Medical/Neurosurgical Glossary
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H-wave Stimulator – An electronic device called an interferential stimulator.  There are several different devices by a number of manufacturers.  These are used to treat pain.

Hansen Disease – Leprosy, an infection of the nervous system with dysfunction of the nerves.

Harris Syndrome (Functional Hypoglycemia Syndrome) – This is the low blood sugar due to excessive insulin, as in the presence of an insulin secreting tumor.

Hartley-Krause Operation – Removal of the gasserian ganglion using a particular approach for facial pain.

Health Maintenance Organization (HMO) – This is a type of insurance which is inexpensive but which limits medical care choices. 

Headache, Primary – These include tension (muscular contraction), vascular (migraine), and cluster headaches. They are not caused by other underlying medical conditions. 

Headache, Secondary – These include all of the headaches that result from other medical conditions.

Heel Reflex of Weingrow – The same as the Guillain-Barrι Sign, plantar flexion and fanning of the toes when the heel is tapped, similar in meaning to Babinski sign.

Hemiparesis – An incomplete weakness of one half of the body, the left or the right side (not the top or bottom), as differentiated from hemiplegia which is complete.

Hemiplegia – Complete loss of strength on one half of the body, similar to hemiparesis but complete.

Hemorrhage – The medical term for bleeding.

Hering-Breuer Reflex – Stretch receptors in the lung keep one breathing and prevent overdistention of the lung.

Herniated Disc – Extrusion of part of the nucleus pulposus material through a defect in the annulus fibrosus.

Hersh Syndrome – A hearing loss associated with a flat nose and other birth defects.

Heterotopic – Indicates a tissue which is growing in the wrong place.  From the Greek roots "hetero-" for "other" and "topos" meaning "place.”

Heterotopic Bone Formation – Bone growth in an abnormal location.

Hibbs Operation – Surgery for tuberculosis of the spine.

Hippel Syndrome, Hippel-Lindau Syndrome, Hippel-Czermak Syndrome – One of the phakomatoses, also von Hippel Lindau syndrome, skin markings associated with vascular malformations.

Hirschfeld Disease – This is an acute, sudden diabetes melitis or high blood sugar.

Hodgkin Disease, Hodgkin-Paltauf-Sternberg Disease – A type of cancer which affects the white blood cells, or lymphatic cells, and is therefore called a lymphoma.  It is malignant but is now, in most cases treatable.

Hoffman-Tinel Sign – A tingling sensation in the distribution of a damaged nerve which occurs when the nerve is lightly tapped.  Normal nerves do not respond to light touch in this way.

Hoffmann Sign – This is a test for spinal cord damage in the arms.  Flicking the index finger will cause the hand to contract forcefully.  It is similar to the Babinski sign in the feet.

Hoffmann Syndrome – The muscular abnormalities seen in severe thyroid disease.

Hole-in-One (H.I.O.) – This is a chiropractic method of adjusting the atlas (the topmost vertebra at the base of the skull). Proponents claim that this will improve health and facilitate correction of subluxations elsewhere in the spine.

Holiday Heart Syndrome – Heart irregularities in an otherwise normal person who engages in holiday binge drinking, this can include irregular heart beats.

Homans Sign – Tenderness of the calf is elicited in patients with deep vein thrombosis or blood clots in the legs which can occur after immobility.  To prevent blood clots after surgery, most hospitals use automatic pumps that squeeze the calves at regular intervals.   

Homeopathic Medicine – The name is derived from the Greek word "homios" (which means "like") and the word "pathos" (meaning "suffering").  The central philosophy of homeopathy is that some poisonous substances can be beneficial if taken in very small doses.

Hook – A metal part attached to a rod and used to fuse the spine.  It is shaped like a fish hook.

Hoover Sign – A test for the hysterical paralysis of one leg. If the opposite leg is raised the patient with an hysterical paralysis will push down with the leg that otherwise does not seem to work.

Horsley Operation – A kidney operation named for a famous early neurosurgeon that also did the first successful spinal laminectomy for a tumor

Hounsfield Unit – This refers to the name of the density of scale used on CT images.  This is named after one of the inventors of the CT machine.

House Brackman Scale – A grading system for facial nerve weakness.

House Officer – This is the name of a doctor in training such as a resident or intern.  This name was originally used since early interns and residents were never allowed to leave the hospital and were therefore always “in house.”

Huntington Chorea, Huntington Disease – A birth defect that does not present until later in life but involves the progressive loss of motor control.  This is usually fatal.

Hutchinson Pupil – This is a dilated or large pupil due to damage to the third cranial nerve.

Hydrocortisone – A hormone secreted by the adrenal cortex which affects metabolism and which naturally decreases inflammation.

Hydroxyapatite (HA) – A type of rock composed of the same minerals and made of the same types of crystals as human bone.

Hyper – This is Latin prefix that is used frequently before many other terms.  It means ”excessive” or “too much.”

Hyperabduction Syndrome – Similar to the thoracic outlet syndrome, this is due to the compression of the brachial plexus and results in poor arm function.

Hyperactive Child Syndrome – This is the same as attention deficit disorder.  It may be that the short attention span causes the extra activity, or that the extra activity interferes with the attention span, but in either case, learning is impaired.

Hyperextension – Too much bending backward or too much extension (to the point of injury) is called hyperextension.

Hyperflexion – Too much bending forward or too much flexion (to the point of injury) is called hyperflexion.

Hyperplastic – The increase in the size of a structure from its expected normal size.

Hypersomnia – This is a problem which is characterized by too much sleeping.

Hypersomnia Sleep Apnea Syndrome – This is associated with too much sleep and a number of cardiac disorders.  It is associated with inadequate respiration while asleep and can cause stroke or heart attack.

Hyperthyroidism – A hormonal condition due to too much thyroid hormone.  It is characterized by a rapid heart beat and swelling behind the eyes.

Hyperventilation Syndrome – Too much breathing, or fast shallow breaths which may be related to anxiety, can cause metabolic abnormalities and occasionally loss of consciousness.

Hypo – A Latin word used as a prefix and meaning “too little.”

Hypochondroplasia Syndrome – A birth defect characterized by short limbs and a normal sized trunk, this relates to malformed cartilaginous end plates on the long bones.

Hypoplastic – The decrease in the size of a structure from its expected normal size.

Hypoplastic Left Heart – An abnormally small left heart, usually found with other malformations.

Hypothyroidism – A hormonal condition due to a lack of thyroid hormone.  It is characterized by edema, lack of energy, slowness of thought and decreased metabolism.

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.

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Last modified: 07/27/08