Glossary

Find the list of medical terms and their definitions:

Amino acids:
Amino acids are the basic building blocks of proteins. They are organic acids containing at least one amine radical (NH2) and one carboxyl radical (CO2H). There are about twenty of them in nature, and 8 of them are considered essential because they are indispensable to our body, which cannot synthesize them.

Lactic acid:
Acid resulting from the use of glucose by cells to produce energy. In cases of intense muscular work, it can accumulate in the muscles and cause cramps.

Nucleic acids:
These are large molecules formed by the chaining of base units, called nucleotides. Each nucleotide comprises a sugar, a base, and a phosphate group.
There are two classes of nucleic acids: DNA and RNA. Deoxyribonucleic acid (DNA) carries the genetic code. In nucleotides, the sugar is always deoxyribonucleic acid, and there are four bases: A for adenine, G for guanine, T for thymine, and C for cytosine. Each gene is a fragment of the DNA molecule characterized by a sequence of A, T, C, and G bases. This is formed of two strands creating a double helix. The other class includes RNA, or ribonucleic acids. Formed of a single-stranded chain, these molecules differ from DNA in several ways. The sugar is a ribose, and the base T is replaced by the base U for uracil. There are three types of RNA: messenger RNA, transfer RNA, and ribosomal RNA. They are involved in the translation phase of protein synthesis.

Ketoacidosis:
Acidosis with accumulation of ketone bodies in the blood. It is observed particularly in diabetes and can even lead to a coma.

Acidosis:
A state defined by a blood pH more acidic than the normal value (7.35 – 7.45). Acidosis is characterized by an excessively low concentration of bicarbonates in the blood.

Lactic acidosis:
Abnormal concentration of lactate levels in body fluids. The body rebalances itself by injecting glucose and sodium bicarbonates.

Tinnitus:
Auditory sensation (often buzzing or whistling) perceived in the absence of external noise.

DNA:
Deoxyribonucleic acid. The molecule that carries genetic material. DNA forms a microscopic coil which, in eukaryotic organisms, is packaged within the cell nucleus. It is located in the chromosomes. This is nuclear DNA.
When uncoiled, it stretches into a very long thread, consisting of a precise sequence of characters in a four-letter biochemical alphabet: the nucleotide or nitrogenous bases A, T, G, and C. The rigorous and specific pairing of these bases constitutes genetic information, a set of instructions enabling the cell to function according to the species’ program. The original structure of DNA, formed of two complementary strands coiled into a helix (“double helix”), allows it to duplicate into two identical molecules during replication.
There is also mitochondrial DNA, which is located in the mitochondria.

AFSSAPS:
French Agency for the Safety of Health Products.

Agenesis:
Total absence of development of a tissue or organ occurring before birth.

ALD:
Long-Term Condition

Allele:
At a given location on a chromosome, the same gene can exist in different forms called alleles. The differences between these alleles of the same gene relate to sequence variations.

Genetic alteration:
This expression refers to any modification of a gene’s structure (breakage, sequence change, etc.).

Gene amplification (technique) or PCR (Polymerase Chain Reaction):
A method that allows in vitro amplification, meaning to copy in large numbers, a known DNA or RNA sequence from a small amount of nucleic acid. It is commonly used for biological diagnosis.

Biochemical analysis of the respiratory chain:
It includes polarographic analysis, spectrophotometric techniques, and histochemical techniques.

Anoxia:
Decrease or suppression of oxygen delivered by the blood to the tissues.

Antioxidant:
An antioxidant is an agent that prevents or slows down oxidation.

Apoptosis or “programmed cell death”:
This term refers to a set of cellular phenomena at the end of which the cell dies under physiological conditions. This active self-destruction program must be distinguished from death by necrosis, which occurs when a cell is in extreme, non-physiological conditions.

Apraxia:
Loss of understanding of object use and inability to perform coordinated movements, caused by a brain lesion.

Apyretic:
Apyretic is the medical term indicating the absence of fever.

Arginine:
An amino acid found in dietary proteins and providing an energy supply for muscles (it is converted into creatine, a substance whose combination with phosphorus plays an important role in energy utilization) and essential for proper sexual function. It is toxic in excessive doses.

RNA:
Ribonucleic acid. A molecule used to transfer genetic instructions inscribed in nuclear DNA to the cytoplasm (in eukaryotes), where these instructions are executed by the cell. RNA, a kind of “photocopy” of DNA, is synthesized from it during transcription. It is also formed by a precise sequence of characters in a four-nucleotide base alphabet: A, U, G, and C.

Artifact:
An artificial or accidental phenomenon disturbing the results of an observation.

Arrhythmia:
Arrhythmia is a disorder characterized by an irregularity of the heart rhythm. It can be caused by neurological disorders or other strictly cardiac problems.

Asthenia:
Weakening of the general condition (severe fatigue) or of the functions of an organ.

Ataxia:
Absence or difficulty in coordinating voluntary movements.

Atonia:
Absence of tone or tension (particularly muscular).

ATP (adenosine triphosphate):
A molecule that contains energy in chemical form and helps living organisms convert glycogen into glucose.

Atrophy:
The literal meaning of “atrophy” is “lack of form.” It refers to the process by which a structure loses its form and function. An example is muscle atrophy, which can occur as a result of illness or a lack of muscle activity. Muscle atrophy is very common in bedridden patients who cannot exercise their muscles normally.

Audiogram:
A curve characterizing the sensitivity of the ears to sounds.

Audiography:
Graphic recording of sound sensitivity, using a device called an audiometer.

Audiometry:
Measurement of the ears’ sensitivity to sounds performed using a device called an audiometer.

Autosomal:
Autosomal transmission refers to when the genetic anomaly is located on one of the 22 pairs of autosomes.

Stroke (Cerebrovascular Accident):
Brain lesion resulting from a decrease in its blood supply or the rupture of a vessel leading to internal hemorrhage. A stroke can cause hemiplegia, loss of sensation and vision, or speech disorders.

Babinski-Weill test:
Also known as the blind walk. An exercise aimed at detecting a neurological deficit. The patient must, with eyes closed, repeatedly take ten steps forward and ten steps backward in a straight line. In cases of certain conditions, the direction of movement deviates with each path, drawing a star shape.

Bioethics:
The science of medical ethics.

Biopsy:
The removal of a tissue fragment from a living or deceased being, with the aim of subjecting it to microscopic or biochemical examination.

Bradykinesia:
Abnormal slowness of voluntary movements.

Bradypnea:
Bradypnea is an abnormal slowing of respiration.

CAMSP:
Early Medico-Social Action Center

CAMPS:
Medico-Psychological Aid Center

Cardiomyopathies:
Abnormalities of the heart muscle that can take various forms. It is now known that they have a strong genetic and hereditary component.

Hypertrophic cardiomyopathy:
The exaggerated growth of myocardial fibers leads to a thickening of the heart walls, particularly in the left ventricle and septum.

Carnitine:
A substance involved in the metabolism of fatty acids in the body. Its deficiency is hereditary and leads to an accumulation of lipids in the tissues.

Karyotype:
A karyotype is the set of chromosomal characteristics of an individual or a species.

Catalepsy:
A state characterized by significant rigidity of the muscles of the face, trunk, and limbs, which remain fixed in their original posture. Catalepsy is observed in certain psychiatric disorders or in cases of certain brain lesions.

Cataphasia:
A speech disorder in which the patient repeatedly repeats the answer to a question asked.

Catheter:
A catheter is a long, hollow, thin, and flexible tube that is inserted into the body for a variety of medical uses.

CECOS:
Center for the Study and Conservation of Human Eggs and Sperm

CEH:
Hospital Ethics Committee

Stem cell:
A cell capable of differentiating, self-renewing, and proliferating, capable of producing other cell types through its daughter cells.

Ketone bodies:
Substances resulting from the breakdown, in the liver, of certain amino acids and fatty acids. These are beta-hydroxybutyric acid, acetoacetic acid, and acetone.
Normally, they are broken down in organs and release energy by undergoing the Krebs cycle. In diabetics, they can accumulate and cause ketoacidosis (acidification of the blood that can lead to a coma).

Brain:
Part of the encephalon comprising two hemispheres. Composed of gray matter and white matter, the brain contains the nerve centers for thought, personality, senses, and voluntary movement.

Cerebellum:
A region of the encephalon located at the base of the skull, behind the brainstem; it plays a role in balance and the control of precise movements.

Respiratory chain:
A cellular system for energy recovery. It is located in the inner membrane of the mitochondrion and consists of V enzymatic complexes.

Visual field:
The visual field is the total area in which visual perception is possible when a person looks straight ahead.

Cholestasis:
A set of manifestations related to the decrease or cessation of bile secretion.

Chromosomes:
Elements appearing, in the dividing cell, as rod-like structures that undergo complex processes of duplication and separation. Chromosomes are the material carriers of genes.
All cells of the same species contain 2n chromosomes (n = 23 in humans), with the exception of mature sex cells (gametes, spermatozoa, and ova), which contain only n chromosomes. When a spermatozoon with n chromosomes (paternal) fertilizes an ovum with n chromosomes (maternal), the result is a fertilized egg, or zygote, with 2n chromosomes paired two by two (“homologous” chromosomes or autosomes). All cells derived from this zygote, through a division process called mitosis, contain n paternal chromosomes and n maternal chromosomes. Only the precursor cells of sex cells undergo a special division called meiosis, which results in gametes with n chromosomes, after the separation of homologous chromosomes.

Chromosome:
An DNA filament located in the cell nucleus that carries genes (several thousands) containing our hereditary patrimony.

Clar’s mirror:
A concave mirror equipped with a lamp at its focal point and pierced with two holes, allowing the physician who fixes it on their forehead to simultaneously examine and illuminate a cavity.

Clinical examination:
An examination performed at the patient’s bedside, without equipment or laboratory tests.

Clonus:
A series of brief, involuntary muscle contractions.

Clonus:
A series of brief, involuntary muscle contractions caused by its stretching. It is due to a degeneration of the bundle of nerve fibers constituting the main voluntary motor pathway (pyramidal tract), i.e., the nerve fibers originating from the brain and destined for the trunk and limbs.

Cochlea:
An element of the inner ear containing the organ of hearing.

Genetic code:
The set of information contained in genes, inscribed in the DNA molecule forming chromosomes and resulting in the formation of proteins.

Coenzyme:
The non-protein part of an enzyme (a substance capable of activating a biochemical reaction) essential for its activity but not undergoing modification during the reaction.

Cofactor:
A substance whose action reinforces that of another element to contribute to a result.

Comitiality:
The characteristic of being related to epilepsy.

Congenital:
Present at birth. Congenital conditions are either hereditary or result from diseases or lesions that occurred during pregnancy or childbirth.

Informed consent:
Informed consent is the permission given by a patient to proceed with a specific study or intervention.

CPK (Creatine Phosphokinase):
An enzyme found only in muscle cells, capable of activating the combination of creatine (a nitrogenous substance) with phosphorus to form phosphocreatine, an energy storage molecule in muscle cells. Its level in the blood increases in cases of muscle damage. A variety of this enzyme, CK-MB, appears in the blood only in cases of cardiac muscle injury (e.g., heart attack). Synonym(s): CK or creatine kinase.

Creatine:
A nitrogenous substance found particularly in muscles, whose combination with phosphorus results in phosphocreatine, a form of energy storage in muscles.

Creatinine:
Creatinine is a normal metabolic waste product that is excreted in urine. It is produced by the body at a constant rate. The determination of creatinine clearance and serum levels serves as an indicator to assess kidney function.

Epileptic Seizure:
An epileptic seizure is characterized by a momentary cessation of normal brain activity, causing involuntary and uncontrollable muscle contractions.

Cytoplasm:
The fundamental living part of the cell containing the nucleus and other organelles. It is a water-rich gel. It contains a large part of the machinery ensuring the life of the cell.

Krebs Cycle (CK):
A degradation pathway for many amino acids. At its conclusion, ketone bodies are present in the urine.

Mitochondrial Cytopathy:
Synonym for mitochondrial disease, with cytopathy meaning disease of the cells.

Decompensation:
A breakdown of the balance by which the harmful effects of an injury or disorder of the body are compensated by the adaptation of certain functions (e.g., decompensation of respiratory failure).

Defibrillator:
A device used to restore a normal heart rhythm through an electric shock. It is used during fibrillations (rapid and disordered contractions of heart fibers) or to treat ventricular tachycardia (an acceleration of the heart rate originating in the ventricle).

Deglutition:
Deglutition is the medical term for the act of swallowing.

Deletion:
Loss of a fragment (e.g., a chromosome segment or a molecular chain), affecting the quality of mtDNA.

Depletion:
A decrease in the amount of fluid contained in an organ or organism.
Consequence of a nuclear gene mutation. A decrease in the quantity of mtDNA, leading to a deficiency of one or more complexes.

Antenatal or Prenatal Diagnosis:
The act by which a physician, observing phenomena in a fetus revealing a functional disorder or lesion, identifies the underlying disease before birth.
Amniotic fluid sampling or placental biopsy allowing for gene research.
All investigations enabling the diagnosis of a serious disease or malformation of the fetus in utero.

Differential Diagnosis:
The act by which a physician, observing phenomena revealing a functional disorder or lesion, rules out the hypothesis of a disease similar to the one they are trying to identify.

Dominant:
Autosomal dominant inheritance refers to the transmission of a chromosome carrying a genetic anomaly from one parent.

Doppler (Examination):
Measurement, using an ultrasound probe, of blood flow velocity in arteries and veins. This examination allows verification of proper blood flow in the vessels and thus detects the presence of a blockage or atherosclerosis.

Double-Blind (Trial):
Refers to a study or trial in which neither the participants nor the doctors know “who is testing what”. The “blind” nature of the trials is lifted at the end of the study, for example, to compare the effects of a substance against a placebo.

PGD:
Preimplantation genetic diagnosis, a genetic examination performed on a 3-day-old embryo conceived by IVF before implantation, allowing for the detection of a genetic mutation or chromosomal anomaly and thus for embryo selection.

Dyskinesia:
Dyskinesia refers to disorders of voluntary movements (regardless of the cause).

Dyslexia:
Dyslexia is a reading disorder characterized by difficulties in deciphering written signs.

Dyspepsia:
Digestive disorder.

Dysplasia:
A medical term referring to a developmental disorder. This term applies to cells (cellular dysplasia) as well as to general morphology, as in the case of anomalies of the skull’s bone structures (cranial dysplasia).

Dyspraxia:
A disorder of motor execution, linked to a disturbance of body representation and spatial organization.

Dystonia:
A disorder of tension or tonicity.

Muscular Dystrophy:
A hereditary muscle disease leading to progressive degeneration and weakening of muscles: see leukodystrophy.

EEG:
Electroencephalogram, recording of the brain’s electrical activity.
An examination that allows for the recording and study of electrical signals emitted by the brain.

Electrocardiography:
An examination that allows for the recording and study of electrical changes in heart rhythm.

Electromyogram (EMG):
It is an examination that consists of analyzing the electrical activity of muscles after amplifying, visualizing it on a screen, and recording it.

Enzyme:
An enzyme allows the transfer of energy from one molecule to another. It is an organic substance that causes a biochemical reaction, by accelerating or facilitating it.

Epilepsy:
Epilepsy is a group of nervous system disorders characterized by repeated episodes of convulsive seizures, sensory disturbances, abnormal behavior, momentary loss of vision, among others.
A neurological condition characterized by irregular electrical discharges throughout or in certain parts of the brain.

Clinical Trial:
A clinical trial (or clinical study or therapeutic trial) is a statistical study conducted to prove the validity of a treatment.

Therapeutic Trial:
A therapeutic trial (or clinical study or clinical trial) is a statistical study conducted to prove the validity of a treatment.

Eukaryote:
An organism composed of cells with a nucleus.

Fibroblasts:
skin cells.

Central Fever:
Fever independent of viral contamination of the body. It is linked to a brainstem fissure, the site of temperature regulation.

IVF:
In vitro fertilization.

IVFC:
In vitro fertilization with the couple’s gametes (sperm or oocytes).

IVFD:
In vitro fertilization with donation (of sperm or oocytes).

FO:
Fundus examination. An examination consisting of observing the inside of the eye (particularly the retina) with an ophthalmoscope, after dilating the pupil beforehand (with eye drops).

Liver:
An organ in the upper right part of the abdomen that performs vital chemical functions, including processing nutrients from the intestine, synthesizing sugars, proteins, and fats, and converting waste products into urea.

Gastrostomy:
A surgical procedure consisting of creating an opening in the abdomen to connect the stomach to the outside. It requires an incision of the abdominal wall. The purpose of this procedure is to insert a tube that will allow food to be introduced directly into the stomach (enteral nutrition).

Blood Gases:
An arterial blood test designed to measure oxygen, carbon dioxide levels, and pH.

Gavage:
Gavage is the administration of nutritional liquids using a tube that passes through the nose to reach the stomach.

Gene:
A constituent element of DNA that determines the transmission and expression of a specific hereditary trait.
A specific segment of a chromosome constituting the basic unit of heredity. It performs a precise cellular function by controlling the synthesis of a particular protein.

Genome:
The complete set of constitutional hereditary factors of an individual.

Autosomal Inheritance:
The transmission from one generation to the next of a particular trait, expressed or not, and encoded in a gene carried by a chromosome (autosome) that is not linked to sex determination.

Recessive Inheritance:
The transmission from one generation to the next of a particular trait that is expressed only if the gene in which it is encoded is carried by both chromosomes of the involved pair.

Heteroplasmy:
Variation in the amount of mtDNA mutation from one cell to another, or from one tissue to another.

Holter (System):
A device allowing the recording of an ECG (graphic recording of electrical currents accompanying heart contractions) on magnetic tape for a long duration. These recordings make it possible to detect heart rhythm disorders or other anomalies that do not appear during a consultation.

Hyponatremia:
Abnormally low sodium level in the blood.

Hypotonia:
A term generally referring to a decrease in muscle tone.

Hypoxia:
A medical term used to describe a decrease in the amount of oxygen delivered to tissues by the blood.

MRI:
Magnetic Resonance Imaging (MRI) is a diagnostic technique that produces cross-sectional images of organs and body structures. It relies on the use of electromagnets that generate bursts of magnetic fields. These bursts stimulate hydrogen atoms in tissues, which emit signals that are recorded and analyzed by a computer to create an image.

Krebs (Cycle):
A series of reactions taking place in certain cell organelles, the mitochondria. Through the degradation of carbohydrates, it leads to the formation of ATP (adenosine triphosphate), the main energy source for the body.

Lactate:
When the mitochondrion cannot use pyruvate, it will not be able to enter the mitochondrion and will transform into lactate.

Lactic (Acid):
An acid with an alcohol function (ch3-choh-cooh), formed during the fermentation of certain sugars by bacteria contained in milk or during muscle contraction (by decomposition of glycogen, the body’s glucose reserve).

CSF:
Cerebrospinal fluid. An aqueous fluid in which the soft tissues of the brain and spinal cord float. This clear fluid is renewed 4 or 5 times a day. It isolates the brain and spinal cord and contains proteins and glucose, which provide the necessary energy for the brain and lymphocytes that protect them against infections. Analysis of its chemical constituents and pressure provides information on many brain disorders and diseases.

Lipomatosis (one of the symptoms of MERRF)

Genetic Disease:
A disease linked to defects, or mutations, in one or more genes. When the disease results from the mutation of a single gene, it is called a “monogenic disease”.
However, most diseases, such as cancers, result from the cumulative alteration of several genes, or from the association of a genetic defect with various environmental factors and/or lifestyle factors.

Orphan Disease:
A pathology for which there is no treatment or therapeutic development. It is not necessarily a rare disease.

Rare Disease:
A pathology whose prevalence is less than one affected person per 2,000 people.

Marker:
An element fixed to a substance, allowing its presence in the body to be demonstrated. A biological marker is a substance whose measurement allows monitoring the evolution of a condition (tumor, hepatitis, …) or a particular phenomenon (inflammation, metabolism, …).

Orphan Drug:
A drug that is not developed due to profitability deemed insufficient by research & development policies.

Metabolism:
The set of chemical reactions whose function is to ensure the survival and reproduction of the cell.

Micturition:
Micturition is the medical term for the emission of urine.

Mitochondrion:
An organelle located in the cytoplasm (substance surrounding the nucleus) of cells, where reactions occur that provide energy (through the formation of ATP, adenosine triphosphate) and the production of certain proteins.

Mitochondrion:
A microscopic part of the cell containing genetic material, which plays a role in storing the energy necessary for cellular functions.
=> This organelle is the site of respiration and the breakdown of fats and sugars to produce energy. Its internal folds contain enzymes that produce a chemical substance called Adenosine Triphosphate (ATP), which provides the energy necessary for most cell functions.

Motricity:
The ability to cause muscle contraction.

Mutagen:
Refers to anything that causes the appearance of new hereditary traits through the modification of the structure of one or more chromosomes.

Mutation:
A mutation is a permanent modification of a cell’s genetic material.
Modification of hereditary material, following a writing error in the genetic message.

Myelin:
Sheath enveloping nerve fibers.

Myocardium:
The heart muscle whose fibers form a network that contracts spontaneously.

Myopathy:
Myopathy is the general medical term used to describe muscle diseases. Myopathies are genetic diseases that often progress gradually.

Miosis:
Constriction of the pupil (central opening of the eye).

Myotonia:
A muscle tone disorder in which muscles relax slowly and with difficulty after a voluntary contraction.

Natremia:
Sodium (Na) level in the blood.

Natriuria:
Or natriuresis. Sodium level in the urine.

Necrosis:
Necrosis is the death and decomposition of tissues in a specific area, outside of which the tissues are healthy.
CBC (Complete Blood Count):
CBC is the medical abbreviation for: Complete Blood Count. The CBC indicates the number and type of red blood cells, white blood cells, and platelets contained in a blood sample.

Neuron:
A nerve cell whose function is to transmit electrical impulses.

Motor neuron:
A nerve cell that transmits impulses to muscles to induce movement.

Neuropathy (peripheral):

Enteral nutrition:
Nutrition via a gastric tube with gastrostomy.

Trace element:
A trace element is an essential dietary compound, such as vitamins or iodine, present in the body in small quantities.

WHO:
World Health Organization (WHO)

Ophthalmoplegia:

Speech therapy:
A term literally meaning “normal pronunciation,” but primarily used to refer to the treatment of written and oral language disorders, such as stuttering.

Orthoptics:
A branch of ophthalmology specializing in eye rehabilitation for binocular vision disorders, in which the axes of eye movements are not parallel (mainly strabismus).

Oocyte:
Or ovocyte. A female germ cell whose maturation and division in the ovary will produce an ovum, expelled from the ovary during each menstrual cycle and intended to be fertilized by a sperm.

P.O.:
Medical abbreviation for: by mouth (Per os)

BP:
Medical abbreviation for: Blood Pressure

Paralysis:
Loss of mobility in a part of the body due to a nervous or muscular disorder. Paralysis can affect a small group of muscles, a limb, the lower part of the body, or its entire right or left half.

Parenteral:
Refers to the administration of a medication by a non-digestive route, generally intravenously, intramuscularly, or subcutaneously.

Pathology:
The study of the causes, signs, and progression of diseases. This term also refers to the set of signs of a disease.

pH:
pH is a parameter used to measure the acidity or alkalinity of a solution. A solution with a pH below 7 is acidic; if the pH is equal to 7, the solution is neutral, and if the pH is above 7, the solution is alkaline (or basic).

MCH:
Abbreviation for maternal and child health.

Lumbar puncture:
When performing a lumbar puncture, a thin trocar is inserted between two vertebrae of the lumbar spine to collect cerebrospinal fluid for diagnostic purposes.

Praxis:
Coordination of voluntary movements for a specific purpose.

Proteins:
Constituents of a living organism, whose production is encoded by genes.

Proteinemia:
The level of proteins in the blood.

Ptosis:
Drooping of the upper eyelid due to a lesion or paralysis of the muscle whose function is to raise it.

Pyruvate:
A substance taken from the cytoplasm by the mitochondrion. Pyruvate is degraded by the Krebs cycle to release energy that is used to produce ATP.

Resuscitation:
All means used to restore and maintain a balance of the body’s vital functions (respiration, circulation, nutrition, excretion, etc.) during trauma or surgical intervention.

Recessive:
Autosomal recessive inheritance refers to a situation where the affected person has received 2 chromosomes carrying the genetic anomaly, each transmitted by the parents.

Basic research – Clinical research:
Basic research in medicine studies the underlying mechanisms of normal and pathological processes.
Clinical research is research applied to humans and focuses on the prevention, diagnosis, and treatment of diseases.
Ketogenic diet: a low-sugar diet.

Kidneys:
Two structures located at the back of the abdominal cavity. The kidneys filter blood and eliminate waste.

MMR:
Abbreviation for measles-mumps-rubella. Name given to the vaccine that prevents these three diseases.

CT scan:
A CT scan is a series of X-ray images of a part of the body visualized on a computer. These images are taken from slightly different angles and allow for “cross-sectional” views of the observed region.

Scintigraphy:
An examination that allows for tracking the path and uptake of a radioactive product in the body. It is particularly applied to the observation of the thyroid, liver, kidneys, brain, lungs, and heart.

Semiological:
Related to the signs of a disease.

Magnetic Resonance Spectroscopy (MRS):
A technology similar to MRI, but providing chemical rather than anatomical data. It is very useful in evaluating the effects of new treatments, as it allows for determining the severity of MS and monitoring its progression.

Deaf-mutism:
The state of a person who is deaf and mute.

Leigh Syndrome:
On an MRI image, white spots are seen in the basal ganglia.

Central Nervous System (CNS):
The Central Nervous System (CNS) is the part of the nervous system that contains the brain and spinal cord.
It receives and reacts to all sensory information.

Peripheral nervous system:
Extends the central nervous system and includes all nerves and their swellings. Nerves, attached at one end to the central nervous system, branch out at the other end into a multitude of fine branches innervating the entire body.

Genetic test:
A genetic test allows for detecting, through DNA analogy, the presence of genes causing or predisposing to diseases.

Gene therapy:
This new, still experimental form of treatment consists of grafting a normal gene onto an organism carrying a genetic defect with the hope of correcting it.

Cell therapy:
Introduction of healthy cells into the body so that they can perform the role that diseased cells can no longer play. It is a cell transplant.

Thrombosis:
Formation of a clot in a blood vessel.

TPR:
Medical abbreviation for temperature, pulse, and respiration.

Cognitive disorder:
Medical term used to describe the deterioration of mental processes such as memory, judgment, understanding, and reasoning.

Ubiquinone (or Coenzyme Q10):
Synthesized intracellularly, it participates in a series of essential cellular processes and is found mainly in the inner membrane of mitochondria. It plays an important role in electron transport in mitochondria and in ATP synthesis.

ICU:
Medical abbreviation for Intensive Care Unit.