(hĕr′nē-āt″ĕd) Enclosed in or protruding like a hernia.
(hĕr-nē-ā′shŭn) The displacement of body tissue through an opening or defect.
cerebral h. Downward displacement of the brain (usually as a result of cerebral edema, hematoma, or tumor) into the brainstem. The resulting injury to brainstem functions rapidly leads to coma, nerve palsies, and death if treatment is ineffective.
h. of nucleus pulposus Prolapse of the nucleus pulposus of a ruptured intervertebral disk into the spinal canal. This often results in pressure on a spinal nerve, which causes lower back pain that may radiate down the leg, a condition known as sciatica. SEE: illus. SEE: Nursing Diagnoses Appendix.
PATIENT CARE: A history is obtained of any unilateral low back pain that radiates to the buttocks, legs, and feet. Almost all herniations occur in the lumbar and lumbosacral region; 8% in the cervical region and only 1% to 2% in the thoracic region. When herniation follows trauma, the patient may report sudden pain, subsiding in a few days, then a dull, aching sciatic pain in the buttocks that increases with Valsalva’s maneuver, coughing, sneezing, or bending. The patient may also complain of muscle spasms accompanied by pain that subsides with rest. The health care professional inspects for a limited ability to bend forward, a posture favoring the affected side, and decreased deep tendon reflexes in the lower extremity. In some patients, muscle weakness and atrophy may be observed. Palpation may disclose tenderness over the affected region. Tissue tension assessment may reveal radicular pain from straight leg raising (with lumbar herniation) and increased pain from neck movement (with cervical herniation). Thorough assessment of the patient’s peripheral vascular status, including posterior tibial and dorsalis pedis pulses and skin temperature of the arms and legs, may help to rule out ischemic disease as the cause of leg numbness or pain.
The patient is prepared for diagnostic testing by explaining all procedures and expected sensations. Tests may include radiographic studies of the spine (to show degenerative changes and rule out other abnormalities), myelography (to pinpoint the level of herniation), computed tomography scanning (to detect bone and soft tissue abnormalities and possibly show spinal compression resulting from the herniation), magnetic resonance imaging (to define tissues in areas otherwise obscured by bone), electromyography (to confirm nerve involvement by measuring the electrical activity of muscles innervated by the affected nerves), and neuromuscular testing (to detect sensory and motor loss as well as leg muscle weakness).
Pain and its management are often crucial elements of care; levels of pain are monitored, prescribed analgesics are administered, the patient is taught about noninvasive pain relief measures (such as relaxation, transcutaneous nerve stimulation, distraction, heat or ice application, traction, ...