Deep gluteal syndrome | |
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Deep gluteal space anatomy | |
Symptoms | Pain in the hip, buttocks, or thigh. Often pain when sitting or with certain hip movements. Often unilateral radiating pain. [1] |
Causes | Most common are (1) fibrotic adhesions tethering the sciatic nerve and (2) piriformis syndrome. [2] |
Diagnostic method | First ruling out lumbar pathology. Then stretch/activation tests, magnetic resonance imaging / magnetic resonance neurography, and diagnostic injections. [3] |
Differential diagnosis | pudendal nerve entrapment, ischiofemoral impingement, greater trochanter ischial impingement, and ischial tunnel syndrome. [1] |
Treatment | Conservative treatments include physical therapy, analgesics, and injections. [2] [4] Surgical treatment is a sciatic nerve decompression and/or muscle resection. [5] |
Deep gluteal syndrome describes the non-discogenic extrapelvic entrapment of the sciatic nerve in the deep gluteal space. [1] It is an extension of non-discogenic sciatic nerve entrapment beyond the traditional model of piriformis syndrome. [4] Symptoms are pain or dysthesias in the buttocks, hip, and posterior thigh with or without radiating leg pain. Patients often report pain when sitting. [1] The two most common causes are piriformis syndrome and fibrovascular bands, but many other causes exist. [2] Diagnosis is usually done through physical examination, magnetic resonance imaging, magnetic resonance neurography, and diagnostic nerve blocks. [6] Surgical treatment is an endoscopic sciatic nerve decompression. [7]
Posterior: the gluteus maximus [1]
Anterior: posterior acetabular column + hip joint capsule + proximal femur [1]
Lateral: gluteal tuberosity + lip of linea aspera [1]
Medial: sacrotuberous ligament [1]
Superior: inferior margin of the greater sciatic notch [1]
Inferior: proximal origin of hamstrings at the ischial tuberosity [1]
The hip has five external rotators: The piriformis, superior gemellus, obturator internus, inferior gemellus, and quadratus femoris. The inferior gluteal nerve/artery, sciatic nerve, pudendal nerve, posterior femoral cutaneous nerve, obturator internus nerve, superior gemellus nerve, quadratus femoris nerve, and inferior gemellus nerves exit the greater sciatic foramen underneath the piriformis. [6] [4] While any of the nerves which exist in this deep gluteal space can be entrapped by deep gluteal space problems, the existing definition of the syndrome tends to focus on sciatic nerve pathology specifically.
As deep gluteal syndrome is defined as entrapment of the sciatic nerve, patients will have sciatica-like pain. [6] These general sciatica symptoms include unilateral, though sometimes bilateral, radiating pain or dysthesias in the affected extremities. [6] [2] There may be abnormal reflexes or weakness of the affected leg. [1] However, significant localized neurological symptoms like foot drop are not typical. [4] Patients also frequently report persistent or intermittent pain or dysthesias in posterior hip, buttocks, or thigh. [4]
Unlike discogenic sciatica, patients with deep gluteal syndrome report exacerbation of symptoms with pressure in the gluteal space, such as tenderness or pain on deep palpation or pain on prolonged sitting. [8] [6] Often patients will be unable to sit more than 20–30 minutes. [6] [2] When patients sit for long periods of time they may exhibit the antalgic position, where weight is shifted to avoid pressure on the affected side. [4] Pain is often increased by activities or positions involving hip flexion on the affected side. [4] [6] Patients with deep gluteal syndrome may have a history of trauma. [1]
Fibrous bands are the most common cause of deep gluteal syndrome, [2] and this frequently seen intraoperatively during endoscopic sciatic nerve explorations. [6] Fibrous tissue, also known as scar tissue, is dense, inelastic tissue that can form after the body heals from an injury. Fibrous bands are fibrous tissue with a long, thin shape like a rope or a band. It's often not clear how internal scarring would materialize. However, many deep gluteal syndrome patients do have a history of falls or trauma in the gluteal space. [9]
Fibrous bands can be compressive / bridge-type bands, adhesive / horse-strap bands, or have an undefined distribution. The bridge-type bands act as a barrier preventing the sciatic nerve from moving past a given point with compression, like a seat belt. The adhesive bands strongly anchor the nerve and completely limit movement beyond a certain point with traction, like a leash. Fibrous bands with an undefined distribution anchor the sciatic nerve in multiple directions, like glue. [6]
Piriformis syndrome is the second most common cause of deep gluteal syndrome, and the most commonly involved among the various musculotendinous structures in the pelvis. [2] There are several mechanisms proposed where the piriformis entraps the sciatic nerve: hypertrophy (muscle size squeezes tissue around it), dynamic nerve entrapment at the muscle (muscle pinches the nerve with certain movements), anomalous course of the nerve, anomalous attachments of the muscle, iatrogenic injury, and trauma. [6] Anatomic variations of sciatic nerve branching were speculated to play a role, however this is unproven, as surgery groups for deep gluteal syndrome tend to have the same prevalence of sciatic nerve branching anomalies found in non-patient cadavers. [4] [6]
There are many other causes of deep gluteal syndrome although less frequent. They include hamstring conditions, [10] [6] gluteal muscles, gemelli-obturator internus syndrome, [11] [6] vascular abnormalities (e.g. dilated veins), [12] [6] [13] quadratus femoris/ischiofemoral impingement, [6] space-occupying lesions (neuroma, ganglion cyst), fibrosis after classic open surgery of piriformis, trauma, and orthopedic causes. [6] [9] [7] [1] Sometimes unusual rare, pathological anatomic variations may be the cause, such as a muscle fiber piercing a nerve. [3]
The sciatic nerve is highly mobile in the deep gluteal space with hip and even knee movements. [7] For example, hip flexion with knee extension (also called a straight leg raise) causes the sciatic nerve in the deep gluteal space to move 28mm towards the center of the body. [14] Hip movements may also create dynamic impingement between muscles. For example, hip flexion, adduction, and internal rotation stretch the piriformis muscle and reduce the space between the piriformis and superior gemellus as well as the piriformis and sacrotuberous ligament. [6]
Normally the sciatic nerve can stretch, glide, and accommodate moderate compression associated with normal hip joint and knee movements, but it may be impeded by various pathologies. Diminished or absent sciatic nerve mobility is believed to be the precipitating cause of sciatic neuropathy in deep gluteal syndrome. [6] This impaired mobility induces strain and compression on the sciatic nerve during various hip movements. [7] Even a 6% stretch on a nerve can result in impaired conduction. [15]
The general workup involves excluding lumbar, pelvic, and hip pathologies, physical examination, magnetic resonance neurography (MRN) imaging, and diagnostic injections. The use of MRN and diagnostic injections are relatively new diagnostic tools that allow making precise diagnoses where standard diagnostic modalities has failed. [3] Nerve testing such as EMG and NCS can be done but there is little evidence it's helpful. [2] Differential diagnoses include pudendal nerve entrapment, ischiofemoral impingement, greater trochanter ischial impingement, and ischial tunnel syndrome. [1]
Diagnosing deep gluteal syndrome is often is a clinical challenge because the symptoms can have considerable overlap with symptoms of pelvic, hip, and spine pathology. [2] [5] [6] [4] In particular lumbar pathology should be excluded early [4] as sciatica that originates in the spine is thought to be more common than sciatica that originates in the deep gluteal space. [16] When assessing the possibility of lumbar pathology, magnetic resonance imaging (MRI) should not be the sole basis for a diagnosis as it has very high sensitivity which may cause non-discogenic sciatic nerve entrapment to be overlooked. [6] On MRI, disc lesions are present in many asymptomatic people. [8]
Intrapelvic problems should be excluded by covering a gynecologic or urologic history. High resolution imaging can also rule out some forms of intrapelvic problems such as endometriosis or vascular abnormalities. [1]
The clinical signs should determine the diagnostic approach. For example, sitting pain is associated with sciatic nerve entrapment under the piriformis, but pain lateral to the ischium when walking is associated with ischiofemoral impingement. [1] The core of the physical examination is palpation and stretch/activation tests of the external hip rotators.
As patients often have tenderness in the gluteal space, palpation can provide information on which structures may be involved. [5] For example, tenderness over the gluteal muscle at the greater sciatic notch may be piriformis syndrome; lateral to the ischial tuberosity may be ischiofemoral impingement; medial to the ischial tuberosity may be pudendal nerve entrapment. [1] [9] Stretch/activation tests of the external hip rotators try to create dynamic impingement with hip/knee movements. The most used ones are the FADIR test (flexion, adduction, and internal rotation), [5] [8] seated piriformis challenge test, [5] [6] [8] and the active piriformis test. [5] [8] [2] Additional tests include Lasegue test (known as the straight leg raise test), Pace's sign, Freiberg's sign, and the Beatty test. [6]
Magnetic resonance imaging (MRI) and magnetic resonance neurography (MRN) are the diagnostic procedures of choice for deep gluteal syndrome. [4] [6] [3] MRN provides additional information that MRI alone can't by visualizing structural properties of the sciatic nerve. [3] As an example of the diagnostic improvement of MRN, when MRI is used to assess piriformis muscle asymmetry, it has 46% sensitivity and 66% specificity for piriformis syndrome. When MRN is used and includes unilateral sciatic nerve hyperintensity at the sciatic notch, the sensitivity increases to 64% and the specificity increases to 93%. [3] MRN's advantage is in identifying anatomic nerve abnormalities by visualizing neural structures such as nerve diameter, nerve fascial edema, fascicular appearance, perifascicular and endoneural signal intensity. [5] [6] Diffusion tensor imaging / Magnetic resonance tractography is expected to be another powerful clinical tool for diagnosis of deep gluteal syndrome because it can reveal additional physiological information about the nerves, but is still in the research phase. [6]
Image-guided perineural injections of the sciatic nerve are nerve blocks with anesthetic and steroids, and they have both diagnostic and therapeutic function. [6] [2] [9] The blocks are used to localize the source of pain when palpation of internal structures is not possible. The image-guidance is to increase accuracy and visualize the spread of the injected material. [3] Ultrasound-guided injections are the gold standard for differentiating deep gluteal syndrome from other sources of pain. [9] Diagnostic injections function in a similar way to deep palpation. While palpation causes a signal to be sent along a nerve which patients can localize relative to their pain (the spot hurts or it doesn't), anesthetics will block signals sent along nerves. Successful blocks are expected to lead to immediate and complete or near-complete pain relief while unsuccessful blocks are expected to have no improvement in pain. [3] [6] The anesthetics used in nerve blocks are typically a mix of lidocaine and bupivicaine, and the numbness will last for 4–6 hours. [17] Nerve blocks can distinguish between different types of nerve lesions as well as distinguish between sciatic and spinal pathology. [3] Blocks can be repeated on the same area or different areas to increase confidence in the diagnosis (e.g. to rule in the suspected diagnosis and rule out differential diagnoses). [6]
The indications for conservative therapy or surgery are not well defined due to a paucity of controlled trials. If patients do not have clear indications for surgery then a gradual approach is recommended where more conservative treatments are tried before more invasive treatments. Despite the recommendation to start with conservative therapy, it fails in as many half of patients with deep gluteal syndrome. [7] In some cases surgery may be immediately indicated, such as imaging finding a mass lesion compressing the sciatic nerve. [4]
The main approaches to conservative treatment of deep gluteal syndrome are rest, activity modification, physical therapy for 6+ weeks, analgesic / anti-inflammatory drugs, and injections. [2] [4] Conservative therapy fails in as many half of patients with deep gluteal syndrome. [7]
The purpose of physical therapy is to restore normal hip and spine biomechanics. This is done by strengthening and stretching the involved muscles (external hip rotators) as well as sciatic nerve glides. [5] [2] There should also be an emphasis on core stabilization (muscles involved in posture, balance, and overall body strength) and flexibility. [5] Compressive, tensile, shearing, and rotatory forces are present during normal movements, and abnormal biomechanics can lead to a pathological distribution of forces leading to stress injuries and scarring of soft tissue. [18] Abnormal biomechanics such as a posterior pelvic tilt can also change the distribution of pressure when sitting both externally and internally. [19] If left untreated, poor biomechanics potentially also lead to compensatory injuries. [20]
Injections are also a first-line therapy. [7] Local anesthetics, corticosteroids, and botox are frequently used in conditions like piriformis syndrome. [21] Ultrasound-guidance is a popular choice for injections, [5] but injections can also be done under CT or MRI-guidance. [4] [6] Controlled studies have found that for patients with suspected piriformis syndrome, botox injections into the piriformis are more effective than a placebo [22] and also more effective than just an anesthetic block alone. [23] [24] The duration of anesthetics is in hours [17] and consequently the anesthetic alone doesn't lead to long-lasting relief. Corticosteroids are often used for its anti-inflammatory effects [25] which can help when nerves are sensitized due to a nearby local inflammation as well as reducing pressure on a nerve from swelling. [26] The duration of steroid injections is unclear but studies on knee osteoarthritis have reported effects lasting at least 1 week and up to 3 months. [27] [28] Botox will paralyze a muscle which can be helpful for chronic muscle spasms causing dynamic entrapment, or hypertrophy placing pressure on a nerve. [24] Botox will last for about 3 months. [29]
Surgery involves a nerve decompression with or without muscle resection. [5] The surgery can be performed with external incisions (open surgery) or endoscopically. Endoscopy allows for complete sciatic nerve visualization and access for decompression in the extrapelvic gluteal space. [1] The goal of surgery is to restore normal nerve kinematics and nerve conduction. During surgery this is measured by nerve conduction studies and electromyography, as well as observing the sciatic nerve mobility while the patients hips are moved. [1] [2] This testing can be done before and after the decompression to verify improvement before concluding the surgery.
The outcomes measures include modified hip harris score (mHHS), VAS score (numerical pain scores), and Benson outcomes questionnaire. [2] At a 2 year follow up, 80% of patients demonstrated good-to-excellent Benson ratings postoperatively. [2] In one study assessing 122 patients, for pain assessments, 90% improved, 8% had no change, and 2% were worse. For strength assessments, it's 86% improved, 9% saw no change, and 5% were worse. If patients had numbness, then 59% saw improvement and 41% did not see improvement. [7] VAS score changes are consistently positive, with an average of 6.7 preoperative (moderate-severe pain) to 2.1 postoperative (mild pain). [7] [30] The endoscopic approach has low complication rate (0% major and 1% minor). Open surgery has higher complication rate (1% major and 8% minor). [7] Major complications are potentially life-threatening and require immediate as well as intensive medical interventions, while minor complications are not life-threatening and can be managed with less aggressive treatment.
There's little epidemiological data on deep gluteal syndrome. The main epidemiological data available is on piriformis syndrome. Due to challenges in defining and diagnosing piriformis syndrome, attempts at quantifying its prevalence have led to conflicting estimates. Recent estimates for the prevalence of piriformis syndrome are 6% and 17% of all patients with low back pain / sciatica. [8] However, this may be an underestimate due to the high sensitivity of MRI to identify lumbar pathologies (leading to incorrect discogenic diagnoses), the lower referral rate of deep gluteal syndrome patients to neurosurgeons and orthopedic spine specialists (leading to missed diagnoses), and the frequent failure to recognize the diagnosis. [3]
The understanding of sciatica has evolved. Discogenic causes were first recognized. Later piriformis syndrome was proposed as a cause of non-discogenic sciatic nerve entrapment. However, piriformis syndrome remained controversial for many years as a distinct pathophysiological entity because there was no objective diagnostic criteria, no reliable treatment, and no reasonable pathophysiology to support its existence. [4] Over time accurate diagnosis, treatment, and pathophysiology were improved upon. This improved understanding of posterior hip anatomy and nerve kinematics helped to identify other locations the sciatic nerve might be entrapped. [1] The eventual development of endoscopic techniques to explore the sciatic nerve radically changed the understanding of non-discogenic sciatic nerve entrapment. It supported further classification because many other causes were found that did not fit into the traditional model of piriformis syndrome. In particular the concept of fibrous bands restricting sciatic nerve mobility and causing entrapment was a radical change in the diagnosis and therapeutic approach to non-discogenic sciatica. [6] The all encompassing term "deep gluteal syndrome" was developed to appreciate the many causes of non-discogenic sciatic nerve entrapment in the deep gluteal space. Piriformis syndrome is now considered one of many causes of deep gluteal syndrome. [1]
1947 - Piriformis syndrome first described. [31]
1999 - Deep gluteal syndrome is first proposed to replace piriformis syndrome. [32]
2003 - First endoscopic surgery to release the piriformis muscle in the deep gluteal space. [33]
2005 - Large study of the diagnosis and treatment of patients with non-discogenic sciatica. Magnetic resonance neurography and image-guided nerve blocks are used to diagnose at least 80% of patients for which standard diagnostic modalities had failed. The various causes of non-discogenic sciatic nerve entrapment are categorized. [3]
2011 - First endoscopic surgery to decompress the sciatic nerve in the deep gluteal space. [34]
2015 - Definition, diagnosis, treatment, etc. proposed for deep gluteal syndrome. [1] [6]
Patients often face challenges when trying to find accurate diagnosis and surgical treatment for deep gluteal syndrome. Pathologies of the pelvic nerves have historically rarely been seriously explored clinically, [35] even though hundreds of thousands of people with sciatica each year have absent lumbar disc herniation on MRI. [3] Difficult access to the nerves has made clinical assessment, and surgical treatment historically impractical. [35] Unreliable imaging of nerves on standard MRI have made it difficult to establish diagnoses. [3] Consequently, the standard treatment regimen has been to treat symptomatically when no etiology is found. [35] However, patients with deep gluteal syndrome can report high VAS scores (6.7 +/-2 [34] ) characteristic of moderate (>3) and severe pain (>7.5), [36] [30] and may not find sufficient relief in conservative or symptomatic treatment. If patients don't respond to non-opioid therapy, physician reluctance to prescribe opioids for chronic non-malignant pain [37] [38] [39] can leave patients with severe uncontrolled pain that can profoundly impact quality of life. [40]
There is unclear ownership among medical specialties for many entrapment neuropathies which adds additional challenges for patients. [41] [42] For example, entrapment neuropathies require a detailed understanding of neurology and neuropathology, but these specialties are paradoxically rarely involved, especially for the pelvic nerves. [43] Instead, patients with entrapment of the pelvic nerves may see specialists who treat related body parts such as urology, gynaecology, physiotherapy, medical and surgical gastroenterology, and orthopaedic surgery who themselves are hampered by deficient knowledge of nerves [35] and diagnostic tools (magnetic resonance neurography and image-guided nerve blocks). The list of specialties that patients may see for sciatic nerve entrapment also includes neurologists (nerves), neurosurgeons (nerve surgery), spine surgeons (radiculopathy), interventional radiologists (injections), and anesthesiologists (pain management). This unclear ownership can lead patients to see many specialists before finding one with the appropriate knowledge and capability to treat them. One study author reported that his successfully treated patients for piriformis syndrome saw a mean of 8.5 specialist physicians for the sciatica before his diagnosis was proposed. [3]
The pudendal nerve is the main nerve of the perineum. It is a mixed nerve and also conveys sympathetic autonomic fibers. It carries sensation from the external genitalia of both sexes and the skin around the anus and perineum, as well as the motor supply to various pelvic muscles, including the male or female external urethral sphincter and the external anal sphincter.
The sciatic nerve, also called the ischiadic nerve, is a large nerve in humans and other vertebrate animals. It is the largest branch of the sacral plexus and runs alongside the hip joint and down the lower limb. It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect. The sciatic nerve has no cutaneous branches for the thigh. This nerve provides the connection to the nervous system for the skin of the lateral leg and the whole foot, the muscles of the back of the thigh, and those of the leg and foot. It is derived from spinal nerves L4 to S3. It contains fibres from both the anterior and posterior divisions of the lumbosacral plexus.
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities like heavy lifting, though gradual onset may also occur. The pain is often described as shooting. Typically, symptoms are only on one side of the body. Certain causes, however, may result in pain on both sides. Lower back pain is sometimes present. Weakness or numbness may occur in various parts of the affected leg and foot.
Pudendal nerve entrapment (PNE), also known as Alcock canal syndrome, is an uncommon source of chronic pain in which the pudendal nerve is entrapped or compressed in Alcock's canal. There are several different types of PNE based on the site of entrapment anatomically. Pain is positional and is worsened by sitting. Other symptoms include genital numbness, fecal incontinence and urinary incontinence.
The piriformis muscle is a flat, pyramidally-shaped muscle in the gluteal region of the lower limbs. It is one of the six muscles in the lateral rotator group.
Piriformis syndrome is a condition which is believed to result from nerve compression at the sciatic nerve by the piriformis muscle. It is a specific case of deep gluteal syndrome. The largest and most bulky nerve in the human body is the sciatic nerve. Starting at its origin it is 2 cm wide and 0.5 cm thick. The sciatic nerve forms the roots of L4-S3 segments of the lumbosacral plexus. The nerve will pass inferiorly to the piriformis muscle, in the direction of the lower limb where it divides into common tibial and fibular nerves. Symptoms may include pain and numbness in the buttocks and down the leg. Often symptoms are worsened with sitting or running.
The gluteal sulcus is an area of the body of humans and anthropoid apes, described by a horizontal crease formed by the inferior aspect of the buttocks and the posterior upper thigh. The gluteal sulcus is formed by the posterior horizontal skin crease of the hip joint and overlying fat and is not formed by the lower border of the gluteus maximus muscle, which crosses the fold obliquely. It is one of the major defining features of the buttocks. Children with developmental dysplasia of the hips are born with uneven gluteal folds and can be diagnosed with a physical examination and sonogram.
Meralgia paresthetica or meralgia paraesthetica is pain or abnormal sensations in the outer thigh not caused by injury to the thigh, but by injury to a nerve which provides sensation to the lateral thigh.
The inferior gluteal nerve is the main motor neuron that innervates the gluteus maximus muscle. It is responsible for the movement of the gluteus maximus in activities requiring the hip to extend the thigh, such as climbing stairs. Injury to this nerve is rare but often occurs as a complication of posterior approach to the hip during hip replacement. When damaged, one would develop gluteus maximus lurch, which is a gait abnormality which causes the individual to 'lurch' backwards to compensate lack in hip extension.
A spinal disc herniation is an injury to the intervertebral disc between two spinal vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical disability. The most conclusive diagnostic tool for disc herniation is MRI, and treatment may range from painkillers to surgery. Protection from disc herniation is best provided by core strength and an awareness of body mechanics including good posture.
The popliteal artery entrapment syndrome (PAES) is an uncommon pathology that occurs when the popliteal artery is compressed by the surrounding popliteal fossa myofascial structures. This results in claudication and chronic leg ischemia. This condition mainly occurs more in young athletes than in the elderlies. Elderlies, who present with similar symptoms, are more likely to be diagnosed with peripheral artery disease with associated atherosclerosis. Patients with PAES mainly present with intermittent feet and calf pain associated with exercises and relieved with rest. PAES can be diagnosed with a combination of medical history, physical examination, and advanced imaging modalities such as duplex ultrasound, computer tomography, or magnetic resonance angiography. Management can range from non-intervention to open surgical decompression with a generally good prognosis. Complications of untreated PAES can include stenotic artery degeneration, complete popliteal artery occlusion, distal arterial thromboembolism, or even formation of an aneurysm.
The superior cluneal nerves are pure sensory nerves that innervate the skin of the upper part of the buttocks. They are the terminal ends of the L1-L3 spinal nerve dorsal rami lateral branches. They are one of three different types of cluneal nerves. They travel inferiorly through multiple layers of muscles, then traverse osteofibrous tunnels between the thoracolumbar fascia and iliac crest.
Magnetic resonance neurography (MRN) is the direct imaging of nerves in the body by optimizing selectivity for unique MRI water properties of nerves. It is a modification of magnetic resonance imaging. This technique yields a detailed image of a nerve from the resonance signal that arises from in the nerve itself rather than from surrounding tissues or from fat in the nerve lining. Because of the intraneural source of the image signal, the image provides a medically useful set of information about the internal state of the nerve such as the presence of irritation, nerve swelling (edema), compression, pinch or injury. Standard magnetic resonance images can show the outline of some nerves in portions of their courses but do not show the intrinsic signal from nerve water. Magnetic resonance neurography is used to evaluate major nerve compressions such as those affecting the sciatic nerve (e.g. piriformis syndrome), the brachial plexus nerves (e.g. thoracic outlet syndrome), the pudendal nerve, or virtually any named nerve in the body. A related technique for imaging neural tracts in the brain and spinal cord is called magnetic resonance tractography or diffusion tensor imaging.
Nerve compression syndrome, or compression neuropathy, or nerve entrapment syndrome, is a medical condition caused by chronic, direct pressure on a peripheral nerve. It is known colloquially as a trapped nerve, though this may also refer to nerve root compression. Its symptoms include pain, tingling, numbness and muscle weakness. The symptoms affect just one particular part of the body, depending on which nerve is affected. The diagnosis is largely clinical and can be confirmed with diagnostic nerve blocks. Occasionally imaging and electrophysiology studies aid in the diagnosis. Timely diagnosis is important as untreated chronic nerve compression may cause permanent damage. A surgical nerve decompression can relieve pressure on the nerve but cannot always reverse the physiological changes that occurred before treatment. Nerve injury by a single episode of physical trauma is in one sense an acute compression neuropathy but is not usually included under this heading, as chronic compression takes a unique pathophysiological course.
The term sacroiliac joint dysfunction refers to abnormal motion in the sacroiliac joint, either too much motion or too little motion, that causes pain in this region.
Anterior cutaneous nerve entrapment syndrome (ACNES) is a nerve entrapment condition that causes chronic pain of the abdominal wall. It occurs when nerve endings of the lower thoracic intercostal nerves (7–12) are 'entrapped' in abdominal muscles, causing a severe localized nerve (neuropathic) pain that is usually experienced at the front of the abdomen.
The sacroiliac joint is a paired joint in the pelvis that lies between the sacrum and an ilium. Due to its location in the lower back, a dysfunctional sacroiliac joint may cause lower back and/or leg pain. The resulting leg pain can be severe, resembling sciatica or a slipped disc. While nonsurgical treatments are effective for some, others have found that surgery for the dysfunctional sacroiliac joint is the only method to relieve pain.
Nerve glide, also known as nerve flossing or nerve stretching, is an exercise that stretches nerves. It facilitates the smooth and regular movement of peripheral nerves in the body. It allows the nerve to glide freely along with the movement of the joint and relax the nerve from compression. Nerve gliding cannot proceed with injuries or inflammations as the nerve is trapped by the tissue surrounding the nerve near the joint. Thus, nerve gliding exercise is widely used in rehabilitation programs and during the post-surgical period.
A nerve decompression is a neurosurgical procedure to relieve chronic, direct pressure on a nerve to treat nerve entrapment, a pain syndrome characterized by severe chronic pain and muscle weakness. In this way a nerve decompression targets the underlying pathophysiology of the syndrome and is considered a first-line surgical treatment option for peripheral nerve pain. Despite treating the underlying cause of the disease, the symptoms may not be fully reversible as delays in diagnosis can allow permanent damage to occur to the nerve and surrounding microvasculature. Traditionally only nerves accessible with open surgery have been good candidates, however innovations in laparoscopy and nerve-sparing techniques made nearly all nerves in the body good candidates, as surgical access is no longer a barrier.
Nerve entrapment involves a cascade of physiological changes caused by compression and tension. Some of these changes are irreversible. The magnitude and duration of the forces determines the extent of injury. In the acute form, mechanical injury and metabolic blocks impede nerve function. In the chronic form, there is a sequence of changes starting with a breakdown of the blood-nerve-barrier, followed by edema with connective tissue changes, followed by diffuse demyelination, and finally followed by axonmetesis. The injury will often be a mixed lesion where mild/moderate compression is a combination of a metabolic block and neuropraxia, while severe compression combines elements of neuropraxia and axonmetesis.