Glossary

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 disorder 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 asgeste 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.