Abduction:
The movement of an extremity away from the median plane.
Absence seizures:
These seizures begin and end suddenly. During these seizures, the patient interrupts their ongoing activity, remains motionless for a few seconds to half a minute with a blank stare, and then resumes their activity without any further symptoms. The patient does not respond to spoken questions during the seizure.
Acetylcholine:
A neurotransmitter chemical.
Adaptive Behavior:
The skills a child needs to participate effectively and appropriately in school, family, and community settings in an age-appropriate manner.
Aerophagia:
The term given to the excessive swallowing of air, which can occur during rapid eating or drinking, or due to anxiety.
Alternative communication methods:
Preferred methods for communicating with people in situations where verbal communication is absent or insufficient.
Amino acids:
The basic building blocks that make up proteins.
Anecdotal:
A report of clinical experience based on individual cases.
Angelman Syndrome (Happy Puppet Syndrome):
This is a genetic disorder that causes difficulties with speech, balance, and walking. Patients may experience developmental disorders as well as neurological problems. Frequent smiling and laughing are among the consequences of Angelman Syndrome. Angelman Syndrome is usually not noticed until the baby is 6–12 months old. Seizures may also appear by the age of 2–3 years. Individuals with Angelman Syndrome can lead normal lives, but their high levels of excitement decrease over time.
Ankle-foot orthosis (AFO):
Orthopedic products used to support the ankle in cases of ankle deformities.
Anorexia:
A type of eating disorder. A psychological disorder characterized by a person’s voluntary refusal to eat.
Anticonvulsant:
A type of medication used to prevent seizures.
Apnea:
The term given to a condition in which breathing stops for a short period of time. It usually occurs during sleep.
Apraxia:
A motor speech disorder that results from the brain’s inability to properly transmit messages to the speech muscles.
Asphyxia:
A condition that develops as a result of insufficient oxygen supply to an organ or tissue, or a decrease in blood flow to the tissue.
Aspiration:
The entry of foreign substances, such as stomach contents, into the respiratory system during breathing.
Aspiration pneumonia:
An infection that occurs when a foreign body, once aspirated, travels into the alveoli of the lungs.
Assay:
A method used to measure chemical and biological compounds.
Ataxia:
A nervous system disorder resulting from cerebral damage that causes incoordination in the use of voluntary and involuntary muscles. It results in balance problems and impaired coordination between movements.
Atom:
A particle consisting of a nucleus (protons and neutrons) and electrons. Atoms differ from one another by having different numbers of protons, neutrons, and electrons. Groups of atoms bonded together are called molecules.
Atonic seizures:
Seizures characterized by sudden muscle relaxation, causing the child to fall to the ground or the head to suddenly drop forward.
Atrophy:
The shrinking of a body, organ, tissue, or cell that was once of normal size.
Atypical:
Different; not typical.
**Auditory Evoked Potential (AEP):
**A test used to determine whether specific parts of the vestibular system in the brain are functioning properly.
Augmentative communication:
Forms of communication that strengthen, modify, or complement spoken and written communication.
Aura:
Usually appears before an epileptic seizure and is a harbinger of an impending seizure. Auras vary from person to person. Individuals may report smelling an odor or hearing a ringing or buzzing sound before the seizure.
Autism:
A developmental disorder that causes impairments in social interaction and verbal and nonverbal communication.
Automatisms:
Involuntary automatic movements that accompany seizures, such as hand clapping, gathering one’s clothes, and chewing.
Autonomic Nervous System:
Regulates and manages vital bodily functions such as respiration, digestion, metabolism, and secretion. It performs all these activities involuntarily.
Autonomic Responses:
Involuntary bodily functions such as breathing, sweating, blood pressure, heart rate, and washing the face.
Autosome:
Any of the first twenty-two chromosome pairs. Except for the sex chromosomes X and Y, all chromosomes are autosomes.
Autosomal Dominant Trait:
Genetic traits carried on autosomes. A disorder occurs when a pair of chromosomes contains an abnormal gene; statistically, it is passed from carrier parents to their children.
Autosomal Recessive Diseases:
Diseases in which a functional change in both genes located at the same locus is necessary for the disease to occur.
Axon:
The cytoplasmic extension that emerges from the cell body and does not branch. Each neuron has one axon. It carries signals from the nerve cell to other nerve cells or effector cells such as muscle or glandular cells and plays a vital role in message transmission.
Babinski Reflex:
When you trace a line from heel to toe on your baby’s foot, the foot will curl inward and the toes will lift. This reflex disappears between 6 months and 2 years of age, after which the toes will begin to curl inward.
Barrett’s esophagus:
Abnormal mucosal changes in the lower part of the esophagus. The main cause is gastroesophageal reflux disease, where stomach contents are constantly exposed to acid reflux.
Basal Ganglia:
Groups of neurons located laterally to the thalamus and deep within both hemispheres. They translate thought into motor activity and play a role in the planning, initiation, and execution of sequential voluntary movements.
Base:
A straight ring structure containing nitrogen, carbon, oxygen, and hydrogen that forms part of nucleotide linkages in a nucleic acid chain. The four bases are adenine (A), thymine (T), guanine (G), and cytosine (C).
Base Pair:
Two bases that are weakly chemically attracted to each other, one on each strand of a double-stranded nucleic acid molecule. Only specific pairs occur: AT (or TA), GC (or CG), AU (or UA).
Beta endorphins:
The body’s natural pain relievers that exhibit properties similar to meperidine and morphine.
Binding:
Adding.
Biogenic amines:
Neurotransmitters such as dopamine, norepinephrine, serotonin, and other amino acids.
Biological marker:
A scientific test that proves the presence of a condition.
Body Jacket:
A molded, padded, thin plastic support designed to apply gentle pressure in appropriate areas to straighten the spine.
Bolus:
The amount that can be given at one time during tube feeding.
Brain Stem Auditory Evoked Response (BAER):
A test that evaluates sound processing by the brainstem.
Brain storage defects:
Metabolic disorders resulting from the inability of certain materials to be metabolized and their subsequent storage in nerve cells in the brain.
Brainstem:
The part of the brain located between the cerebellum and the spinal cord.
Breathholding:
A rapid inhalation of a single full breath followed by delayed exhalation during which breathing stops. Also known as aerophagia.
Bruxism:
Teeth grinding; the act of grinding the teeth, commonly seen in Rett Syndrome.
Carnitine:
An amino acid that helps transport long-chain fatty acids.
Cell:
The smallest unit of living matter capable of self-sustaining; an organized set of chemical reactions capable of reproduction. A cell is bounded by a membrane that separates the inside of the cell from the outside environment.
Cell Membrane:
The membrane that protects the cell components and cell fluid.
Central Apnea:
The cessation of breathing with exhalation.
Central Nervous System (CNS):
Part of the nervous system consisting of the brain and spinal cord. It controls voluntary movement and thought processes.
Cerebral cortex:
The outer part of the brain.
Cerebral palsy:
A movement and posture disorder caused by a non-progressive defect in the brain.
Cerebrospinal Fluid (CSF):
The clear fluid surrounding the brain and spinal cord.
Cerebrum:
The largest region in the brain; it consists of four lobes and is connected to the corpus callosum.
Chiropractic:
A method of treating diseases, particularly those involving manipulation of the spinal vertebrae; used in the treatment of nerve and muscle diseases.
Chromatin:
The structure formed by DNA in the nucleus together with small, basic proteins called histones.
Chromosome:
Short, curved rod-shaped chromatin threads responsible for heredity in cells of humans, animals, and plants.
Chromosome analysis:
The examination of forty-six possible chromosome structures that contain the genetic code for physical and biochemical characteristics.
Chronological age:
The child’s actual age in years and months.
Clinical Diagnosis:
A conclusion based on findings from the patient’s history and physical examination, generally not as definitive as laboratory diagnoses.
Clonus:
Alternate muscle contractions followed by rapid, successive relaxations.
Code (Genetics):
The system representing the arrangement of amino acids within a protein, based on the arrangement of nucleotides in DNA.
Cognitive Disability:
An educational term, often synonymous with the medical term for intellectual disability.
Cognitive Skills:
Thinking abilities, often represented by IQ scores.
Colony:
A group of identical cells derived from a single ancestor.
Computerized Axial Tomography (CAT Scan):
An X-ray technique used to examine soft tissues by recording body “slices” and reconstructing cross-sectional images via computer.
Congenital:
Before or during birth.
Constipation:
A condition characterized by infrequent bowel movements, hard and small stools, or difficulty or pain during bowel movements.
Contracture:
Irreversible shortening of muscle fibers that leads to reduced joint mobility.
Corpus Callosum:
A white matter bridge connecting the two hemispheres of the brain.
Convulsion:
A series of involuntary muscle contractions.
Cortex:
The gray matter located on the outer part of the cerebrum.
Cyanosis:
A bluish discoloration of the skin and mucous membranes due to insufficient oxygen in the blood.
Cytological:
The examination of cell structure using a microscope.
Cytoplasm:
The jelly-like substance surrounding the nucleus of a cell.
Deceleration:
In Rett Syndrome, deceleration usually refers to a slowing of the head growth rate (circumference).
Degenerative CNS disorder:
A marked regression in brain development. Rett syndrome is no longer considered a degenerative CNS disorder.
Deletion:
The loss of genetic material from a chromosome.
Dementia:
A disorder defined as a significant decline in intellectual ability and loss of cognitive skills.
Dendrite:
The part of a nerve cell that makes contact with another nerve cell and transmits stimuli to the cell body.
Deoxyribonucleic acid (DNA):
A fundamental component of living tissue whose primary function is to carry genetic code.
Developmental arrest:
The complete cessation of developmental progress after normal development.
Developmental Delay:
A delay in the development of skills and abilities that typically develop with age.
Diagnostic Test:
A test that provides a comprehensive assessment of a skill area, including strengths, weaknesses, and error patterns.
Differential:
A situation in which the symptoms of one disease are similar to those of other diseases.
Diffuse:
Spreading; as in diffuse cerebral palsy, where both sides of the brain are affected rather than a localized area.
Distal:
Located far from the body’s midline.
Dominant:
A gene that is dominant in determining traits.
Dorsiflexion:
The backward flexion of the foot or hand.
Duodenum:
The upper part of the small intestine.
Dysmotility:
A term generally used for body parts that function automatically and show impaired movement.
Dyspraxia:
Partial impairment of the ability to perform coordinated motor movements.
Dystonia:
A neurological movement disorder causing involuntary muscle contractions and twitching in part or all of the body.
Electrocardiogram (ECG):
A monitoring device that records changes in electrical potential during a heartbeat.
Electroencephalogram (EEG):
A test used to measure and record brain waves. In Rett Syndrome, although clinical seizures are not observed, the EEG is almost always abnormal.
Electromyelogram (EMG):
A test that measures the level of muscle contraction and relaxation, as well as muscle performance.
Empirical:
Data based on experience or expertise.
Encephalopathy:
Diseases in which degenerative changes generally occur in brain tissue.
Encoding:
A nucleotide sequence that specifies the inclusion of one or more specific amino acids into a protein.
Endometrial ablation:
A laser procedure that completely or partially stops menstrual bleeding.
Endorphins:
The body’s natural opioids that enhance the perception of pain and pleasure.
Endoscopy:
A diagnostic method used to visualize the inside of a hollow organ such as the esophagus.
Enzyme:
A protein molecule specialized for accelerating a biological chemical reaction.
Epiglottis:
A valve-like structure located at the entrance of the trachea that prevents aspiration into the lungs during swallowing.
Epilepsy:
A neurological disorder characterized by excessive activation of nerve cells in affected areas of the brain.
Epileptiform Patterns:
Patterns that exhibit seizure-like characteristics.
Equilibrium:
Balance.
Equinus:
The involuntary downward extension of the foot due to a firm or overactive heel.
Esophagitis:
Inflammation of the esophagus.
Esophagus:
The tube extending from the pharynx to the stomach.
Exon:
A region of RNA that codes for a portion of a protein.
Fine Motor Coordination:
The ability to use small muscles to perform tasks requiring precision.
Flexion:
The bending of a joint.
Flexor:
A muscle whose primary function is joint flexion.
Form Frustu (Forme fruste):
An expression referring to a form that is difficult to define precisely, such as a Rett variant possessing most, but not all, classic characteristics.
Fortunate Activation:
In females, one of the two copies of the X chromosome is randomly deactivated. Fortunate activation refers to suppression of the abnormal X chromosome, allowing the normal copy to function.
Frontal lobe:
The front part of the cerebrum where voluntary muscle movements, behavior, and memory are controlled.
Fundoplication (fundal plication):
A surgical procedure performed to treat gastroesophageal reflux disease.
Gagging:
The voluntary or involuntary rhythmic movement of the epiglottis behind the tongue.
Gait:
The manner or pattern of walking.
Gastroenterologist:
A physician specializing in disorders of the digestive system.
Gastroesophageal reflux disease (GER):
The movement of stomach contents into the esophagus.
Gastrostomy (G-tube):
A feeding tube surgically inserted into the stomach through the abdominal wall.
Gel electrophoresis:
A method used to separate molecules based on size and electrical charge.
Gene:
A unit of heredity; a sequence of nucleotides forming part of a chromosome.
Gene Cloning:
A method used to produce many identical copies of a specific DNA segment.
Gene expression:
The process by which genetic information is converted into functional protein structures.
Gene Therapy:
A technique involving the insertion of a normal gene into cells carrying a defective gene to correct missing or faulty proteins.
Generalized Seizure:
A seizure that affects the entire brain.
Genetic Engineering:
The field of research involving the manipulation and modification of genetic material.
Genetic Map:
A representation of the relative positions of DNA regions based on recombination frequency.
Genome:
The complete set of chromosomes containing all genetic information.
Genotype:
The genetic makeup of an individual.
Germ cells (gametes):
Reproductive cells.
GI:
Gastrointestinal.
Grand Mal Seizure:
A major seizure involving loss of consciousness and widespread motor involvement.
Gray Matter:
A major component of the central nervous system containing neuron cell bodies and short nerve cell extensions.
Gross:
Macroscopic examination of visible organs and structures without a microscope.
Grossly Normal:
Refers to a detailed assessment indicating no visible abnormalities.
Gross Motor Coordination:
Coordination of large muscle groups enabling activities such as walking and running.
Gyri:
Folds on the surface of the brain.
Habilitation:
Teaching new skills.
Head Circumference:
A measurement used to determine whether a baby’s head growth and development are progressing normally.
Heredity:
The transmission of genetic traits from parents to offspring.
Hip Dislocation:
In infants, a condition in which the head of the femur is displaced from its normal socket.
Hip subluxation:
Partial displacement of the femoral head that may progress to hip dislocation.
Hippotherapy:
Therapeutic horseback riding used to improve motor and sensory function.
Histones:
Small, basic proteins found mainly in eukaryotic cells that help package DNA into chromatin.
Human Genome:
The complete chromosomal structure containing all genetic information.
Hydrotherapy:
Physical therapy performed in water using specially designed pools.
Hypertonia:
A condition characterized by abnormally increased muscle tone and reduced ability of the muscle to stretch.
Hypsarrhythmia:
An abnormal EEG pattern characterized by chaotic, high-amplitude slow waves and spikes.
Hypoplasia:
Incomplete or abnormal development of an organ or tissue.
Hypothesis:
An assumption or proposed explanation made on the basis of limited evidence.
Hypotonia:
Abnormally low muscle tone, often accompanied by muscle weakness.
Hypoxia:
A deficiency of oxygen reaching the tissues and organs.
Ictus:
Relating to a sudden, severe seizure, such as an epileptic seizure.
Idiopathic:
Of unknown cause.
Ileum:
The lower part of the small intestine.
Incidence:
The frequency of occurrence of a condition or disease.
Independent Living Skills:
A child’s ability to meet basic needs such as eating, drinking, dressing, and personal hygiene without assistance.
Intelligence Quotient (IQ):
A scale comparing a child’s test performance to that of peers of the same age.
Intelligence Test:
A test used to determine a child’s cognitive and academic functioning level.
Intubation:
Insertion of a tube into the trachea to provide ventilation and ensure adequate oxygenation.
Intussusception:
A condition in which part of the intestine slides into an adjacent part, causing bowel obstruction.
Invasive test:
Diagnostic procedures performed by entering the body, such as through a tube or injection.
In utero:
The period of development occurring before birth, within the uterus.
JOY:
The feeling we get from your daughter’s smile.
Karyotyping:
A photographic representation of a cell’s chromosomal structure.
Ketogenic Diet:
A diet based on high fat intake, used especially in the management of certain seizure disorders.
Ketosis:
A buildup of acids (ketone bodies) in the body; an important metabolic state in the ketogenic diet.
Kinesthesia:
Unconscious awareness of body position and movement.
Kyphosis:
An abnormal curvature of the spine, often described as a “hunchback.”
Lumbar Puncture (Spinal Tap):
A procedure in which a needle is inserted into the spinal canal to obtain cerebrospinal fluid (CSF) for diagnostic purposes.
Lysosomal Enzymes:
Enzymes involved in the digestive processes within cells.
Magnetic Resonance Imaging (MRI):
An imaging procedure that uses magnetic fields and radio waves to produce detailed images of the inside of the body.
Medulla:
Part of the brainstem.
Meiosis:
A type of cell division in which a diploid cell divides to produce haploid gametes.
Melatonin:
A hormone involved in regulating sleep–wake cycles and circadian rhythms.
Meninges:
Three layers of connective tissue membranes that surround and protect the brain and spinal cord.
Mental Age:
The age at which a child begins to acquire the ability to think abstractly and realistically.
Mental retardation:
A condition originating in childhood characterized by significant limitations in intellectual functioning and adaptive behavior.
Metabolic Disorder:
A congenital condition resulting from impaired processing of proteins, fats, or carbohydrates.
Metabolites:
Substances formed as a result of metabolic activity.
Microcephaly:
A condition in which head circumference is smaller than normal for age and sex.
Mitochondria:
Intracellular structures that convert chemical energy from food into usable cellular energy.
Mitosis:
A type of cell division that produces two identical daughter cells.
Molecule:
A group of atoms bonded together.
Mucopolysaccharides:
Metabolic products that can accumulate in cells and lead to progressive neurological disorders.
Music Therapy:
A therapeutic approach using music to develop communication, social, cognitive, and motor skills.
Mutation:
A permanent change in the DNA or RNA sequence within an organism’s genome.
Myelination:
The process by which axons are coated with myelin to improve nerve signal transmission.
Myoclonic:
Relating to myoclonus, characterized by sudden, involuntary muscle contractions.
Myopathy:
A disease affecting muscle tissue.
Nasogastric Tube (NG Tube):
A temporary plastic feeding tube inserted through the nose into the esophagus and then into the stomach.
Neurologist:
A physician specialized in the diagnosis and treatment of disorders of the nervous system.
Neurons:
Nerve cells of the brain and nervous system.
Neuropathy:
Disorders of the nerves that cause weakness, numbness, or pain.
Neurotransmitters:
Chemical substances that enable nerve cells to transmit signals to one another.
Neurotrophic:
Relating to the nourishment, growth, or maintenance of nerve (brain) tissue.
Nonspecific findings:
Findings obtained from physical examination and laboratory tests that are not specific to a single disease.
Nucleotide:
A chemical compound consisting of a phosphate group, a five-carbon sugar, and a nitrogenous base; the basic building block of DNA and RNA.
Nucleus:
The part of the cell that controls cellular activity, carries genetic information, and enables cell division.
Nystagmus:
Rapid, involuntary movements of the eyes.
Obstipation:
Severe and persistent constipation that can lead to stool impaction.
Occipital Lobe:
The posterior part of each cerebral hemisphere of the brain.
Occupational Therapy:
Therapeutic activities guided by occupational therapists to help individuals integrate mental processes with voluntary motor movements.
Organic Acids:
Errors in organic acid metabolism that can lead to acidosis, coma, and developmental and psychomotor delay in children.
Oropharyngeal Dysfunction:
Insufficient function of the mouth and pharynx, resulting in difficulties with swallowing and oral control.
Orotic Acids:
Excessive excretion of orotic acids, indicative of certain genetic metabolic disorders.
Orthopedic:
Relating to bones, joints, and the musculoskeletal system.
Orthosis:
An externally applied orthopedic device used to support, align, prevent, or correct deformities, or to improve function of movable body parts.
Osteoarthritis:
Joint inflammation characterized by degenerative changes and sometimes increased bone and cartilage volume.
Osteopenia:
Reduced bone mineral density.
Osteoporosis:
Loss of bone mineral content leading to fragile bones.
Osteotomy:
Surgical reconstruction or cutting of bone, often used in cases such as hip subluxation.
Outpatient Treatment (Ambulatory):
Medical services provided to patients in a clinic or outpatient setting without hospital admission.
Palmar Grasp:
The act of grasping an object using the palm of the hand rather than the fingertips.
Parietal Lobe:
One of the main divisions of each cerebral hemisphere; contains the sensory cortex and associated brain regions.
Pathologic Fractures:
Fractures that occur as a result of minimal trauma due to underlying bone weakness.
Pedigree:
A diagram showing relationships and inheritance patterns across multiple generations.
Peripheral Nervous System:
The part of the nervous system outside the brain and spinal cord that connects the central nervous system to limbs and organs.
Phenotype:
A patient’s clinical appearance, history, and physical findings, as distinct from genotype.
Phenylketonuria (PKU):
A congenital disorder caused by the absence of phenylalanine hydroxylase.
Ph Probe:
A diagnostic test used to detect gastroesophageal reflux (GER).
Physical Therapy:
Treatment administered by a physiotherapist to improve motor skills and strengthen body functions.
Pincer Grasp:
A hand movement using the thumb and index finger to grasp small objects.
Plantar Flexion:
Bending of the foot or toes downward toward the sole.
Pneumonia:
An infection of the lung tissue, including alveolar and interstitial spaces.
Polymorphism:
A normal variation in a gene within a population.
Positioning:
Determining and maintaining appropriate body posture for daily activities such as eating and standing.
Positron Emission Tomography (PET Scan):
An imaging technique that evaluates organ metabolism using radioactively labeled compounds.
Prenatal:
The period before birth.
Prevalence:
The total number of cases of a condition present in a population at a given time.
Probe:
A labeled fragment of DNA or RNA used to identify complementary genetic sequences.
Prognosis:
A prediction of the likely course or outcome of a disease.
Progressive:
Describes a condition that worsens over time.
Prolonged QT Syndrome:
A condition characterized by prolonged intervals between heartbeats.
Proprioceptive input:
Unconscious sensory information regarding joint position, movement, and body orientation.
Protein:
A class of large molecules composed of amino acids, essential for body structure and function.
Pseudo-arthritis:
Joint degeneration affecting bones.
Pseudobulbar Palsy:
Weakness of muscles controlled by nerves originating from the brainstem.
Pulmonary:
Relating to the lungs.
Pyramidal Tract:
A neural pathway in the brainstem involved in voluntary motor control.
QT interval:
The total time required for the ventricles of the heart to depolarize and repolarize.
Range of Motion:
The measured amount of movement available at a joint.
Receptive language:
The ability to understand language used in communication.
Recessive:
A gene whose effect appears only when paired with another gene of the same type.
Recombination:
The process by which DNA strands break and rejoin to form new combinations of genetic material.
Restriction Mapping:
A procedure using restriction endonucleases to create specific cuts in DNA for analysis.
Retinopathy:
A disease of the retina; not observed in Rett Syndrome.
Rigidity:
Abnormal stiffness of muscles.
RNA (Ribonucleic Acid):
A single-stranded molecule composed of nucleotides that plays a key role in protein synthesis.
Rotation:
Movement of a body part around its long axis.
Rumination:
The act of chewing food after swallowing in order to regurgitate it.
Salivation:
Increased production of saliva in the mouth after smelling, seeing, or thinking about food.
Scoliosis:
A curvature of the spine, usually associated with neurological disorders.
Segmental Rolling:
A rotational movement around the child’s own axis involving a twisting motion between the shoulders and hips.
Seizure:
An electrical disturbance in nerve cells of the brain resulting from changes affecting brain function.
Self-Help Skills:
The ability to independently meet personal needs such as dressing and eating.
Sensory Modalities:
Processes by which a person perceives and interprets environmental stimuli through the senses.
Sequence:
The ordered arrangement of DNA, RNA, or nucleotides.
Serial Casting:
A series of casts applied to correct shortened heel cords.
Sex Chromosomes:
The X and Y chromosomes that determine biological sex.
Short-term instructional objective:
A clearly defined statement describing what a child is expected to accomplish within a short educational period.
Simple Partial Seizures:
Seizures involving electrical activity in only one area of the brain.
Sleep Myoclonus:
Sudden muscle jerks occurring just before falling asleep.
Somatic:
Relating to body cells not involved in reproduction.
Spastic:
Characterized by increased muscle tone causing stiffness and difficulty with movement.
Spatial Disorientation:
Impaired perception of one’s position in space.
Splint:
A device used to protect or immobilize a body part.
Sporadic:
Occurring incidentally with a low probability of recurrence.
Static:
Unchanging; refers to a brain disorder that does not worsen over time.
Stem Cell:
A precursor cell that is undifferentiated and capable of developing into specialized cell types.
Stereotypies:
Repetitive, purposeless movements.
Storage diseases:
Metabolic disorders in which certain materials accumulate in brain nerve cells.
Strabismus:
A condition causing the eyes to look in different directions.
Substrate:
The substance upon which an enzyme acts.
Sulci:
Grooves or fissures on the surface of the cerebrum.
Synapse:
The neurochemical gap between two neurons.
Syncope:
Temporary loss of consciousness (fainting).
Systemic Illness:
A disease affecting the entire body rather than a single organ.
Temporal Lobe:
The part of the brain located in both the right and left hemispheres, involved in hearing, memory, and language.
Tongue Thrust:
An oral–motor eating problem in which voluntary tongue movement is poorly controlled.
Tonic:
A state of continuously increased muscle tone.
Tonic-Clonic Seizures:
Seizures characterized by initial muscle stiffening followed by rhythmic jerking movements.
Transgenic Organisms:
Organisms that incorporate foreign DNA into their own genetic material.
Transcription:
The process by which information in DNA is copied into RNA.
Transgene:
DNA from transgenic organisms that is integrated into the reproductive tract.
Transitional Movements:
Movements that allow a person to change body position.
Translocation:
The transfer of a segment of one chromosome to another chromosome.
Truncal Ataxia:
Poor coordination of the muscles of the trunk due to cerebellar dysfunction.
Treatment:
Interventions aimed at improving medical or cognitive outcomes by reducing clinical symptoms.
Trophic Foot Disturbances:
Abnormalities in foot growth.
Unfortunate Activation:
In females, one of the two X chromosomes in each cell is randomly deactivated. Unfortunate activation occurs when the healthy chromosome is inactivated instead of the diseased one.
Upper Motor Neuron:
Neurons that receive movement-related signals from the brain’s cortex and transmit them to lower motor neurons.
Urinary Incontinence:
Loss of bladder control.
Vagal Tone:
A stimulus originating from the vagus nerve that influences heart rate and digestive activity.
Vagus Nerve:
The tenth cranial nerve; its efferent fibers exert a parasympathetic effect, accelerating digestion while slowing other bodily systems.
Valgus:
Outward rotation or angulation of the ankle.
Valsalva Maneuver:
A breath-holding maneuver that causes changes in blood pressure and heart rate.
Varus:
Inward turning or angulation of the ankle.
Vasomotor Disturbance:
A disorder of the nerves that control blood vessel muscles, affecting blood flow regulation.
Vestibular:
Relating to the system that coordinates posture, movement, and balance.
Vestibular Input:
Unprocessed information from the inner ear regarding balance, gravity, motion, and spatial orientation.
Video EEG:
Simultaneous visual recording and electroencephalographic monitoring.
Volvulus:
Twisting of the intestine that causes bowel obstruction.
Weight-for-Height:
A measure of nutritional status.
Weight shift:
The movement of the body’s center of gravity in any direction.
White Matter:
The part of the brain composed primarily of axons.
X-Inactivation / Randomness:
In females, one of the two X chromosomes is randomly inactivated. Because females have a second healthy X chromosome, X-linked diseases are more common in males.
X-Linked Dominant Disorder:
A disorder caused by a dominant gene located on the X chromosome.
X-Linked Dominant Trait:
In X-linked disorders, the presence of a dominant gene mutation on the X chromosome is sufficient for the trait or disorder to manifest.