Glossary
This section contains definitions of some of the words and terms that you might come across in the area of Parkinson’s disease.
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A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
A
Adjunct therapy – treatment/drug that is added to the patient's existing treatment.
Aetiology – Cause, or the study of the cause, of a disease.
Agnosia – Inability to recognise objects through either sight, sound or touch, despite adequate sensory information. Caused by damage to areas of the brain involved in interpretation and recall.
Akinesia – complete, or almost complete, loss of movement.
Alzheimer's disease (AD) – disease of the brain that mainly affects the elderly. It involves gradual loss of nerve cells in the brain, and is characterised by progressive memory loss. In the later stages of the disease, patients may also experience movement difficulties.
Anticholinergics – Drugs that block the action of acetylcholine, a neurotransmitter that has opposing effects to dopamine. By blocking acetylcholine's action, these drugs increase dopamine's ability to control movement.
Aphasia – Loss of language skills.
Apraxia – Inability to perform purposeful movements, due to nerve damage.
Arthralgia – Joint pain.
Asthenia – Weakness.
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B
Bradykinesia – slow movement.
Basal ganglia – Specialised nerve cell clusters of grey matter deep within each cerebral hemisphere and the upper brainstem, including the striate body and other cell groups. The basal ganglia assist in initiating and regulating movement.
Bioavailability – Proportion of a drug that reaches the target organ. It is often expressed as a percentage of the total dose given, e.g., 100% bioavailability means that the whole dose reaches the target.
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C
Cerebellum – Second largest portion of the brain. It is involved in the coordination of movement, the regulation of posture and balance, and all skilled motor activities.
Cerebrum – Largest portion of the brain, consisting of two cerebral hemispheres. It is responsible for the initiation and coordination of all voluntary activity, and is the seat of all intelligent behaviour.
Chorea – Movement disorder characterised by the display of restless, purposeless movements that randomly move from one body part to the next.
Combination therapy – situation where two or more drugs are used together to treat one illness.
COMT inhibitors – type of drug used as a treatment for Parkinson's disease. COMT inhibitors are given alongside levodopa to prevent it being broken down in the body and brain.
Corticobasal degeneration (CBD) – rare, progressive form of parkinsonism. It causes stiffness, difficulties with recognition, jerky movements and memory problems.
CT scan – computerised tomography (CT) is a type of X-ray where the scanner rotates around the body to produce an image of the body or brain in cross section.
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D
Deep brain stimulation (DBS) – surgical method used in some patients with Parkinson's disease. Devices are implanted in the body and brain to send electrical currents to specific overactive parts of the brain, prevent their action, and reduce symptoms of abnormal movement.
Dopa-decarboxylase inhibitors (DDIs) – type of drug that is given with levodopa (often in the same tablet) to improve its action, reduce the dose needed, and limit side effects.
Dopamine – one of many chemicals (neurotransmitters) that send messages between nerve cells. Dopamine sends signals between some of the nerve cells that control movement.
Dopamine agonists – rapidly expanding group of drugs that can be given as a first treatment for Parkinson's disease to delay the need for levodopa. They may also be given with levodopa to treat the fluctuations caused by long-term treatment.
Dopaminergic drugs – drugs that work by increasing the level of dopamine.
Drug-induced parkinsonism – disorder where Parkinson's disease-like symptoms are caused by a drug. When the drug is removed, the symptoms disappear.
Dysarthria – difficulty with pronouncing words.
Dyskinesia – group of disorders that produce uncontrolled, abnormal movements.
Dystonia – type of dyskinesia (abnormal movement) that produces muscle spasms in the face, neck and limbs. This can lead to awkward, fixed body positions.
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E
Epidemiology – Science that studies, at the level of population, the spatial and temporal characters (frequency, distribution, transmission, etc) of a disease .
Essential tremor – shaking of the limbs that is made worse by movement. Often confused with the tremor that is seen in Parkinson's disease.
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F
Freezing – symptom of advanced Parkinson's disease where the person becomes ‘glued' to the spot for a few seconds or minutes before being able to walk.
Freezing of gait (FOG) – Common disabling symptom of advanced Parkinson's disease, which involves the patient feeling stuck to the ground (i.e., “frozen”). As the disease progresses, this symptom can lead to falls and loss of general mobility.
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G
Gait – posture/positioning of the body during walking.
H
Hallucinations – symptom that can be produced by disease or medications, which makes a person believe they are seeing, hearing or feeling things that are not really there.
Hoehn & Yahr scale – system used to rate Parkinson's disease as one of five stages – stage 0 means no symptoms, and stage 5 means the most severe disease stage.
Hypomimia – loss of facial expression, caused by poor action of the face muscles in Parkinson's disease.
Hypophonia – abnormally quiet/whispering speech.
Hyperkinesia – Too much movement.
Hypertension – High blood pressure.
Hypokinesia – Condition characterised by too little movement.
Hyphothalamus – Region of the brain with centres controlling body temperature, thirst, hunger and eating, water balance and sexual function. It is also connected with emotional activity and sleep functions.
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I
Idiopathic – Disorder or condition of spontaneous origin; self-originated or of unknown cause. The term is derived from the prefix “idio-” meaning one's own and “pathos” meaning disease.
Insomnia – inability to sleep.
L
Lesioning – surgical method used to destroy specific overactive parts of the brain that cause symptoms in Parkinson's disease. such as fluctuations and dyskinesias.
Levodopa – most commonly used drug for the treatment of Parkinson's disease – the ‘gold standard'. After administration, levodopa is converted into dopamine, and is able to raise the levels of dopamine in the brain. It produces effective control of Parkinson's disease symptoms, although its long-term use is associated with complications
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M
MAO-B inhibitors – class of drugs that are commonly used to treat Parkinson's disease in combination with levodopa. They stop dopamine being broken down in the brain, and can help to ease levodopa motor fluctuations.
Micrographia – very small handwriting.
Motor – term used to refer to movement.
Motor fluctuations – in Parkinson's disease, motor fluctuations are when the patient switches between good and bad movement control with levodopa treatment. Patients begin to experience motor fluctuations after long-term treatment with levodopa.
MRI scan – magnetic resonance imaging (MRI) is a type of scan that uses radio waves to generate an image of body tissues. It is especially useful for examining the nervous system, muscles and bones.
Multiple system atrophy (MSA) – type of parkinsonism that is difficult to distinguish from Parkinson's disease, although poor balance and low blood pressure on standing up are the main problems in MSA. It does not typically respond to standard Parkinson's disease treatments.
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N
Nausea – feeling sick/queasy.
Nerve cell transplantation – type of surgery that is being investigated for use in Parkinson's disease. It involves implanting new dopamine-producing nerve cells in the brain to replace those lost in Parkinson's disease.
Neurodegeneration – Deterioration of the structure or function of tissue within the nervous system.
Neurological – describing any condition or symptom that affects the nervous system.
Neurology – area of medicine that is concerned with the nervous system.
Neurone – another name for a nerve cell.
Neuroprotection – protection of nerve cells. This is a strategy for Parkinson's disease treatment in the future, with research into drugs that can prevent nerve cell loss and damage in the brain.
Neurotoxin – Substance that interferes with the electrical activity or functioning of neurones, preventing them communicating with each other.
Neurotransmitter – type of chemical that is present in the nervous system to carry messages between different nerve cells. Examples of neurotransmitters include dopamine, acetylcholine and noradrenaline.
Noradrenaline – Excitatory neurotransmitter that acts at noradrenergic synapses.
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O
OFF time – period when Parkinson's disease symptoms respond poorly to treatment, making movement difficult.
ON time – period when Parkinson's disease symptoms respond well to treatment, allowing good movement control.
ON–OFF fluctuations – changes between good and bad periods of movement control. These correspond to how well the medication is working, and often appear after many years of treatment with levodopa.
Orthostatic/postural hypotension – low blood pressure in response to a person standing up from a sitting or lying position. It is caused by the blood rushing to the legs as the person becomes upright.
Osteoporosis – wasting disease of the bones.
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P
Pallidotomy – type of surgery where the globus pallidus region of the brain is destroyed. It is used to reduce overactivity in this area of the brain, and improve symptoms of Parkinson's disease including levodopa-induced dyskinesia.
Parkinson's disease (Parkinson's disease) – long-term, progressive movement disorder which is caused by a loss of dopamine-producing nerve cells in the brain.
Parkinsonism – refers to a group of disorders, including Parkinson's disease, that produce similar sorts of slow movement-related symptoms.
PET scan – positron emission tomography (PET) is a type of scan that can detect chemicals in the brain. It is sometimes used to produce pictures (scans) showing the arrangement of dopamine-producing nerve cells.
Postural instability – difficulty with keeping steady body positions such as standing, sitting upright or walking.
Postural reflexes – The automatic chains of nerve impulses that control the maintenance of posture.
Progressive disorder – condition that becomes worse over time.
Progressive supranuclear palsy (PSP) – type of parkinsonism that produces early symptoms such as problems with balance and walking, vision, speech and swallowing. It does not respond to drugs as well as Parkinson's disease.
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R
Rigidity – stiffness.
S
Schwab & England scale – system that is used to rate a person with Parkinson's disease according to their level of independence. 100% relates to total independence, and this falls to a minimum of 0%, which relates to a state of complete dependence.
Somnolence – Excessive sleepiness during the day, which cannot be attributed to normal causes such as a lack of sleep or over-exertion. It is distinct from fatigue.
SPECT scan – single photon emission computed tomography (SPECT) is a type of scan that can produce images of the brain. In Parkinson's disease it is sometimes used to detect dopamine-producing nerve cells in the brain.
Striatum – Area of the brain that control movement and balance. It consists of the caudate nucleus and putamen, and is connected to and receives signals from the substantia nigra.
Substantia nigra – area of the brain where dopamine is produced.
Subthalamotomy – type of surgery where the subthalamic nucleus region of the brain is destroyed. It is used to reduce overactivity in this area of the brain, and improve symptoms of Parkinson's disease.
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T
Thalamotomy – type of surgery where a part of the brain called the thalamus is destroyed. It reduces overactivity in this area of the brain, and improves symptoms of Parkinson's disease including tremor.
Titration – way in which doses of medication are gradually altered to find a dose that is effective, but does not produce unacceptable side effects.
Tremor – rhythmic shaking of part of the body. It is one of the main symptoms of Parkinson's disease.
U
Unified Parkinson's Disease Rating Scale (UPDRS) – scoring system that is used to follow the progression of Parkinson's disease by monitoring a patient's physical and mental abilities, and their response to treatment.
W
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Wearing off – term used to describe the gradual return of symptoms that occurs at the end of a dose of levodopa. This pattern appears when a patient has been using levodopa for many years.
Y
Young-onset Parkinson's disease – type of Parkinson's disease that occurs in people aged below 40 or 50 years. This is more unusual than the form of Parkinson's disease that is found in the elderly, and displays some different symptoms. Young-onset Parkinson's disease appears to have some family inheritance patterns.