Chiari malformation: The downward (caudal) displacement of part of the cerebellum or brainstem below the foramen magnum. May also have/cause hydrocephalus, cord symptoms. More about Chiari malformation.
Chorea: A disorder, usually of childhood, characterized by irregular, spasmodic involuntary movements of the limbs or facial muscles. More about spasticity.
Choroid plexus: A vascular structure in the ventricles of the brain that produces cerebrospinal fluid.
Coccyx: The small bone at the end of the spinal column, formed by the fusion of four rudimentary vertebrae (commonly called the "tail bone").
Coma: A state of profound unconsciousness from which one cannot be roused.
Computerized tomography (CT) scan: A diagnostic imaging technique that rapidly x-rays the body in cross-sections, or slices. A computer pieces together the x-rays to create a three-dimensional map of soft tissue or bone.
Concussion: A disruption, usually temporary, of neurological function resulting from a blow or violent shaking. More about concussion.
Contrast medium (dye): Any material (usually opaque to x-rays) employed to delineate or define a structure during a radiologic procedure.
Coronal suture: The line of junction of the frontal bones and the parietal bones of the skull. More about craniofacial anatomy.
Corpectomy: Removal of the body of a vertebra. The body is the solid bony mass, almost circular in appearance, that forms the front part of each vertebra.
Corpus callosum: The fibrous band connecting the hemispheres of the brain.
Cortex: The external layer of gray matter covering the hemispheres of the cerebrum and cerebellum.
Craniectomy: Surgical removal of a portion of the skull.
Craniopharyngioma: A congenital tumor arising from the embryonic duct between the brain and pharynx. More about craniopharyngiomas.
Cranioplasty: The operative repair of a defect of the skull.
Premature closure of cranial sutures, limiting or distorting the growth of the skull. More about craniosynostosis and other craniofacial anomalies.
Craniotomy: Surgical opening of the skull, usually by creating a flap of bone.
Cranium: The part of the skull that holds the brain.
CT scan (computed tomography scan): A diagnostic imaging technique in which a computer reads x-rays to create a three-dimensional map of soft tissue or bone.
Diphenylhydantoin: Dilantin; a medication used to control seizures. More about epilepsy in adults and epilepsy in children.