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Glossary

A

Apert syndrome: A genetic disorder. Craniosynostosis, the early fusing or closing of the skull bones, is part of Apert syndrome. It often involves closing of the coronal sutures (on each side of the forehead) and midface hypoplasia (the center of the child’s face does not form properly). Children with this problem often have dental problems and webbed fingers and toes, hydrocephalus and possible developmental delay.
Arteries: They carry blood away from the heart.
Astrocytomas: Tumors that begin in the brain or spinal cord. They develop from star-shaped cells called astrocytes. They are also called astroglial tumors. They can be low grade (benign) or high grade (malignant).

B

Bacteria: Groups of living organisms only seen with a microscope. Each bacterium consists of one cell, but they are very powerful and live nearly everywhere. Some do good things, like help our digestion. Other bacteria cause infections, illness and even death.
Biopsy: A process that helps surgeons and other doctors diagnose a patient’s condition. For example, to find out if a tumor is cancerous or not, they remove a small piece of tissue. A pathologist looks at it under a microscope. The pathologist determines the type of cells present and makes a diagnosis.
Brainstem: The structure connecting the spinal cord with other parts of the brain. It plays an important role in the body and helps your child be conscious (aware), breathe and regulate her body temperature. All information moving between the body and the brain passes through the brainstem.

C

Cancer: The uncontrolled growth of abnormal cells. Cancer cells can multiply and gather in one spot or spread throughout a person’s body by a process called metastasis. Cancer cells can cause disability and death when they prevent important organs from working.
Central nervous system (CNS): Includes the brain and spinal cord. It is the main “processing center” for the body’s nervous system – its network of nerves – and controls all that goes on in the body.
Cerebellum: The part of the brain that controls muscle coordination and equilibrium (balance). It is in the back and lower part of the brain.
Cerebral angiogram: This procedure requires the skills of a doctor called an interventional radiologist who uses radiology or X-rays to diagnose and treat patients. The radiologist puts a small tube into an artery and threads it up the necessary area of the brain. He injects dye into an artery through the tube to make the vessels visible on an X-ray. The result is a picture of the normal and abnormal blood vessels of your child’s brain.
Cerebrospinal fluid (CSF): A clear fluid produced in the brain’s ventricular system – the four cavities in the brain. It travels throughout the brain and in the area outside the brain and spinal cord. It bathes, protects, nourishes and cushions the brain and spinal cord.
Cerebrum: The part of the brain that deals with reasoning, learning, perception, memory, movement, sensation and emotions. It is the upper portion of the brain and fills most of the skull. The cerebrum has two halves (hemispheres), the right and the left.
Cervical spine: In the cervical area of the spine, commonly called the neck, and includes the first seven vertebrae.
Chemotherapy: A cancer treatment that uses medicine to stop the growth of cancer. It kills the cancer cells or stops them from multiplying. Chemotherapy may be used:1) To shrink a tumor; 2) After surgery to kill remaining cancer cells and prevent the cancer from coming back; 3) As your child’s main cancer treatment with or without radiation. Chemotherapy involves different medicines for different types of tumors.
Clubfoot: A deformity present at birth (congenital). The foot is not able to move well — your child may be unable to move his foot up or down or inward or outward.
Cognitive development: Refers to the growth process of certain mental abilities that involve reasoning, judgment, intuition, memory and gaining knowledge.
Computerized Tomography (CT) scan: An X-ray that produces cross-sectional pictures of the body. These allow doctors to see the inside of your child’s body and diagnose and understand his illness or injury.
Congenital: Refers to disorders and medical conditions present at birth. They are noticed before birth (prenatal), at birth or even many years later. Causes of congenital disorders include genetic abnormalities or something that happens during pregnancy, such as the mother smoking or drinking alcohol. Sometimes the causes of congenital abnormalities may not be known. Congenital disorders range from birthmarks to heart and brain problems.
Cortical dysplasia: Refers to abnormalities of the cerebral cortex (a part of the brain). Patches of abnormal brain tissue cause seizures and developmental delays. Larger-than-normal neurons may be involved, causing brain signals to misfire.
Craniofacial: Means involving the skull and face and generally refers to birth defects. Examples are craniosynostosis, cleft lip and palate and hemifacial microsomia.
Craniotomy: A surgery that allows a neurosurgeon to get to your child's brain. First, he cuts and removes a piece of bone from the skull. Next he cuts the tough membrane called the dura mater — the membrane that protects the brain. Then he removes or treats the diseased area of the brain such as a brain tumor. The neurosurgeon then closes the dura mater and closes up the skull using the same piece of bone he removed, if possible. Sometimes we use hardware such as micro plates, screws and wires to close the child's skull.
Crouzon syndrome: A genetic condition that can include coronal synostosis and facial abnormalities (abnormal development of the eye sockets and midface). Developmental delay and hydrocephalus can occur but are more uncommon than in Apert syndrome.
Cyanotic heart disease: A congenital (present at birth) heart defect. It causes lack of oxygen within the body, which makes lips, fingers and toes look blue. The organs of the body may also be affected.
Cyst: An abnormal, closed sac containing fluid, semi-fluid or solid material. A cyst can happen anywhere in the body including within the brain and on the spinal cord. Doctors often check cysts to make sure they are not cancerous. If a cyst causes symptoms, it may need treatment.

D

DNA: A material found in almost all living organisms. It is the carrier of genetic information.
Dermal sinus tract: A small opening that runs from a child's skin into the brain or spinal canal. It sometimes has a dimple or other abnormality at the skin site. It causes problems if it does not completely close by a baby's birth.
Down syndrome: One of the most common genetic defects. It includes a combination of developmental delays and specific facial features. Children with Down syndrome tend to have infections, heart defects, vision and hearing problems and other health issues.
Dura mater: The leather-like membrane covering the brain and spinal cord. Its role is to protect the brain and spinal cord.
Dystonia: A congenital (present at birth) defect affecting speech and motor skills.

E

Electrodes: Carry electrical signals to and from an object. They may be used to monitor brain wave activity or nerve and muscle activity during surgery.
Environmental factors: Things in our lives that can cause physical changes. For example, radiation may be an environmental risk factor for developing brain tumors.
Ependymoma tumors: Develop from ependymal cells. These cells make up supportive tissues that line the ventricles of the brain and the center of the spinal cord.

F

Fibromuscular dysplasia: Abnormal cellular development or growth involving the walls of one or more arteries in the body. This can cause stenosis, a narrowing of the artery. Common places for this to occur are the arteries that supply the kidneys with blood and the carotid artery, in the neck, which supplies the brain with blood.
Filum terminale: The very end of the spinal cord.
Folic acid: Also called folate, it is a B vitamin found in some enriched foods like bread and in vitamin pills. Taken regularly by a pregnant mother, it may prevent her baby from developing myelomeningocele, the most serious form of spina bifida and its associated brain and spine abnormalities.
Functional cortex: Refers to the sections of the brain's cortex and their responsibilities for higher-level brain functions. These functions include, for example, problem solving, processing what we see and understanding language and speech.

G

Genes: With chromosomes, genes store and use genetic information during prenatal (before birth) development and throughout a person's life. A gene consists of DNA or RNA. A person's genes can change from exposure to certain substances in the environment. Gene changes can lead to disease not seen before in family members.
Genetic: Refers to the traits passed on from biological family members, such as hair color, eye color and height. Certain illnesses and conditions are also genetic.

H

Hemimegalencephaly: Involves a brain with one side abnormally larger than the other. The abnormal brain tissue causes seizures and movement problems on the opposite side of the body.
Hormones: Chemicals produced by the body. They are carried throughout the body in body fluids. Hormones help control many functions such as metabolism, blood sugar, menstruation and sexual characteristics.

I

Intervening capillaries: The small blood vessels at the ends of arteries that drain into veins.

L

Laminectomy: Surgery that involves removing one or more sides of the back arches of a spinal bone (vertebra). A neurosurgeon performs this surgery to gain access to your child's spinal canal to treat problems such as a tumor or scar tissue inside the canal.
Lesions: Any tissue or organ changes that result from disease or injury. Some lesions are described by whether or not cancer caused them. We describe some by what they look like, their size, their location or their function in the body.
Lumbar puncture: Involves placing a special needle between two spinal bones (vertebrae) in the lower back (lumbar vertebrae) and then on into the spinal cord to get a sample of cerebrospinal fluid. This helps doctors diagnose certain diseases. This is also called an LP or a spinal tap.
Lumbar spine: Includes the first through fifth spinal bones (lumbar vertebrae) in the lower back. They are immediately below the thoracic vertebrae and just above the sacrum.

M

Magnetic Resonance Imaging (MRI): A process that creates high-quality pictures of the inside of the body. An MRI uses a large magnet to create these pictures.
Malignant: Refers to tumors or other cells that have been examined and found to be cancer. Cancer cells can grow rapidly and/or spread to other areas.
Medulloblastoma: A malignant brain tumor in the cerebellum that is much more common in children than in adults.
Membranes: The thin layers of tissue surrounding a body part, like the brain.
Meninges: The three tissue that cover the brain and spinal cord. Its three layers are the dura mater, the arachnoid and the pia mater.
Meningitis: A disease involving inflammation of the meninges, caused by either a virus, bacteria or some other irritant.
Mesial temporal sclerosis: An abnormality of the brain's temporal lobe associated with seizures.
Micro plates: Small closures, about 3 to 4 mm long, used to bridge two pieces of skull bone that were removed and replaced during surgery. Tiny screws hold them in place.
Motor function: Refers to the ability to move and do physical activities. Small (fine) motor skills involve the body's small muscles, like those in the hands, for activities like handwriting and buttoning shirts and jackets. Large (gross) motor skills involve the larger muscles, like those in the arms and legs, for activities such as throwing a ball and running.

N

Neurofibromatoses (NF): A set of genetic disorders that cause tumors that may grow along the brain, spinal cord or nerves throughout the body. This disorder gets worse with time. It is one of the most common genetic disorders in the United States. Neurofibromatoses are also associated with hyper-pigmentation spots, called “café au lait” spots.
Neurological: Refers to the nervous system. Neurology is the branch of medicine dealing with the nervous system and its disorders that are treated medically. Neurosurgery involves neurological disorders that are treated with surgery.
Neuromonitoring: Involves placing electrodes on your child's body and in her brain or spinal cord. These electrodes monitor her nerves during surgery.
Neuronal glial tumors: Tumors that appear to be a mix of both mature nerve cells and glial cells. The mature nerve cells are what people generally think of as brain cells. Glial cells make up what's called a 3D matrix for the nerve cells to grow in. These glial cells do not transmit any signals, as other brain cells do.
Neurons: Nerve cells, the basic unit of the nervous system. They create signals and send them throughout the body.

P

Pilocytic astrocytomas: Low-grade (benign) astrocytomas that happen mainly in children.
Plastic surgeons: Restore and rebuild face and body tissues that are misshaped by disease, birth defects, disorders or trauma. They reduce scarring and restore function as well as improve appearance.
Porencephalic cysts: Appear in the brain tissue or ventricles. They are caused by trauma to the area, such as a head injury, stroke or needle tap to the ventricle.
Primitive neuroectodermal tumor (PNET): Looks identical to a medulloblastoma under the microscope. PNETs happen in the upper part of the brain (the cerebrum).

R

Radiosurgery: Also called stereotactic radiosurgery (SRS). It treats brain abnormalities, tumors and other function disorders. Its 3D (three-dimensional) computer-aided pictures help doctors plan your child’s treatment. SRS delivers an exact, very high dose of radiation to the correct site — such as a tumor — while avoiding healthy brain tissue.
Rasmussen's encephalitis: Long-lasting (chronic) inflammation of one half of the brain. It does not get better or worse over time. The affected side of the brain can cause seizures and weakness on the opposite side of the body.

S

Scoliosis: Curvature of the spine. For some children, scoliosis is a small curve of the spine with no symptoms. For others it happens along with other abnormalities, causing many physical problems. A child with severe scoliosis may need a surgery called spinal fusion. A surgeon puts rods in the child's spine or surgically connects (fuses) vertebrae.
Seizures: Involve a sudden change in a child's consciousness (awareness), motor activity or physical sensation. Abnormal electrical activity in the brain causes seizures, which can vary in intensity. They are called chronic if they keep happening over time. A seizure can involve many muscle groups or seem to be as simple as staring into space.
Sensory: Refers to certain experiences that help us interact with and understand our world. Sound, movement, touch, smell, sight and taste are sensory experiences.
Spina bifida: A neural tube defect that happens in the first month of pregnancy. Normally, the neural tube in a fetus develops into its brain and spinal cord. With spinal bifida, the arches of the vertebrae do not grow and close around the spinal cord as they should. This leaves the spinal cord open and unprotected. Often, the meninges and spinal cord protrude out from the child's spine. Myelomeningocele is the most severe form of spina bifida.
Spinal column: Also called the spine or vertebral column. It includes 33 bones separated by disks and held together by ligaments. The spinal column supports your child's head and encloses and protects her spinal canal and spinal cord.
Sturge-Weber syndrome: A genetic disorder of the veins in one half of the brain. It involves facial discoloration and developmental delays. The abnormal blood vessels cause seizures and a stiffening (calcification) of the cortex. Removing these problem areas from the brain often helps.
Subarachnoid spaces: They lie between the three membranes protecting the brain. Cerebrospinal fluid moves through these spaces. Delicate connective tissue extends across them.
Sutures: The fibrous joints between the bones of a baby's skull. Sutures allow your baby's head to fit through the birth canal, and they allow his skull to grow as the brain grows. Sutures slowly grow together (fuse) during childhood, fully closing about age 2-3. The fusion process is fully complete in adulthood.

T

Temporal artery: The main artery that supplies blood to the head, eyes and optic nerve.
Thecal sac: The area inside the spinal canal containing cerebrospinal fluid and the spinal cord. A tough, protective membrane (the dura mater) surrounds the thecal sac.
Thoracic spine: Refers to the twelve vertebrae (T-1 through T-12) located between the cervical vertebrae in the neck area, and the lumbar vertebrae in the lower back area of the spine.
Tuberous sclerosis (TS): A genetic disorder that causes tumors to form in the brain, eyes, heart, kidney, skin and lungs. It can also involve seizures.
Tumors: Growths of tissue that form an abnormal mass. They have no useful function and can crowd healthy tissue. Benign tumors grow slowly and do not usually spread. But in the brain, they can put pressure on the surrounding brain tissue and cause disability and even death. A malignant tumor grows fairly fast and can spread within the brain and spinal cord and cause death.

V

Vascular system: The network of blood vessels that runs throughout the body. It consists of arteries, veins and capillaries.
Vein of Galen: One of the large blood vessels in the skull that drains the cerebrum — the front part of the brain.
Veins: Veins carry blood back to the heart.
Ventricles: The four small cavities in the brain that produce cerebrospinal fluid (CSF). This fluid flows through the ventricles to the area around the brain and spinal cord.
Vertebrae: The 33 bones that make up the spinal column (spine). They enclose and protect the spinal canal, which contains the spinal cord.

W

Wada test: Looks at language and memory on one side of the brain at a time. Language (speech) is controlled by one side of the brain (in most people, the left side), and the Wada will tell the doctors which side controls language in your brain. Memory can be controlled by both sides of the brain; the Wada tells which side of your brain has better memory. If the side that controls language or has better memory is where seizures may be coming from, the surgeon may consider performing an fMRI or brain mapping before surgery.