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Glossary of Terms
When you or a loved one has been diagnosed with multiple system atrophy, it can feel overwhelming. Learning the language of MSA can be a helpful tool throughout your journey.
A-C
D-F
G-J
K-P
Q-S
T-V
W-Z
A-C
Agonist
A drug that imitates a neurotransmitter. Dopamine agonists are drugs that imitate the actions of dopamine.
Akinesia
Inability to move (“freezing”) or difficulty in beginning or maintaining a body motion.
Anticholinergic
A drug that blocks the action of acetylcholine, a neurotransmitter in the brain. Anticholinergic drugs are often effective in reducing the tremor of Parkinson’s disease.
Ataxia
A mobility-impairment condition marked by loss of balance and decreased coordination.
Basal ganglia
Large clusters of neurons deep within the brain that are responsible for voluntary movements such as walking and movement coordination. Includes the striatum, the subthalamic nucleus, and the substantia nigra.
Bradykinesia
The slowing down and loss of spontaneous and voluntary movement.
Cogwheel Rigidity
A type of rigidity in which a muscle responds with cogwheel-like jerks when the muscle is stretched or the limb is bent.
CT (CAT) Scan
Computed tomography, a technique that uses a series of X-rays to create image “slices” of the body from different orientations to create a two-dimensional image of the body. The term CAT Scan (computed axial tomography) refers to a specific orientation of images.
D-F
Dysarthria
Slurred or otherwise impaired speech.
Dysequilibrium
Unsteadiness or balance problems.
Dyskinesias
Involuntary, uncontrollable, and often excessive movement. These movements can be lurching, dance-like or jerky, and are distinct from the rhythmic tremor commonly associated with Parkinson’s disease. A common side effect of many drugs used to treat Parkinson’s disease.
Dysphagia
Difficulty in swallowing.
Dystonia
Abnormal and awkward posture or sustained movements of a hand, foot, or other part of the body; may be accompanied by rigidity and twisting.
Festination
A quickening of steps and shuffling after starting to walk.
Freezing
Abrupt and temporary inability of Parkinson’s patients to move that frequently occurs at a boundary such as a door or when exiting a car.
G-J
Globus Pallidus
A structure (group of nerve cells) deep in the brain affecting movement, balance, and walking.
Hypomimia
Immobile, expressionless face with reduced blinking.
K-P
Micrographia
Small, cramped handwriting that is a symptom for many Parkinson’s patients.
Monoamine oxidase inhibitors (MAO)
Drugs that enhance the effect of dopamine by preventing enzymes from breaking them down.
Movement disorders
Refers to several conditions, many of them neurodegenerative, that prevent normal movement. Some are characterized by either lack of movement (bradykinesia, hypokinesia, etc) or excessive movement (chorea, athetosis, dystonia, tremor). Besides Parkinson’s, other conditions often defined as movement disorders include essential tremor, multiple system atrophy, progressive supranuclear palsy, Huntington’s disease, Tourette’s syndrome and cerebral palsy.
MRI (Magnetic Resonance Imaging)
Three-dimensional images of the brain obtained in a scanner using a powerful magnet.
Neurodegenerative
Refers to conditions such as Parkinson’s that are characterized by the loss of cells in the central nervous system.
On-Off Phenomenon
Sudden loss of activity of levodopa lasting minutes to hours after a brief period of effectiveness. The term also sometimes refers to a cyclical response to medication where the patient can function adequately at times but is too stiff and immobile to function at other times.
Orthostatic hypotension
Sudden drop in blood pressure (>20 mm Hg systolic) upon standing and accompanied by symptoms such as dizziness, fatigue and syncope.
Parkinsonism
Generic term referring to slowness and mobility problems that look like Parkinson’s disease. Several conditions, such as multiple system atrophy and progressive supranuclear palsy, and a number of medications produce this appearance.
PET scan
An acronym for “positron emission tomography,” an imaging technique used to monitor and produce pictures of metabolic or biochemical activity in the brain.
Pill-rolling
One of the characteristic slower tremors in the fingers of Parkinson’s patients; the alternating movements of the thumb and forefinger give the appearance of rolling a small object between the fingers.
Q-S
Rigidity
Abnormal stiffness in a limb or other body part. It is most apparent when an examiner moves a patient’s limb — as in cogwheeling.
Striatum
Also known as the corpus striatum, it is the largest component of the basal ganglia in the brain and controls movement, balance, and walking.
Substantia Nigra
Literally means “black substance.” A part of the basal ganglia, located in the midbrain, that is rich in dopamine-producing nerve cells and the black pigment neuromelanin (hence its name). In Parkinson’s the loss of nerve cells from this region leads to a dopamine deficit and subsequently to Parkinson’s symptoms.
Subthalamic Nucleus (STN)
A nerve center near the substantia nigra. The STN may be targeted for deep brain stimulation (DBS) to reduce Parkinson’s symptoms.
T-V
Thalamus
A mass of gray matter (nerve cells) located deep in the brain that is responsible for motor control and serves as a relay center for sensory signals.
Tremor
Unwanted rhythmic movements (may be fast or slow) that may affect the hands, head, voice or other body parts.
Trigger Event
An external or environmental factor such as head trauma, exposure to a toxin, or stress that contributes to the development of a condition or disease.
W-Z
Wearing Off
Loss of effectiveness of Parkinson’s medications between doses. If the effectiveness of a medication does not last until the next dose is due, it “wears off.”
