Medical/Neurosurgical Glossary
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Pain Threshold – The point at which a stimulus causes a feeling of pain.  

Paget Disease – A disorder of bone remodeling sometimes associated with breast cancers and causing very weak bones. 

Palliative Treatment – This includes any therapy that relieves symptoms, such as pain, but does not alter the course of the disease.  Its primary purpose is to improve the quality of life.

P.A.L. technique (positive anatomical leg length) – This is a technique for detecting differences in leg length which is commonly used by chiropractors to do "health screenings" in malls and at health fairs.

Palsy – A paralysis of a muscle or group of muscles.

Pancoast Syndrome – An injury to the nerves to the arm caused by a tumor at the top of the lung.  The top of the lung is next to the nerves and the nerves may be the first tissue damaged by a cancer in this area. 

Panel QME - a medical legal examination by a physician selected by the California WCAB computers.

Paraneoplastic Syndrome – The effects of cancer such as loss of appetite, weakness and fatigue. 

Paraparesis – The incomplete loss of the use of both legs, usually from an injury to the thoracic or lumbar spine.  This implies some residual function, usually some remaining strength or sensation.  It differs from paraplegia where the loss is complete. 

Paraplegia – The complete loss of the use of both legs, usually from an injury to the thoracic or lumbar spine.

Parinaud Syndrome – A loss of upgaze and other problems related to increased pressure inside the skull from trauma or tumor.

Parkinson’s disease – This is a disease where the cells in the back of the brain (the substantia nigra) deteriorate.  The loss of these cells causes a tremor and poor movement.  This can be treated with medications or surgery.

Pars Interarticularis – This is a Latin phrase that means a part between two joints.  In the lumbar spine it is part of the lamina of the back of the vertebral bone and it is commonly broken.  A broken pars interarticularis is called a spondylolysis.  If painful, a fusion may be needed to fix this.

Parsonage-Turner Syndrome – This is a painful weakness of the muscles of the arm.  This is a rare disease that is diagnosed frequently and incorrectly.

Pathology – The study of diseases, or how injury and illnesses affect the human body.

Patellar Tendonitis – An inflammatory condition of the patellar ligament, usually due to overuse. 

Pathologist – A physician who diagnoses diseases by studying cells and tissues under a microscope.

Pedicle – Part of the vertebral bone that extends from the front to the back of each of vertebra. There is one pedicle one each side of a vertebra (right and left). Surgeons frequently place screws in these parts to repair the spine.

Pedicle Screw – This is a special type of screw that is used in spinal surgery to solidly hold a vertebral bone. Screws are used in combination with rods when repairing the spine.

Pelvic deficiency (P.D.) – A condition described by proponents of activator methods define as an "apparent" difference in leg-length which is not an anatomical difference. It is also called "functional short leg." To determine where the alleged problem is located, the practitioner holds the patient's feet in various ways while the patient lies face-down on an examining table

Pelvic Obliquity – This means a tilting of the pelvis so that it is no longer horizontal.

Pelvis – The large bone between the legs and the lower spine which includes the ilium, pubis, and ischium. The hip joints are part of the pelvis.  The lumbosacral junction refers to the connection between L5 (last lumbar vertebra), the sacrum, and the rest of the pelvis.

Penalties - monetary fines imposed when a party violates the law; applies only to the California state system.

Periodic Report - a report submitted to the insurance company by the doctor after some visits; required by law; describes the current complaints, examination findings, treatment advice, etc.; applies only to the California state system.

Periosteum – A fibrous membrane that covers the surface of bone.

Personal Injury – This is a type of tort or law suit where one seeks to recover money for medical costs, pain and suffering caused by another person. 

Permanent and Stationary (P&S) - a point in time when problems related to an injury are relatively stable and most treatment has been completed; the time when temporary disability payments stop and permanent disability payments start; the time when the disability rating can be assessed; applies only to the California state system.

Permanent Disability (PD) - a numeric percentage rating (from 1% to 100%) that reflects an injured worker's loss of ability to compete in the labor market; the percent of jobs he/she can no longer do; applies only to the California state system.

Perthes Disease (or Legg Perthes disease) – Damage to the top of the femur bone in young men. 

Pettibone Method – An upper cervical chiropractic adjustive technique that utilizes an instrument to adjust the atlas. Orthogonal lines are used to measure the full spine.

Phalen's Test – A test for carpal tunnel syndrome in which the wrists are flexed for one minute.

Photophobia – A painful sensitivity to light.

Physician - under California workers' compensation law this includes medical doctors, osteopaths, chiropractors, and acupuncturists are considered physicians.  Other practitioners are not.

Physiatrist – The physician who specializes in physical medicine and rehabilitation.

Physical Therapy – A collection of treatments consisting of exercising specific parts of the body such as the legs, arms, hands or neck, in an effort to strengthen muscles, improve range of motion, re-teach coordination, and generally to rehabilitate the musculoskeletal system.

Physiology – The science which studies the functioning of living organisms and their component systems or parts.

Pick Disease – This is a progressive degeneration of the frontal lobes which results in behavioral and other problems.

Pickwickian Syndrome – This type of difficulty breathing and heart insufficiency is related to extreme obesity and was discussed in the famous book by Charles Dickens, The Pickwick Papers.

Pierce-Stillwagon Method – A chiropractic technique similar to Sacro-Occipital Technique which involves contacts and other maneuvers applied to cervical and pelvic areas to produce effects in remote muscles, organs, and joints. A full-spine x-ray examination is considered essential for pelvic analysis. This uses a heat-detecting instrument (Derma Therm-O-Graph) to monitor subluxation correction.

Pinched Nerve – This is a common term used to describe nerve irritation and pain, numbness, or weakness.  The nerve is usually compressed by a disc herniation, spinal stenosis, or foraminal stenosis.

Piriformis Muscle Syndrome – A pinching of the sciatic nerve caused by a hypertrophied pyriformis muscle deep within the buttocks, this causes leg pain.

Pituitary Gland – A gland at the base of the brain that secretes hormones which then regulate and controls other hormone-secreting glands and many bodily processes.

Plaintiff – An injured person with a legal case under the personal injury system, or one who complains, is a plaintiff.

Plantar -  The bottom surface of the foot, the surface on which we walk.

Plantarflexion - To bend the ankle downward, to move the foot toward the downward surface.

Plasma - The watery, straw-colored fluid makes up the majority of the volume of the blood.  The plasma carries the cellular elements of the blood through circulation.

Platelets – Small fragments of cells found in the blood.  These are “little plates” and cause blood to clot.

Plumb Line – This is a straight line formed by a string attached to a hanging weight.  It establishes a vertical line which is straight up and down.  In medicine, one uses a plumb line to make sure that the spine is straight. If the spine is not straight, it is called an “offset from the plumb line.”

Point-of-Service Plans – Point-of-service (POS) insurance plans are managed care plans similar to both HMO’s and PPO’s.  They offer more choice but typically cost more to purchase.  They reward members for using less care and saving the insurance company money.

Pons – A portion of the brainstem between the midbrain and the medulla, this connects the brain to the cerebellum.

Positron Emission Tomography (PET) – A nuclear scanning procedure that gives three-dimensional views of various organs and can identify some cancers long before other conventional imaging techniques.

Post-Concussion Syndrome – The late effects of a severe head injury can include pain as well as difficulty concentrating and thinking clearly.

Posterior – Located behind a structure, or referring to an area behind another, such as the back side of the human body.

Posterior Longitudinal Ligament – A tough fibrous band that runs along the backs of the vertebral bones and helps keep the spinal bones aligned.

Posterior Spinal Artery Syndrome – This is like a stroke of the back of the spinal cord.  The back of the cord loses its blood supply and the posterior columns stop working.  This causes balance problems.

Post-irradiation Syndrome – Late damage caused by radiation therapy or from exposure to an atomic weapon.  This includes problems absorbing food and replacing damaged tissues.

Post-lumbar Puncture Syndrome – Headaches following a spinal tap, and sometimes back pain, are both common.  The important thin to remember is that most lumbar punctures are uneventful and cause no problems.

Post-traumatic Syndrome – The late effects of a near fatal injury.

Pott Disease – Also known as David disease, this is from damage to a vertebral bone from tuberculosis.

Predisposition – A tendency to develop a certain disease.

Prednisone – One type of corticosteroid medication, usually used for inflammation.

Preexisting Conditions – This is an insurance term which refers to an old medical problem that was present before the insurance became effective.  Typically an insurance company will not pay for costs related to a preexisting condition.

Preferred Provider Organizations -- Preferred provider organizations (PPO’s) are managed health care insurance programs where patients have a limited amount of choice.  They are better and more expensive than HMO’s but are not as expensive or as good as indemnity plans.

Premium – This is the money that the insurance company charges a patient or their employer to provide coverage for a loss.  This is usually a monthly fee.  The fee is larger for better insurance like indemnity insurance and is lower for lesser coverage like an HMO.

PR-2 - a form completed by a doctor after each visit; describes the current complaints, examination findings, treatment advice, etc. (click here for the form)

PR-3 - a form completed by a doctor after a patient is "permanent and stationary;" describes the "subjectives," "objectives," "loss of capacity," and other disability issues (click here for the form).

Prevalence – A statistic that equals the total number of people in a population with a certain disease at a given time.

Primary Treating Physician (PTP) - the one doctor, usually selected by the injured worker, who is primarily responsible for giving care and reporting to the insurance company; applies only to the California state system.

Prognosis – A prediction of the course of the disease.

Prominence – A high spot or raised area.  A space that is more visible or “prominent.”

Prosthesis – An artificial body part such as an artificial leg or arm. The term prosthesis is also used to describe some of the implants used in the body, such as a hip or knee replacements.

Pronate – To turn the palms down or the feet inward.  This is the opposite of supinate.

Proximal – The part nearest the center of the body.  It is the opposite of distal.

Pseudoarthrosis – Literally this means a false joint.  It is another term that describes what happens when a bone does not fuse properly following some spinal surgeries.  It is also called a "non-union," or failure to fuse, and can be painful.  It sometimes requires revision surgery in order to make a solid fusion.

Pyriformis Syndrome – This is a painful condition caused by damage to the sciatic nerve as it passes under or through the pyriformis muscle, a small triangular muscle in the buttocks.  It cause sciatica or leg pain.

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