Spinal cord lies within protective covering of vertebral column.
Begins just below foramen magnum of the skull.
Ends opposite 2nd lumbar vertebra.
Below L2 continue as a leash of nerve roots known as cauda equina.
Prolongation of the pia matter forms filum terminale.
Spinal cord structure
The spinal cord consists of central core of grey matter containing nerve cell bodies, and outer layer of white matter of nerve fibers.
Within the grey matter, the dorsal horn contains sensory neurons, the ventral horn contains motor neurons and the lateral horn contains preganglionic sympathetic neurons.
Within the white matter run ascending and descending nerve fiber tracts, which link the spinal cord to the brain.
The principle ascending tracts are the spinothalamic tracts, spinocerebellar tracts and dorsal columns. The coticospinal tracts is an important descending tract.
The spinal cord receives information from, and controls the trunk and limbs.
This is achieved through 31 pairs of spinal nerves which join the cord at intervals along its length and contain afferent and efferent nerve fibers connecting with the structures at the periphery.
Causes of spinal cord lesions
congenital; spinal stenosis.
Infection; TB ,abscess.
Trauma; vertebral body fracture or facet joint dislocation.
Inflammatory; Rheumatoid arthritis.
Disc and vertebral lesion.
Vascular; epidural and subdural hemorrhage.
Congenital spinal stenosis
The patient is born with a narrow spinal canal due to abnormally formed parts of the spine.
This condition is most common in patients with a short stature, such as achondroplastic dwarves.
Other causes of spinal stenosis
aging process (most common cause )
bone and joint enlargement
used when conservative treatment failed.
-laminectomy (removing bone behind the spinal cord).
-foramenotomy (removing bone around the spinal nerve).
-discectomy (removing the spinal disc to relieve pressure).
Instability of the spine