Dermatome: A localized area of skin that is has its sensation supplied by a single nerve from a single nerve root of the spinal cord. The dermatomes are named according to the spinal nerve which supplies them. The dermatomes form into bands around the trunk but in the limbs their organization is more complex. http://www.apparelyzed.com/dermatome.html

DEXA: Dual-energy x-ray absorptiometry. See definition for Bone density. http://www.idifwb.com/services/exam%20descriptions/bonedensity.htm

Disability: Alteration of an individual’s capacity to meet personal, social, or occupational demands or statutory or regulatory requirements because of impairment. Disability is a relational outcome, contingent on the environmental conditions in which activities are performed.

Discectomy: A surgical procedure in which a portion of an intervertebral disc, which is causing pain by stressing the spinal cord or radiating nerves, is removed. Advances in options have produced effective alternatives to traditional discectomy procedures, i.e. microdiscectomy. A laminectomy is often involved to permit access to the intervertebral disc in a traditional discectomy.

Disk: A fibrocartilage (cushion/pad) that separates spinal vertebra absorbs shock to the spine, and helps protect the nervous system. The disc is composed of two distinct layers called the annulus fibrosus on the outside and the nucleus pulposus on the inside.

Disc Desiccation: Drying, thinning of the disc as a result of accelerated wear and tear.

Diskitis: Term describing an inflammation, irritation, and swelling of the intervertebral disk space (the space between the bones of the spine). Diskitis is an uncommon condition, which is usually seen in children younger than age 10, and can be caused by a bacterial or viral infection or other inflammatory processes, such as auto-immune diseases (conditions in which the immune system mistakenly attacks certain cells in the body), or immunodeficiencies.

Dizziness: A sensation of unsteadiness accompanied by a feeling of movement in the individual.