Radiculopathy is a term derived from radicular nerves or nerve roots which exit the foramina of the vertebral bones. When these nerve roots are compressed by a herniated disc or prolapsed disc, there is a resultant sensation of discomfort, burning and pain felt in the distribution of the nerve giving rise to the term radiculopathy. The nerve roots are classified as cervical, thoracic, lumbar and sacral, according to the region in which they leave the spinal cord.
Patients tend to complain of severe neck and arm pain in the case of cervical radiculopathy; there are also symptoms of burning and tingling. The distribution of these symptoms however, follows a myotomal pattern rather than a dermatomal pattern . There is concomitant loss of motor function and altered reflexes in the nerves affected . The pain felt in cervical radiculopathy manifests through the shoulder girdle, arm and forearm, the paresthesias and numbness is mostly felt in the central portion of the hand and muscular weakness is felt in the arm and forearm . In one study, symptoms were preceded by some sort of physical exertion or trauma in 15% cases . Although there are no criteria for the confirmed diagnosis of cervical radiculopathy, the history and examination of the patient usually give evidence enough to make the diagnosis  . On examination, certain maneuvers further confirm the diagnosis of cervical radiculopathy, these include holding up the affected arm on top of the head  or moving the head to look down and away from the side of pain tends to improve the pain; whereas rotation of or bending of the head towards the side of symptoms tends to increase the pain .
Thoracic radiculopathy is characterized by sharp, burning pain felt in chest, arm or abdomen. The symptoms worsen with coughing, straining or sneezing. Lumbar radiculopathy, commonly known as sciatica, presents as numbness, tingling and muscle weakness in the lower back radiating all the way down to one or both the legs and feet.
Laboratory studies are often not necessary to diagnose radiculopathy. Although the erythrocyte sedimentation rate and C-reactive protein levels may be increased in many patients with spinal infection or cancer, these tests are not specific .
Radiographs of the affected region of the spine are usually obtained; lateral, anteroposterior, and oblique views are helpful . However, radiographs have a low sensitivity for the detection of tumors or infections; they are also insufficient to detect disk herniation and the intervertebral narrowing . Magnetic resonance imaging (MRI) is the modality of choice when a detailed workup is required in patients with radiculopathy . MRI is indicated if substantial pain is still present four to six weeks after the initiation of treatment or if there are progressive neurologic deficits . Computed tomography (CT) is of limited value in assessing radiculopathy, due to the lack of soft tissue visualization, but it is useful in assessing the extent of bony spurs, narrowing of foramina, or the extent of ossification of the posterior longitudinal ligament  .
The main objectives of treatment are to provide symptomatic relief from pain and improve function . Analgesics, including opioids and non-steroidal antiinflammatory drugs (NSAIDs), are usually used as first-line therapy . Patients suffering from acute pain have been given a short course of prednisone, starting with a dose of 70 mg per day and decreasing by 10 mg every day . Some studies have reported favorable results with epidural injections of corticosteroids. These show that up to 60 % of patients were relieved of their symptoms and were able to return to their routine activities . Epidural injections, however, come with several rare and serious complications including neurologic sequelae from infarction of the spinal cord or brainstem .
Short-term immobilization (less than two weeks) with a hard or a soft collar (either continuously or every at night) also aids in pain control in cervical radiculopathy, according to some researches . Rarely, surgery is recommended in cases where there is compression of the spinal cord and substantial evidence of moderate to severe myelopathy . It is also recommended for those who have persistent and debilitating pain after a minimum of 6 to 12 weeks of nonsurgical management . It is recommended to join a progressive exercise program once the pain is under control .
Cervical radiculopathy is due to the narrowing of the foramina in the vertebrae in 70% of the cases . This occurs because of changes taking place in these bones due to old age and osteoporosis. In many cases, there is no actual pathology and the symptoms are due to excessive tension and stretching in neck and shoulder muscles due to prolonged periods of poor posture and muscle use .
Lumbar radiculopathy, on the other hand, is mostly caused by degenerative conditions such as lumbar spinal stenosis or herniated disc. Studies have identified extradural masses such as synovial cysts and gas-containing ganglion cysts as less common causes . Other occasional causes of lumbar radicular syndromes include obstruction of venous outflow, venous congestion and lumbar epidural varix .
Certain symptoms, when present, signal toward a more serious, albeit unusual  etiology like cancer or infection. These symptoms include history of cancer itself, fever, chills, unremitting night time pain and unexplained weight loss . An important differential diagnosis to keep in mind when a patient complains of radiculopathy is signs and symptoms of myelopathy. These may be mild such as diffuse numbness and clumsiness, urinary urgency and frequency, or advanced like urinary retention and incontinence .
The most common causes of radiculopathy include compression of nerve roots, osteoarthrosis of joints, disk degeneration and prolapsed intervertebral disks . Prolapsed lumbar disk is seen mostly in the age group of 20-39 years of age and is mostly due to sitting for prolonged periods of time such as when driving motor vehicles or in sedentary occupations; pregnant women at full term are also at risk for prolapsed disk .
The likelihood of osteoarthrosis of the cervical and lumbar spine increases with age . Disk degeneration is also related to age where the initial stages occur from the ages of 20 to 29 years and osteophyte formation occurs from the age of 50 years onwards . According to research conducted in Rochester, Minnesota of the United States of America, the annual incidence of cervical radiculopathy for men is 107.3 per 100,000 and for women are 63.5 per 100,000 . Lumbosacral radiculopathy is estimated to affect around 3 to 5% of the population in the US.
The pathophysiology behind radiculopathy is still undetermined. However, studies have shown that symptoms tend to arise when the dorsal-root ganglion is also involved  . Once there is superimposed hypoxia, the symptoms are further aggravated . It has been documented through several studies that a number of inflammatory mediators are released by herniated intervertebral disks including prostaglandin E2, matrix metalloproteinases, interleukin-6 and nitric oxide causing the symptoms of radiculopathy   .
While some causes of radiculopathy are not avoidable, there are certain ways to reduce the risk of developing a radiculopathy. These include maintaining good posture and a healthy weight. In order to avoid complications, one must use safe techniques when lifting heavy objects and take frequent breaks when performing repetitive tasks. A regular exercise regime not only helps with physical fitness but also improves strength and flexibility of muscles, this hinders the chances of developing a radiculopathy.
Radiculopathy is the discomfort or pain which is perceived when there is nerve root damage due to pathology in the surrounding tissues such as muscles, tendons, cartilage or bone . When the nerve roots are compressed, there is inflammation  resulting in numbness, weakness, and pain. Cervical radiculopathy most commonly occurs due to disc herniation or degenerative changes, or as in most cases, both . Thoracic radiculopathy is a less common condition. Lumbar radiculopathy occurs mostly due to a structural problem like a herniated disc. Treatment varies according to the type of pathology and the severity of the disease.
Radiculopathy is usually due to nerve root compression which may occur due to a number of reasons. While mostly the reasons are disc compression and herniation, certain morbid conditions may also be the cause of discomfort. Hence a follow up with your physician is advised. Radiculopathy most often results in pain, weakness and numbness. The modes of treatment usually involve pain medication and physiotherapy. Surgery is indicated only in advanced cases when the spinal cord itself is being compressed. The best way to prevent any sort of radiculopathy is to exercise regularly and maintain the strength of ones muscles and bones by taking a balanced diet.