If you’re living with multiple sclerosis (MS), you know it can be a pain in the butt — literally. Many people living with MS have to deal with frustrating symptoms such as numbness and tingling in the legs, lower back, and buttocks. Unfortunately, these sensations affect 8 out of 10 people living with the neurodegenerative autoimmune condition. However, it’s possible that not all your nerve pain is caused by MS.

Another medical condition, piriformis syndrome, can cause nerve pain in the legs and buttocks. Piriformis syndrome and multiple sclerosis (MS) can both lead to similar symptoms, but they have different causes. However, people with MS might have issues that irritate the nerves outside the brain and spinal cord, which can result in conditions like piriformis syndrome.

Some clues can help you determine when numbness, tingling, or pain in the legs may not be related to MS. Continue reading to learn more about piriformis syndrome, a distinct condition with unique symptoms, causes, and treatments.

What Is Piriformis Syndrome?

Piriformis syndrome is the uncomfortable result of problems in the piriformis muscle. This muscle, which is deep in the buttock region, begins at the lower spine and attaches to the top of each femur (thigh bone). It’s important for hip rotation and stability.

The piriformis muscle can cause pain in the buttocks region during spasms (sudden uncontrolled muscle contractions). You may also feel pain when the muscle presses on or irritates the nearby sciatic nerve. The largest nerve in the body, the sciatic nerve, runs beneath — or in some people, through — the piriformis muscle. The sciatic nerve connects the spinal cord with the skin and muscles in the legs and feet to detect sensations and control movement. Pain, numbness, and tingling caused by piriformis syndrome are often confused with sciatica because the symptoms are very similar.

Common Symptoms of Piriformis Syndrome

Piriformis syndrome often leads to pain or tingling in the buttocks, hip, or upper legs. Back pain can happen, too. Common symptoms include a dull aching in the buttocks and pain down the back of the thigh, which may radiate to the calf and foot, as well as less range of hip motion. Symptoms of piriformis syndrome are often described as:

• Pain
• Tingling
• Aching
• Numbness
• Shooting
• Burning

Certain activities can make symptoms worse. Walking uphill or up stairs may hurt, and pain may worsen after sitting for long periods of time.

Causes of Piriformis Syndrome

If you have signs or symptoms of piriformis syndrome, you may wonder why you are experiencing the pain and tingling. In most cases, the exact reasons are not known. However, medical experts suggest the following causes of piriformis syndrome:

• Spasms in the piriformis muscle
• Muscle tightness in the piriformis
• Bleeding in the area around the piriformis muscle
• Inflammation (swelling) in the piriformis muscle or nearby tissues
• Scarring in the piriformis muscle

Symptoms of piriformis syndrome may result from any of the above problems or a combination of them. If you think you might have piriformis syndrome, tell your doctor about all of your symptoms.

Piriformis Syndrome and MS

Numbness, tingling, and pain can be uncomfortable and stressful symptoms of MS. In fact, more than 33,000 MyMSTeam members have reported numbness as a symptom of MS. These sensations are often caused by damage to the myelin sheath, which forms a protective layer around the nerves in the central nervous system (CNS) — the brain, spine, and optic nerve. MS can cause painful sensations, including:

• Facial pain
• Muscle spasms
• Feelings of burning, tingling, or aching in the lower legs
• Shock-like sensations traveling from your back to your lower limbs

Neuropathic pain (pain caused by nerve damage) and other abnormal sensations can occur due to MS-related damage to the CNS. However, the causes of piriformis pain syndrome are related to the piriformis muscle spasming or pressing on the sciatic nerve. Certain lifestyle habits, such as sitting for long periods, are also more likely to worsen piriformis syndrome pain.

Can MS Cause Piriformis Syndrome?

MS-related nerve pain and piriformis syndrome have different root causes, but having MS may make you more likely to develop piriformis syndrome. MS nerve pain comes from damage to the myelin sheath, the protective layer surrounding the nerves in the CNS. This damage is what leads to neuropathic pain like tingling, burning, and shock-like sensations. In contrast, piriformis syndrome happens when the piriformis muscle irritates the sciatic nerve. Several factors link MS and piriformis syndrome:

• Decreased mobility — Reduced activity levels due to MS symptoms can lead to prolonged sitting, which tightens the piriformis muscle.
• Muscle spasticity — Muscle stiffness, a common MS symptom, may increase the risk of piriformis syndrome.

What’s the Connection?

Although MS nerve pain and piriformis syndrome have different causes, there is a connection between the two conditions. MyMSTeam members often report pain from piriformis syndrome along with their MS symptoms.

One MyMSTeam member reported, “Over the last few years, [I] had tingling, pins and needles, and some numbness in my leg, feet, and toes. More recently in my left arm. It was replaced with nerve pain, which has become more painful with each occurrence.”

MS can lead to changes in a person’s activity level. For example, decreased mobility and muscle spasticity may lead to more time spent sitting, which is known to tighten the piriformis muscle and trigger piriformis syndrome.

Another MyMSTeam member shared their experience dealing with numbness and loss of mobility. “It has limited my activities a lot,” they wrote. “I have been checked for carpal tunnel, but that is minimal. My feet are also a problem. The more I use them, the worse they become that day. I don’t walk any distances anymore, because they hurt more and more if I do. I have a lot of other issues, but the most debilitating is the numb hands.”

Additionally, a study published in 2017 found that MS nerve damage can affect the sciatic nerve in some people who have MS. This research revealed that people living with MS have slightly more lesions on the sciatic nerve compared with people without MS. However, this publication is one of very few studies showing lesions on the peripheral nervous system — MS lesions are generally confined to the CNS.

Treating Piriformis Syndrome and Multiple Sclerosis

The combination of piriformis syndrome and MS can worsen quality of life. Interventions such as pain management medications and physical therapy can help relieve some of the discomfort caused by piriformis syndrome.

Piriformis Syndrome Treatments

Successful treatment of piriformis syndrome usually requires a combination of measures to address the symptoms:

• Pain management interventions with over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin) can help reduce swelling and inflammation. Opiates may be prescribed for severe pain.
• Muscle relaxants may provide temporary relief by reducing muscle spasms.
• Injections of corticosteroid (steroid), botulinum (Botox), or local anesthetics reduce inflammation and pain at the muscle and nerve sites.
• Physical therapy gently stretches the piriformis muscle and surrounding muscles and corrects posture that may be straining the muscle or sciatic nerve.
• Lifestyle changes, such as getting more exercise and improving sitting posture, can help reduce piriformis muscle flare-ups.
• Losing weight and wearing loose-fitting clothes can ease pressure on the sciatic nerve for some.
• Alternative therapies such as acupuncture and chiropractic adjustments can help align the body to relieve pain.
• Surgery, although rarely used for piriformis syndrome, might be performed in severe sciatica cases that result in loss of bowel or bladder control.

Why Won’t My Piriformis Heal?

If you’ve tried multiple treatment options and haven’t had success, there could be a few reasons why. It could be due to ongoing inflammation or muscle spasms that haven’t responded to treatment. It could also be from poor posture or underlying triggers, such as prolonged sitting or repetitive strain on the muscle. Talk to your doctor about whether it might be a good idea to try new therapies or interventions.

Can Piriformis Syndrome Be Permanent?

Piriformis syndrome is typically not permanent, but it may persist if left untreated. Chronic cases can develop if the muscle remains tight or inflamed over an extended period. Early intervention with physical therapy, lifestyle changes, and targeted treatments can make a big difference. However, in rare cases where symptoms do not improve despite treatment, surgery may be necessary.

It may be difficult to tell the difference between various kinds of nerve-related pain, so be sure to talk with your healthcare provider if you experience new or worsening pain. Since certain medications may interfere with your MS treatments or cause side effects, your doctor or healthcare team can help you determine which treatments are right for you.

Talk With Others Who Understand

On MyMSTeam, the social network for people with multiple sclerosis and their loved ones, more than 218,000 members come together to ask questions, give advice, and share their stories with others who understand life with multiple sclerosis.

Do you have symptoms that could be caused by either multiple sclerosis or piriformis syndrome? Have you been diagnosed with both conditions? Share your experience in the comments below, or start a conversation by posting on your Activities page.