Glossary of Medical Terms for TSC Patients & Families
A complex condition like TSC comes with a lot of medical terminology. Here are a few of the most common words you may encounter.
A through C
See Retinal Achromic Patch.
See Facial Angiofibroma.
See Attention Deficit Hyperactivity Disorder.
Adrenocorticotropic Hormone (ACTH)
Adrenocorticotropic hormone is an antiepileptic medication shown to be effective in treating children with TSC who are suffering from infantile spasms.
See Antiepileptic Drug.
Amniocentesis is a prenatal diagnostic test in which a small amount of amniotic fluid is collected from the uterus for genetic testing. The test is usually performed between 16 and 20 weeks of gestation and involves inserting a fine needle into the uterus to draw a sample of the amniotic fluid.
See Facial Angiofibroma.
An angiomyolipoma is a benign tumor that can occur in multiple organs, including the kidney, adrenal gland, liver, ovary, and pancreas. In TSC they are most commonly associated with the kidney. The name of these tumors refers to their composition: an abnormal collection of blood vessels (angio), smooth muscle (myo), and fat (lipoma).
Antiepileptic Drug (AED)
An antiepileptic drug is a medication prescribed to help control seizures. Also known as an anticonvulsant drug.
Ash Leaf Spot
See Hypomelanotic Macule.
Asymptomatic means showing or causing no obvious symptoms.
An atonic seizure is an abnormal discharge of electrical activity in the brain that causes sudden, uncontrolled relaxation of most or all muscles in the body. Atonic seizures may result in what experts generally refer to as drop attacks, in which an individual suddenly collapses or is thrown to the ground.
Attention Deficit Hyperactivity Disorder (ADHD)
Attention deficit hyperactivity disorder is a neurobehavioral disorder that makes learning and social interactions difficult, even for those with normal cognitive abilities, by causing individuals to be easily distracted and frustrated, fidgety, impulsive, and forgetful.
Autism is a neurological disorder of the brain that may result in difficulties with communication and social interaction as well as repetitive behaviors. Autistic traits vary in severity. Also known as autism spectrum disorder.
Autosomal dominant means that only one copy of a gene, inherited from either the mother or the father, needs to have the mutation for the child to have the disorder. All of the chromosomes except the sex chromosomes are autosomes.
Bayley Scales of Infant Development
The Bayley Scales are diagnostic tests that measure the motor skills, mental development, and behavior of infants from birth to 15 months.
A benign tumor is a noncancerous growth that does not spread to other parts of the body. Benign tumors can cause problems, however, depending on the number of tumors, where they grow, and the rate of growth.
A cardiac rhabdomyoma is a benign tumor of the heart. Rhabdomyomas are composed of tissue normally present in the heart (rhabdo), that grows in a disorganized mass (myoma).
A cardiologist is a physician who is trained and certified to treat problems of the cardiovascular system, including the heart, arteries, and veins. Children may see a pediatric cardiologist.
Chorionic Villi Sampling
Chorionic villi sampling is a method of prenatal diagnosis in which a small piece of fetal placenta, or chorionic villi, is removed early in pregnancy for genetic testing.
Chromosomes are structures located in the nucleus of the cell that contain our genetic material (genes). Humans have 23 pairs of chromosomes: half of each pair is inherited from our mother, and the other half from our father.
Computed Tomography (CT)
Computed tomography is a procedure that uses x-rays and computer technology to produce cross-sectional images of the body that are more detailed than traditional x-ray images. Also known as a CAT scan.
Confetti Skin Lesions
Confetti skin lesions are small, lightly pigmented spots 1-2 mm in diameter.
Congenital refers to a condition that is present at birth.
A cortical tuber is a region of the brain that develops abnormally. These lesions are benign tissue growths that displace normal tissue growth possibly contributing to neurological problems such as seizures, and learning and behavioral issues. Tuberous sclerosis complex is named after these growths. Also known as tuber.
Cryosurgery (also called cryotherapy) is the use of extreme cold to freeze and destroy abnormal tissue, such as lesions or growths on the skin. For external tumors, liquid nitrogen (or argon gas) is applied directly to the cells with a cotton swab or spraying device.
See Computed Tomography.
A cyst is a closed sac of air, fluid or semisolid material. Cysts can occur in multiple organs, including the kidneys, lungs, adrenal glands, liver, ovaries and pancreas.
D through F
Dental pits are pits in the enamel of the permanent teeth. They occur more frequently in individuals with TSC than in people who do not have TSC.
Deoxyribonucleic Acid (DNA)
DNA is made up of molecules that encode all the instructions necessary for a living organism to grow. Two long strands of DNA make up the familiar spiral-shaped double helix.
Dermabrasion is a surgical procedure in which the physician uses a sanding device to remove the top layer of skin. Dermabrasion is typically used to treat scars and other skin imperfections.
A dermatologist is a physician specializing in the diagnosis and treatment of skin conditions and disorders.
A developmental pediatrician is a physician who addresses the special needs or special care issues of children with developmental disorders such as TSC.
Dialysis is a medical treatment to remove excess fluid and waste from the body after the kidneys no longer function or have been removed.
See Deoxyribonucleic Acid.
An echocardiogram is a high-resolution form of ultrasound used to view the heart.
Electrocardiogram (ECG, EKG)
An electrocardiogram is a noninvasive procedure that measures the heart's electrical activity.
Embolization is a type of treatment that involves cutting off the flow of blood that feeds a growing tumor, causing the tumor to regress.
Epilepsy is a disorder of the brain characterized by disturbances of brain function called seizures.
A facial angiofibroma is a small reddish spot or bump that consists of fibrous tissue and blood vessels. They are most commonly found around the nose, cheeks, and chin, often combining to form a distinctive butterfly-shaped pattern. Previously known as adenoma sebaceum.
Foramen of Monro
The foramen of Monro is a narrow passage that carries spinal fluid between the lateral ventricles and the third ventricle of the brain.
Similar to a shagreen patch, a forehead plaque is a fibrous, flesh-colored patch raised above the surface of surrounding skin. They arise on the forehead or scalp and vary in size from a few millimeters to several centimeters in diameter.
Funduscopy is an examination of the eye using an ophthalmoscope, a lighted instrument used to view the inner eye including the retina and optic nerve. Also called ophthalmoscopy.
G through J
A gene is a unit of DNA that codes for the formation of a specific protein. Genes are the fundamental units of heredity. Genes come in pairs: one half of each pair is inherited from our mother, and the other half from our father.
Generalized seizures are thought to involve both sides of the brain at seizure onset. Secondarily generalized seizures begin as partial seizures originating from a specific region of the brain, but very rapidly become generalized.
A genetic counselor is a healthcare professional who has advanced degrees in medical genetics and counseling. Genetic counselors are trained in discussing the genetic components of conditions and genetic test results.
A genetic disorder is a medical condition caused by permanent changes, or mutations, in the DNA sequence of a gene or a number of genes or chromosomes.
Germ line refers to the body's reproductive cells, either the egg or the sperm.
Germline mosaicism is a genetic mutation that arises at the germ line, or gonadal level, meaning that some of either the mother's eggs or the father's sperm cells carry the mutation. The other cells in the body do not have the mutation, and the parent doesn't show any symptoms. TSC results when an egg or a sperm cell that carries the mutation is involved in fertilization.
A gingival fibroma is a nodular, or lumpy, tumor of the gums.
A glial cell is a specialized cell that surrounds nerve cells providing structural and metabolic support. It is estimated that glial cells outnumber neurons by as much as 50 to 1. Also known as neuroglia or glia.
Gonadal refers to the body's reproductive organs, either the testicles or the ovaries.
A growth factor is a naturally occurring protein that stimulates cell growth and division.
Hamartin is the protein coded by the TSC1 gene.
A hamartoma is a collection of abnormally shaped cells that multiplies excessively to form a benign tumor.
Hydrocephalus is a buildup of spinal fluid in the ventricles of the brain, causing intracranial pressure.
A hypomelanotic macule is a patch of skin lighter than the surrounding area that varies in size from several millimeters to several centimeters in diameter. They also vary in shape but are generally elliptical or lance shaped. Also known as hypopigmented macules or ash leaf spots.
Individualized Education Plan (IEP)
An Individualized Education Plan is a written education plan for a student with learning disabilities that is developed by a team of professionals (teachers, therapists, etc.) and the student's parents. An IEP is based on a multidisciplinary evaluation of the student, describing how the student is currently doing, what the student's learning needs are, and what services the student will need.
Infantile spasms are a serious type of seizure typically occurring during infancy, usually with onset between five and nine months. The seizures may be identified by a sudden jerking of the body, in which the child flexes or extends at the trunk. The indication may also be more subtle, such as staring or blinking. Infantile spasms commonly appear in clusters, typically occurring as the child is going to sleep, or soon after waking.
Intractable seizures are seizures that are difficult to control with antiepileptic medications.
K through M
The ketogenic diet is an alternative therapy to treat epilepsy. It is a high-fat, low-carbohydrate, low-protein diet that may reduce or eliminate seizures.
A learning disability is a condition that either prevents or hinders somebody from learning basic skills or information at the same rate as most people of the same age.
A lesion is a wound, injury, or destructive change in body tissue. Lesion is sometimes used as another word for tumor or tuber.
Lymphangioleiomyomatosis is a degenerative disease of the lungs that involves the proliferation of the LAM cell within the lung. As the name suggests, lymphangioleiomyomatosis is caused by the excessive growth (matosis) of abnormal smooth muscle-like cells (leiomyo), also called LAM cells, around the bronchial tubes, blood vessels (angio), and lymphatic vessels (lymph) of the lung. LAM is a progressive lung disease that affects primarily women and occurs much more frequently in people with TSC than in the general population.
Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging is a noninvasive procedure that uses radio waves and magnetic fields to produce images of body tissue.
Major features are a group of clinical findings used in diagnosis that are seen very frequently in people with TSC and significantly less often in the general population. The eleven major features of TSC include brain abnormalities, such as cortical tubers and subependymal nodules, skin lesions, such as angiofibromas and periungual fibromas, and so on. If a TSC evaluation reveals either two major features or one major and two minor features, the physician considers the TSC diagnosis definite.
A malignant tumor is a growth made up of cancerous cells that can invade surrounding tissue or move to other parts of the body.
Minor features are a group of clinical findings used in diagnosis that are common in TSC, but also common in the general population. The nine minor features of TSC include abnormalities of the gums, teeth, kidneys, skin, and other areas. If a TSC evaluation reveals either two major features or one major and two minor features, the physician considers the TSC diagnosis definite.
Molecular Diagnostic Test
A molecular diagnostic test looks at a person's DNA for the existence of a mutation. Also known as a genetic test or a DNA test.
See Magnetic Resonance Imaging.
A mutation is a permanent change in DNA. Mutations can be inherited or can occur spontaneously.
A myoclonic seizure is a single, intense muscular contraction that results from abnormal electrical discharge of the brain and usually involves a single powerful jerk of the limbs, trunk, or face. These events may be partial, originating on one side of the brain, or generalized, originating on both sides. Myoclonic seizures may result in what experts generally refer to as drop attacks, in which an individual suddenly collapses or is thrown to the ground.
N through P
A nephrologist is a physician who has been educated and trained in kidney diseases, kidney transplantation, and dialysis therapy. Children may see a pediatric nephrologist.
A nephrologist is a physician who has been educated and trained in kidney diseases, kidney transplantation, and dialysis therapy. Children may see a pediatric nephrologist.
Neurofibromatosis is a genetic disorder caused by a mutation to the NF1 or NF2 gene. Neurofibromatosis 1 (NF1) is characterized by multiple benign tumors and patches of skin pigmentation called café au lait spots. Neurofibromatosis 2 (NF2) is characterized by tumors of the hearing and balance nerve.
A neurologist is a physician who specializes in disorders of the nervous system. A neurologist who treats people with TSC is trained to recognize the neurological symptoms and brain abnormalities characteristic of the disorder.
A neuron is a specialized cell that transmits electrical and chemical signals in the body's nervous system. Also known as a nerve cell.
A neuropsychologist is a psychologist with specialized training in brain-behavior relationships and the evaluation of cognitive functions. Neuropsychologists use a battery of standardized tests to assess specific cognitive and behavioral functions and identify areas of cognitive impairment as they relate to brain functioning. A neuropsychologist who treats people with TSC is knowledgeable about the specific cognitive and behavioral issues that are common to the disorder and knows what treatment options are most effective for these issues.
A neurosurgeon is a physician who specializes in performing surgery on the central nervous system, including the brain. A neurosurgeon who treats people with TSC is trained in the identification and removal of SEGAs. A neurosurgeon who specializes in epilepsy surgery is trained in the removal of specific regions of the cerebral cortex identified as the primary location of seizure activity. A neurosurgeon may also be trained to implant a vagus nerve stimulator (VNS) to help control seizures.
Nucleotides are the chemical bases that make up DNA. The four chemical bases are adenine, thymine, cytosine, and guanine (usually referred to by the first letter of their chemical name: A, T, C, and G). These bases pair up with each other to form the rungs of the twisted-ladder-shaped DNA molecule.
A nutritionist is a medical professional who specializes in diet and metabolism. A nutritionist who is knowledgeable about TSC-related seizures and has had specialized training in administering the ketogenic diet can provide background and instructions on how to implement this alternative therapy.
An ophthalmologist is a physician who specializes in the medical and surgical care of the eyes and visual system and in the prevention of eye disease and injury. An ophthalmologist is trained to recognize the various eye manifestations of TSC and to ascertain the significance of these abnormalities in terms of eye function.
Ophthalmoscopy is an examination of the eye using an ophthalmoscope, a lighted instrument used to view the inner eye including the retina and optic nerve. Also called funduscopy.
Partial seizures originate from a localized, or specific, part of the brain. There are two types of partial seizures: simple partial seizures, which do not alter an individual's consciousness, and complex partial seizures, which may cause a sensation of dreaminess, dramatic mood change, or complete unresponsiveness. All seizures in TSC are thought to be partial in onset.
A pedigree is a genealogical diagram that shows all family members as well as how a particular trait or disease has been inherited.
A periungual fibroma is a flesh-colored or reddish lesion that grows around fingernails and toenails. Periungual fibromas vary in size from a few millimeters to about 1 cm in diameter.
Photocoagulation is a laser treatment used to treat conditions of the eye. Photocoagulation can be used to remove or reduce the size of a retinal hamartoma by eliminating the network of blood vessels that feeds the tumor.
See Polycystic Kidney Disease.
Pneumothorax occurs when a cyst in the lung ruptures, creating a small hole in the lining of the lung that allows air to escape into the surrounding chest cavity, causing the lung to collapse. This condition requires immediate medical attention.
Polycystic Kidney Disease (PKD)
Polycystic kidney disease is a rare inherited genetic disorder causing multiple cysts in the kidneys. This disease is closely related to TSC.
A psychiatrist is a medical doctor who specializes in the diagnosis and treatment of mental disorders. A psychiatrist who treats people with TSC is familiar with the cognitive and behavioral issues that are common to the disorder and knows what treatment options are most effective for these issues.
A psychologist is a professional who has earned a doctoral degree in psychology and has undergone clinical training. He or she is a specialist in the diagnosis and treatment of mental and emotional problems. His or her role involves evaluation, testing, counseling, and/or psychotherapy, without the use of medications.
Pulmonary Computed Tomography (CT)
See Computed Tomorgraphy.
A pulmonologist is a physician with specialized training in the anatomy, physiology, and pathology of the lungs and pulmonary system.
Q through S
A radiologist is a medical professional who creates and interprets images, including x-rays, ultrasounds, MRIs, and CT scans. A neuroradiologist is trained to recognize abnormalities of the nervous system, including the brain findings associated with TSC.
Rapamycin is a drug originally designed for use in immune suppression in transplant patients, but is also known to inhibit cell growth. Rapamycin is being investigated for use in treating the tumors associated with tuberous sclerosis complex.
Renal Cell Carcinoma
Renal cell carcinoma is the most common type of kidney cancer in adults. This aggressive cancer grows in the lining of very small tubes, or tubules, inside the kidney.
A renal cyst is a fluid-filled mass that appears in the kidneys. Doctors recognize two types of renal cysts. The more common of the two typically remains small (2 mm to 1 cm in diameter), appears as a single cyst or in small numbers, and has little effect on kidney function. The second type, which affects 2 to 3 percent of people with TSC, is large (1 cm to 5 cm in diameter), often occurs in large numbers, and typically affects both kidneys. This condition is similar to a disorder called polycystic kidney disease.
Retinal Achromic Patch
Retinal achromic patches are spots on the retina that are lighter or darker in pigment than surrounding tissue.
A retinal hamartoma is a benign tumor of the eye. Generally, hamartomas are collections of abnormally shaped cells that multiply excessively to form benign tumors. In the eye, hamartomas are composed of abnormal neurons.
See Cardiac Rhabdomyoma.
Rheb (Ras homologue enriched in brain) is a protein in the signaling pathway that involves the TSC proteins.
See Subependymal Giant Cell Astrocytoma.
A seizure is a sudden discharge of electrical activity in the brain that may cause a change in behavior, awareness, or sensation.
See Subependymal Nodule.
A shagreen patch is a firm yellowish-red or pink area of nodules slightly elevated above the surrounding skin and often described as having the texture of an orange peel. They vary in size from a few millimeters to more than 10 cm in diameter. In individuals with TSC, they are nearly always found on or around the lumbar region of the back, but can appear on other parts of the body as well.
Shave excision is a surgical procedure in which the physician uses a blade to remove the top layer of skin. Shave excision is typically used to remove benign skin growths.
A social worker is a professional trained to counsel individuals and their families about emotional, social, and physical needs, and facilitate access to services and organizations.
A spontaneous mutation is a mutation that is not inherited. Instead, the mutation occurs in the affected individual during the earliest stages of development, at or just after fertilization. Also known as a new, or sporadic, mutation.
In sporadic TSC, neither parent carries the mutation. Instead, the mutation occurs spontaneously in the affected individual during the earliest stages of development, at or just after fertilization. Also known as a new mutation.
Subependymal Giant Cell Astrocytoma (SEGA)
A subependymal giant cell astrocytoma is a large subependymal nodule (SEN). They are benign and composed of undifferentiated dysfunctional cells, including balloon cells. In rare cases, SEGAs grow large enough to obstruct the flow of cerebrospinal fluid through the lateral ventricles of the brain and may cause hydrocephalus, an enlargement of the skull and pressure on the brain.
Subependymal Nodule (SEN)
A subependymal nodule is a benign growth that develops and grows along the wall (ependymal lining) of the brain's lateral ventricles, the spaces that contain cerebrospinal fluid. While only 15 percent of SENs grow larger than 1 cm in diameter, those that do become classified as SEGAs and are cause for concern.
T through Z
Target of Rapamycin (TOR)
TOR is a protein in the signaling pathway involving the TSC proteins. TOR sends signals to the nucleus of a cell and to the protein synthesis machinery to tell the cell to take up more nutrients, to make more proteins, and to grow. TOR is also a drug target for the drug Rapamycin.
A tonic seizure involves a prolonged contraction of muscles and stiffening of limbs without the rhythmic motion characteristic of most seizures. Tonic seizures may result in what experts generally refer to as drop attacks, in which an individual suddenly collapses or is thrown to the ground.
A tonic-clonic seizure begins with the tonic phase, which often involves a fall to the floor, stiffening of the limbs, and clenching of teeth. This is followed by the clonic phase, which presents itself as the violent rhythmic jerking of the limbs and torso. Previously known as a grand mal seizure.
See Target of Rapamycin.
See Cortical Tuber.
Tuberin is the protein coded by the TSC2 gene.
A tumor is an abnormal, uncontrolled growth or mass of body cells that has no physiological function. A tumor may be malignant or benign.
An ultrasound is a procedure that uses high-frequency sound waves to visualize internal organs.
An ungual fibroma is a flesh-colored or reddish lesion that grows under fingernails and toenails. Ungual fibromas vary in size from a few millimeters to about 1 cm in diameter.
A urologist is a physician who has specialized knowledge and skill regarding problems of the male and female urinary tract and the male reproductive organs.
Vagus Nerve Stimulator (VNS)
The vagus nerve stimulator (VNS) is an alternative therapy to treat seizures. This technique relies on a pacemaker-like device that is implanted under the skin of the chest and supplies intermittent electrical impulses to the vagus nerve as it passes through the neck. Intermittent stimulation of this nerve with low-intensity electrical impulses may reduce seizures in some people.
Vigabatrin is an antiepileptic medication shown to be effective in treating children with TSC who are suffering from infantile spasms.
See Vagus Nerve Stimulator.
A Wood's lamp is an ultraviolet light used to help locate white patches on the skin.