Research glossary

Our glossary helps to explain some of the scientific terms you may come across related to Parkinson's.

If you feel we've missed off an important term from the list, let us know by emailing research@parkinsons.org.uk

Search for terms beginning with:

A B C D E F G H I K L M N O P R S T V

A

alpha-synuclein

A protein found inside Lewy bodies. It is found to be altered in some people with inherited Parkinson's.

antioxidants

Enzymes or other substances that can help to counteract the damaging effects of oxidative stress inside cells

B

basal ganglia

A part of the brain involved in co-ordinating movements

biomarker

Biological substances or properties that can be measured to provide information about state of health. For example, blood pressure can be used to determine risk of stroke and blood sugar levels help people to monitor diabetes.

bradykinesia

Slowness of movement

C

cognitive impairment

Problems with mental processes such as thinking, learning and judging

complementary therapies

Non-conventional health treatments, such as acupuncture and reflexology, which may be used in addition to conventional medical treatments

compulsive behaviour

Out-of character uncontrollable urges, for instance gambling. Often linked to medication.

COMT inhibitors

Drugs that prevent the break down of the drug levodopa.

clinical trial phase 1-3

Closely-supervised scientific studies into effectiveness and safety of treatments in human subjects

D

deep brain stimulation (DBS)

A surgical procedure used to treat Parkinson's. It involves implanting electrodes in carefully chosen parts of the brain, which are connected to a pacemaker-like device implanted in the chest. The 'pacemaker' can be switched on and off to stimulate the chosen part of the brain.

delusion

A fixed false belief that is resistant to reason or confrontation with actual fact

dementia

The progressive decline in cognitive function (thinking, planning, organising, problem solving, etc) beyond what might be expected from normal aging

There are two main forms associated with Parkinson's:

Dementia with Lewy bodies (DLB) - when cognitive problems begin within one year of the initial movement problems
Parkinson's disease dementia (PDD) - when cognitive problems begin more than one year after the initial movement problems

DNA

A molecule containing the genetic instructions that control our cells and ultimately our bodies

dopamine

A chemical messenger produced by cells in specific parts of the brain. It transmits messages that play an important role in the co-ordination of movement.

dopamine agonist

A group of drugs used to treat Parkinson's that mimic the effects of the chemical messenger dopamine which is depleted in Parkinson's

dyskinesia

An involuntary or abnormal movement affecting any part of the body. Can be caused by some Parkinson's drugs.

E

enzyme

A natural molecule, usually a protein, that increases the rate of a chemical process.

experimental model

An animal (often a rat or mouse) that has been given Parkinson's-like symptoms to mimic the disease.

expression

The process by which a gene's coded information is converted into the structures present and operating in the cell

F

familial Parkinson's

A rare form of inherited Parkinson's

free radical(s)

Toxic molecules that are produced by normal chemical reactions inside cells. These molecules can build up and damage cells and tissues in a process called oxidative stress.

G

gait

A pattern of walking

gene

A section of DNA containing the instructions for a particular thing (e.g. eye colour, making an enzyme, etc).

gene therapy

Manipulating or adding genes to cells to help them work more effectively, for instance produce more dopamine

genetics

The study of heredity and variation and the nature of genes

genetic engineering

The direct manipulation of an organism's genes in the lab

graft/grafting

Transplanting tissues from one place to another

H

hallucination

An experience of something that does not exist outside the mind. They may be caused by physical and mental disorders, or as a side effect of medications. Usually appear as visual or auditory images.

homeopathy

A complementary therapy based on the principle that 'like can be cured by like'. The remedies used contain very dilute amounts of a substance, which in larger quantities would produce similar symptoms to the illness being treated.

hormone

Chemical messengers that instruct cells to do things

hybrid embryo

Created by inserting the nucleus of an adult human cell into an animal egg which has had its genetic material removed.

I

idiopathic

Refers to a disease or condition whose cause is unknown

impulse control disorders

See compulsive behaviours

in vitro

Performing an experiment outside of a living organism

in vivo

Performing an experiment inside a living organism

K

knock-out

An animal missing a single gene (that has been removed). Knock-out animals are very helpful in research to work out what the missing genes do normally.

L

levodopa

A chemical that occurs naturally in the brain and is converted into dopamine (the chemical messenger lacking in Parkinson's). Also known as L-Dopa

Lewy bodies

Clumps of proteins often seen in the brains of people with Parkinson's. They are a typical hallmark of the condition.

M

mitochondria

The cells' batteries that produce the energy to needed to power all the cells' activities.

monoamine oxidase type-B inhibitor

Drugs that prevent the break down of dopamine

motor fluctuations

'On-off' periods, wearing off, dose failures, and freezing associated with long-term levodopa use

MPTP

A chemical that destroys dopamine-producing nerve cells and mimics Parkinson's disease.

mutation

Process by which a gene undergoes a structural change

N

nervous system

The network of cells that carries messages around the body, co-ordinating movements and allowing sensations

neurodegeneration

Death of nerve cells in the brain

neuro-imaging

Techniques that allow the visualisation of structures within the brain that cannot otherwise be seen or measured. Techniques used include PET, SPECT and functional MRI.

neurons

Nerve cells that make up the nervous system and communicate by sending and receiving electrical and chemical messages

neuroprotective agents

Drugs or techniques that protect nerve cells from damage

neurotransmitters

Naturally-occurring chemicals released by nerve cells that carry messages to other nerve cells (e.g. dopamine)

O

'on-off' periods

Describes the abrupt and unpredictable changes in mobility in some people with Parkinson's. During the 'on' state, people are able to move and in the 'off' state are virtually immobile.

oxidative stress

A harmful condition that occurs when cells are overwhelmed by too many toxic chemicals (free radicals) and/or cells lack sufficient protective molecules (antioxidants)

P

parkinsonism

A term used to describe movement disorders that share similar symptoms to Parkinson's. These include multiple system atrophy (MSA) and progressive supranuclear palsy (PSP).

Parkinson's nurse

A nurse who specialises in Parkinson's, and works closely with people with Parkinson's, carers, doctors and other healthcare professionals

placebo

A substance or procedure a patient accepts as medicine or therapy, but which has no specific therapeutic activity

the placebo effect

The healing effect of a placebo, which is generally attributed to the psychosocial aspect, or power of suggestion. The placebo effect can be extremely strong, so trials must be very carefully designed in order to show the true benefit of new treatments.

primary care

Health services that play a central role in the local community; these include GPs, nurses, occupational therapists, dietitians, etc.

proteins

An essential element in the body; they are the building blocks of muscles, and organs and also participate in all processes within cells.

R

receptors

Part of the cell that detects, receives and relays chemical messages

RNA

A single stranded version of the DNA code which provides cellular machinery with the instructions for making proteins.

S

stem cells

Unspecialised cells that have the ability to develop into different types of cells:

embryonic stem cells - found in developing embryos, can become any type of cell
adult stem cells - found in adult tissues (e.g. bone marrow), can develop into a limited number of cell types