Glossary
Acquired Immunodeficiency Syndrome (AIDS):
A syndrome that is a result of being infected with human immunodeficiency virus resulting in killing or impairing of the T4 cells—essential for immune system function. The result is an inability of the body to fight infections and certain cancer, and delayed development in infected children.
Asperger Syndrome:
A pervasive developmental disorder characterized by an inability to understand how to interact socially. Other typical features of the syndrome include clumsy and uncoordinated motor movements, social impairment with extreme egocentricity, limited interests and/or unusual preoccupations, repetitive routines or nrituals, speech and language peculiarities, and non-verbal communication problems.
Atherothrombotic Stroke:
Condition that results from the occlusion of one or more cerebral arteries leading to necrosis of the brain tissue dependent on the blood flow. This may lead to transient (reversible ischemic neurological deficit) or permanent loss of neurological function. Most frequently, it is due to embolization of the atherosclerotic plaque or the thrombus forming in it (i.e., breaking off of material in the aorta, carotid, or vertebral arteries with material floating downstream until it lodges in one of the smaller cerebral arteries).
Autism:
A developmental disorder that is characterized by impaired development in communication, social interaction, and unusual and repetitive behavior.
Autism is classified as a Pervasive Developmental Disorder (PDD), which is part of a broad spectrum of developmental disorders affecting young children and adults.
Benzodiazepine:
Among the best known and most widely prescribed drugs in the world, benzodiazepines are used mainly as tranquilizers for the control of symptoms due to anxiety or stress.
Bipolar Depression:
A psychiatric disorder also known as manic-depressive illness involving dramatic mood swings from periods of excessive activity and rapid thought (manic phase) to periods of hopelessness and depression (depressive phase).
Cerebral Palsy:
A term describing a group of chronic conditions affecting body movement and muscle coordination. It is a non-communicable, non-progressive disorder that is a result of injury to the motor areas of the brain that occurred during pregnancy, birth, or early childhood. The condition may present with a combination of different symptoms, including: spasticity (stiff and difficult movement), hypotonia (muscle weakness), ataxia (inability to coordinate voluntary movement, unsteadiness), dyskinesia (inability to coordinate smooth movements resulting in fragmented or jerky movements), or dystonia (involuntary muscle contractions and spasm).
Community-Based Rehabilitation (CBR):
A strategy to use and build on resources of the community in order to equalize opportunities for impaired, disabled, and handicapped persons, their families, and the community.
Down's Syndrome (Trisomy 21):
A chromosomal abnormality which manifests itself in a set of common physical and mental characteristics, including: extra fold over the eyes, floppy muscles, loose joints, mental retardation, hearing loss, and visual problems. This abnormality is due to the presence of an extra chromosome and has an increased incident related to maternal age.
Dyscalculia:
A specific developmental disability affecting a person's ability to conceptualize and perform mathematics. Mild cases can often be compensated for with use of a calculator, but those with severe dyscalculia will need special education services.
Dyskinesia:
The presence of involuntary movements, such as the choreaform movements seen in some cases of rheumatic fever or the characteristic movements of tardive dyskensia. Some forms of dyskensia are a side effect of using certain medications, particularly L-Dopa and, in the case of tardive dyskensia, the anti-psychotics.
Dystonia:
A state of abnormal (either excessive or inadequate) muscle tone. There are many forms of dystonia. Dystonia disorders cause involuntary movements and prolonged muscle contraction, resulting in twisting body motions, tremor, and abnormal posture. These movements may involve the entire body, or only an isolated area.
Framingham Study:
A landmark study begun in 1948 in which some 12,000 residents of the town of Framingham, Massachusetts, were enrolled in a study designed to gather medical data and, more recently, DNA samples. The participants in the Framingham study came in for regular medical exams and provided the information that researchers requested. This extraordinary longitudinal (long-term) study has yielded a vast set of data from which invaluable health information has been extracted.
Hemorrhagic Stroke:
Neurological deficit caused by the bursting of an intracerebral artery. The disruption of brain tissue and increase in cranial pressure are often fatal and almost always disabling.
Human Immunodeficiency Virus (HIV):
Virus responsible for attacking the T4 cells of the immune system resulting in the body's inability to ward off infection.
Hypotonia:
Decreased tone of skeletal muscles; in a word, floppiness. Hypotonia is a common finding in cerebral palsy and other neuromuscular disorders. Untreated hypotonia can lead to hip dislocation and other problems.
Infectious Diseases:
Any illness that is caused by a specific microorganism.
Intrauterine Growth Retardation:
Poor fetal growth, usually due to a fetal defect or to failure of the placenta to provide adequate nutrients. Intrauterine growth retardation causes the fetus to be smaller than expected for the length of gestation. Intrauterine growth retardation may be due to a chromosomal defect, such as Down's syndrome.
Low Birth Weight (LBW):
A baby weighing less than 2500 grams at birth.
Neonatal:
Pertaining to the newborn period which, by convention, is the first four weeks after birth.
Neural Tube Defect:
A developmental failure affecting the spinal cord or brain in an embryo. This defect leads to failure of the bony arch to fuse over the back of the spinal cord, thus causing spina bifida. The best known neural tube defects
are anencephaly (absence of the cranial vault and absence of most or all of the cerebral hemispheres of the brain) and spina bifida (an opening in the vertebral column protecting the spinal cord), sometimes with a meningomyelocele (protrusion of the meningeal membranes that cover the spinal cord).
Neurocysticercosis (NCC):
Cysts found in the brain (and other parts of the body) as a result of ingestion of the pork tapeworm, Taenia solium. The most common symptoms include seizures, headaches, confusion, lack of attention to surroundings, difficulty with balance, and hydrocephalus.
Nosocomial:
Originating, taking place, or acquired in a hospital.
Onchocerciasis:
Also known as river blindness, a disease caused by a parasitic worm (Onchocerca volvulus) which is transmitted to persons by biting blackflies (buffalo gnats) that breed in fast-flowing rivers. The adult worms can live for up to 15 years in nodules beneath the skin and in the muscles of infected persons, where they produce millions of worm embryos (microfilariae) that invade the skin and other tissues, including the eyes.
Otitis media:
Infection and inflammation of the middle ear space and ear drum. Symptoms include earache, fever and in some cases, diminished hearing.
Perinatal:
Pertaining to the period immediately before and after birth. The perinatal period is defined in diverse ways. Depending on the definition, it starts at the 20th to 28th week of gestation and ends 1 to 4 weeks after birth.
Phenylketonuria (PKU):
A rare, inherited metabolic disease that causes mental retardation due to an absence of phenylalanine hydroxylase—the enzyme that converts phenylalanine to tyrosine. The build-up of phenylalanine is toxic but can be controlled by diet.
Posttraumatic Stress Disorder (PTSD):
A psychiatric disorder associated with a traumatic event (war, rape, tragic accident, etc.) resulting in the patient reliving the event through nightmares and disturbing recollections during the day.
Psychosocial:
Relating social conditions to mental health.
Risperidone:
An antipsychotic medication that works on nerves throughout the body and brain by blocking several of the receptors on nerves (dopamine type 2, serotonin type 2, and alpha 2 adrenergic receptors). This alters the chemical messages which nerves transmit to each other.
Schizophrenia:
Chronic and disabling disorder which typically has an onset in young adults (teens or early 20s) that may be the result of altered brain chemistry or brain structure. It is defined by characteristic but nonspecific disturbances in the form and content of thought, perception, emotion, sense of self, volition, social relationships, and psychomotor behavior.
Tay Sachs Disease:
An inherited condition that is caused by an absence of the enzyme hexosaminidase A (Hex-A), resulting in the accumulation of the lipid GM2 ganglioside. This accummulation, primarily in neurons, progressively damages the cells and results in death of the child by age
Unipolar Depression:
A psychiatric disorder also known as major depressive illness that is clinically diagnosed when five or more symptoms (sad mood, loss of interest in activities that were once enjoyed, difficulty sleeping or oversleeping, physical slowing or agitation, energy loss, feeling of worthlessness, difficulty concentrating, and thoughts of death or suicide) are present for at least a two-week period and interfere with daily living.
EPIDEMIOLOGICAL TERMS
Disability-Adjusted Life Years (DALYs):
A measurement for estimating the burden of disease by taking into account both mortality and non-fatal conditions by summing years of life lost and years lived with disability. The calculation is based on assumptions put forth by Murray and Lopez, The Global Burden of Disease, 1997.
Incidence:
Ratio of the number of new cases of the disease occurring in a population during a specified time to the number of persons at risk for developing the disease during that period.
Prevalence:
Ratio of the number of cases of a specific disease present in a population at a specific time to the number of persons in the population at the time specified.
Primary Prevention:
Prevention of the development of disease in a person who does not have the disease.
Secondary Prevention:
Prevention of recurrence of a disease in a person who has already been diagnosed with the disease.
Tertiary Prevention:
Prevention of disability, poor quality of life, and death in persons with advanced stages of a disease.
Years Lived with Disability (YLD):
The number of years lived with a disability or non-fatal health outcomes.
Years of Life Lost (YLL):
The number of life years lost prior to a given age of expected survival, usually 65 years.
Definitions for this glossary were compiled from the following sources:
Dorland's Illustrated Medical Dictionary, 28th ed. Philadelphia: W.B. Saunders Co., 1994.
Medicine.Net. Medical terms and glossary. Available at http://www.medicinenet.com, 2001.
Medline plus (date of last update March 18, 2000). Available at http://www.nlm.nih.gov/.