Sandbox spinalcord

Causes

Common causes of acute spinal cord compression include trauma, tumor, epidural abscess, and epidural hematoma.

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.

Acute SCC can result from trauma, disk herniation, bony fracture, spinal subluxation, or penetrating injuries (e.g., gunshot wounds, knife wounds, iatrogenic causes). Chronic SCC results from degenerative bony reaction, slow tumor growth, or infection in the spaces around the thecal sac. Both acute and chronic presentations will reach a common endpoint, when the cord or nerve roots can no longer function correctly.

Injury to the spinal cord or nerve roots arises from stretching or from pressure. This results in injury to the white matter (myelinated tracts) and the gray matter (cell bodies) in the cord with loss of all or some of the sensory modalities (pinprick, joint position sense, vibration, hot/cold, pressure) and motor function.

The spinal cord and nerve roots depend on a constant blood supply for appropriate energy stores and substrate, to perform axonal signaling. Conditions that interfere, either directly or indirectly, with the blood supply will cause malfunction of the transmission pathway. Nerve tracts most vulnerable to mechanical pressure include the corticospinal and spinocerebellar tracts, and the posterior spinal columns.