G.Bertelli Piriformis Syndrome

Generality

Piriformis syndrome is a neuromuscular disorder that occurs when the piriformis muscle, located in the gluteal region, compresses or irritates the sciatic nerve (or ischiatic if you prefer).

The symptoms are similar to those generated by other conditions that evolve into sciatica, such as a herniated disc; however, piriformis syndrome does NOT refer to problems with spinal nerve roots and / or compression of an intervertebral disc.

The involvement of the sciatic nerve, in fact, occurs a little further from its origin, precisely at the level of the buttock, where it remains trapped due to alterations of the piriformis muscle . This can cause pain often perceived as a tingling or numbness that involves the lower part of the body and runs through the leg, radiating from the buttock to the foot.

Pain may worsen during daily activities such as climbing stairs, walking, running or sitting for long periods of time. Piriformis syndrome is often confused with a lumbar disc problem, as the symptoms are similar to an irritation of the sciatic nerve root.

Piriformis syndrome can be caused by several causes, which include anatomical changes in the muscle-nerve relationship or trauma in the gluteal region, such as a car accident or a fall.

There is no immediate test to make a diagnosis . The condition is defined mainly on the basis of the symptoms that the patient manifests and on the physical examination, after the exclusion of other possible causes.

In general, the therapeutic approach to the disorder begins with physical exercises and stretching, which allow rehabilitation of the movement. Most treatments are aimed at reducing the pressure exerted by the piriformis muscle on the sciatic nerve.

To control local pain and inflammation, analgesic and anti-inflammatory drugs can be prescribed; a local corticosteroid injection may provide temporary relief. In some cases, surgery is recommended.

What's this

What is meant by Piriformis Syndrome?

Piriformis syndrome is a condition in which the piriformis muscle can irritate or compress the proximal sciatic nerve due to trauma and / or contracture .

The disorder typically causes spasms and pain in the buttock, but may also extend to the nearby sciatic nerve, causing numbness, weakness and tingling along the back of the leg and in the foot (similar to sciatic pain caused by the herniated disc).

In general, conditions of this type are referred to as TRAPPING NEUROPATHIES .

Pyriform Muscle: Features and Functions

The piriformis is a small triangular-shaped muscle, located deep in the buttock, behind the large buttock.

The piriformis muscle:

It originates from the inner surface of the sacrum and is inserted into the ipsilateral femur;
It is classified among the external muscles of the hip (group of external rotators of the hip);
It is important to assist the external / internal rotation of the hip, and turn the leg and foot outwards. In general, this muscle is important in the movement of the lower part of the body, as it stabilizes the hip joint and, by contracting, externally rotates the femur and allows walking, shifting the weight from one foot to the other and keeping the equilibrium;
The sciatic nerve passes below the piriformis muscle, with which it is in close contact.

Causes and Risk Factors

Piriformis Syndrome: what are the Causes?

When the piriformis muscle is affected by shortening or excessive elongation, piriformis syndrome may occur. About 50% of patients with piriformis syndrome have a traumatic episode at the buttock, hip or lower back.

The exact causes of the piriformis syndrome are unknown, but some hypotheses include:

Spasm of the piriformis muscle or of an adjacent structure, in response to a traumatic event or excessive effort;
Muscular abnormalities with hypertrophy ;
Nerve anomalies (partial or total);
Lumbar hyperlordosis ;
Fibrosis (due to a trauma);
Pseudoaneurities of the inferior gluteal artery;
Excessive physical activity .

Each of these causes, or their combination, can affect the piriformis muscle (causing pain in the buttocks) and the adjacent sciatic nerve (causing pain, tingling or numbness in the back of the thigh, calf or foot).

Abuse injuries at the origin of the piriformis syndrome can derive from activities performed in a sitting position that involve intense use of the legs, such as rowing or cycling .

Piriformis syndrome can also be caused by excessive pronation of the foot, where the piriformis muscle contracts repeatedly, by a compensation mechanism, at every step.

The result of the spasm of the piriformis muscle can affect not only the sciatic nerve, but also the pudendal nerve, which controls the muscles of the viscera and bladder. The symptoms of pudendal nerve entrapment include numbness and tingling in the groin area and can lead to urinary and fecal incontinence.

Symptoms and Complications

Piriformis Syndrome: How is it manifested?

Typical symptoms of piriformis syndrome may include:

Intense and deep pain in the buttock, which can radiate to the buttocks;
Pain, tingling muscle weakness, or numbness in the lumbar region, along the back of the thigh, calf and foot (similar to sciatica);
Pain when walking up the stairs or on a slope;
Reduced movement of the hip joint .

What activities can exacerbate pain?

Symptoms of piriformis syndrome often worsen during physical activities involving the piriformis muscle or after taking a prolonged sitting position, while they may improve with rest in the supine position.

To learn more: Symptoms Piriformis Syndrome »

Diagnosis

How is the Diagnosis of Piriformis Syndrome Formulated?

The diagnosis of piriformis syndrome is often difficult, due to the lack of validated and standardized diagnostic tests; in this regard, two examinations have been well described and clinically validated:

Electrophysiological test, called FAIR-test : this exam allows to measure the delay of sciatic nerve conduction;
Magnetic resonance neurography : it is a sophisticated version of MRI and allows to highlight inflammation and the effects on the nerves involved.

Some specialists believe that the most important criterion for diagnosis is the exclusion of sciatica resulting from the compression / irritation of the spinal nerve roots. The piriformis syndrome, in fact, does not involve the herniation of the discs .

However, the diagnosis of piriformis syndrome is based on the review of the patient's medical history, physical examination and some diagnostic tests.

history

In the diagnostic procedure, the anamnesis includes a thorough examination of the symptoms reported by the patient, investigating specifically:

Which positions or activities alleviate or worsen the pain;
The duration of the events;
The possible association of symptoms with a recent and previous accident.

Physical examination

Piriformis syndrome is often defined through a series of diagnostic tests that exclude other conditions capable of causing similar symptoms in the patient, such as a herniated lumbar disc or sacroiliac dysfunction.

The visit includes a hip and leg exam for:

Evaluate if the movement causes exacerbation of pain in the back or lower limbs;
Measure local tenderness and muscle strength.

Generally, the movement of the hip and the forced rotation of the extended thigh cause pain, while through a careful and deep palpation it is possible to detect a spasm of the piriformis muscle .

Diagnostics for Images

Traditional imaging tests are not able to diagnose piriformis syndrome.

However, investigations such as computed tomography ( CT ) and magnetic resonance imaging ( MRI ) can be conducted for:

Exclude other conditions responsible for similar symptoms;
Detect if the sciatic nerve is compressed by other causes.

An injection of anesthetic, with or without corticosteroids, can help confirm whether the piriformis is the source of the symptoms.

Treatment and Remedies

Piriformis Syndrome: what is the expected treatment?

In most people, the symptoms of piriformis syndrome improve with treatment and lifestyle changes .

Depending on the severity of the pain and other symptoms, some treatment options may be recommended.

If the pain is caused by certain actions, it is useful to try to temporarily avoid the activities and the positions that trigger it.
Rest can help relieve symptoms.
A doctor or physiotherapist can suggest to each patient a personalized exercise program that helps reduce sciatic nerve compression.
Some health professionals may recommend anti-inflammatory, muscle relaxant or local injections of a corticosteroid .
Other therapies can also be used, such as ionophoresis and botulinum toxin injection (example: Botox ®), which can relieve muscle stiffness and sciatic nerve compression.
Rarely, in very severe and persistent cases, surgery is performed to relieve pressure on the sciatic nerve.

A comprehensive approach to the management of piriformis syndrome may include a combination of the following treatments.

Exercise, stretching and massages

An effective treatment includes stretching and strengthening of the muscle groups affected by the piriformis syndrome (gluteus medius, adductor muscles and hip extensors, etc.). Exercises involving movements to lengthen the piriformis muscle and decrease spasm can alleviate the painful symptoms along the sciatic nerve and rehabilitate the patient in a few days.

Massotherapy, practiced by an expert, can contribute to the healing of piriformis syndrome, increasing blood flow to the area and reducing muscle spasm.

Cold and hot packs

At the onset of pain, it is useful to start by applying a cold compress on the painful area several times a day, for about 15 minutes at a time. Repeat if necessary every 2-4 hours, continuing until it benefits, even for a couple of days.

Sometimes, it may be more useful to gently massage the area with an ice cube, especially if they are specific activities that cause an increase in pain (if the ice is placed directly in contact with the skin, limit the application to 8-10 minutes to avoid cold burns).

The cold pack reduces inflammation and muscle tension related to the piriformis syndrome, due to a natural analgesic effect.

Once the acute pain is relieved, it is good to try to relax the contracted muscles : in this case, heat (like a hot water bottle) may be useful.

Some people with piriformis syndrome find it useful to alternate between cold and hot packs .

drugs

Non -steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, help relieve pain during the acute phase of piriformis syndrome and help reduce inflammation.

If the pain does not tend to improve, the doctor can inject a corticosteroid drug directly into the piriformis muscle, to reduce muscle spasm.

The purpose of a local drug injection is to decrease acute pain to allow progress in physical therapy.

For a persistent spasm of the piriformis muscle, resistant to treatment with analgesics and anti-inflammatories, it may be useful to resort to an injection of botulinum toxin, to help the muscle relax and help reduce pressure on the sciatic nerve.