The epidural space is part of the spinal anatomy, running down the spine from the area where the vertebrae meet the skull to the very end. It is of medical interest because it is used to introduce certain medications, such as epidurals used for pain management in the lower body. Clinicians must be able to locate the epidural space reliably because there is a risk of damaging delicate tissues when placing a needle in the spine.
This part of the spinal anatomy consists of the area between the dura mater, the tough fibrous tissue that surrounds the spinal cord and cerebrospinal fluid, and the lining of the vertebral canal. In different people, the size of the epidural space can vary. Along the length of the spine, this space also grows and shrinks along with the spinal cord. In areas where the spinal cord is thick, the space may be almost nonexistent because the spinal cord fills most of the spinal canal.
The body has a highly efficient design, and the epidural space is far from empty. It contains fat and blood vessels along with nerve roots that branch out from the spinal cord to innervate various areas of the body. It provides some insulation for the spinal cord, protecting it from injury, and its durability makes it a popular choice for administering medications because it is difficult to provoke inflammation or kill cells in the epidural space.
Medical imaging studies sometimes show the epidural space, depending on what angle is being used for the study and the angle used for the imaging. It is also visible during spinal surgeries that involve opening up the vertebrae to access the spinal cord. In situations where people have collapsed or slipped discs, the spinal cord may not have enough wiggle room and this can lead to pinched nerves and other problems.
Also known as the extradural or peridural space, this part of the spine can be located by care providers with palpation of the spine and careful placement of a needle. Needles specifically designed for use in the epidural space are often used because they are safer and more reliable than other types of needles for injections in this area. Clinicians have to be careful to avoid puncturing the dura mater and introducing the contents of the syringe into the spinal cord itself, a very undesirable situation.