Glossary & Terms


Acetylcholine:  The main neurotransmitter of the parasympathetic nervous system that contracts smooth muscles, dilates blood vessels, increases bodily secretions, and slows the heart rate, and often involved in memory and movement.  

active memory:  A collection of bits of information (memory chunks) retained for a short period of time, usually for no more than 30 seconds.  

adrenaline:  a hormone secreted by the adrenal glands, especially in conditions of stress, increasing rates of blood circulation, breathing, and carbohydrate metabolism and preparing muscles for exertion. 

Alzheimer’s disease:  The most common form of dementia. a type of cortical dementia marked by disorientation, memory loss and language difficulties. 

amyloid plaque:  Damaged and insoluble bits of protein found in the brain between the nerve cells and interfere with communications and nurturant transfer between brain cells.  Excessive buildup of plaques damages the cells and eventually eliminates the communication link between neurons causing cognitive impairment.

amyotrophic lateral sclerosis (ALS) or often called Lou Gehrig’s disease.  a rare neurological disease that affects motor neurons—those nerve cells in the brain and spinal cord that control voluntary muscle movement. Voluntary muscles are those we choose to move to produce movements like chewing, walking, and talking.

aneurism:  A form of a stroke defined as a broken blood vessel in or near the brain causing death to the affected area of the brain.  It often causes sudden, intense pain in or near the head, and can be instantly fatal.

antidepressants:   A prescription medicine used to treat depression. Depression is more than feeling a little sad or “blue” for a few days. Note: Antidepressants can cause further complications in a patient with dementia.  Do not use unless directed by a physician.  

aphasia:  A general medical term meaning impaired language skills.  It can indicate problems with receptive and/or expressive language.

apraxia:  A problem with motor functionality in which a person cannot perform certain acts even though they know how to do it.

Aricept:  A medication that maintains the amount of acetylcholine in the synapse between neurons thereby slowing the rate of damage caused by dementia. 

atrophy: The decrease in size of normally developed organ or tissue.

axons:  Long fiber-like process which conducts nerve impulses away from the nerve body, and coupled together with thousands of other axons, forms a nerve.


basal ganglia:  Structures deep in the brain used for movement, emotion and cognition.

beta-amyloid:  A protein fragment that builds up in the brain and plays an essential role in neural growth and repair. Beta-amyloid is chemically “sticky” and gradually builds up into plaques that can become corrupted and destroy nerve cells, impacting thought and memory.  


cerebral cortex:  The outermost layer of the brain associated with our highest mental capabilities and constructed of grey matter (neural tissue made up of neurons)

Cerebrovascular accident (CVS):  The medical term for a stroke.

Cerebral cortex: The cerebral cortex is the largest site of neural integration in the central nervous system.  It plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The cerebral cortex is part of the brain responsible for cognition.

cerebrovascular disease:  A medical definition for the various conditions that limit the flow of blood to the brain, causing damage or death to the affected area.

central nervous system (CNS):  The brain and spinal cord and controls thought, movement, emotion, breathing, heart rate, hormones, and body temperature.  It also combines information from the entire body and coordinates activity across the entire body. 

chorea:  A condition causing involuntary jerky movements that may appear dance-like.

chronic traumatic encephalopathy:  A degenerative brain disease caused by repetitive head trauma often associated with sports such as football or boxing

circulatory system:  The blood vessel system that carries blood and lymph fluid through the body. 

cognition:  Cognition includes all the conscious and unconscious processes involved in thinking, perceiving, and reasoning.

cortex:  The outer layer of the brain that is associated with awareness and many thinking skills and called the bark or gray matter and is associated with awareness, cognition, thought, memory, language, consciousness and many thinking skills. 

condition:  A broad term that includes all diseases, lesions, disorders, or nonpathological conditions that normally receive medical treatment, such as pregnancy or childbirth.

cortical dementia:  One of the types of dementia specifically associated with degeneration in the cerebral cortex and often called Alzheimer’s disease.

Corticobasal degeneration:  A form of subcortical dementia involving damage to basal ganglia marked by movement difficulties and impaired thinking abilities.

Creutzfeldt-Jakob disease:  A rapidly progressive and fatal cortical dementia marked by impaired memory, behavioral changes and vision and coordination difficulties and often referred to as Mad Cow disease.  Although it is thought to be caused b a mutated prion, it is not related to mad cow disease that affects cattle.

crystallized intelligence:  Well-learned knowledge and skills, such as vocabulary


diagnosis:  A clinical examination to determine whether dementia is present should include a careful discussion of the patient’s medical history and the development of symptoms, an examination of memory and other cognitive skills, physical examination, blood tests, and neuroimaging. Special additional tests, such as an electroencephalogram to record electrical activity of the brain, may be required when there are indications that one of the more unusual causes of dementia might be present.

(The) Diagnostic and Statistical Manual (DSM):  A manual printed by the American Psychiatric Association that provides diagnosis guidelines for dementia and other psychiatric conditions.

delusions:  Beliefs that are not in touch with reality and are often held despite evidence contradicting them.

delirium:  An acute state of confusion or impaired consciousness, cognitive functioning and perception.  It can appear within hours, days, weeks or months, depending upon the cause or severity.  

dementia:  A clinical syndrome that describes a person’s serious impairment in thinking skills and a decline in functional skills (daily activities) or independence. It is an acquired syndrome and usually a progressive condition marked by the development of multiple cognitive deficits and the inability to plan and initiate complex behavior.  It is diagnosed only when both memory and another cognitive function are each affected severely enough to interfere with a person’s ability to perform routine daily activities. 

denial:   A declaration of something to be untrue or unwilling to accept.  Sometimes confused with loss of insight in individuals with dementia conditions.

diabetes:  A chronic (long-lasting) health condition that affects how your body turns food into energy.  The body uses the stored sugar (glucose) in the bloodstream as energy for the cells.  When the body does not produce enough insulin to properly signal the pancreas to release the stored sugar (type 1 diabetes) or does not effectively use insulin (type 2), the continued increase in sugar in the bloodstream eventually can cause heart disease, vision loss and kidney disease.  

disease:  A disease is a particular abnormal condition that negatively affects the structure or function of part or all of an organism, and that is not due to any external injury. A disease may be caused by external factors such as pathogens, or by internal dysfunctions like hypersensitivity, allergies, and autoimmune disorders.  In humans, disease is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person afflicted. In this broader sense, it sometimes includes injuries, disabilities, disorders, syndromes, infections, isolated symptoms, deviant behaviors, and atypical variations of structure and function, while in other contexts and for other purposes these may be considered distinguishable categories. Diseases can affect people not only physically, but also mentally, as contracting and living with a disease can alter the affected person’s perspective on life.

disorder:  A disturbed order of normal functioning of the mind or body and caused by genetic factors, disease or trauma. A disorder may indicate that a specific disease is possible, but there is not enough clinical evidence for diagnosis. Typically, a disorderly or abnormally functioning organ or system.

dopamine:  A neurotransmitter (messenger) involved in movement and fine motor control.  Loss of dopamine producing neurons (nerve cells) is implicated in Parkinson’s disease and Lewy body disease.

DSM:  The Diagnostic and Statistical Manual of the American Psychiatric Association that provides diagnosis guidelines for dementia and other psychiatric conditions.


electron microscope:  The electron microscope uses a beam of electrons and their wave-like characteristics to magnify an object’s image, unlike the optical microscope that uses visible light to magnify images.

executive functions:  A term used to describe a class of thinking skills that relate to goal directed behaviors.  It includes skills involved in determining a goal, making a plan, accomplishing the goal, initiating actions, ignoring distractions, multi-tasking and reasoning.

exsiccosis:   Bodily dehydration (anhydremia) due to insufficient intake of fluids.  Often those with impaired cognitive functions do not drink enough fluids or have fluids in their food.  Dehydration can quickly become fatal if not recognized.


fluid intelligence:  The ability to reason and solve new problems without needing previously learned knowledge (Deductive reasoning).

frontal lobe:  A section in the front of the brain responsible for movement and deciding to move, including reasoning and decision-making.  It controls behavior and is involved in emotion personality, reasoning, concentration, and memory

frontotemporal degeneration:  A type of cortical dementia when brain deterioration starts in the frontal and or temporal lobe, usually beginning with behavioral changes or language problems.

Frontotemporal Degeneration (FTD) or frontotemporal lobar degeneration (FTLD):  Common names for this disease are frontotemporal dementia (common form of dementia for FTD), frontotemporal lobar degeneration (FTLD), or Pick’s disease.  It usually shows signs in people under the age of 60 and may be initially diagnoses as early-onset dementia.  Symptoms include difficulty in planning or organizing activities, inappropriate behaviors in social or work environments, and can impact motor functions and language.  


gland:  An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk and releases substances that perform a specific function in the body.   Endocrine glands are ductless glands and release the substances that they make (hormones) directly into the bloodstream. Exocrine gland (e.g., sweat glands, lymph nodes) release their product through a duct and do not produce hormones.


hallucinations:  A sensory perception (such as a visual image or a sound) that occurs in the absence of an actual external stimulus and usually arises from neurological disturbance.  It is often deemed as a form of the loss of being in touch with reality when a person experiences sensory experiences that are not real, such as hearing voices or seeing something that is not really there.  

highly active anti-retroviral therapy (HAART):  Treatment that uses a combination of three or more drugs to treat HIV infection. HAART stops the virus from making copies of itself in the body.

hippocampus:  A structure in the deep temporal lobes of the brain that is responsible for memory function.  It acts as an index forming new long-term memories.  It is impacted when diseased by dementia. 

Huntington’s disease:  The subcortical form of dementia marked by mood changes, cognitive impairment and motor dysfunction that includes jerky movement called chorea.

Hydrocephalus:  A neurological disorder caused by an abnormal buildup of cerebrospinal fluid in the ventricles (cavities) deep within the brain.

hyperparathyroidism:  Hyperparathyroidism is a condition in which one or more of your parathyroid glands become overactive and release (secrete) too much parathyroid hormone and calcium levels in the blood become high (hypercalcemia).

hypoparathyroidism:  Hypoparathyroidism is a rare condition where the parathyroid glands, which are in the neck near the thyroid gland, produce too little parathyroid hormone causing a drop in blood calcium levels and a rise in blood phosphorus levels in the body.


insanity:  Unsoundness of mind or lack of the ability to understand that prevents one from having the mental capacity required by law to enter into a particular relationship, status, or transaction or that releases one from criminal or civil responsibility.  This condition may be perceived outside of the medical community as dementia.

insight:  Awareness, underrating the true nature of one condition.

intelligence:  The ability to build knowledge and skills and then apply and use them.


Judgment impairment:  Dementia can affect a person’s ability to make decisions because the damage to the parts of the brain involved in remembering, understanding, and processing information are often impacted by dementia. This does not necessarily mean that a person with a diagnosis of dementia lacks the ability to make decisions, the level of impairment caused by the progression of dementia may impact the cognitive ability to make a decision. 


knot or tangle:  The result of fibers (tau) that form inside the neurons in the brain and form tangles or knots eventually causing interference with signal communication between neurons, and reduces transportation of nutrients.  Excessive knot or tangle buildup eventually results in the death of the neuron.  


lacunar infarct/stroke:  An ischemic stroke is caused when a small artery that penetrates deep in the brain is blocked.  It causes a small cavity of dead space and can result in some movement of sensory difficulties at times.  People who have had a lacunar stroke are more likely to get dementia after the fact. The older you are when you have a lacunar stroke, the higher the likelihood of experiencing changing abilities after the event.

Levodopa:  A precursor chemical in the body can change into dopamine.  As a medicine, it is used as a primary treatment for conditions such as Parkinson’s disease.

Lewy bodies:  Clumps of protein that form in the brain causing malfunction of the brain.  Symptoms include memory loss, movement impairment, decline in thinking skills, and changes in mood and behavior.  

Lewy body disease:  A type of dementia marked by fluctuations in cognitive difficulties, mild movement difficulties, and visual hallucinations.  It is related to dopamine loss and buildup of Lewy bodies in the brain.

long-term memory/storage:  Long-term memory refers to the memory process in the brain that takes information from the short-term memory store and creates long lasting memories. These memories can be from an hour ago or several decades ago. Long-term memory can hold an unlimited amount of information for an indefinite period of time.


Madness:  A severe mental disorder that makes normal thinking and behavior impossible that may be perceived outside of the medical community as dementia.

Major neurocognitive disorder:  A term created to replace dementia and meant to be more inclusive, including multitude of brain disorders that impact all age levels.

Mild cognitive impairment (MCI):  A term to describe someone with marked serious cognitive impairment with no significant functional difficulties or loss on independence.  It is a risk sign for developing dementia in the future.

Mild neurocognitive disorder:  A term used to replace mild cognitive impairment.  

Mixed dementia:  A combination of several types of dementia often resulting in a faster progression of deficits.  Common combinations include a diagnosis of Alzheimer’s and vascular dementia or Lewy bodies dementia.

Multiple system atrophy:  A subcortical dementia marked by loss of mobility and movement, as well as problems with automatic systems such as blood pressure or breathing.

Myelin sheath:  A fatty tissue that surrounds and protects the axons of neurons and improves nerve impulse transmissions. 


neoplasm:  An abnormal tissue growth in some part of the body, that can be cancerous (malignant), noncancerous (benign) or precancerous (may cause cancer if not removed).  Most benign tumors cause no harm, however, the ones that grow in the brain can become life threatening if not removed.  

Nerve cell (also called neuron):  The fundamental units of the brain and nervous system, the cells responsible for receiving sensory input from the external world, for sending motor commands to our muscles, and for transforming and relaying the electrical signals at every step in between.

neural integration:  The process used by neurons to interpret incoming information and create the outgoing signal to another neuron.  

neurodegenerative:  Something that causes or is related to the loss and degeneration of neurons. 

neurofibrillary tangle:  Clumps of twisted fibers of tau proteins and portions of neurons that interfere with normal transporting nutrients and other important substances from one part of the nerve cell to another.

Neurologist:  A physician who studies the physical aspects of the brain and nervous system and provides treatment.

neurons (also called nerve cells):  The fundamental units of the brain and nervous system, the cells responsible for receiving sensory input from the external world, for sending motor commands to our muscles, and for transforming and relaying the electrical signals at every step in between.

neuron tangles:  Thin strands of abnormal accumulations of a protein called tau that accumulate as a tangle inside neurons.

Neuropsychologist:  A psychologist specializing in understanding the treating disorders of the interaction between the brain and behavior.

neurotransmitter:  A chemical signal used by neurons to communicate with other neurons.

normal:  A characteristic, appearance or behavior that is typical, regular, conforming to a type, or normal in presentation.

normal pressure hydrocephalus:  An accumulation of cerebrospinal fluid (CSF) that causes the ventricles in the brain to become enlarged, sometimes with little or no increase in intracranial pressure. Approximately 50% of the affected patients die before 3 years of age and about 80% die before reaching adulthood.

not normal:  A characteristic, appearance or behavior that is atypical, irregular, abnormal, not conforming to a type, or abnormal in presentation.


occipital lobe:  A rear section of the brain responsible for processing visual information.


paraneoplastic syndrome:  A rare disorder that is triggered by an altered immune system response to a neoplasm.  Peripheral neuropathy is the most common neurologic paraneoplastic syndrome that can cause mild motor weakness, sensory loss, and absent distal reflexes. 

parasympathetic nervous system:  A division of the autonomic nervous system that slows the heartbeat, constricts bronchi of the lungs, and dilates the smooth muscles of the digestive tract and blood vessels. 

parietal lobe:  A middle and top section of the brain responsible for tactile and sensory information and awareness of the area around the body.

Parkinson’s disease:   A degenerative condition where neurons fail to product dopamine.  Motor control becomes weakened causing tremors, rigidity, and impaired walking.  Cognitive impairment may also occur exhibiting difficulty in processing complex information.

Parkinson’s Plus condition:  A condition that includes Parkinson’s and other forms of impairment such as Lewy bodies disease or multiple system atrophy.

parkinsonism:  A clinical syndrome that is the manifestation of Parkinson’s disease.

PET (Positron-Emission Tomography) scan:  A type of functional brain imaging scan using tracers to determine brain functionality.  

Pick’s disease:  A type of frontotemporal dementia (FTD), a condition that causes progressive damage and disruptions in a person’s brain at younger ages than expected for age-related brain disorders.

Plaques:  Plaques form when protein pieces (beta-amyloids) clump together, potentially becoming harmful to the brain. 

Positron-Emission Tomography (PET):  A type of functional brain imaging scan using tracers to determine brain functionality. 

post-traumatic stress disorder (PTSD):  A debilitating psychological condition triggered by a major traumatic event such as war, rape, terrorist act, natural disaster, death of loved one or a catastrophic accident.  Often PTSD is triggered by events, thoughts or memories that evoke inappropriate actions, anxiety, stress, or increased awareness of surroundings.  It may also manifest as severe personality changes.

primary memory:  A collection of bits of information (memory chunks) retained for a short period of time, usually for no more than 30 seconds.  

prions:  Misfolded proteins that can pass into other proteins in the brain. In humans, prions are believed to be the cause of Creutzfeldt-Jakob disease.  In animals, it is called mad cow disease.  Early symptoms include memory problems, behavioral changes, poor coordination, and visual disturbances.  Later symptoms include involuntary movements, blindness weakness, dementia, coma, and eventually death.

processing speed:  The speed at which the brain processes information.

progressive supranuclear palsy:  A degenerative subcortical condition found in Parkinson’s Plus condition. 

protein plaques:  Plaques form when protein pieces (beta-amyloids) clump together, potentially becoming harmful to the brain.

pseudodementia:  A term used to describe the condition in which depression causes cognitive deficits that masquerade as dementia. Patients will often present with difficulties in memory and concentration and deny depressive symptoms.  It is not permanent; and once the depression is successfully treated, the cognitive symptoms will disappear.

Psychiatrist:  A physician specializing in mental health or emotional aspect of the brain.

psychosis:  loss of contact of reality and exhibited as confusion, delusion, agitation and or hallucinations.


Quality of care:  The degree to which health services for individuals and populations increase the likelihood of desired health outcomes. 

Quality of life:  The standard of health, comfort, and happiness experienced by an individual or group that are the things needed for a good quality of life.


receptive and or expressive language:  The ability to listen (receptive) and talk (expressive) Receptive language is the understanding of information provided usually by sound and words, movement and gestures, and signs and symbols.  Expressive language is the ability to communicate our thoughts and feelings through words, gestures, signs, and/or symbols.  As dementia progresses, often the ability to use language skills developed in early life become more difficult or disappear entirely.  


senile/senility:  Often referred to as a loss of physical abilities in old age, but it usually refers to decreased memory and mental faculties. Originally called ‘senile dementia’, it is understood today that cognitive impairment is not a normal aging condition.

short-term memory/storage:  A collection of bits of information (memory chunks) retained for a short period of time, usually for no more than 30 seconds.  

small vessel ischemic disease:  A disease that reflects the damage to the cerebrovascular systems and contributes to cognitive decline.  Often called white matter disease that includes damage to the brain white matter from lesions, microbleeds and small empty spots caused by small artery bleed.  

stroke:  A cerebrovascular accident where the brain dies due to impaired blood flow from a blockage or broken blood vessel.

subcortical:  An area in the brain relating to the subcortex, beneath the cerebral cortex.

subcortical dementia:  A type of dementia such as Parkinson’s disease that is associated with degeneration of the subcortical regions.

symptom:  A physical or mental problem or issue that a person experiences that may indicate a disease of condition.  Symptoms cannot be seen and do not show up on medical tests.  Symptoms may be a headache, fatigue, nausea, and pain.

sympathetic nervous system:  A part of the nervous system that accelerates the heart rate, constricts blood vessels, and raises blood pressure.

synapse:  The space between two neurons through which chemical messages are passed.

Syndrome:  A group of signs and symptoms which consistently occur together, or a condition characterized by a set of associated symptoms that depict a particular abnormality or condition.  It can also be a set of concurrent things (emotions, actions) that usually form an identifiable pattern. Examples are Post-traumatic Stress Syndrome, Acquired Immune Deficiency Syndrome, and Down’s Syndrome.


tangles / tau tangles:  tau tangles are thin strands of abnormal accumulations of a protein called tau that collect inside neurons and coil around and inside brain cells.

tau:  Proteins that give structure to neurons and cause Alzheimer’s disease when damaged or defective.  

temporal lobes:  An area on each side of the brain that is used in hearing or auditory senses.

traumatic brain injury (TBI): An injury to the brain caused by trauma to the head or body, or damage caused by an object going through the brain such as a bullet or skull fragments.  Suspect traumatic brain injury when trauma causes a change in consciousness.


Uremia:  Uremia is a buildup of toxins in your blood. It occurs when the kidneys stop filtering toxins out through your urine. Symptoms include Cognitive dysfunction (problems with thinking and remembering) and maybe misdiagnosed as dementia or delirium.


vascular dementia:  One of the types of dementia specifically caused by a stroke or excessive cerebrovascular disease. Symptoms and deficits depend upon the affected area of the brain.  

vascular system:  The circulatory system that used blood vessels to carry blood and lymph fluid through the body.

visuospatial skills:  The ability to perceive and understand visual objects and spatial relationships such as drawing or building objects.


white matter disease:  A group of conditions known as small vessel ischemic disease, where the brain is damaged by microbleeds, lesions in the white matter and small empty spots caused by small artery bleeds or blockages.  Cognitive decline is one of the symptoms.

wasting:  A decrease in size of normally developed organ or tissue.  

Wernicke-Korsakoff syndrome:  A syndrome that happens when a severe lack of thiamine (vitamin B1) damages the brain.  Usually Wernicke-encephalopathy is characterized by changes in vision and eye function, confusion, leg or muscle tremors, and a decrease in mental function. Korsakoff syndrome consists of impaired memory, confabulation (making up stories) and hallucinations, and often a chronic condition. -Symptoms may mimic dementia or Parkinson’s disease.




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