A procedure in which cerebrospinal fluid is removed from the spinal canal for diagnostic testing or treatment. Abbreviated LP. The patient usually lies sideways for the procedure, although LPs in infants are often done upright. After local anesthesia is injected into the small of the back (the lumbar area), a needle is inserted between two vertebrae and into the spinal canal. Spinal fluid pressure can then be measured, and cerebrospinal fluid can be removed for testing. LP is particularly helpful in the diagnosis of inflammatory diseases of the central nervous system (CNS), especially meningitis and other infections. It can also provide clues to the diagnosis of stroke, spinal cord tumor, and cancer in the CNS. An LP can also be done for therapeutic purposes, as a way of administering antibiotics, cancer drugs, or anesthetic agents into the spinal canal. Spinal fluid is sometimes removed via LP to decrease spinal fluid pressure in patients with conditions such as normal-pressure hydrocephalus or benign intracranial hypertension. Risks related to LP include headache, brain herniation, bleeding, and infection. These complications are uncommon, with the exception of headache, which can appear up to a day after LP. Headaches are less likely to occur if the patient remains lying flat for 1 to 3 hours after the procedure. Also known as spinal tap, spinal puncture, thecal puncture, and rachiocentesis.
- Lumbar radiculopathy
Nerve irritation caused by damage to the discs between the vertebrae. Damage to the disc occurs because of degeneration (“wear and tear”) of the outer ring of the disc, traumatic injury, or both. As a result, the central softer portion of the disc can rupture (herniate) through the outer ring of the disc and abut […]
- Lumbar spinal stenosis
A condition whereby either the spinal canal (central stenosis) or vertebral foramen (foraminal stenosis) becomes narrowed, leading to compression of the spinal nerves. Symptoms are pain in the lower back and weakness, numbness, pain, and loss of sensation in the legs. The most common cause of lumbar spinal stenosis is degenerative arthritis (osteoarthritis), but other […]
- Lumbar strain
A stretching injury to the ligaments, tendons, and/or muscles of the low back. The stretching incident results in microscopic tears of varying degrees in these tissues. Lumbar strain is one of the most common causes of low back pain. The injury can occur because of overuse, improper use, or trauma. It is classified as “acute” […]
- Lumbar vertebrae
The five vertebrae situated between the thoracic vertebrae and the sacral vertebrae in the spinal column. The lumbar vertebrae are represented by the symbols L1 through L5.
A luminous term referring to the channel within a tube such as a blood vessel or to the cavity within a hollow organ such as the intestine. Lumen is a luminous term because it is Latin for light, including the light that comes through a window. When a hollow organ is cut across, you can […]