Pinched Nerve Root

Spinal nerve roots play a crucial role in transmitting sensory and motor signals between the spinal cord and the body. When these nerve roots are affected by various conditions, it can lead to significant pain and functional impairment.

A pinched nerve root, also known as a compressed nerve root, happens when too much pressure is applied to a nerve by the surrounding tissues, such as bones, cartilage, muscles, or tendons. This pressure can cause pain, numbness, tingling, or weakness in the area where the nerve travels. Sometimes, people get confused between a pinched nerve root and sciatica because they both involve pain and nerves. But they are not the same thing! Let’s learn the difference in a simple way.

A pinched nerve root happens when something presses on a nerve root that comes out from the spinal cord. This pressure can cause pain and other problems. Sciatica is a specific type of pain that happens when the sciatic nerve, the largest nerve in your body, gets pinched or irritated. The sciatic nerve runs from your lower back, through your hips and buttocks, and down each leg.

How Are They Different?

  • Location of Pain: A pinched nerve root can happen anywhere along the spine and cause pain in different parts of the body. Sciatica specifically causes pain that starts in the lower back and goes down one leg.
  • Cause: Sciatica is usually caused by a pinched nerve root in the lower back affecting the sciatic nerve, but a pinched nerve root can happen anywhere along the spine.
  • Type of Pain: Sciatica pain is usually sharp and travels down the leg, while a pinched nerve root pain can be sharp or burning and might stay in one area.

Anatomy of the Spinal Cord and Spinal Nerve Roots

The spinal cord is a vital part of the central nervous system, running from the base of the brain down the vertebral column. It is surrounded by protective layers, including the dura mater, arachnoid mater, and pia mater. The spinal cord ends at the conus medullaris, typically around the L1-L2 vertebral level, and continues as the cauda equina—a bundle of nerve roots.

Spinal Nerve Roots

Spinal nerve roots emerge from the spinal cord and are divided into two types:

  • Dorsal (Posterior) Roots: Carry sensory information from the body to the spinal cord.
  • Ventral (Anterior) Roots: Carry motor information from the spinal cord to the muscles.

Spinal cord schematic diagram

Each spinal nerve root corresponds to a specific segment of the spinal cord and exits the spinal canal through an intervertebral foramen. There are 31 pairs of spinal nerves:

  • 8 cervical (C1-C8)
  • 12 thoracic (T1-T12)
  • 5 lumbar (L1-L5)
  • 5 sacral (S1-S5)
  • 1 coccygeal (Co1)

Pinched Spinal Nerve Root

A pinched nerve root, also known as a compressed nerve root, happens when too much pressure is applied to a nerve by the surrounding tissues, such as bones, cartilage, muscles, or tendons. This pressure can cause pain, numbness, tingling, or weakness in the area where the nerve travels.

How Does a Pinched Nerve Root Happen?

Model of a herniated disc of the lumbar spine. 3D Illustration

Model of a herniated disc of the lumbar spine.

Our spine is made up of bones called vertebrae, and between these bones are soft discs that cushion them. Nerve roots come out from the spinal cord between the vertebrae and go to different parts of our body. If something presses on one of these nerve roots, it can cause a pinched nerve.

Here are some common reasons why a nerve root might get pinched:

1. Herniated Disc

A herniated disc occurs when one of the discs between the vertebrae slips out of place or breaks open. This can press on a nerve root and cause pain.

2. Bone Spurs

Sometimes, extra bone grows on the vertebrae, called bone spurs. These can press on the nerve roots and cause problems.

Spinal Canal Stenosis. Lumbar vertebra with intervertebral disc and herniated nucleus pulposus, illustration

Spinal Canal Stenosis. Lumbar vertebra with intervertebral disc and herniated nucleus pulposus, illustration

3. Spinal Stenosis

Spinal stenosis is when the spaces in the spine get too narrow. This can squeeze the nerve roots.

4. Injuries

Injuries from accidents, falls, or sports can cause swelling or misalignment that puts pressure on nerve roots.

Symptoms of a Pinched Nerve Root

When a nerve root gets pinched, it can cause different symptoms, depending on where the nerve is. Common symptoms include:

  • Pain: Sharp or burning pain in the area where the nerve travels. For example, if a nerve in the lower back is pinched, you might feel pain down your leg (sciatica).
  • Numbness: A loss of feeling in the area served by the nerve.
  • Tingling: A “pins and needles” feeling.
  • Weakness: Muscles served by the nerve might feel weak.

Work-Up and Diagnosis

Diagnosing conditions related to spinal nerve root pain involves a thorough approach:

  1. Clinical Examination: A detailed history and physical examination to assess pain characteristics, neurological function, and specific nerve root involvement.
  2. Imaging Studies:
    • MRI: Provides detailed images of soft tissues, including discs, nerve roots, and any compressive lesions.
    • CT Scans: Offer a detailed view of bone structures, useful for identifying fractures and bony stenosis.
    • X-Rays: Help identify structural abnormalities such as spondylolisthesis or osteoarthritis.
  3. Electrodiagnostic Studies (occasionally needed):
    • EMG (Electromyography) and Nerve Conduction Studies: Assess the electrical activity of muscles and the function of peripheral nerves, helping to pinpoint the level and severity of nerve root involvement.

Treatment Options

Treatment for spinal nerve root pain ranges from conservative approaches to advanced interventional modalities, depending on the specific condition and its severity.

Interventional Treatment Modalities

  1. Epidural Steroid Injections (ESIs): Injections of corticosteroids into the epidural space reduce inflammation and provide pain relief. They are commonly used for radiculopathy due to herniated discs or spinal stenosis.
  2. Selective Nerve Root Blocks: Targeted injections of anesthetics and corticosteroids around the affected nerve root can confirm the diagnosis and provide temporary relief.
  3. Pulsed Radiofrequency Ablation of Dorsal Root Ganglion (pRFA): This procedure uses radiofrequency energy to disrupt pain signals from nerves affected by conditions such as chronic radiculopathy.
  4. Percutaneous Discectomy or Disc-Fx: A minimally invasive procedure to remove the herniated portion of a disc compressing a nerve root, providing relief from radicular pain.
  5. Spinal Cord Stimulation (SCS): Electrodes are implanted near the spinal cord to deliver electrical impulses that interfere with pain signals, used in chronic, refractory cases.
  6. Dorsal Root Ganglion Stimulation (DRG Stim): Electrodes are implanted over the nerve root to deliver electrical impulses that interfere with pain signals, used in chronic, refractory cases where a very specific nerve can be identified as a culprit.
  7. Surgical Interventions:
    • Endoscopic Microdiscectomy: Removal of herniated disc material pressing on a nerve root using a small opening and an endoscope.
    • Microdiscectomy: Removal of herniated disc material pressing on a nerve root through a larger surgical opening.
    • Laminectomy: Removal of part or all of the lamina to relieve pressure on the nerve roots, typically used for spinal stenosis.
    • Foraminotomy: Surgical widening of the narrowed bony foramina through which a nerve root is exiting.
    • Minuteman Procedure: Stabilizes the spine in cases of spondylolisthesis or severe degenerative changes.
    • Spinal Fusion: Aggressive stabilization of the spine using screws and rods, in cases of spondylolisthesis or severe degenerative changes. This procedure is rarely needed.

Conclusion

Pain related to spinal nerve roots can significantly impact a patient’s quality of life. Accurate diagnosis through clinical evaluation and imaging is essential for effective management. While conservative treatments are often beneficial, interventional modalities offer advanced solutions for persistent or severe symptoms. By addressing the underlying causes and employing targeted treatments, healthcare providers can help patients achieve relief and improve their overall well-being.

References

  1. Bogduk N. “Clinical Anatomy of the Lumbar Spine and Sacrum.” Elsevier Health Sciences. 2005.
  2. Manchikanti L, Boswell MV, Singh V, et al. “Comprehensive review of therapeutic interventions in managing chronic spinal pain.” Pain Physician. 2009.
  3. Deyo RA, Mirza SK, Martin BI. “Back pain prevalence and visit rates: estimates from U.S. national surveys, 2002.” Spine. 2006.
  4. Chou R, Qaseem A, Snow V, et al. “Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society.” Annals of Internal Medicine. 2007.
  5. Friedly JL, Comstock BA, Turner JA, et al. “Long-term effects of repeated injections of local anesthetic with or without corticosteroid for lumbar spinal stenosis: a randomized trial.” Archives of Physical Medicine and Rehabilitation. 2017.

These references provide further insights into the anatomy, clinical conditions, and advanced treatment modalities for spinal nerve root pain.

Location Map:

Contact Us Today

  • * All indicated fields must be completed.
    Please include non-medical questions and correspondence only.
  • This field is for validation purposes and should be left unchanged.