Sandbox spinalcord
Causes
Common causes of acute spinal cord compression include
- Trauma is a leading cause of acute spinal cord compression
- Primary or secondary metastatic spinal tumor
- Vertebral compression fractures due to osteomalacia, osteoporosis, corticosteroid therapy
- Intervertebral disk herniation
- Epidural abscess
- Epidural hematoma
Risk factors
Common risk factors in the development of spinal cord compression include
- Cervical spondylosis
- Atlantoaxial instability
- Congenital conditions (tethered cord)
- Osteoporosis
- Ankylosing spondylitis
- Rheumatoid arthritis of the cervical spine
Less common risk factors
- IV drug abuse
- Immunocompromised
Pathophysiology
Anatomy
- The spinal cord extends from the foramen magnum down to the level of the first and second lumbar vertebrae.
- At L2 level spinal cord transforms into spinal roots and forms a cone-shaped structure called conus medullaris.
- The cord is protected by the vertebral column, which is mobile and allows for movement of the spine.
- It is enclosed by the dura mater and the vessels supplying it.
- The cord floats in the cerebrospinal fluid which acts as a buffer to movement and early degrees of compression.
- The cord substance contains a gray area centrally and is surrounded by white matter communication tracts, both ascending and descending.
Pathophysiology
- The spinal cord and nerve roots depend on a constant blood supply to perform axonal signaling.
- Conditions that interfere, either directly or indirectly, with the blood supply will cause malfunction of the transmission pathway.
- Injury to the spinal cord or nerve roots arises from stretching or from pressure.
- It initiates a cascade of events in the gray matter and white matter, and results in hypoperfusion and eventually hemorrhagic necrosis.
- The extent of necrosis depends on the severity of the trauma, concomitant compression, perfusion pressures and blood flow, and administration of pharmacological agents.
- The tissue responses by gliosis, demyelination, and axonal loss.
- This results in injury to the white matter (myelinated tracts) and the gray matter (cell bodies) in the cord with loss of sensory reflexes (pinprick, joint position sense, vibration, hot/cold, pressure) and motor function.
- Rapid compression will result in the collapse of the venous system, resulting in vasogenic edema.
- Vasogenic edema exacerbates parenchymal pressure and may lead to rapid progression of dysfunction.