Skip to content
My WebMD Sign In, Sign Up

Alzheimer's Disease Health Center

Font Size

Glossary of Alzheimer's Disease Terms


Case management: A term used to describe formal services planned by care professionals.

Cell: The fundamental unit of all organisms; the smallest structural unit capable of independent functioning.

Central nervous system (CNS): One of the two major divisions of the nervous system. Composed of the brain and spinal cord, the CNS is the control network for the entire body.

Cerebral cortex: The outer layer of the brain, consisting of nerve cells and the pathways that connect them. The cerebral cortex is the part of the brain in which thought processes take place. In Alzheimer's disease, nerve cells in the cerebral cortex degenerate and die.

Cerebrospinal fluid (CSF): The fluid that fills the areas surrounding the brain and spinal cord.

Chest X-ray (CXR, chest film): An image on film of the structures of the chest (heart, lungs, and bones); the procedure to get the image uses small amounts of radiation.

Choline: A natural substance required by the body that is obtained from various foods, such as eggs; an essential component of acetylcholine.

Choline acetyltransferase (CAT): An enzyme that controls the production of acetylcholine. CAT appears to be depleted in the brains of individuals with Alzheimer's disease.

Cholinergic system: The system of nerve cells that uses acetylcholine to communicate between cells and is damaged in the brains of individuals with Alzheimer's disease.

Cholinesterase: An enzyme that breaks down acetylcholine into active parts that can be recycled.

Chromosome: An H-shaped structure inside the cell nucleus made up of tightly coiled strands of genes. Each chromosome is numbered (in humans, 1-46). Genes on chromosomes 1, 14, 19, and 21 are associated with Alzheimer's disease.

Clinical psychologist: See psychologist.

Clinical social worker: An individual who has specialized training in identifying and accessing community resources, such as adult daycare, home care, or nursing home services, as well as skills in individual and group counseling.


Co-existing illness: A medical condition that exists simultaneously with another, such as arthritis and dementia.

Cognitive abilities: Mental abilities, such as judgment, memory, learning, comprehension, and reasoning.

Cognitive symptoms: In Alzheimer's disease, the symptoms that relate to loss of thought processes, such as learning, comprehension, memory, reasoning, and judgment.

Combativeness: Episodes of aggression.

Competence: A person's ability to make informed choices.

Computed (axial) tomography (CAT or CT) scan: A technique in which multiple X-rays of the body are taken from different angles in a very short period of time. These images are collected by a computer to give a series of images that look like "slices" of the body. In diagnosing dementia, CT scans can reveal tumors and small strokes in the brain.

Conservator: In some states, the guardian who manages an individual's assets.


WebMD Medical Reference

Today on WebMD

alzheimer's disease warning signs
Alzheimers Overview
Best Memory Boosting Games
Alzheimers Dementia
daughter and father
senior man
Making Diagnosis
Woman comforting ailing mother
mri scan of human brain
senior woman with lost expression
Antioxidants Memory