Glossary
The following glossary was created to help
clarify the information included in this website. Please note that the
definitions below are given in the specific context of dystonia, and
that some of the words and phrases may have additional meanings and
implications beyond dystonia.
Ablation (pronounced:
ab-lay’-shun): When used in terms of brain surgery, a
category of procedures in which an area of the brain is permanently
altered or disabled to reduce unwanted movement symptoms. Examples
include pallidotomy or thalamotomy.
Acetylcholine (pronounced:
ah-see’-til-koh-leen): A neurotransmitter
chemical that allows nerve cells and muscles to communicate.
Acetylcholine transmits signals from the nerve endings into the muscle,
signaling the muscle to contract.
Adult
onset: A category of dystonia in which the symptoms
begin in
adulthood, typically after the age of 30. The term “late onset” may
also be used.
Athetoid/Athetosis (pronounced:
atha-toid’/atha-toe’-sis):Athetosis is a
specific kind of involuntary muscle movement. Athetoid movements are
slow and continuous with a “writhing” quality. Athetosis especially
involves the hands and may also affect the torso and other parts of the
body.
ATP1A3: The ATP1A3 gene is
the gene associated with rapid-onset
dystonia-parkinsonism.
Autosomal dominant (pronounced
oh’-toe-so-mal): An autosomal dominant disorder
is
a disease in which only one parent needs to have the mutated gene for a
child to inherit the disease. An example is DYT1
dystonia.
Autosomal recessive (pronounced
oh’-toe-so-mal): An autosomal recessive disorder is a disease
in which both parents must have the mutated gene for a child to inherit
the disease. An example is a form of dopa-responsive dystonia
associated with the hTH
gene.
Axial: Dystonia that
affects
the ‘midline’ of the body—chest, abdominal, and back muscles—may be
referred to as axial dystonia. Axial dystonia is often a component of
generalized
dystonia.
Ballistic/Ballism: Ballistic
movements are severe, often swinging or jerking, involuntary muscle
movements that involve portions of the limb such as the shoulder and
elbow, and hip and knee. Ballism may be seen in conjunction with
chorea.
Basal
ganglia: An
area deep inside the brain that is believed to play a major role in the
coordination of voluntary muscle movement. The basal ganglia are a
group of structures that include the globus pallidus (also called the
pallidum), the thalamus, and the subthalamic
nucleus.
Blepharospasm (pronounced
blef-arrow’-spazim): Focal dystonia that affects the muscles
of the eyelids and brow is called
blepharosm.
Brain pathways: The
brain communicates with strings or “pathways” of individual brain cells
that fire signals at each other in circuits or patterns. The signals
are chemical messages needed to complete a task. These circuits are how
areas of the brain communicate with one another and with the rest of
the body. In an individual with dystonia, the circuits that facilitate
the movement of the foot are disrupted by abnormal
activity.
Central nervous
system: The brain and spinal cord.
Cervical dystonia (spasmodic
torticollis): Focal dystonia that affects the
muscles of the neck and shoulders.
Childhood
onset: A category of dystonia in which the symptoms
begin in
childhood, typically before the age of 30. The term ‘early onset’ may
also be used.
Choreic/Chorea (pronounced
kor-ee’-ick/kor-ee’-yah): Choreic movements are typically
brief, rapid, involuntary movements of the limbs and facial muscles
that serve no purpose. When mild, choreic movements may resemble
fidgeting. Chorea is often the characteristic movement symptom of
Huntington’s disease.
Choreoathetosis (pronounced
kor-ee-ah-thuh-toe’-sis): A term used to
describe
chorea and athetosis occuring simultaneously.
Cranial: Dystonia
that affects any muscle above the neck—eyes, mouth, jaw, tongue—may be
referred to as cranial dystonia.
Diurnal
fluctuation (pronounced “die-urn-al
fluck’-shoo-ay-shun): The
phenomenon where symptoms of a disorder are mild early in the day and
gradually become more severe as the day goes on. This is a
characteristic feature of dopa-responsive
dystonia.
Dominant: An autosomal
dominant disorder is a disease in which only one parent needs to have
the mutated gene for a child to inherit the disease. An example is DYT1
dystonia.
Dopamine: A
neurotransmitter chemical found in the brain and believed to play a
role in many dystonias.
Dyskinesia (pronounced
dis’-keh-neez-yah): A general term to describe
any
kind of involuntary muscle movement. For example, dyskinesias may be
dystonic, chroeic, ballistic, resemble other movement disorders, or
occur in
combination.
Dystonic/Dystonia: Dystonic
movements are typically patterned and repetitive, causing twisting
movements and abnormal postures. Dystonia occurs when opposing muscles
are contracting simultaneously. The activation of these muscles may
"overflow" to other muscle groups
unintentionally.
DYT1: The gene
associated with a specific form of early onset generalized dystonia
(also called Oppenheim’s dystonia) is the DYT1 gene.
Early
onset: A category of dystonia in which the symptoms
begin in
childhood, typically before the age of 30. The term “childhood onset”
may also be used.
Epsilon-sarcoglycan (pronounced ep’-sih-lon
sar-koh-gly’-kan): The gene
associated
with myoclonic dystonia is called the epsilon-sarcoglycan (SGCE)
gene.
Familial: A disorder that
is
inherited and occurs in multiple members of an extended family. Some
forms of dystonia are described this way.
Focal: A general
term for any dystonia that affects one area of the body such as the
eyes, mouth/jaw, neck, vocal cords, and
hands.
GAG
deletion: The specific
mutation in the DYT1 gene that is associated with DYT1 dystonia may be
referred to as the GAG deletion because the mutation causes the gene to
be lacking in a specific sequence of bases: guanine-adenine- guanine
(GAG).
Generalized: Generalized
dystonia affects the limbs, trunk, and other major body areas
simultaneously.
Genetic: Genetic
dystonias are cause by specific mutations in an individual’s
DNA.
GTP-CH1: The most common
form
of dopa-responsive dystonia is believed to be caused by a mutation in
the GTP-CH1 gene.
Hemidystonia: Dystonia
symptoms that affect multiple body areas on only one side of the body
may be called hemidystonia. This form is almost always
secondary.
hTH: A specific form
of
dopa-responsive dystonia is caused by a recessive mutation in the hTH
gene.
Hypnogenic (pronounced:
hip-no-jen’-ick): A word used to describe symptoms that occur
during sleep
Idiopathic (pronounced:
id’-ee-oh-path-ick): With regard to dystonia, this term is
used to describe a form of the diorder in which no direct cause (such
as brain injury due to trauma, medications, another disorder or
condition, or a specific gene mutation) can be identified. This word
was once often used to describe forms of dystonia that were presumed to
be genetic.
Inherited: With
regard
to dystonia, a form that is passed on genetically from parent or
ancestor to a child
Intrathecal (pronounced
in-tra-thee’-kal): A method to deliver medication
directly into the spinal canal by surgically implanting a catheter and
pump-like device. An example is intrathecal baclofen, otherwise known
as the baclofen pump.
Kinesigenic (pronounced
kin-eez’-ah-jen-ick): With regard to movement
disorders, symptoms that are triggered by sudden body movements such as
a startle or by specific activities may be described as kinesigenic.
This is most often used to describe certain paroxysmal dyskinesias—i.e.
paroxysmal kinesigenic dyskinesias
Laryngeal dystonia (spasmodic
dysphonia): A focal dystonia that affects the
vocal
cords.
Late onset: A
category of dystonia in which the symptoms begin in adulthood,
typically after the age of 30. The term “adult onset” may also be
used.
Lesioning: When used in
terms of brain surgery, a lesioning procedure is one in which an area
of the brain is permanently altered or disabled to reduce unwanted
movement symptoms. Examples include pallidotomy or thalamotomy. Also
known as “ablation.”
Lingual: Dystonia
that specifically affects the tongue may be called lingual
dystonia.
Movement
disorder: A movement disorder is a chronic
neurological
condition that affects the ability to control muscle movement. The
three most common movement disorders are tremor, Parkinson’s disease,
and dystonia.
Myoclonic/Myoclonus (pronounced
my’-oh-klon-ick/my’-oh-kloh-nus): Myoclonus is a
movement disorder characterized by sudden, brief, shock-like movements.
Individuals with myoclonic dystonia exhibit symptoms of dystonia plus
very prominent myoclonic movements. Many people with primary
generalized dystonia have myoclonic
jerks.
Nerve
cell: A neuron; one
of the cells that makes up the nervous system. May describe a brain
cell.
Nervous
system: The body’s
system to receive and interpret stimuli and send instructions to the
organs and peripheral parts of the body. The nervous system includes
the brain, spinal cord, and
nerves.
Neurological disorder: Any
disease or condition that affects the nervous
system.
Neuron: A nerve cell; one
of the cells that makes up the nervous system. May describe a brain
cell.
Neurotransmitter: A
chemical in the body that serves as a “messenger” and transmits signals
between nerve cells (also called neurons) or between the nerves and
muscles or
organs.
Non-kinesigenic: With
regard to movement disorders, symptoms that are not triggered by sudden
or specific body movements (such as a startle) may be called
non-kinesigenic. This is most often used to describe certain paroxysmal
dyskinesias—i.e. paroxysmal non-kinesigenic dyskinesias, in which
symptoms may be triggered by fatigue, stress, alcohol, caffeine intake,
temperature, or other factors.
Oromandibular
dystonia (pronounced oh’-roh-man-dib-u-lar): Focal
dystonia that
affects face, mouth, and/or jaw. May be referred to as “cranial
dystonia.”
Pallidotomy: A
surgical procedure for dystonia in which a part of the brain called the
globus pallidus (part of the basal ganglia) is permanently altered.
This is done to reduce the signals sent to the muscles that instruct
them to contract
involuntarily.
Parkinsonian/
Parkinsonism: Parkinson’s disease is a degenerative
neurological disorder with a range of symptoms. Some of the
characteristic movement symptoms are a slowness of movement (also
called bradykinesia), rigidity of the
muscles, and a resting tremor.
Symptoms that resemble these elements of Parkinson’s disease may affect
people diagnosed with several kinds of movement
disorders.
Paroxysmal (pronounced:
pear-ocks-is’-mal): Symptoms that occur only in episodes or
“attacks” may be referred to as
paroxysmal.
Penetrance: The
percentage of people who inherit a specific disease gene mutation who
actually develop symptoms of the disease. For example, approximately
30% of people who inherit the DYT1 mutation for early onset dystonia
will develop symptoms. This phenomenon may be referred to as reduced,
variable, or incomplete
penetrance.
Peripheral: With
regard to dystonia, a phenomenon (such as trauma or surgery) that
impacts an area of the body away from the central nervous system, such
as nerve endings or
muscles.
Preimplantation genetic
diagnosis: A method of in vitro fertilization in
which
couples
can dramatically reduce the possibility of a child inheriting a
disease-causing genetic mutation. Several of a woman’s eggs are
fertilized outside her body and those conceptions that test negative
for the disease mutation are re-implanted into her uterus. The
procedure is feasible for forms of dystonia that are associated with a
single gene mutation such as DYT1 dystonia.
Primary: Those
forms of the disorder that occur without the symptoms of any other
neurological or metabolic
disease.
Psychogenic: A term used
to describe physical symptoms that originate from a psychological or
psychiatric
condition.
Ramisectomy: A
specific
surgical maneuver included in selective denervation for cervical
dystonia that involves removing a specific branch of one or more spinal
nerves along the cervical vertebrae.
Rating
scale: A measure created by movement disorder
experts to
quantify and assess the severity of an individual’s dystonia. An
example is the Burke-Fahn-Marsden Dystonia Rating Scale which is names
for the physicians who created
it.
Rhizotomy: A specific
surgical
procedure in which a specific nerve is removed at the
root.
Recessive: An autosomal
recessive disorder is a disease in which both parents must have the
mutated gene for a child to inherit the disease. An example is a form
of dopa-responsive dystonia associated with the hTH
gene.
Secondary: Those
forms of dystonia that are attributed to an outside factor such as
physical trauma, exposure to certain medications, and additional
neurological or metabolic diseases.
Segmental: A
word used to describe dystonia that affects several adjoining parts of
the body, for example the neck, shoulders, and
arm.
Sensory
trick: A phenomenon
where a person with dystonia may temporarily reduce symptoms by gently
touching part of the body. Common examples include a person with
cervical dystonia placing a finger under the chin to straighten the
head, or a person with dystonia of the jaw placing a toothpick in the
mouth to reduce symptoms. Some symptoms respond to sensory tricks and
others do not, and the same sensory tricks may not work for different
people, even if they have similar symptoms. Also known as
geste
antagoniste.Spasmodic
dysphonia: A synonym for laryngeal
dystonia
Spasmodic
torticollis: A synonym for cervical
dystonia
Sporadic: A case of
dystonia that is genetic or presumed to be genetic when the affected
person does not have a history of dystonia in the
family.
Tardive: A term used to
describe secondary dystonia or dyskinesias that are specifically
attributed to exposure to specific drugs
(“drug-induced”).
Task-specific: A
term used to describe forms of dystonia such as writer’s cramp
and musician’s dystonia that occur only when the individual
is performing a specific task (such as writing or playing a musical
instrument).
Thalamotomy: A
surgical procedure for dystonia in which a part of the brain called the
thalamus (which is part of the basal ganglia) is permanently altered.
This is done to reduce the signals sent to the muscles that instruct
them to contract involuntarily.
Torsion (pronounced tor’-shun): The
word torsion is usually used in
reference to generalized, axial, or segmental dystonia. Torsion refers
to the twisting element of dystonia. It describes muscles contracting
against each other
TorsinA (pronounced:
tor’-sin-ay): The name of the protein associated with the
DYT1
gene and early-onset generalized
dystonia.
Writer’s cramp: A focal
dystonia that affects the forearm, hand, and fingers.
X-linked: A
disease that is inherited in an x-linked pattern is caused by a
mutation in one of the sex chromosomes. Sex chromosomes determine an
individual’s gender, and so the symptoms of an x-linked disorder will
affect females and males differently. For example, in x-linked dystonia
parkinsonism, women may be carriers of the mutation but rarely develop
symptoms. Men, however, may inherit the mutation from their mothers and
almost always develop symptoms when they do.
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