Glossary

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I

Iatrogenic:

a disease or disorder that is induced inadvertently by a physician or surgeon or by medical treatment or diagnostic procedures.

A disorder or condition of spontaneous origin; self-originated or of unknown cause. The term is derived from the prefix “idio-” meaning one’s own and “pathos” indicating disease.

Idiopathic:

Idiopathic epilepsy:

Recurrent seizures of unknown origin or cause; repeated episodes of uncontrolled electrical activity in the brain that occur in the absence of detectable brain lesions. Also known as essential or primary epilepsy, these conditions are often thought to have a genetic component. This may suggest that affected individuals have an inherited predisposition for recurrent seizures.

Immunofluorescence:

This technique uses antibodies linked to a light-emitting or fluorescent dye in order to study foreign substances in a tissue sample.

Immunogenicity:

The ability to or the degree to which a particular substance may provoke an immune response; having the properties of an antigen or any substance that may trigger a particular immune reaction, such as the production of antibodies.

Implantable Pulse Generator (IPG):

A device that is placed under the skin near the collarbone as part of a surgical procedure known as deep brain stimulation. Wire leads from electrodes implanted in the brain are connected to the pulse generator, which then delivers continuous high frequency electrical stimulation to the thalamus via the implanted electrodes. This form of stimulation probably “jams” the nucleus and therefore modifies the message in the movement control centers of the brain, serving to suppress tremor.

Inhibition:

The restraint, suppression, or arrest of a process or the action of a particular cell or organ; the prevention or slowing of the rate of a chemical or an organic reaction. The term “reciprocal inhibition” refers to the restraint or “checking” of one group of muscles upon stimulation (excitation) and contraction of their opposing (antagonist) muscles.

Inhibitor:

A substance that blocks, restricts, or interferes with a particular chemical reaction or other biologic activity.

Innervate:

To supply a body part, tissue, or organ with nerves or nervous stimulation.

Insidious:

Of subtle, gradual, or imperceptible development; referring to the development of symptoms that may not be recognized by an affected individual until the disorder in question is established.

Intravenous:

Within a vein or veins, as in introducing certain substances, such as fluids, nutrients, or medications, directly into a vein.Within a vein or veins, as in introducing certain substances, such as fluids, nutrients, or medications, directly into a vein.

Ion:

An electrically charged atom or group of atoms due to the loss or gain of one or more electrons. Positively charged ions, known as cations, include potassium, calcium, sodium, hydrogen, ammonium, and magnesium. Negatively charged ions, called anions, include chloride, phosphate, and bicarbonate. The transfer of ions across cellular membranes plays an essential role in vital bodily processes, including enzyme activation, protein metabolism, acid-base balance, nerve impulse transmission, and muscle contraction.