Glossary – Early Symptoms of Alzheimer’s & Dementia

Medical terms explained


Medical Term Definition
Amyloid A protein that forms in the brain causing deterioration.
Amyloid Plaque Abnormal cluster in the brain of amyloid proteins, dead/dying brain and nerve cells.
Atrophy In Alzheimer's disease the wasting and loss of brain mass.
Behavioral Symptoms In Alzheimer's disease abnormal behaviors of action or emotion e.g. anxiety, depression, hostility and wandering.
Biomarker Indicate biological processes, detection of biomarkers specific to a disease can aid diagnosis and treatment prior to symptoms.
Caregiver Primary carer of an individual with Alzheimer's disease, usually a family member.
Cerebrospinal Fluid (CSF) Fluid surrounding brain and spinal cord. Analysis of CSF can be used to diagnose Alzheimer's disease.
Cognitive Symptoms In Alzheimer's disease abnormal brain functions of thinking, remembering, learning, reasoning and planning e.g. loss of memory, confusion and understanding/expressing speech.
Dementia The loss of brain functions severe enough to interfere with daily life. Also includes changes in personality, mood and behavior. Not a disease itself but a group of irreversible symptoms accompanying a disease e.g. Alzheimer's disease.
Early Stage/Prodromal Alzheimer's Early Alzheimer’s when the first symptoms appear, experiences of very mild to moderate brain functioning impairments.
Early-onset Alzheimer's Alzheimer's disease diagnosed before the age of 65.
Enzyme A protein that causes a reaction of other substances without being altered or destroyed.
Frontotemporal dementia A form of dementia that usually affects speech and personality.
Gene A section of DNA coding for a particular trait.
Hippocampus Section of the brain important for memory and learning.
Korsakoff’s Syndrome Loss of coordination, disorientation and memory loss often caused by heavy drinking.
Mild Cognitive Impairment (MCI) Mild cognitive impairment is a term that is often used to describe the cognitive disturbances that occur before the clinical diagnosis of dementia, however, not everyone diagnosed with mild cognitive impairment will go on to develop dementia.
Magnetic Resonance Imaging (MRI) A technique used in diagnosis to scan the brain which can detect abnormal tissue.
Memory The ability to process and retrieve information.
Neurodegenerative Disease - degeneration of the nervous system Disease that results in deterioration of the nervous system.
Neurological Disorder Disturbance of nervous system function or structure often due to disease.
Neuron A nerve cell.
Onset The point at which disease begins.
Pathological Related to disease.
PET Scan A technique used in diagnosis to scan the brain by detecting functioning.
Prodromal Early stage of symptoms indicating onset of disease
Protein Molecules in the body that create structures transmit signals and are essential to growth and repair.
Risk Factors Factors that increase the chance of developing Alzheimer's disease e.g. age, medical history and genetics.
Tangles Protein deposits made of tau protein found inside neurons in Alzheimer's sufferers.
Tau Protein A major protein involved in maintaining the internal structure of the nerve cell. In Alzheimer's disease this protein is abnormally modified and makes up the neurofibrillary tangles.

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