Medical/Neurosurgical Glossary
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Lambert Syndrome (Eaton-Lambert Syndrome) – This is a proximal weakness, especially in the pelvic girdle muscles.  This is similar to myasthenia gravis.

Lampert Syndrome – Craniosynostosis of one particular type, that is the premature fusion of one of the joints or sutures of the skull

Lamina – The posterior portion of a vertebral bone. It is a flat piece of bone that covers and protects the dura, the nerves and the spinal cord.

Laminectomy – An operation to remove a part, or all of, the lamina of a vertebral bone.  It is performed in order to be able to remove part of an intervertebral disc protrusion or to decompress a pinched nerve root.

Lasθgue Sign, Lasθgue Test – A straight leg raising test performed with the patient lying on the back, which causes leg pain, is indicative of a ruptured disc.

LASER – An acronym for “Light Amplified by Stimulated Emission of Radiation.” The device produces a focused beam of light of a defined wavelength.  Laser light can vaporize tissue and be used to resect small structures without damaging delicate surrounding tissue.

Lateral – Situated away from the midline of the body.

Lateral Cerebellar Syndrome – Damage to the outside portion of this back part of the brain causes poor coordination in the limbs. 

Lateral/Peroneal Compartment Syndrome – This is the combination of pain and weakness of the deep peroneal nerve due to pressure.

Lateral Recess – This refers to the edges of the spinal canal. This lateral recess can become too small for the nerves.  A decompression is sometime needed to give the nerves extra room and “un-pinch” them. 

Lavage – The process of washing (cleaning) of an organ such as the bowel or stomach.

Laxatives – Also called cathartics, these medications relieve constipation.

LC §4600 - The section of California law section that applies to the rights of injured workers.

Leander's Method – This is a chiropractic method that utilizes a motorized table for loosening or mobilizing the spine with flexion-distraction-type stretching before a spinal adjustment.

Leber Disease – Hereditary optic atrophy, a kind of blindness, this is a rare disease.

Legg Disease, Legg-Calvι-Perthes Disease – Damage to the top of the femur bone in the leg resulting in a deformity, this problem is most common in young boys. 

Leg-Length Testing – A chiropractic method used to detect alleged subluxations. It is used as part of Activator Methods, Logan basic, Bio Energetic Synchronization Technique, Thompson terminal point technique, and Sacro-occipital technique.

Lennox Syndrome, Lennox-Gastaut Syndrome – A particularly difficult type of seizure disorder which responds to very few medications, this fortunately is rare.

Lesch-Nyhan Syndrome – This is a rare disease where mental retardation and self mutilation are common.

Levator Sign – A peripheral facial nerve palsy where the levator muscle of the eyelid works but the larger orbicularis muscle, which ordinarily closes the eye, does not.

Levator Syndrome – This is an intermittent pain in the region of the coccyx (tailbone) due to weakness of the muscles at the bottom of the pelvis which are called levators.

Levine Sign – This is the characteristic clutching of the chest which is almost a reflex in patients experiencing angina or heart attack pain.

Leyden-Mφbius Syndrome – A type of muscular dystrophy, also called limb girdle muscular dystrophy, involves the limbs and the attachments of the limbs, this is relatively common.

Lhermitte Sign – This is a sudden painful lightning-like shock due to a pinching of the spinal cord and is a sign of a possible quadriplegia producing problem.

Lifetime Policy Limit – Some health insurance companies limit or cut benefits in serious cases.  A lifetime limit of $500,000 to $1,000,000 is not uncommon.  Once the limit is passed, no more treatment is covered by the insurance plan.  Any expenses are the responsibility of the patient.

Liability - responsibility to pay for an injury.

Ligament – A band of flexible, fibrous connective tissue that is attached both bones at around a joint or from one vertebra to another. The main function of a ligament is to attach bones to one another, to provide stability of a joint, and to prevent or limit motion.

Ligamentum Flavum – Latin for “yellow ligament.”  This ligament is between the lamina bones.  It provides strength and protects the spine and roots.

Listing – abbreviated description of the position or movement of a "subluxated" vertebra. Many techniques have their own listing system, which can make it difficult for chiropractors to communicate with each other.

Litigation - a law suit.

Load Sharing – This describes a spine implant which provides partially supports the bones.  It allows some movement.  Some doctors believe that load sharing bone plates are encourage a more normal healing while others argue that these slow recovery.

Locked-In Syndrome – This is a damage to the brainstem that does not interfere with consciousness but does not allow the victim to move or even communicate except by blinking.

Locked Spinal Joint – This is a chiropractic term for a sudden binding of a joint that occurs when two joint surfaces are shifted out of their normal alignment. The result may also be called an "acute locked back." 

Logan Method -- A non-thrusting chiropractic method in which thumb pressure is used to correct alleged sacral subluxations and leg deficiency claimed to affect the entire spine.

Long-Lever Manipulation – A chiropractic method of spinal manipulation in which a general technique is used to stretch or loosen several vertebrae at a time.

Long Term Disability (LTD) - a private disability insurance policy that pays when people are unable to work for a "long" period (usually more than three to six months).

Loose Body – The name given to an object, located within a joint, which has become detached.

Lordosis – A backward bending of the spine.  This is normal in the low back and in the neck.  The convexity faces the front of the body and the back is concave or hollowed out slightly.

Loss of capacity - decreased ability to perform work tasks, one component of the disability rating.

Lou Gehrig Disease – Amyotrophic lateral sclerosis, a progressive and disabling weakness suffered by the ball player Lou Gehrig and also by the physicist Hawking.

Louis-Bar Syndrome – A progressive ataxia or a loss of coordination beginning in infancy.

Low-Force Technique – The use of an adjusting machine and/or reflex technique said to be an alternative to forceful manipulation ("dynamic thrust").

Lower Back – Also called lumbar spine.  This is a complex structure that connects the upper body to the lower body.  It consists of vertebrae, disks, spinal cord, and nerves.

Lumbago – An old term for low back pain.  This is different from (but often used with) the old term “sciatica,” which refers to leg pain only.

Lumbar – The lower part of the spine. It is the low back.  It is between the thoracic spine and the sacrum. The lumbar spine usually consists of five vertebrae but occasionally may have either four or six levels.

Lumbar Vertebrae – Any of the five bones in the lower portion of the spine.

Lumbar Endoscopic Discectomy (LED) – LED is a controversial operation to remove herniated disc material from the spine. Many doctors feel that the procedure is unsafe, and not as good as, the standard microdiscectomy.

Lumbo-Pelvic Techniques – These are chiropractic techniques used to adjust any "manipulative lesion" in the joints of the lumbar spine and pelvis. Lumbo-pelvic "distortions" are attributed to postural alterations, leg-length inequality, tilting of the lumbar vertebrae, loss of mobility, and other "lesions" that require manipulation over the pelvis and lower back. Leg-length testing is often used to detect lumbo-pelvic distortions.

Lumbosacral Strain – A strain or injury of joints or ligaments at the base of the spine where the last

Lumen – The opening of a tube, such as the hole in a blood vessel.

Luschka Foramen – A hole deep in the brain where cerebral-spinal fluid (CSF) can circulate.

Lust Phenomenon, Lust Sign – An abnormality of the peroneal nerve where percussion of the nerve causes tetanus (a forced contraction).

Lyme Disease – A tick-borne bacterial infection where there are neurological and systemic symptoms of pain, weakness and lethargy.

Lymphatic System – This includes all of the tissues and organs, including bone marrow, spleen, thymus, and lymph nodes that produce, store, and carry white blood cells to fight infection and disease.  

Lymphocyte – Any one of a group of white blood cells of crucial importance to the adaptive part of the body's immune system.


If you are aware of any useful spine and neuromusculoskeletal terms which are not included in this list, or if you have suggestions for better definitions,  your help would be greatly appreciated.  Please send me any upgrades and I will update the web site appropriately.  Click here to send a comment.






The information in this site briefly describes issues related to medical treatments, and has been licensed by from Northern California Neurosurgery Medical Group, Inc., who is solely responsible for said content.  This web site is not a substitute for good medical care or for a consultation with a spine specialist. It should not be used to plan your treatment. The well considered advice of a specialist who has personally examined you is always superior to even the best internet pages.


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Last modified: 07/27/08