and s1 vertebrae, indicating probable prolapsed intervertebral disc – a classic picture computed tomographyscan is the most sensitive imaging modality to examine the bony structures of the spine. ct imaging allows for the evaluation of calcified herniated discs or any pathological process that may result in bone loss or destruction. it is deficient for the visualization of nerve roots, making it unsuitable in the diagnoses of radiculopathy. magnetic resonance imaging is the gold standard study for confirming a suspected ldh. with a diagnostic accuracy of 97%, it is the most sensitive study to visualize a herniated disc due to its significant ability in soft tissue visualization. mri also has higher inter-observer reliability than other imaging modalities. it suggests disc herniation when it shows an increased t2-weighted signal at the posterior 10% of the disc. degenerative disc diseases have shown a correlation with modic type 1 changes. when evaluating for postoperative lumbar radiculopathies, the recommendation is that the mri is performed with contrast unless otherwise contraindicated. mri is more effective than ct in distinguishing inflammatory, malignant, or inflammatory etiologies of ldh. it is indicated relatively early in the course of evaluation (<8 weeks) when the patient presents with relative indications like significant pain, neurological motor deficits, and cauda equina syndrome. diffusion tensor imaging is a type of mri sequence used for detecting microstructural changes in the nerve root. it may be beneficial in understanding the changes that occur after herniated lumbar disc compresses a nerve root, and might help in differentiating the patients that need surgical intervention. in patients with a high suspicion of radiculopathy due to lumbar disc herniation, yet the mri is equivocal or negative, nerve conduction studies are indicated. t2-weighted images allow for clear visualization of protruded disc material in the spinal canal. mri scan of cervical disc herniation between c5 and c6 vertebrae mri scan of cervical disc herniation between c6 and c7 vertebrae mri scan of large herniation (on the right) of the disc between l4 and l5 vertebrae a rather severe herniation of the l4–l5 disc example of a herniated disc at l5–s1 in the lumbar spine myelography. an x-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces will reveal displacement of the contrast material. it can show the presence of structures that can cause pressure on the spinal cord or nerves, such as herniated discs, tumors, or bone spurs. because myelography involves the injection of foreign substances, mri scans are now preferred for most patients. myelograms still provide excellent outlines of space-occupying lesions, especially when combined with ct scanning (ct myelography). ct myelography is the imaging modality of choice to visualize herniated discs in patients with contraindications for an mri. however, due to its invasiveness, the assistance of a trained radiologist is required. myelography is associated with risks like post-spinal headache, meningeal infection, and radiation exposure. recent advances with a multidetector ct scan have made the diagnostic level of it nearly equal to the mri. the presence and severity of myelopathy can be evaluated by means of transcranial magnetic stimulation (tms), a neurophysiological method that measures the time required for a neural impulse to cross the pyramidal tracts, starting from the cerebral cortex and ending at the anterior horn cells of the cervical, thoracic, or lumbar spinal cord. this measurement is called the central conduction time (cct). tms can aid physicians to: determine if myelopathy exists identify the level of the spinal cord where myelopathy is located. this is especially useful in cases where more than two lesions may be responsible for the clinical symptoms and signs, such as in patients with two or more cervical disc hernias assess the progression of myelopathy with time, for example before and after cervical spine surgery tms can also help in the differential diagnosis of different causes of pyramidal tract damage. electromyography and nerve conduction studies (emg/ncs) measure the electrical impulses along nerve roots, peripheral nerves, and muscle tissue. tests can indicate if there is ongoing nerve damage, if the nerves are in a state of healing from a past injury, or if there is another site of nerve compression. emg/ncs studies are typically used to pinpoint the sources of nerve dysfunction distal to the spine. differential diagnosis tests may be required to distinguish spinal disc herniations from other conditions with similar symptoms. discogenic pain mechanical pain myofascial pain abscess aortic dissection discitis or osteomyelitis hematoma mass lesion or malignancy benign tumor like neurinoma or meningeoma myocardial infarction sacroiliac joint dysfunction spinal stenosis spondylosis or spondylolisthesis treatment in the majority of cases spinal disc herniation can be treated successfully conservatively, without surgical removal of the herniated material. sciatica is a set of symptoms associated with disc herniation. a study on sciatica showed that about one-third of patients with sciatica recover within two weeks after presentation using conservative measures alone, and about three-quarters of patients recovered after three months of conservative treatment. however the study did not indicate the number of individuals with sciatica that had disc herniations. initial treatment usually consists of nonsteroidal anti-inflammatory drugs (nsaids), but long-term use of nsaids for people with persistent back pain is complicated by their possible cardiovascular and gastrointestinal toxicity. epidural corticosteroid injections provide a slight and questionable short-term improvement for those with sciatica, but are of no long-term benefit. complications occur in up to 17% of cases when injections are performed on the neck, though most are minor. in 2014, the us food and drug administration (fda) suggested that the "injection of corticosteroids into the epidural space of the spine may result in rare but serious adverse events, including loss of vision, stroke, paralysis, and death", and that "the effectiveness and safety of epidural administration of corticosteroids have not been established, and fda has not approved corticosteroids for this use". lumbar disc herniation non-surgical methods of treatment are usually attempted first. pain medications may be prescribed to alleviate acute pain and allow the patient to begin exercising and stretching. there are a number of non-surgical methods used in attempts to relieve the condition. they are considered indicated, contraindicated, relatively contraindicated, or inconclusive, depending on the safety profile of their risk–benefit ratio and on whether they may or may not help: indicated education on proper body mechanics physical therapy to address mechanical factors, and may include modalities to temporarily relieve pain (i.e. traction, electrical stimulation, massage) nonsteroidal anti-inflammatory drugs (nsaids) weight control spinal manipulation. moderate quality evidence suggests that spinal manipulation is more effective than placebo for the treatment of acute (less than 3 months duration) lumbar disc herniation and acute sciatica. the same study also found "low to very low" evidence for its usefulness in treating chronic lumbar symptoms (more than 3 months) and "the quality of evidence for ... cervical spine-related extremity symptoms of any duration is low or very low". a 2006 review of published research states that spinal manipulation "is likely to be safe when used by appropriately-trained practitioners", and research currently suggests that spinal manipulation is safe for the treatment of disc-related pain. contraindicated spinal manipulation is contraindicated when the etiology of the herniation is the result of a motor vehicle collision (mvc) spinal manipulation is contraindicated for disc herniations when there are progressive neurological deficits such as with cauda equina syndrome. a review of non-surgical spinal decompression found shortcomings in most published studies and concluded that there was only "very limited evidence in the scientific literature to support the effectiveness of non-surgical spinal decompression therapy". its use and marketing have been very controversial. surgery surgery may be useful when a herniated disc is causing significant pain radiating into the leg, significant leg weakness, bladder problems, or loss of bowel control. discectomy (the partial removal of a disc that is causing leg pain) can provide pain relief sooner than non-surgical treatments. small endoscopic discectomy (called nano-endoscopic discectomy) is non-invasive and does not cause failed back syndrome. invasive microdiscectomy with a one-inch skin opening has not been shown to result in a significantly different outcome from larger-opening discectomy with respect to pain. it might however have less risk of infection. failed back syndrome is a significant, potentially disabling, result that can arise following invasive spine surgery to treat disc herniation. smaller spine procedures such as endoscopic transforaminal lumbar discectomy cannot cause failed back syndrome, because no bone is removed. the presence of cauda equina syndrome (in which there is incontinence, weakness, and genital numbness) is considered a medical emergency requiring immediate attention and possibly surgical decompression. when different forms of surgical treatments including (discetomy, microdiscectomy, and chemonucleolysis) were compared evidence was suggestive rather than conclusive. a cochrane review from 2007 reported: "surgical discectomy for carefully selected patients with sciatica due to a prolapsed lumbar disc appears to provide faster relief from the acute attack than non‐surgical management. however, any positive or negative effects on the lifetime natural history of the underlying disc disease are unclear. microdiscectomy gives broadly comparable results to standard discectomy. there is insufficient evidence on other surgical techniques to draw firm conclusions." regarding the role of surgery for failed medical therapy in people without a significant neurological deficit, a cochrane review concluded that "limited evidence is now available to support some aspects of surgical practice". following surgery, rehabilitation programmes are often implemented. there is wide variation in what these programmes entail. a cochrane review found low- to very low-quality evidence that patients who participated in high-intensity exercise programmes had slightly less short term pain and disability compared to low-intensity exercise programmes. there was no difference between supervised and home exercise programmes. epidemiology disc herniation can occur in any disc in the spine, but the two most common forms are lumbar disc herniation and cervical disc herniation. the former is the most common, causing low back pain (lumbago) and often leg pain as well, in which case it is commonly referred to as sciatica. lumbar disc herniation occurs 15 times more often than cervical (neck) disc herniation, and it is one of the most common causes of low back pain. the cervical discs are affected 8% of the time and the upper-to-mid-back (thoracic) discs only 1–2% of the time. the following locations have no discs and are therefore exempt from the risk of disc herniation: the upper two cervical intervertebral spaces, the sacrum, and the coccyx. most disc herniations occur when a person is in their thirties or forties when the nucleus pulposus is still a gelatin-like substance. with age the nucleus pulposus changes ("dries out") and the risk of herniation is greatly reduced. after age 50 or 60, osteoarthritic degeneration (spondylosis) or spinal stenosis are more likely causes of low back pain or leg pain. 4.8% of males and 2.5% of females older than 35 experience sciatica during their lifetime. of all individuals, 60% to 80% experience back pain during their lifetime. in 14%, pain lasts more than two weeks. generally, males have a slightly higher incidence than females. prevention because there are various causes of back injuries, prevention must be comprehensive. back injuries are predominant in manual labor, so the majority of low back pain prevention methods have been applied primarily toward biomechanics. prevention must come from multiple sources such as education, proper body mechanics, and physical fitness. education education should emphasize not lifting beyond one's capabilities and giving the body a rest after strenuous effort. over time, poor posture can cause the intervertebral disc to tear or become damaged. striving to maintain proper posture and body alignment will aid in preventing disc degradation. exercise exercises that enhance back strength may also be used to prevent back injuries. back exercises include the prone push-ups/press-ups, upper back extension, transverse abdominis bracing, and floor bridges. if pain is present in the back, it can mean that the stabilization muscles of the back are weak and a person needs to train the trunk musculature. other preventative measures are to lose weight and not to work oneself past fatigue. signs of fatigue include shaking, poor coordination, muscle burning, and loss of the transverse abdominal brace. heavy lifting should be done with the legs performing the work, and not the back. swimming is a common tool used in strength training. the usage of lumbar-sacral support belts may restrict movement at the spine and support the back during lifting.