Somasimple: Fascial Entrapments of Nerves
A potentially underrecognized and treatable cause of chronic back pain: entrapment neuropathy of the cluneal nerves.
J Rheumatol. 1996 Dec;23(12):2179-81. Related Articles

Berthelot JM, Delecrin J, Maugars Y, Caillon F, Prost A.

Department of Rheumatology, Nantes University Hospital, France.

We describe a case of longstanding low back pain related to entrapment neuropathy of the L1-L2 dorsal ramus over the iliac crest. As 3 local anesthetic pain blocks (at the trigger point, 7 cm left of the L5 spine process and just above the iliac crest) were successful for 3 weeks each, a surgical procedure was performed. This corrected patient stricture of a voluminous dorsal ramus within a rigid osteofibrous orifice between the upper rim of the iliac crest and the thoracolumbar fascia. Pain decreased dramatically the same day and disappeared completely within less than a week.

Publication Types:
  • Case Reports

PMID: 8970063 [PubMed - indexed for MEDLINE]
Anatomic considerations of superior cluneal nerve at posterior iliac crest region.
Clin Orthop. 1998 Feb;(347):224-8. Related Articles
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Lu J, Ebraheim NA, Huntoon M, Heck BE, Yeasting RA.

Department of Orthopaedic Surgery, Medical College of Ohio, Toledo 43614, USA.

No previous studies describe the anatomic relationship of the superior cluneal nerve to the posterior iliac crest and thoracolumbar fascia. In the current study, 15 cadavers were dissected to determine the relationship of the superior cluneal nerve to the posterior iliac crest and thoracolumbar fascia. The distances from the medial branch of the superior cluneal nerve to the posterior superior iliac crest and the midline were 64.7 +/- 5.3 mm and 81.0 +/- 9.2 mm, respectively. The distances between the level of the iliac crest and perforating points of the superior cluneal nerve on the thoracolumbar fascia were 5.8 +/- 1.8 mm inferiorly for the medial branch, 2.2 +/- 1.8 mm superiorly for the intermediate branch, and 12.0 +/- 4.4 mm superiorly for the lateral branch, respectively. The proximal dissection above the perforating point of the nerve showed that the medial branch of the superior cluneal nerve is confined within a tunnel consisting of the thoracolumbar fascia and the superior rim of the iliac crest as it passes over the iliac crest. The intermediate and lateral branches of the superior cluneal nerve either pierce the thoracolumbar fascia or pass through an orifice or fissure in the thoracolumbar fascia. In two specimens, the medial branches of the superior cluneal nerve were constricted within the osteofibrous tunnel. The nerve was entrapped between the rigid fibers of the thoracolumbar fascia and the iliac crest.

PMID: 9520894 [PubMed - indexed for MEDLINE]
Anatomical basis of chronic pelvic pain syndrome: the ischial spine and pudendal nerve entrapment.
Med Hypotheses. 2002 Sep;59(3):349-53. Related Articles
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Antolak SJ Jr, Hough DM, Pawlina W, Spinner RJ.

Departments of Urology, Radiology, Anatomy, and Neurologic Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA. antolak.stanley@mayo.edu

Chronic pelvic pain syndrome is a conundrum that may be explained partly by pudendal nerve entrapment (PNE), which causes neuropathic pain. In men with PNE, aberrant development and subsequent malpositioning of the ischial spine appear to be associated with athletic activities during their youth. The changes occur during the period of development and ossification of the spinous process of the ischium.

Publication Types:
  • Review
  • Review, Tutorial

PMID: 12208168 [PubMed - indexed for MEDLINE]
Anatomical course of the lateral femoral cutaneous nerve and its susceptibility to compression and injury.
Plast Reconstr Surg. 1997 Sep;100(3):600-4. Related Articles

Aszmann OC, Dellon ES, Dellon AL.

Department of Anatomy, University of Maryland School of Medicine, Baltimore, USA.

The anatomy of the lateral femoral cutaneous nerve was investigated through dissection of 52 human anatomic specimens. The variability of its course and locations as it exists the pelvis is described and related to soft-tissue and bony landmarks. Five different types are identified: type A, posterior to the anterior superior iliac spine, across the iliac crest (4 percent); type B, anterior to the anterior superior iliac spine and superficial to the origin of the sartorius muscle but within the substance of the inguinal ligament (27 percent); type C, medial to the anterior superior iliac spine, ensheathed in the tendinous origin of the sartorius muscle (23 percent); type D, medial to the origin of the sartorius muscle located in an interval between the tendon of the sartorius muscle and thick fascia of the iliopsoas muscle deep to the inguinal ligament (26 percent); and type E, most medial and embedded in loose connective tissue, deep to the inguinal ligament, overlying the thin fascia of the iliopsoas muscle, and contributing the femoral branch of the genitofemoral nerve (20 percent). The results of this study suggest that the lateral femoral cutaneous nerve is most susceptible to mechanical trauma when the nerve is type A, B, or C.

PMID: 9283556 [PubMed - indexed for MEDLINE]
Dorsal ramus irritation associated with recurrent low back pain and its relief with local anesthetic or training therapy.
J Spinal Disord. 1995 Feb;8(1):8-14. Related Articles,

Sihvonen T, Lindgren KA, Airaksinen O, Leino E, Partanen J, Hanninen O.

Department of Clinical Neurophysiology, University Hospital of Kuopio, Finland.

Nerves leave the spinal cord as mainly motor primary rootlets and sensory rootlets. These join to nerve root before leaving the spinal canal. After the root canal, the nerve root branches into the ventral root, which contains sensory and motor fibers innervating the extremities, and the dorsal root, that is, the dorsal ramus, which innervates the posterior structures, for example, back muscles: the dorsal ramus itself may become irritated (dorsal ramus syndrome). Especially predisposed to entrapment is the medial branch of the dorsal ramus, which innervates the multifidus muscle and also contains pain fibers. Here we describe the influence of local anesthesia and back-muscle-training therapy on subjective and objective pain parameters in 21 low-back-pain patients who had similar clinical status and neurophysiologic findings and whose recurrent low back pain was most apparently associated with dorsal ramus neuropathy, without any radiologic or neurophysiologic evidence of more proximal ventral nerve root damage in the spinal cord or at the nerve root origin. After treatment, all were pain free and back muscle activity during lumbar-pelvic rhythm was normalized.

Publication Types:
  • Case Reports

PMID: 7711374 [PubMed - indexed for MEDLINE]
Fibrous adhesive entrapment of lumbosacral nerve roots as a cause of sciatica.
Spinal Cord. 2001 May;39(5):269-73. Related Articles
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Ido K, Urushidani H.

Department of Orthopaedic Surgery, Kurashiki Central Hospital, Okayama, Japan.

STUDY DESIGN: Report of seven patients with fibrous adhesive entrapment of lumbosacral nerve roots as a cause of sciatica, whose radiographic findings were negative and who experienced relief from sciatica immediately after the entrapment was released. OBJECTIVES: To describe a new clinical entity of fibrous adhesive entrapment of lumbosacral nerve roots with negative radiographic findings. SETTING: Orthopaedic department, Japan. METHODS: Clinical evaluation and post-operative outcome in seven patients with entrapment of lumbosacral nerve roots because of fibrous adhesion confirmed intraoperatively. RESULTS: Radiographic examinations by magnetic resonance imaging (MRI), myelography, and computed tomographic (CT) myelography demonstrated neither disc herniations nor spinal stenosis in all seven patients, and differential nerve root block was effective for relieving sciatica and low back pain. We confirmed, intraoperatively, entrapment of the nerve root by fibrous adhesion, and all seven patients were relieved from sciatica and low back pain postoperatively. CONCLUSION: This study presented seven patients with sciatica caused by fibrous adhesive entrapment of lumbosacral nerve roots who underwent decompression and release of fibrous adhesion. Radiographic examinations, such as MRI, myelography and CT myelography, showed no compressive shadows and also differential nerve root block was effective for its diagnosis. This study seems to be the first report of patients with entrapment of lumbosacral nerve roots caused by fibrous adhesion, whose radiographic findings were negative.

Publication Types:
  • Case Reports

PMID: 11438843 [PubMed - indexed for MEDLINE]

Ilioinguinal nerve entrapment: a little-known cause of iliac fossa pain.

Postgrad Med J. 1989 Sep;65(767):632-5. Related Articles

Knockaert DC, D'Heygere FG, Bobbaers HJ.

Department of General Internal Medicine, University Hospital Gasthuisberg, Leuven, Belgium.

The ilioinguinal nerve entrapment syndrome is an abdominal muscular pain syndrome, characterized by the clinical triad of muscular type iliac fossa pain with a characteristic radiation pattern, an altered sensory perception in the ilioinguinal nerve cutaneous innervation area, and a well-circumscribed trigger point medial and below the anterosuperior iliac spine. Relief of pain by infiltration of a local anaesthetic confirms the diagnosis. This report describes retrospectively the clinical picture of ilioinguinal nerve entrapment in 32 mainly non-surgical patients. In 14 cases a definite diagnosis was established and in 18 patients the diagnosis was considered probable. The mean delay in diagnosis was 12.8 months. Better knowledge of this syndrome may avoid invasive investigations and be cost saving.

PMID: 2608591 [PubMed - indexed for MEDLINE]

Meralgia paresthetica in differential diagnosis of low-back pain.

Clin J Pain. 2002 Mar-Apr;18(2):132-5. Related Articles
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Erbay H.

Medical Faculty, Anesthesiology and Reanimation Department, Pamukkale University, Denizli, Turkey. rherbay@pamukkale.edu.tr

OBJECTIVE: Meralgia paresthetica is a syndrome of pain or dysesthesia or both in the anterolateral thigh, caused by entrapment of the lateral femoral cutaneous nerve at the anterior superior iliac spine. The aim of this report is to emphasize that meralgia paresthetica can be confused with low-back pain. PATIENT: A 21-year-old man was admitted to hospital because of low-back and thigh pain. He had a history of low-back pain. Physical examination and radiologic studies for low-back pain and radiculopathy showed no pathologic findings. It was suspected that the most likely cause was lateral femoral cutaneous neuropathy, caused by the wide military belt he continuously wore tightly around his waist. INTERVENTIONS: The nerve was blocked with 10 ml of bupivacaine 0.25%, which provided immediate pain relief. A nonsteroidal anti-inflammatory drug was administered orally. RESULTS: After 15 days of bed rest and 45 days without the belt, he was completely symptom-free. CONCLUSIONS: It is important to be rigorous in investigating the etiology of low-back pain. Meralgia paresthetica can mimic low-back pain because of the similarity of the symptoms. It can be treated by conservative or ablative therapeutic interventions; however, conservative methods should be considered primarily.

Publication Types:
  • Case Reports

PMID: 11882778 [PubMed - indexed for MEDLINE]
Microanatomy of the structures contributing to abdominal cutaneous nerve entrapment syndrome.
J Am Board Fam Pract. 1997 Sep-Oct;10(5):329-32. Related Articles

Applegate WV, Buckwalter NR.

Department of Family Practice, Kaiser Permanente Medical Center, San Diego, USA.

BACKGROUND: Family physicians commonly see patients who complain of abdominal pain, the cause of which cannot be readily diagnosed. Often this pain results from abdominal cutaneous nerve entrapment syndrome. METHODS: Photomicrographs were obtained of the pertinent structures of the ninth thoracolumbar nerve where it passes through the rectus muscle channel. Standard hematoxylin and eosin staining techniques were used after the paraffin autopsy tissue block was positioned to show the entire length of the rectus neurovascular bundle from anterior to posterior surfaces of the muscle (anatomically front to back). Gomori trichrome staining with aniline blue was also done to differentiate further the connective tissue structures. RESULTS: The photomicrographs presented here support the first author's earlier clinical and gross anatomic findings, especially regarding the fibrous ring in the rectus muscle, through which the neurovascular bundle travels. Special attention is given to the rectus fibrous ring, which is so important in producing the syndrome of abdominal cutaneous nerve entrapment. This structure is clearly delineated, and its role in the pathophysiology of this syndrome is described. CONCLUSIONS: Three pictures presented here show the relevant microstructures involved in abdominal cutaneous nerve entrapment syndrome. The photomicrographs confirm the existence of a fibrous ring within which the neurovascular bundle can move freely. If this bundle is pushed or pulled too far from behind or in front, however, compression of the bundle against the ring causes nerve ischemia and symptoms of abdominal cutaneous nerve entrapment. Family physicians can save their patients unnecessary pain and expense by being aware of this syndrome.

PMID: 9297657 [PubMed - indexed for MEDLINE]
Nerve entrapment in painful heel syndrome.
Foot Ankle Int. 2002 Mar;23(3):208-11. Related Articles

Oztuna V, Ozge A, Eskandari MM, Colak M, Golpinar A, Kuyurtar F.

Department of Orthopaedics, Mersin University School of Medicine, Eski Otogar Yani, Ihsaniye Mah., Icel, Turkey. oztuna67@mersin.edu.tr

Subcalcaneal heel pain is one of the most common foot ailments, yet the exact etiology is still controversial. Nerve entrapment has been suggested as one of the possible causes of this painful condition in recalcitrant cases. The purpose of this study is to determine the role of nerve entrapment in painful heels. Twenty patients with heel pain (25 heels) were compared with an age and body mass index-matched control population using electrodiagnostic methods. The results of the study revealed 22 heels (88%) with heel pain had lateral plantar nerve entrapment signs with or without medial plantar nerve findings on EMG. There were no abnormal values in the control group. Nerve entrapment syndrome has previously been considered only in cases with intractable heel pain, but this study suggests that it may play a role the early phases of painful heel syndrome.

PMID: 11934062 [PubMed - indexed for MEDLINE]
Nerve entrapment syndromes as a cause of pain in the hip, groin and buttock.
Sports Med. 1999 Apr;27(4):261-74. Related Articles

McCrory P, Bell S.

Department of Neurology, Olympic Park Sports Medicine Centre, Melbourne, Victoria, Australia. pmccrory@compuserve.com

In sports medicine, chronic hip, groin and buttock pain is a common diagnostic problem. Because of the complex anatomy of this region and the many potential neurological causes for pain, few sports clinicians have a detailed understanding of this problem. This paper discusses the clinical aspects of nerve entrapment syndromes related to sport and takes a regional approach in order to provide a diagnostic framework for the general sports physician. The various neurological syndromes are discussed and the surgical management elaborated in detail. For some specific conditions, such as the so-called 'piriformis syndrome', the pathophysiological understanding has changed since the early descriptions and now this particular diagnosis is often ascribed to almost any cause of buttock and/or hamstring symptoms. We discuss the nature of the origin of local symptoms and note that the often described symptoms are more likely due to compression of structures other then the sciatic nerve. Furthermore, the role of piriformis hypertrophy or anatomical nerve variations in the genesis of this syndrome must be questioned. We suggest renaming this the 'deep gluteal syndrome' to account for all of the observed phenomena. As sports medicine continues to develop a scientific basis, the role of nerve entrapments as the basis for chronic symptomatology is undergoing a new understanding and clinicians need to be aware of the diagnostic possibilities and be able to advise patients accordingly on the basis of scientific fact not anecdotal fiction.

Publication Types:
  • Review
  • Review, Tutorial

PMID: 10367335 [PubMed - indexed for MEDLINE]

Obturator nerve entrapment. A cause of groin pain in athletes.

Am J Sports Med. 1997 May-Jun;25(3):402-8. Related Articles

Bradshaw C, McCrory P, Bell S, Brukner P.

Olympic Park Sports Medicine Centre, Melbourne, Australia.

Chronic groin pain in athletes is often difficult to diagnose and treat. There are many anatomic structures in the inguinal and groin region that have the potential to cause pain. We report 32 cases of a previously undescribed condition in athletes of "obturator neuropathy," a fascial entrapment of the obturator nerve where it enters the thigh. This condition represents a type of groin pain in athletes that is treatable by surgical means. There is a characteristic clinical pattern of exercise-induced medial thigh pain commencing in the region of the adductor muscle origin and radiating distally along the medial thigh. Needle electromyography demonstrates denervation of the adductor muscles. Surgical neurolysis treatment provides the definitive cure of this problem, with athletes returning to competition within several weeks of treatment. The surgical findings are entrapment of the obturator nerve by a thick fascia overlying the short adductor muscle. The role of conservative treatment in the management of this condition is unknown at present.

PMID: 9167824 [PubMed - indexed for MEDLINE]
Obturator neuropathy. An anatomic perspective.
Clin Orthop. 1999 Jun;(363):203-11. Related Articles
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Harvey G, Bell S.

Department of Orthopaedic Surgery, Austin Hospital, Heidelberg, Victoria, Australia.

Entrapment of the anterior division of the obturator nerve is a recently described cause of medial groin pain. This anatomic study examines the extrapelvic course of the nerve and related fascia in the adductor region to provide an anatomic basis for the syndrome and to aid in surgical treatment. Twelve anatomic specimen limbs were dissected to document the extrapelvic course of the obturator nerve, the myofascial arrangement, and the vasculature. A thirteenth limb was prepared with intraarterial glycerin to examine the vessels in more detail. A distinct fascial plane was found deep to the adductor longus and pectineus overlying the anterior division of the obturator nerve. The arterial supply to the adductor muscles is related intimately to the nerve and its branches, with associated local thickening of the fascial connective tissue. The relationship between the nerve, vessels, and fascia appears sufficient to result in an entrapment syndrome. The anatomic findings from this series will help plan the surgical treatment of this condition.

PMID: 10379324 [PubMed - indexed for MEDLINE]
Pudendal nerve entrapment as source of intractable perineal pain.
Am J Phys Med Rehabil. 2003 Jun;82(6):479-84. Related Articles
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Ramsden CE, McDaniel MC, Harmon RL, Renney KM, Faure A.

School of Medicine, Medical College of Georgia, Augusta, Georgia, USA.

Perineal pain caused by pudendal nerve entrapment is a rarely reported entity, with only a handful of cases in the modern literature. A 25-yr-old male medical student had refractory unilateral orchialgia for 32 mo and concomitant proctalgia for 14 mo. Pain was positional in nature, exacerbated by sitting and partially relieved when standing or recumbent. Pudendal nerve entrapment was diagnosed clinically, with computed tomography-guided nerve blocks providing temporary relief. A prolonged left pudendal nerve distal motor latency on electrodiagnostic testing later confirmed the diagnosis. At surgery, the left pudendal nerve was found flattened in the pudendal canal of Alcock and in contact with the sharp inferior border of the sacrospinous ligament. After surgical decompression and rehabilitation, the patient experienced significant relief of pain and returned to medical school. This case suggests pudendal nerve entrapment should be considered in the differential diagnosis of chronic urogenital or anorectal pain, particularly if the pain is aggravated by sitting or if there is a history of bicycle riding.

Publication Types:
  • Case Reports
  • Review
  • Review of Reported Cases

PMID: 12820792 [PubMed - indexed for MEDLINE]
Superior cluneal nerve entrapment.
Reg Anesth Pain Med. 2000 Nov-Dec;25(6):648-50. Related Articles
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Talu GK, Ozyalcin S, Talu U.

Department of Algology, Medical Faculty of Istanbul, Istanbul University, Monoblok, Capa Klinikleri, 34390 Capa, Istanbul, Turkey.

BACKGROUND AND OBJECTIVES: Pain due to superior cluneal nerve entrapment is an infrequent cause of unilateral low back pain. Here we present a case of acute unilateral low back pain treated by superior cluneal nerve (SCN) block. CASE REPORT: A 55-year-old woman presented to the outpatient clinic suffering from unilateral low back pain localized to right iliac crest and radiating to the right buttock. Her history was taken, physical examination was performed, and a thorough radiologic evaluation was performed to minimize radiculopathy and facet syndromes as causative. After transient pain relief with a diagnostic trigger point injection, entrapment of SCN was diagnosed and therapeutic nerve block with local anesthetic and steroid combination was performed. CONCLUSION: SCN is prone to entrapment where it passes through the fascia near the posterior iliac crest. Unilateral low back pain and deep tenderness radiating to the ipsilateral buttock are the clinical findings accompanying SCN entrapment. The case presented emphasizes the relief of possible SCN after limiting other etiologic causes of low back pain.

Publication Types:
  • Case Reports

PMID: 11097676 [PubMed - indexed for MEDLINE]
The lateral cutaneous branches of the dorsal rami of the thoraco-lumbar junction. An anatomical study on 37 dissections.
Surg Radiol Anat. 1989;11(4):289-93. Related Articles

Maigne JY, Lazareth JP, Guerin Surville H, Maigne R.

Laboratoire d'Anatomie, UER Pitie-Salpetriene, Paris, France.

Thirty-seven dissections have shown that the skin of the low back is innervated by the lateral branches of the dorsal rami of T12 and LI in 22 cases (60%) or T12 L1 and L2, in 10 cases (27%) or T12 L1 and L2 receiving an anastomosis from L3 in 5 cases (13%). The most medial nerve crossed the iliac crest through a rigid osseo-aponeurotic orifice located 7-8 cm from the midline which was seen compressing the nerve in 2 instances. This pattern of distribution may sometimes explain unilateral low back pain.

PMID: 2533408 [PubMed - indexed for MEDLINE]
The segmental dorsal ramus neuropathy as a common cause of chronic and recurrent low back pain.
Electromyogr Clin Neurophysiol. 1992 Oct-Nov;32(10-11):507-10. Related Articles

Sihvonen T.

Department of Clinical Neurophysiology, University Hospital of Kuopio, Finland.

The causes of recurrent and chronic low back pain usually remain unknown. The dorsal ramus lesion was found in 57 of 200 low back pain patients in this study in L5 or L4 segment without any neurophysiologic or neuroradiologic evidence of proximal ventral root compression. The neuropathy of dorsal rami, especially in their medial branches seems to be surprisingly common finding associated with low back pain and referred symptoms.

PMID: 1332840 [PubMed - indexed for MEDLINE]
Thoracic dorsal ramus entrapment. Case report.
J Neurosurg. 1989 Jan;70(1):124-5. Related Articles

Gonzalez-Darder JM.

Department of Neurosurgery, Faculty of Medicine, University of Cadiz, Spain.

Entrapment of the dorsal ramus of a thoracic spinal nerve is described in a patient with chronic back pain and sensory disturbance in the cutaneous territory served by the T3-5 dorsal rami. The dorsal ramus of the T-4 nerve was found to be compressed by a bone spur involving the inferior T-4 apophyseal facet. The point of entrapment was a tunnel bounded by the transverse process, apophyseal joint, rib, and superior costotransverse ligament.

Publication Types:
  • Case Reports

PMID: 2521245 [PubMed - indexed for MEDLINE]
Trigger point of the posterior iliac crest: painful iliolumbar ligament insertion or cutaneous dorsal ramus pain? An anatomic study.
Arch Phys Med Rehabil. 1991 Sep;72(10):734-7. Related Articles

Maigne JY, Maigne R.

Department of Physical Medicine and Rehabilitation, Hotel-Dieu Hospital, Paris, France.

A trigger point is frequently found over the iliac crest at 7 to 8 cm from the midline in low-back-pain syndromes. Previously, this was described as either a painful insertion site of the iliolumbar ligament or pain in the distribution of the cutaneous dorsal ramus of the first or second lumbar nerve. The authors performed 37 dissections, and they report their anatomic findings. The iliac insertion of the iliolumbar ligament is inaccessible to palpation, being shielded by the iliac crest. The dorsal rami of L1 or L2 nerve roots, however, cross the crest at 7 cm from the midline, and this distance closely correlates with the dorsal projection of the iliolumbar ligament insertion. These rami are superficial and dorsal to the crest, easily accessible to palpation. In two of the 37 dissections performed, some rami were found to be narrowed as they crossed through an osteofibrous orifice over the crest, thus being susceptible to an entrapment neuropathy. The authors conclude that the trigger point sometimes localized over the iliac crest at 7 cm from the midline likely corresponds to elicited pain from a cutaneous dorsal ramus originating from the thoracolumbar junction rather than from the iliac insertion of the iliolumbar ligament.

PMID: 1834038 [PubMed - indexed for MEDLINE]