Radiculopathies, The Pinched Nerves in The Spine

Radiculopathies or pinched nerves are clinical conditions caused by compression or damage of the nerve roots at the spine level. Radicle is Latin for root. In the spine there are seven vertebrae in the neck, 12 in the chest and five in the lower back plus the tailbone. Radiculopathies are therefore labeled as cervical (neck), thoracic (chest), and lumbosacral (lower back). The vertebral bodies are separated by discs that provide cushion from downward compression and provide space between the vertebrae for the nerve roots to exit. The spinal cord travels through a tunnel in the vertebral bodies and connects the brain to the rest of the body by sending nerve roots out. At each inter-vertebral level on either side, a pair comprising of one sensory and one motor nerve root leaves the spinal canal through an opening in the vertebral bones called foramen. The sensory nerve roots transmit all the sensations such as pain, touch, temperature, and movement from a specific area of the body back to the spinal cord. The motor nerve roots transmit the signal from the spinal cord to a specific group of muscles to move them.

Symptoms due to any specific nerve root compression or damage depend on the degree of involvement of sensory and/or motor nerve roots and also on the number of levels involved. When the nerve roots are affected at more than one level, it is termed a polyradiculopathy. Symptoms include loss of strength, loss of sensations, and abnormal sensations or a combination of the above in the affected nerve root territories. Common symptoms include pain, numbness, tingling, burning, cramping etc. in the specific territory of the affected nerve root(s). Weakness may develop in a specific set of muscles supplied by the affected nerve root(s). Focal pain in the neck, chest, or lower back may accompany because of local structural changes. Pain radiating or shooting from neck or back into the specific nerve root territories is a common symptom. For example cervical radiculopathy at C6 on the right side may cause numbness and pain in the right thumb and index finger that are supplied by C6 sensory nerve root and may cause weakness of right deltoid and biceps muscles that are supplied by the C6 motor nerve root. Pain in the lower neck may also radiate into the right arm and hand.

Radiculopathies are often caused by disc herniations that compress the nerve roots in the foramen as they exit the spinal canal. The disc herniations are quite often caused by some form of trauma and tend to occur in younger people more often than in older people. The other common cause is narrowing of the spinal canal called spinal stenosis that occurs due to a combination of factors including disc degenerations, osteophyte or bone spur formation, ligament hypertrophy, and spondylolisthesis (degeneration and misalignment of vertebrae). In rare cases focal compression on the nerve roots due to causes such as inflammation or malignancy can produce a similar picture.

Diagnostic evaluation usually includes clinical examination, imaging studies, and electrodiagnostic studies. Clinical examination may shows loss of sensations, weakness, and decreased reflexes in specific nerve root territories. Imaging studies such as MRI or CT scan are used to visualize the spinal structures. MRI is the preferred imaging modality because it shows the soft tissues such as discs and nerves better than the CT scan does. A CT myelogram may be used in selected cases to visualize the nerve roots and their surroundings. An EMG nerve conduction study can help to determine the nature and extent of nerve root injury and can help to distinguish it from other causes of numbness, pain, and weakness affecting the same areas.

Treatment of radiculopathies is based on the symptoms, the degree, and the cause of damage to the nerve roots. In mild cases conservative treatment including a combination of physical therapy, anti-inflammatory drugs, muscle relaxants, pain killers, and traction therapy may resolve the symptoms. Epidural injections containing steroids and local anesthetics can produce significant relief, though often temporary, by reducing the inflammation. More advanced techniques such radio frequency ablation (RFA) may be helpful in some cases. Surgical decompression is required when there is clear clinical or laboratory evidence of nerve root damage. In some cases surgical decompression is needed to control pain especially if conservative management does not resolve the symptoms. Surgical treatment may involve removal of the problematic disc or disc fragment and stabilization of the spine with fusion and hardware placement. Regeneration of damaged nerve roots is a slow process and dependent on the length of the nerve from the spine to the target organ. Depending upon the nature and location of damage, the regeneration can take several months to sometimes years to complete after the surgery. For example a nerve root injury in the lumbar spine may take upto three years to complete. Therefore it is important to quickly determine the nature of radiculopathies and treat them accordingly to prevent further damage and to allow them to heal.