliitis. Instead, healthcare providers pool data from a person's medical history, physical exam, and various tests to make the diagnosis.
A neurologist, which is a doctor that specializes in diseases of the nervous system, diagnoses MS by reviewing a person's symptoms and performing neurological exam. Results from one or more of the following tests is also considered:
Sacroiliitis typically is diagnosed by a primary care provider, rheumatologist, physiatrist, or orthopedic surgeon using some combination of the following diagnostic tools and tests:
No cure yet has been found for MS. Sacroiliitis, on the other hand, may be reversed, depending on the underlying cause.
The treatment of MS usually involves taking a disease-modifying treatment (DMT). DMTs are intended to help reduce MS relapses (flare-ups of symptoms) and slow disease progression.
Since DMTs are "big-picture" drugs, daily MS symptoms like pain, constipation, or spasticity are managed with a combination of lifestyle habits, medications, and rehabilitation therapies.
Specifically, lower back or hip pain in MS is usually treated with physical therapy, and an over-the-counter (OTC) pain medication like Tylenol (acetaminophen) or a nonsteroidal anti-inflammatory drug (NSAID) like Motrin or Advil (ibuprofen). A muscle relaxant like Kemstro (baclofen) may be prescribed if the pain stems from spasticity.
The treatment of sacroiliitis entails two main goals:
Pain is controlled through a combination of physical therapy and medications, including topical drugs like lidocaine (a numbing agent) and oral drugs like ibuprofen. A corticosteroid injection into the inflamed joint is also sometimes incorporated into the treatment plan.
Radiofrequency ablation (a minimally invasive procedure in which radio waves are used to heat and disrupt nerve function) may be tried if the other treatments don't work.
Joint fusion surgery (when the two bones of the SI joint are connected using a metal device) is generally considered a last resort treatment option for sacroiliitis.
Other treatments may be warranted depending on why a person develops sacroiliitis. For example, an anti-tumor necrosis factor (TNF) may be recommended if sacroiliitis is due to ankylosing spondylitis. Anti-TNF drugs, like Enbrel (etanercept) , work to suppress or quiet inflammation in the body.
Healthy lifestyle behaviors may be helpful in protecting against or treating MS or sacroiliitis.
The following lifestyle habits may help decrease MS disease activity or prevent MS onset in certain individuals:
Depending on the underlying cause, certain lifestyle behaviors can help prevent sacroiliitis onset or worsening.
For example, if you are pregnant, avoiding positions that place extra stress on the SI joint (e.g., crossing your legs) can help prevent sacroiliitis.
Likewise, if you have AS, engaging in exercise therapy can help reduce pain and protect against long-term SI joint damage.
Multiple sclerosis (MS) and sacroiliitis can both cause lower back or hip pain, although through unrelated means. Pain in MS stems directly from nerve damage or indirectly from muscle/soft tissue damage. The pain of sacroiliitis stems from inflammation of the sacroiliac joint.
Apart from the goal of easing pain, the diagnosis and treatment of MS and sacroiliitis are also distinct.
Whether you are experiencing pain from sacroiliitis or MS, it's important to get it checked out by your healthcare provider. Each condition requires a careful assessment and thoughtful discussion about therapy options. As you navigate the challenges of MS or sacroiliitis, practice self-compassion and reach out to loved ones for support.
Certain autoimmune conditions, like ankylosing spondylitis, may cause sacroiliitis. That said, non-autoimmune conditions, like osteoarthritis, can also cause sacroiliitis.
Some conditions may mimic or resemble sacroiliitis, including Paget's disease (a condition with bone overgrowth), sarcoidosis (an inflammatory condition that produces lumps of cells in tissues), diffuse idiopathic skeletal hyperostosis (hardening of ligaments where they attach to the spine), lymphoma (cancer of the lymphatic system), and bone cancer.
MS does not cause joint inflammation. People with MS may experience joint pain as a result of compensating for their MS symptoms (e.g., muscle weakness, walking/balance problems, or numbness).
An X-ray of the pelvis is usually sufficient for diagnosing sacroiliitis. An MRI scan may be ordered if sacroiliitis does not show up on an X-ray but is still strongly suspected.
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National MS Society. Pain and itching.
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