The spine, the body’s central support column, consists of stacked bones called vertebrae, cushioned by intervertebral discs. This structure houses and protects the spinal cord. Spinal compression is a common medical condition that occurs when the space within this bony column narrows, placing abnormal pressure on the delicate nervous tissue inside. This pressure can disrupt the normal flow of nerve signals, leading to pain and functional impairment throughout the body.
Defining the Mechanics of Spinal Compression
Spinal compression arises from a reduction in the space available for neural structures, a condition broadly termed spinal stenosis. Compression can affect the nerve roots or the spinal cord itself.
Compression of an individual nerve root, often occurring as it exits the spinal column through the intervertebral foramen, is known as radiculopathy. The physical narrowing of the foramen, called foraminal stenosis, is a frequent mechanical cause of this nerve root irritation.
When the central spinal canal narrows, it exerts pressure directly on the spinal cord, resulting in myelopathy. Myelopathy often develops in the cervical (neck) or thoracic (mid-back) regions.
The mechanical result is a disruption of nerve signal transmission, which occurs due to direct physical pressure or by hindering necessary blood flow to the nervous tissue. Symptom severity is directly related to the degree of physical narrowing and the amount of pressure exerted on the nerve structures.
Common Causes and Risk Factors
Spinal compression causes are broadly categorized as degenerative, traumatic, or systemic. Degenerative changes are the most frequent cause, typically resulting from the natural aging process. Wear and tear on spinal joints leads to osteoarthritis, causing the formation of bone spurs that project into the spinal canal or foramina.
Intervertebral discs also contribute, losing hydration and elasticity over time, which reduces the height between vertebrae. This loss of disc height destabilizes the spine and narrows neural pathways. Additionally, a herniated or bulging disc occurs when the soft inner material pushes out, placing pressure on nearby nerve roots or the spinal cord.
Acute compression often follows traumatic injury, such as a fall or car accident, causing a vertebral fracture. A vertebral compression fracture occurs when the bony vertebral body collapses. Conditions like osteoporosis, which causes bones to become porous and brittle, significantly increase the risk of such fractures.
Other risk factors include obesity, which places higher mechanical stress on the lower back, and occupational activities involving repetitive heavy lifting or twisting. Systemic diseases, such as cancer that metastasizes to the spine or spinal infections, can also compromise bone structure, leading to compression. People over the age of 50 are at higher risk, particularly for compression caused by degenerative changes.
Recognizing the Physical Symptoms
The physical manifestations of spinal compression vary based on the specific location of the pressure. Localized pain is often felt as stiffness or discomfort at the point of compression in the neck, mid-back, or lower back. This pain may worsen with movements like standing or walking, and may improve when sitting or lying down.
When nerve roots are compressed, the patient experiences radicular pain, a sharp, burning sensation that radiates along the path of the affected nerve. For example, lumbar compression can cause sciatica, pain that travels down the leg. Cervical compression may cause radiating pain, numbness, or tingling down one or both arms.
Sensory changes are common, including numbness or a “pins and needles” feeling in the extremities. If compression is severe or involves the spinal cord, muscle weakness can develop, sometimes causing foot drop, which makes lifting the front part of the foot difficult. The most serious symptom involves the cauda equina nerves in the lower spine, resulting in sudden, severe weakness and loss of bladder or bowel control.
Diagnosis and Treatment Approaches
The medical pathway for diagnosing spinal compression begins with a thorough physical examination. The physician assesses reflexes, muscle strength, and sensation patterns to pinpoint the nerve levels affected and determine if the compression involves a nerve root or the spinal cord.
Diagnostic imaging visualizes the spine and neural structures. X-rays reveal bone alignment issues, decreased disc space, and bone spurs. Magnetic Resonance Imaging (MRI) is often the preferred test, providing a detailed view of soft tissues, including the spinal cord, nerve roots, and intervertebral discs. Computed Tomography (CT) scans are used to examine bony structures.
Treatment begins with conservative, non-surgical methods, unless the compression is severe or an acute medical emergency. Nonsteroidal anti-inflammatory drugs (NSAIDs) manage pain and reduce inflammation around the irritated nerves. Physical therapy focuses on strengthening supporting muscles and improving flexibility and posture to reduce stress on the spine.
If symptoms persist, targeted treatments like epidural steroid injections may deliver anti-inflammatory medication directly to the area of nerve compression. If conservative options fail, or if neurological deficits are severe or worsening, surgery may be considered.
Surgical procedures decompress the neural structures by physically creating more space. A laminectomy involves removing a portion of the bony arch of the vertebra to enlarge the spinal canal. A discectomy removes the portion of a herniated disc pressing on a nerve root. For significant instability or severe fracture, a spinal fusion may be necessary to permanently join two or more vertebrae to stabilize the spine following decompression.