Glossary

A line drawn from the midline, dorsal surface of the anterior Foramen Magnum to the ventral (anterior) tip of the dens.  If the length of this lines exceeds 12 mm then an occipitalcervical dissociation is suggested.

Hemoglobin S/Beta Zero Thalassemia.  A condition similar to Sickle Cell Disease where one abnormal hemoglobin S gene and one abnormal hemoglobin beta thalassemia gene are inherited resulting in the disease.  This condition is less severe than Sickle Cell Disease.

Hemoglobin SS Disease or Sickle Cell Disease. A genetic blood disorder where two copies of the abnormal hemoglobin S gene are inherited, resulting in the production of abnormal hemoglobin molecules that can form rigid, sickle-shaped red blood cells.

Human chorionic gonadotrophin – a hormone normally produced by the placenta in a pregnant woman. It is also produced by embryonal tumors and a finding of elevated blood or CSF levels of this tumor may be indicative of the existence of such a tumor.

The national regulatory agency of Canada that is tasked with monitoring the safety of its health devices, pharmaceuticals, other health products, food, biologics, toxins and consumer goods.

High grade glioma

hypothalamic harmatomas – a non-neoplastic mass that consists of a disorganized accumulation of neurons and their supporting glial cells occurring within the hypothalamus.

Hereditary Hemorrhagic Telangectasia – also known as Osler-Weber-Rendu Disease or Syndrome. This is an autosomal dominant disorder characterized by abnormal blood vessel formation in the skin, mucosa membranes in addition to other organs such as the liver, lungs and brain.

This is an area in a hospital, usually located closely to the intensive care unit, where care that is intermediate between that delivered in an intensive care unit and that delivered on a normal patient care ward.

Human immunodeficiency virus – a slowly replicating retrovirus that attacks the human immune system causing destruction of its T-lymphoytes and macrophages. This is the caustive factor for acquired immunodeficiency syndrome (AIDS), a condition where there is a progressive failure of the host’s immune system.