encephalo-, encephal-

(Greek: brain; that which is inside the head)

I use not only all the brains I have, but all I can borrow.
—Woodrow Wilson
Congenital absence of the brain and the spinal cord.
A congenital absence of the brain and cranial vault, with the cerebral hemispheres completely missing or greatly reduced in size.
Exhibiting anencephaly; having no brain; brainless.
anencephalology (s) (noun)
The science of congenital absence of the brain and cranial vault.
Characterized by a partial or a total absence of a brain.
anencephaly (s) (noun), anencephalies (pl)
1. Congenital defective development of the brain that includes the absence of the bones of the cranial vault: "The baby was born with anencephaly which was a birth defect in which most of the brain and parts of the skull were missing."
2. A partial or total absence of the brain at birth: "Doctor Darrin indicated that there are some babies who have been born with anencephalies at his hospital."
The part of the primitive embryonic brain from which the forebrain and midbrain develop.
atelencephalia, ateloencephalia
Congenital anomaly with imperfect development of the brain.
diencephalic syndrome
1. A syndrome of early childhood, characterized by progressive emaciation in spite of high caloric intake, a euphoric appearance, and occasionaly vertical nystagmus (oscillatory movement of the eyeballs), tremor, and ataxia, due to a tumor in the diencephalon.
2. Convulsive equivalent, a form of epilepsy, especially in children.
The part of the brain between the telencephalon and the mesencephalon, including the thalami and most of the third ventricle: also known as, betweenbrain, interbrain.
An instrument that in a painless and noninvasive manner uses the differential transmission and reflection of ultrasonic waves to create a detailed visual image of the brain.
The process whereby an instrument is used in a painless and noninvasive manner that uses the differential transmission and reflection of ultrasonic waves to create a detailed visual image of the brain.
A pictorial representation of intracranial structures, obtained by echoencephalography.
electroencephalogram, EEG
1. The record obtained by means of the electroencephalograph which presents a record of electric currents generated in the cortex of the active brain.
2. A technique for studying the electrical currents within the brain.

Electrodes are attached to the scalp and wires attach these electrodes to a machine, which records the electrical impulses.

The results are either printed out or displayed on a computer screen where different patterns of electrical impulses can indicate various forms of epilepsy.

3. A graphic record of the minute changes in electric potential associated with the activity of the cerebral cortex, as detected by electrodes applied to the surface of the scalp.
4. A graphic chart on which is traced the electric potential produced by the brain cells, as detected by electrodes placed on the scalp.

The resulting brain waves are called alpha, beta, delta, and theta rhythms; according to the frequencies they produce, which range from two to twelve cycles per second.

Variations in brain wave activity are correlated with neurological conditions, psychological states, and levels of consciousness.

electroencephalograph, EEG
1. An instrument that measures and records brain wave or the electrical potentials on the scalp and generates a record of the electrical activity of the brain.
2. An apparatus for receiving and recording the electric potential produced by the brain cells.

It consists of a vacuum tube amplifier that magnifies the electrical currents received through electrodes placed on the scalp and electromagnetically records the patterns on a graphic chart.

3. An appliance that is used to amplify and to record the electrical activity of the brain, either through the intact skull and scalp, or directly from the exposed cerebral cortex (electrocorticography).

It is made up of a number of channels, each of which consists of an amplifying and recording instrument that records the electrical events beneath and between a pair of recording electrodes.