Superior cluneal nerves | |
---|---|
Details | |
From | dorsal rami of L1-L3 nerve roots |
Innervates | upper buttocks |
Identifiers | |
Latin | nervi clunium superiores |
TA98 | A14.2.05.006 |
TA2 | 6493 |
FMA | 75468 |
Anatomical terms of neuroanatomy |
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 (the middle and inferior cluneal nerves being the other two). They travel inferiorly through multiple layers of muscles, then traverse osteofibrous tunnels between the thoracolumbar fascia and iliac crest. [1]
Dysfunction of the superior cluneal nerves is often due to entrapment as the nerves cross the iliac crest – this can result in numbness, tingling or pain in the low back and upper buttocks region. Superior cluneal nerve dysfunction is a clinical diagnosis that can be supported by diagnostic nerve blocks. [1]
The superior cluneal nerves were first described by Maigne et al. in 1989 as a source of low back pain. [2]
These nerves are grouped as the superior cluneal nerves due to their trajectory over the iliac spine, as opposed to the lateral, medial and inferior cluneal nerves. These nerves most commonly originate from the dorsal rami of the L1, L2, and L3 nerve roots. In cadaver studies, a small percentage of patients will also have origins at the L4 and L5 nerve roots. [3] [4]
After they branch off the dorsal rami, they pass through the erector spinae muscle, psoas major, paraspinal muscles, and then inferior latissimus dorsi to reach the iliac crest. [5]
The nerves then pass through an osteofibrous tunnel created by the thoracolumbar fascia and rim of the superior iliac crest. [6] Cadaver studies have noted that some patients have boney grooves along the rim that house the superior cluneal nerves. On average, these grooves are found between 5–7 cm from the midline. [7] [8] These grooves can often be visualized with an ultrasound. [8]
The nerves terminate over the gluteal fascia distal to the iliac crest.[ citation needed ]
Damage to the cluneal nerves can be from direct injury or from entrapment between the muscles or in the osteofibrous tunnel. Direct injury to the cluneal nerves can happen during posterior iliac crest harvest to obtain bone mineral for other surgeries, such as spinal arthrodesis. [9] [10] Entrapment of the nerve can occur at any point but is most common across the osteofibrous tunnel.[ citation needed ]
Dysfunction of the superior cluneal nerves lead to many different neuropathic symptoms such as burning pain, numbness, tingling, and dysesthesia around the low back and upper gluteal area. The most common symptoms are localized unilateral low back pain, though up to anywhere between 40 and 82% of patients may complain of leg symptoms – pain or dysethesia. [5] [11] [12] The onset of pain can vary, with some patients report sudden onset of pain with a known inciting incident. [13] These symptoms can be exacerbated by lumbar flexion, extension, and rotation. [1] Manual compression over the posterior superior iliac crest, such as with wearing tight clothing and belts, can also reproduce symptoms. [1] [5] Many patients also have tender points located around the posterior iliac crest, approximately 7 cm from midline which correlates with cadaver studies demonstrating the location at which the nerves cross the iliac crest. [5] [14] On physical exam, the pain can be reproduced by the excessive motions listed above or by tapping along the posterior superior iliac crest, which would be a positive Tinel-like sign. [5] [14] In the setting of nerve entrapment between the muscles, activation of the muscles with lumbar extension can reproduce the pain. [5] Besides pain, patients can also have reduced sensation to light touch over the nerve distribution. [1] [5] [14]
Diagnosis of superior cluneal nerve dysfunction requires the help of a skilled clinician as it requires a good history and physical examination. Imaging, such as magnetic resonance imaging, can be used to rule out other pathologies. In many cases, this diagnosis is made after treatment of more common pathologies with similar symptoms. The most common overlapping pathologies include facet joint pain, sacroiliac joint dysfunction, and lumbosacral radiculopathy. Electrodiagnostic studies, including electromyography and nerve conduction studies, can also help rule out other pathologies. [1] Currently, there is no consistent protocol for testing the superior cluneal nerves with a nerve conduction study. Diagnosis of superior cluneal nerve entrapment can be aided by diagnostic blocks of the nerve across the iliac crest. [1] [5]
The treatment for superior cluneal nerve dysfunction can vary based on the clinician and severity of symptoms. There is currently limited evidence for treatment at this time. Physical therapy can be initiated to improve strength and flexibility. The addition of non-steroidal anti-inflammatory medications can help with overall discomfort but has not been shown to have direct effects of the nerve. Specifically, the use of COX-2 inhibitors is a reasonable first step. [1] Other treatments of superior cluneal nerve dysfunction include both minimally invasive interventions and surgical options. Minimally invasive treatments include nerve blocks, neuroablation, and neuromodulation. [5] Efficacy of these interventions are still being studied and no clear evidence to show long term benefits in larger studies. Minimally invasive treatments can be performed with ultrasound or fluoroscopy to improve safety and accuracy.
Nerve blocks are injections that target specific nerves to serve as both therapeutic and diagnostic purposes. They have been used for a variety of neuropathic conditions including facet joint pain. Nerve block injections specifically targeted at the superior cluneal nerves are limited. [5] However, these blocks are minimally invasive and involve injecting medications at the nerves as they cross the iliac crest. [11] These blocks can be done with local anesthetics with or without corticosteroids. [1] [5] [11] Improvement in pain after these blocks suggest that these nerves are the source of the patient's symptoms, however these blocks are often temporary and studies regarding corticosteroid reported 68% of patients had improved back pain after 1-3 repetitive blocks. [11] These injections can be performed with or without image modalities, though the use of ultrasound guidance may help optimize medication delivery [11] [8] [15] These procedures can also be done under fluoroscopy.
Neuroablation can be performed with chemical neurolysis or radiofrequency ablation. These techniques are often used on the medial branch nerves to treat low back pain and have been applied to the superior cluneal nerves. The use of phenol has been noted to relieve pain for up to 9 months but may not completely resolve symptoms. [5]
Neuromodulation of the cluneal nerve with peripheral nerve stimulation has not been widely established as an effective treatment, though there are some studies that show significant benefits. [5] [16]
Surgical intervention typically involves decompression of the nerves from the osteofibrous tunnels. Few studies have shown long term benefits of surgical intervention. [17] [18]
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.
Diabetic neuropathy includes various types of nerve damage associated with diabetes mellitus. The most common form, diabetic peripheral neuropathy, affects 30% of all diabetic patients. Symptoms depend on the site of nerve damage and can include motor changes such as weakness; sensory symptoms such as numbness, tingling, or pain; or autonomic changes such as urinary symptoms. These changes are thought to result from a microvascular injury involving small blood vessels that supply nerves. Relatively common conditions which may be associated with diabetic neuropathy include distal symmetric polyneuropathy; third, fourth, or sixth cranial nerve palsy; mononeuropathy; mononeuropathy multiplex; diabetic amyotrophy; and autonomic neuropathy.
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.
Occipital neuralgia (ON) is a painful condition affecting the posterior head in the distributions of the greater occipital nerve (GON), lesser occipital nerve (LON), third occipital nerve (TON), or a combination of the three. It is paroxysmal, lasting from seconds to minutes, and often consists of lancinating pain that directly results from the pathology of one of these nerves. It is paramount that physicians understand the differential diagnosis for this condition and specific diagnostic criteria. There are multiple treatment modalities, several of which have well-established efficacy in treating this condition.
The pterygopalatine ganglion is a parasympathetic ganglion in the pterygopalatine fossa. It is one of four parasympathetic ganglia of the head and neck,.
Tarsal tunnel syndrome (TTS) is a nerve compression syndrome or nerve entrapment syndrome causing a painful foot condition in which the tibial nerve is entrapped as it travels through the tarsal tunnel. The tarsal tunnel is found along the inner leg behind the medial malleolus. The posterior tibial artery, tibial nerve, and tendons of the tibialis posterior, flexor digitorum longus, and flexor hallucis longus muscles travel in a bundle through the tarsal tunnel. Inside the tunnel, the nerve splits into three segments. One nerve (calcaneal) continues to the heel, the other two continue on to the bottom of the foot. The tarsal tunnel is delineated by bone on the inside and the flexor retinaculum on the outside.
Nerve block or regional nerve blockade is any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief. Local anesthetic nerve block is a short-term block, usually lasting hours or days, involving the injection of an anesthetic, a corticosteroid, and other agents onto or near a nerve. Neurolytic block, the deliberate temporary degeneration of nerve fibers through the application of chemicals, heat, or freezing, produces a block that may persist for weeks, months, or indefinitely. Neurectomy, the cutting through or removal of a nerve or a section of a nerve, usually produces a permanent block. Because neurectomy of a sensory nerve is often followed, months later, by the emergence of new, more intense pain, sensory nerve neurectomy is rarely performed.
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 lateral cutaneous nerve of the thigh is a cutaneous nerve of the thigh. It originates from the dorsal divisions of the second and third lumbar nerves from the lumbar plexus. It passes under the inguinal ligament to reach the thigh. It supplies sensation to the skin on the lateral part of the thigh by an anterior branch and a posterior branch.
Percutaneous tibial nerve stimulation (PTNS), also referred to as posterior tibial nerve stimulation, is the least invasive form of neuromodulation used to treat overactive bladder (OAB) and the associated symptoms of urinary urgency, urinary frequency and urge incontinence. These urinary symptoms may also occur with interstitial cystitis and following a radical prostatectomy. Outside the United States, PTNS is also used to treat fecal incontinence.
A neurectomy, or nerve resection is a neurosurgical procedure in which a peripheral nerve is cut or removed to alleviate neuropathic pain or permanently disable some function of a nerve. The nerve is not intended to grow back. For chronic pain it may be an alternative to a failed nerve decompression when the target nerve has no motor function and numbness is acceptable. Neurectomies have also been used to permanently block autonomic function, and special sensory function not related to pain.
Sacral nerve stimulation, also termed sacral neuromodulation, is a type of medical electrical stimulation therapy.
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.
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual in onset and improve with leaning forward. Severe symptoms may include loss of bladder control, loss of bowel control, or sexual dysfunction.
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.
Femoral nerve dysfunction, also known as femoral neuropathy, is a rare type of peripheral nervous system disorder that arises from damage to nerves, specifically the femoral nerve. Given the location of the femoral nerve, indications of dysfunction are centered around the lack of mobility and sensation in lower parts of the legs. The causes of such neuropathy can stem from both direct and indirect injuries, pressures and diseases. Physical examinations are usually first carried out, depending on the high severity of the injury. In the cases of patients with hemorrhage, imaging techniques are used before any physical examination. Another diagnostic method, electrodiagnostic studies, are recognized as the gold standard that is used to confirm the injury of the femoral nerve. After diagnosis, different treatment methods are provided to the patients depending upon their symptoms in order to effectively target the underlying causes. Currently, femoral neuropathy is highly underdiagnosed and its precedent medical history is not well documented worldwide.
Iliocostal friction syndrome, also known as costoiliac impingement syndrome, is a condition in which the costal margin comes in contact with the iliac crest. The condition presents as low back pain which may radiate to other surrounding areas as a result of irritated nerve, tendon, and muscle structures. It may occur unilaterally due to conditions such as scoliosis, or bilaterally due to conditions such as osteoporosis and hyperkyphosis.
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.
Deep gluteal syndrome describes the non-discogenic extrapelvic entrapment of the sciatic nerve in the deep gluteal space. In simpler terms this is sciatica due to nerve irritation in the buttocks rather than the spine or pelvis. It is an extension of non-discogenic sciatic nerve entrapment beyond the traditional model of piriformis syndrome. Where sciatic nerve irritation in the buttocks was once thought of as only piriformis muscle, it is now recognized that there are many other causes. Symptoms are pain or dysthesias in the buttocks, hip, and posterior thigh with or without radiating leg pain. Patients often report pain when sitting. The two most common causes are piriformis syndrome and fibrovascular bands, but many other causes exist. Diagnosis is usually done through physical examination, magnetic resonance imaging, magnetic resonance neurography, and diagnostic nerve blocks. Surgical treatment is an endoscopic sciatic nerve decompression where tissue around the sciatic nerve is removed to relieve pressure.
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.