Parkinson's Disease Glossary

Many of the terms associated with Parkinson's disease are unfamiliar to anyone without a medical degree. Below are some of the words that you may run across in researching about Parkinson's, with simple definitions to make it easier to understand.


A

Acetylcholine
Acetylcholine is a chemical messenger made by your nerves. Some medicines that are used to treat Parkinson's work by stopping acetylcholine from doing its job.

Action Tremor
A tremor of one of your limbs when you start doing something like writing or picking something up. It usually appears in the later stages of Parkinson's disease.

Agonist
A drug or chemical that mimics the action of a neurotransmitter like dopamine. Dopamine agonists are one of the first medical treatments used with Parkinson's disease. They work by tricking the brain into thinking that they are dopamine. Akinesia Inability to move (freezing) or difficulty in producing bodily movements.

Amantadine
A medication used to treat Parkinson's disease. It stimulates the brain and triggers the release of dopamine. It may be used alone or together with L-dopa. vodopa.

Anticholinergics
A family of medications used to treat the tremors associated with Parkinson's disease. They inhibit the actions of chemical messengers like acetylcholine and relieve tremors.

Ataxia
Lose of balance and coordination.

Athetosis
Repetitive, slow movements that are not under your control, particularly in the hands. A symptom of Parkinson's disease.

Atypical Parkinsonisms
Conditions that are related to Parkinson's disease and have some of the same symptoms, but have their own symptoms that distinguish them from Parkinson's disease.

Autonomic Nervous System
The part of the nervous system that operates automatically, without conscious thought. The Autonomic nervous system controls things like breathing, sweating and your heart rate.

B

Basal Ganglia
A group of nerve cells at the base of your brain that control voluntary movements like walking.

Benign Essential Tremor
A condition that is sometimes mistaken for Parkinson's disease. It has some of the same symptoms, particularly tremors in the hands, head and voice, but it's a different kind of tremor than is usually found in Parkinson's disease, and it isn't accompanied by rigidity of slowness.

Bilateral
Occurring on both sides of the body.

Blood-brain barrier
A sort of 'brain filter', the Blood-brain barrier is a layer of cells that between the brain and the blood stream. It blocks many substances from entering the brain.

Blepharospasm
Spastic blinking or forced closing of the eyelids, sometimes seen in cases of Parkinson's disease.

Bradykinesia
Slowed movements characteristic of Parkinson's disease. It's one of the five main symptoms of the disease

Brainstem
The lowest part of the brain, located at the top of the spinal cord. Parts of the brain stem are responsible for most automatic muscle movements

Bromocriptine
The generic name of a dopamine agonist

C

Carbidopa
A drug that is used with levodopa (L-dopa) to help the body use L-dopa more efficiently. Carbidopa blocks the breakdown of L-dopa in the body before it reaches the brain.

Central Nervous System
The brain and spinal cord are the central nervous system

Cerebellum
The largest part of the brain; responsible for thought, reasoning, memory, sensation, voluntary movement.

Chorea
Random involuntary movements of the type often seen in Parkinson's disease as a result of too much medication.

Cognitive Function
The ability to organize information in the brain; thinking, remembering and planning are all parts of cognitive function

Cogwheel Rigidity
Rigidity is one of the five major symptoms of Parkinson's disease. It's characterized by muscle stiffness with a jerky quality when the arm or leg joints are moved.

COMT Inhibitor
A class of drugs used to fight parkinsonism by blocking an enzyme that breaks down L-dopa in the intestinal tract and allows more L-dopa to reach the brain. COMT inhibitors include entacapone (Comtan) and tolcapone (Tasmar).

D

Deep Brain Stimulation (DBS)
A surgical procedure that is being used with considerable success to treat the symptoms of Parkinson's disease. It involved implanting permanent electrodes in the brain so that continuous pulses of electricity can stimulate the various areas of the brain into activity. The electrodes are connected to a transmitter that is implanted in the wall of the chest, like a pacemaker.

Delusions
A symptom of dementia which often accompanies later stages of Parkinson's disease. Delusions are erroneous and sometimes bizarre beliefs in the patient which cannot be changed by rational argument.

Dementia
Dementia is a late stage symptom of Parkinson's disease. It is characterized by confusion, losing touch with reality, loss of time awareness and often poor impulse control and rapid, unexpected mood changes.

Dopamine
Dopamine is a chemical produced by the brain that helps the brain to communicate messages between nerve cells. It helps control actions and movement of the muscles, both voluntary and involuntary. The cause of Parkinson's disease symptoms is the lack of dopamine which results as the cells that produce dopamine in the brain die off.

Dopamine Agonist
One of the primary classes of medications used to treat early stages of Parkinson's disease. Dopamine agonists act like dopamine in the body, and stimulate the nerve cells in the same way that dopamine does. This tricks the body into believing that the brain is producing dopamine and often relieves the tremors and rigidity that accompany Parkinson's disease.

Dopamine Receptor
An area in nerve cells that is stimulated by dopamine and triggers the nerve's response to the stimulation.

Dopaminergic
Drug or chemical reaction related to dopamine

Dysarthria
Dysarthia is a symptom that is usually associated with advanced Parksinson's disease. It occurs when the disease affects the muscles associated with speech, and is manifested in slurred or impaired speech.

Disequilibrium.
Poor balance or unsteadiness. Disequilibrium is a common symptom of Parkinson's disease that is related to the characteristic posture and balance problems.

Dyskinesia
Dyskenesia is a common side effect of the medications used to treat Parkinson's disease. It refers to abnormal involuntary movements which result from the abnormal transmission of messages to the nerve cells. These movements are part of the reason that Parkinson's disease is often embarrassing to those who have it.

Dysphagia
One of the symptoms associated with later stages of Parkinson's disease, dysphagia is difficulty swallowing due to the muscles that control swallowing being affected by the disease.

Dystonia
Another characteristic of Parkinson's disease, dystonia is tightness, spasm or cramping of muscles. It may also refer to bizarre twisting or posturing of muscles affected by Parkinson's.

E

End-of-dose-failure
Levodopa (L-dopa) is one of the commonly used medications to treat Parkinson's disease. One of the problems related to L-dopa is that it eventually loses its effectiveness. One of the first signs that a does of L-dopa is losing its effectiveness is 'end-of-dose-failure', when the medication wears off before the next dose is due.

Enzyme
A chemical or protein that is found in the body whose job it is to speed up a biological reaction.

Essential Tremor
A term used to describe a tremor that occurs when you are doing something such as writing or picking something up.

Etiology
Etiology is a medical term that means 'how you get the disease'. Parkinson's disease is of unknown etiology.

F

Festination
A term used to describe a walking gait that is peculiar to patients with Parkinson's disease. It is characterized by small, slow shuffling steps.

Freezing
Getting 'stuck' in the middle of a movement. Freezing is one of the five primary symptoms of Parkinson's disease and generally doesn't appear until the later stages of the disease.

G

Gait
The way that you walk is called your gait. Most people with Parkinson's disease find that the disease affects their gait because of the loss of balance and muscle rigidity.

Globus Pallidus
A part of your brain that is located in the basal gantlia. A cluster of nerves in the globus pallidus is responsible for the tremors associated with some of the symptoms of Parkinson's. A pallidotomy is a surgery that destroys that cluster of nerves and often relieves the symptoms.

H

Hallucinations
One of the symptoms of dementia that sometimes is a result of Parkinson's disease in its later stages. A hallucination is seeing, hearing or feeling something that isn't really there.

High-dopa dyskinesias
A side effect of levodopa, a medication used to treat Parkinson's disease. When L-dopa is at its highest level in the blood, patients may experience abnormal movements and muscle twitches.

Hypokinesia
Slow movements that are traditionally associated with Parkinson's disease.

Hypomimia
The mask-like expression typical of people with Parkinson's disease. Because Parkinson's affects the muscles of the face and involuntary movements, it often appears that people with Parkinson's disease have no facial expressions.

I

Idiopathic
A medical adjective that means 'without a known cause'. The most typical form of Parkinson's disease is idiopathic.

Intention Tremor
One of the type of tremors associated with Parkinson's disease. An intention tremor occurs when a person attempts a voluntary movement.

L

Levodopa (L-DOPA)
Levodopa is the generic name for the most commonly used drug to treat Parkinson's disease. L-dopa is a precursor of dopamine which means that the body can change it to dopamine in the brain. L-dopa works by replacing the dopamine that the brain is no longer able to produce in Parkinson's disease. In the United States, the brand name of L-dopa is Sinemet.

Lewy Bodies
Lewy bodies are abnormal pink spheres that are found in the brains of those with Parkinson's disease. They are the result of dying or dead cells that produce dopamine. They are the most certain way to diagnose Parkinson's disease.

Low-Dopa Dyskinesias
When L-dopa is wearing off, a patient may experience abnormal movements that are outside their control. Those are called 'low-dopa dyskinesias'.

M

Mentation
A term used to refer to mental and cognitive functioning. This includes your thought processes and judgment.

Micrographia
Small, very cramped and often illegible handwriting. Micrographia is common in those with Parkinson's disease because of the problems that the disease causes with fine motor movements.

Monoamine Oxidase-B (MAO-B)
MAO-B is an enzyme produced by the body that helps break down dopamine for use in the nerve receptors.

Monoamine Oxidase-B (MAO-B) Inhibitors
One class of medications being used to treat Parkinson's disease. MAO-B inhibitors prevent the enzyme MAO-B from breaking down dopamine in the area of the dopamine receptors so that more of the dopamine makes it to the brain.

Motor Fluctuations
The term used to describe complications of Parkinson's medications that affect the way that patients move. Dyskinesias and wearing-off dose are examples of motor fluctuations.

Myoclonus
Involuntary jerky movements of the arms and legs which usually occur during sleep. They may result in disturbed sleep in patients with Parkinson's disease.

N

Neurodegenerative
Diseases in which the nervous system degenerates, like Parkinson's disease and Alzheimer's. They are characterized by the loss of cells in the central nervous system.

Neurotransmitter
Your body makes special chemicals that help carry messages from the brain to nerve cells and between nerve cells. These are called neurotransmitters. The loss of the neurotransmitter dopamine is the cause of most of the symptoms of Parkinson's disease.

Norepinephrine
A neurotransmitter that is responsible for feelings of well-being. Studies show that as Parkinson's disease progresses, levels of norepinephrine are reduced, and researchers speculate that it may be the end result of a process that starts with the loss of dopamine.

O

On-Off Phenomenon
A side effect of long term therapy with levodopa, the most common treatment for Parkinson's disease. The on-off phenomenon is described as 'fluctuations in the ability to move'. It's a sign that the effectiveness of L-dopa is wearing off.

Off
Patients and doctors describe the difference between when medication is working and when it is not in terms of 'off' and 'on'. When the medication is not working, or is wearing off, the patient is 'off', and the Parkinson's symptoms reappear.

On
When medication is working at its best, the state of motor activity is described as 'on'.

P

PD
Abbreviation for Parkinson's disease.

Palilalia
Stuttering or stammering in speech. When Parkinson's disease affects the muscles that control speech, palilalia is one of the results.

Pallidotomy
A surgical treatment to help relieve the symptoms of advanced Parkinson's disease. It involves the destruction of a small group of cells in the globus pallidus to prevent 'scrambled messages' from leaving the brain and causing abnormal movements and other symptoms.

Paranoia
A symptom of dementia that appears in some patients with late stage Parkinson's disease. It is a belief that others are 'out to get' the patient in the absence of any evidence. It is one of many psychological conditions that researchers believe eventually result from the lose of the dopamine producing cells in the brain.

Parkinson's Mask
Because Parkinson's disease affects small muscle movement, both voluntary and involuntary, facial expressions are often affected in people who have Parkinson's. This results in an unmoving, mask-like expression that is referred to as Parkinson's mask.

Parkinsonian Syndromes
A number of disorders that are related to Parkinson's disease and share some of the symptoms, particularly bradykinesia and rigidity and tremor. They have other symptoms and pathology that distinguish them from Parkinson's disease, though.

Parkinsonism
Parkonsonism is a clinical term that refers to an entire group of conditions that share the most typical symptoms of Parkinson's disease.

Postural Instability
A term that simply means problems with balance.

Postural Tremor
One of the tremors associated with Parkinson's disease. A postural tremor gets worse when you stretch your hands out in front of you.

Prognosis
A medical term that means 'what will probably happen in this disease'. Most people use it to mean the eventual outcome of a disease.

Propulsion
Forward movement, usually associated with walking.

Psychosis
One of the symptoms of dementia which is sometimes a result of Parkinson's disease. It's characterized by losing contact with reality, and includes delusions, hallucinations and paranoia.

R

Range of Motion
Range of motion is a measure of how far a joint will move between completely straight to fully bent. Rigidity that is associated with Parkinson's disease compromises the range of motion by affecting the muscles dependent on the joint.

Resting Tremor
Generally, the first symptom of Parkinson's disease that is noticed. It's a shaking that happens when a limb is relaxed.

Retropulsion
Stumbling or falling backwards. It's a term that's used to describe one of the problems of balance in Parkinson's disease.

Rigidity
One of the five major symptoms of Parkinson's disease, rigidity is tightness or tensing in the muscle when it is at rest. A patient may feel is as 'stiffness'.

S

Serotonin
One of the neurotransmitters produced by the brain. People in the later stages of Parkinson's disease often have reduced levels of serotonin, which leads researchers to believe that there is a subtle connection between dopamine levels and the ability of the brain to produce other chemical neurotransmitters.

Shaking Palsy
When James Parkinson originally described the symptoms of the disease that is named for him, he called it 'shaking palsy'.

Sialorrhea
The medical term for drooling, which is often seen in late stage Parkinson's disease.

Side Effect
An effect of taking a drug that is different from the reason for which it is prescribed. Many of the drugs prescribed to treat Parkinson's disease have side effects that interfere with normal functioning.

Striatum
A part of the brain that contains dopamine receptors. It is the largest part of the basal ganglia and controls walking, balance and movement.

Substantia Nigra
The part of the brain that is affected by Parkinson's disease. It's located in the brainstem, and contains the cells that produce dopamine. It's the loss of those cells that produce the symptoms of Parkinson's disease.

T

Thalamic (or Pallidal) Stimulation
One of the newer treatments for Parkinson's disease that involves electrically stimulating cells in the thalamus or globus pallidus to treat symptoms of Parkinson's, rather than surgically destroying the cells.

Thalmatomy
A traditional treatment to stop tremors on one side of the body. It involves surgically destroying a small group of cells in the thalamus, and results in improving the symptoms of tremors on the opposite side of the body. the side of the body opposite the surgery.

Thalamus
A major area of the brain that receives information from the basal ganglia. One treatment for symptoms of Parkinson's disease is to destroy a small group of cells in the thalamus.

Tremor
One of the major symptoms of Parkinson's disease. A tremor is the rhythmic shaking of a limb that occurs when the muscles are at rest, or when they are initiating (or starting) a movement. In later stages, tremors may also appear during movements.

W

Wearing-Off
The end period of effectiveness of a dose of L-dopa, used to treat Parkinson's disease. In long-term treatment, the wearing-off period often occurs after only a few hours, long before the next dose is due.