Glossary

Exposure of the body to elevated levels of oxygen.  If prolonged and severe this can be toxic to the brain, lungs, and other organs.  Conseuqntly, it is prolonged hyperoxia is generally avoided.

The state of overactive or exaggerated body reflexes.  Hyperactive reflexes.

An abnormal growth of hair. It can occur anywhere in the body but when it occurs over the spine it can be a sign of an underlying abnormality effecting the spine and spinal cord. In such a situation an medical evaluation is indicated.

Internal carotid artery

Indocyanine green.  A dye injected into the veins which can be seen to fluoresce.  The dye has a half-life of 3-4 minutes and is rapidly cleared by the liver.  It is used to visualize blood circulation within the brain.

Intracranial Hemorrhage.  Bleeding within the skull (in spaces surrounding the brain and within the brain itself).

Intracranial pressure. This refers to the pressure within the skull that is due to its fluids and tissue contents.  This pressure can be thought of as a head-wall against which the blood must flow to perfuse the brain and other contents within the skull.

International Commission on Radiology Units and Measurements – established in 1925 by the International Congress of Radiology to recommend the measurement of quantities of ionizing radiation and how it reacts with matter (in particular biologic matter).

Image-guide radiation therapy.  This refers to using CT or MRI imaging to define the dimensions of the volume of tissue being treated by radiation.  The three dimensional volume of the targeted area of radiation are defined on the images then related to the space in the patient that contains the target for radiation precisely.  Once so defined the coordinates for the target as defined on the images is used to guide the delivery of radiation to the precisely related volume of the target within the patient.

The normal immune system cells have proteins on their surfaces that serve as “off switches” or checkpoints that serve to prevent immune cells from attacking normally functioning cells of the body. Cancer cells have the ability to activate these switches, preventing immune cells attacking them.  Checkpoint inhibitors can block these switches allowing the immune cells to attack tumor cells.