Nerve compression

Association of Pain, neuropathic pain is defined as pain initiated or caused by a primary lesion, dysfunction in the nervous system". Neuropathy can be divided broadly into peripheral and central neuropathic pain, depending on whether the primary lesion or dysfunction is situated in the peripheral or central nervous system. In the periphery, neuropathic pain can result from disease or inflammatory states that affect peripheral nerves (e.g. diabetes mellitus, herpes zoster, HIV) or alternatively due to neuroma formation (amputation, nerve transection), nerve compression (e.g. tumours, entrapment) or other injuries (e.g. nerve crush, trauma). Central pain syndromes, on the other hand, result from alterations in different regions of the brain or the spinal cord. Examples include tumour or trauma affecting particular CNS structures (e.g. brainstem and thalamus) or spinal cord injury. Both the symptoms and origins of neuropathic pain are extremely diverse. Due to this variability, neuropathic pain syndromes are often difficult to treat. Some of the clinical symptoms associated with this condition include spontaneous pain, tactile allodynia (touch-evoked pain), hyperalgesia (enhanced responses to a painful stimulus) and sensory deficits. 

Carpal tunnel syndrome caused by nerve compression from the swollen tissue... 

Nerve compression and stretch injuries Cryoglobulinemic neuropathy lepromatous neuropathy... 

Thyroid orbitopathy is an inflammatory disease of the orbital tissues. This inflammation is mediated through cytokine release, proliferation of fibroblasts, increased deposition of extracellular matrix, and adipocyte differentiation and proliferation. These cellular changes result in enlargement of the extraocular muscles and increased volume of orbital soft tissues, which presents clinically as exophthalmos and optic nerve compression. Edema, inflammation, and late fibrosis account for the decreased function of the extraocular muscles despite relative preservation of the muscle fibers themselves. 

Transcutaneous electrical nerve stimulation (TENS) helps some sufferers it may act by promoting the release of endorphins. Ketamine (see p. 353) or lidocaine (Ugnocaine) (by i.v. infusion) are used in special circumstances. Pain due to nerve compression may be reUeved by a corticosteroid injected loccally. 

Nerve compression can be relieved by local corticosteroid (prednisolone) or nerve block (local anaesthetic) nerve destruction can be achieved by alcohol, phenol. 

Regional damage from methylmethacrylate is generally the result of poor surgical technique, whereby the cement inadvertently reaches other tissues and structures. For example, leaking methylmethacrylate cement during fixation of the acetabular cup in a total hip replacement can cause sciatic nerve compression and result in severe lasting leg pain (5). 

Epidural anesthesia can mask a neurological deficit, such as nerve compression of the femoral nerve and lateral femoral cutaneous nerve of the thigh from the lithotomy position (SEDA-22, 137). 

Therapy is directed at decreasing osteoclastic bone resorption. Bisphosphonates (alendronate, risedronate, pamidronate, and etidronate) and calcitonin are effective in decreasing bone pain, serum ALP, and markers of bone resorption. Patients may occasionally need surgery for skeletal deformity that limits mobility or for arthritic changes, fractures, or nerve compression. 

Pain with motion of affected muscle Signs of nerve compression... 

Muscle 30%-50% for most sites 70%-100% for thigh, iliopsoas, or nerve compression Risk of significant blood loss with femoral/retroperitoneal bleed bed rest for iliopsoas or other retroperitoneal bleeding... 

TTX can result in peripheral neuropathy, although this disorder is uncommon. The prevalence is generally low, depending on the duration of the condition, which is thought to be about 5% clinically, but increases to 8% in subchnical cases (Roquer and Cano, 1993). Nerve entrapment, similar to hypothyroidism, can also occur. The most common is median nerve compression, commonly known... 

Repeated flexing of the wrist can injure the tendons, tendon sheaths, muscles, ligaments, joints and nerves of the hand and forearm. These repetitive strain injuries commonly occur in occupations involving repeated hand-wrist deviations (e.g., keyboard and computer operators), and frequently involve nerve compression at the wrist (e.g., carpal tunnel syndrome) (Chemiack, 1999). 

Fig. 5.16. a Giant ICA aneurysm inducing optic nerve compression in a 10-year-old boy with visual deficit on the right eye. b Brain stem aneurysm between origin of the superior cerebellar artery and posterior cerebral artery resulting in right sided oculomotor palsy. c,d Pcom aneurysm (c DSA, lateral view) in a 46-year-old-patient with oculomotor palsy note the close relationship of the aneurysm and the oculomotor nerve (arrow) but without visible contact (d, sagittal reconstruction of CISS sequence)... 

The major complication during acrylic cement injection is epidural overflow with spinal nerve compression. Monitoring the vertebral filling by lateral fluoroscopy during the injection of the pasty cement minimizes this risk. The next most serious complication is infection to avoid this complication, strict sterility during the intervention is mandatory. 

Fig. 12.7a-c. Endocrine orbitopathy (EO) is among the most common causes for proptosis. Axial (a), coronal (b) and sagittal (c) MDCT images of the orbit demonstrate severe bilateral thickening of intra-orbital muscles, which is usually most pronounced in the medial and inferior rectus muscles (arrows), leaves out the tendons, and may result in optic nerve compression at the aperture of the optical nerve canal (curved arrows). Hypertrophy of intra-orbital fat tissue is another feature typical of EO... 

Scheie syndrome is a clinically milder form of Hurler syndrome. Onset of the disease occurs at about age 5 years. Growth and intelligence are normal. The development of joint stiffness is pronounced. Clouding of the corneas is severe. With increasing age the development of aortic valve disease becomes apparent. Median nerve compression and cervical cord compression occur and require immediate intervention. 

Harvie P, Patel N, Ostlere SJ (2003) Ulnar nerve compression at Guyon s canal by an anomalous abductor digit minimi muscle the role of ultrasound in clinical diagnosis. Hand Surg 8 271-275... 

Davison BD, Polak JE (2004) Arterial injuries a sonographic approach. Radiol Clin North Am 42 383-396 Delfiner JS (1996) Dynamic and pathophysiology of nerve compression in the upper extremity. Orthop Clin North... 

Provost N, Bonaldi VM, Sarazin L (1997) Amputation stump neuroma ultrasound features. J Clin Ultrasound 25 85-89 Puig S, Turkof E, Sedivy R et al (1999) Sonographic diagnosis of recurrent ulnar nerve compression by ganglion cysts. J Ultrasound Med 18 433-436... 

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