OHSU

Glossary of Brain and Nervous System Terms

A | B | C | D | E | F | G | H | I | K | L | M | N | O | PR | S | T | W | X

acetylcholine - a chemical in the brain that acts as a neurotransmitter.

action tremor - a tremor that increases when the hand is moving voluntarily.

activities of daily living (ADLs) - personal care activities necessary for everyday living, such as eating, bathing, grooming, dressing, and toileting; a term often used by healthcare professionals to assess the need and/or type of care a person may require.

acute spinal cord injury (SCI) - due to a traumatic injury that results in a bruise (contusion), partial tear or complete tear in the spinal cord. SCI is a common cause of permanent disability and death in children.

Adjustment disorder - Emotional and/or behavioral problems following a specific stressor, which significantly interferes with social, work, or school functioning.

Adolescent medicine - a subspecialty of pediatric medicine with a focus on providing healthcare to adolescent patients and treating medical problems that are common during adolescence.

advance directives - documents (such as a Living Will) completed and signed by a person who is legally competent to explain his/her wishes for medical care should he/she become unable to make those decisions at a later time.

Affective disorder (Also known as mood disorder.) - a category of mental health problems that include depressive disorders.

agitation - a non-specific symptom of one or more physical, or psychological processes in which vocal or motor behavior (screaming, shouting, complaining, moaning, cursing, pacing, fidgeting, wandering) pose risk or discomfort, become disruptive or unsafe, or interfere with the delivery of care in a particular environment.

agonist - a drug that increases neurotransmitter activity by stimulating the receptors of a neurotransmitter directly.

Agoraphobia - a Greek word that literally means "fear of the marketplace." This anxiety disorder involves the fear of experiencing a panic attack in a place or situation from which escape may be difficult or embarrassing.

akinesia - no movement.

Alzheimer's disease - A progressive, degenerative disease that occurs in the brain and results in impaired memory, thinking, and behavior.

Amnesia - a memory impairment exhibited by the inability to learn new information or recall previous learned information.

amyotrophic lateral sclerosis (ALS) - a terminal neurological disorder characterized by progressive degeneration of motor cells in the spinal cord and brain. It is often referred to as "Lou Gehrig's disease."

anencephaly - a condition that is present at birth and affects the formation of the brain and the skull bones that surround the head, resulting in only minimal development of the brain. There is no bony covering over the back of the head and there may also be missing bones around the front and sides of the head.

Anorexia nervosa (also called anorexia) - an eating disorder in which people intentionally starve themselves. It causes extreme weight loss, which the National Institute of Mental Health (NIMH), part of the National Institutes of Health (NIH), defines as at least 15 percent below the individual's normal body weight.

Antisocial personality disorder - persons with this disorder characteristically disregard the feelings, property, authority, and respect of others, for their own personal gain. This may include violent or aggressive acts involving or targeting other individuals, without a sense or remorse or guilt for any of their destructive actions.

Anxiety - an intense feeling of fear or discomfort, often accompanied by physical symptoms, such and a pounding heart, sweating, nausea, rapid breathing, dizziness, or numbness.

arteriogram (also called angiogram) - a procedure that provides a scan of arteries and/or veins going to and through the brain.

ataxia - loss of balance.

athetosis - slow, involuntary movements of the hands and feet.

atrophy - wasting, shrinkage of muscle tissue or nerve tissue.

Attention-deficit/hyperactivity disorder (ADHD) - a behavior disorder, usually first diagnosed in childhood, which is characterized by inattention, impulsivity, and, in some cases, hyperactivity.

Avoidant personality disorder - persons with this disorder are hypersensitive to rejection and thus, avoid situations with any potential for conflict. This reaction is fear-driven; however, persons with avoidant personality disorder become disturbed by their own social isolation, withdrawal, and inability to form close, interpersonal relationships.

axon - the long, hair-like extension of a nerve cell that carries a message to the next nerve cell.

top

basal ganglia - several large clusters of nerve cells, including the putamen and globus pallidus, deep in the brain below the cerebral hemispheres.

Bell's palsy - An unexplained episode of facial muscle weakness or paralysis that begins suddenly and steadily worsens.

Binge eating disorder - a disorder that resembles bulimia nervosa and is characterized by episodes of uncontrolled eating (or bingeing). It differs from bulimia, however, because its sufferers do not purge their bodies of the excess food, via vomiting, laxative abuse, or diuretic abuse.

Bingeing - persons with bulimia nervosa engage in a destructive pattern of excessively overeating called bingeing.

Bipolar disorder - a spectrum of mood swing disorders (see manic depression) which can specify the rhythms of cycles an individual experiences.

blink rate - the number of times per minute that the eyelid automatically closes - normally 10 to 20 per minute.

blood-brain barrier - the protective membrane that separates circulating blood from brain cells.

Body dismorphic disorder - the excessive preoccupation with either a small or imagined defect in one's physical appearance.

Borderline personality disorder - persons with this disorder present instability in their perceptions of themselves, and have difficulty maintaining stable relationships. Moods may also be inconsistent, but never neutral - their sense of reality is always seen in "black and white." Persons with borderline personality disorder often feel as though they lacked a certain level of nurturing while growing up and, as a result, incessantly seek a higher level of caretaking from others as adults. This may be achieved through manipulation of others, leaving them often feeling empty, angry, and abandoned, which may lead to desperate and impulsive behavior.

bradykinesia - slowness of movement.

bradyphrenia - slowness of thought processes.

brain abscess - an infection in the brain that is encapsulated (confined within its own area) and localized to one or more areas inside of the brain. This condition causes problems with brain and spinal cord functions.

brain attack (also called stroke) - happens when brain cells die because of inadequate blood flow to the brain or when function of a part of the brain is suddenly lost because of the rupture of a blood vessel in the brain.

top

 

central nervous system - the brain and the spinal cord.

cerebellum - a large structure consisting of two halves (hemispheres) located in the lower part of the brain; responsible for the coordination of movement and balance.

cerebral embolism - a brain attack that occurs when a blood clot (embolus) or some other particle forms in a blood vessel and travels to a blood vessel in the brain to the point where it blocks blood flow in the vessel; often the clot forms away from the brain, usually in the heart.

cerebral hemorrhage - a type of stroke occurs when a defective artery in the brain bursts, flooding the surrounding tissue with blood.

cerebral palsy (CP) - a broad term that describes a group of neurological (brain) disorders. It is a life-long condition that affects the communication between the brain and the muscles, causing a permanent state of uncoordinated movement and posturing. CP is the result of an episode that causes a lack of oxygen to the brain.

cerebral spinal fluid analysis (also called spinal tap or lumbar puncture) - a procedure used to make an evaluation or diagnosis by examining the fluid withdrawn from the spinal column.

cerebral thrombosis - the most common type of brain attack; occurs when a blood clot (thrombus) forms and blocks blood flow in an artery bringing blood to part of the brain.

cerebrum - consists of two parts (lobes), left and right, which form the largest and most developed part of the brain; initiation and coordination of all voluntary movement take place within the cerebrum. The basal ganglia are located immediately below the cerebrum.

Chiari malformation - a problem present at birth that affects the area in the back of the head where the brain and the spinal cord connect.

Child and adolescent psychiatrist - licensed physicians (M.D. or D.O.) who specialize in the evaluation, diagnosis, and treatment of mental disorders in children and adolescents. Their medical and psychiatric training with children and adolescents prepares them to treat children and adolescents either individually, as part of and involving the family unit, and/or in a group setting. Child and adolescent psychiatrists can prescribe medications, if needed.

chorea - rapid, jerky, dance-like movement of the body.

Circadian rhythm sleep disorder - a disruption in the normal sleep-wake cycle over a period of time, as found in shift work, jet lag, or other delayed sleep.

computed tomography scan (also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.

computed tomography scan (also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.

congenital - present at birth

cortex - the outer layer of the cerebrum, densely packed with nerve cells.

craniosynostosis - a condition in which the sutures (soft spots) in the skull of an infant close too early, causing problems with normal brain and skull growth. Premature closure of the sutures may also cause the pressure inside of the head to increase and the skull or facial bones to change from a normal, symmetrical appearance.

cryothalamotomy - a surgical procedure in which a super-cooled probe is inserted into a part of the brain called the thalamus in order to stop tremors.

top

 

Delirium - an altercation in consciousness, with a decrease in the ability to focus, hold ,or shift attention.

delusions - a condition in which the patient has lost touch with reality and experiences hallucinations and misperceptions.

Delusions - a perception that is thought to be true by the person experiencing it, although the perception is wrong. There are many types of delusions (i.e., delusions of grandeur).

dementia - not a disease itself, but group of symptoms that characterize diseases and conditions; it is commonly defined as a decline in intellectual functioning that is severe enough to interfere with the ability to perform routine activities.

dendrite - a threadlike extension from a nerve cell that serves as an antenna to receive messages from the axons of other nerve cells.

Dependent personality disorder - persons with this disorder rely heavily on others for validation and fulfillment of basic needs. Often unable to properly care for themselves, persons with dependent personality disorder lack self confidence and security, and are deficient in making decisions.

Depression - a depressive disorder characterized by extreme feelings of sadness, lack of self-worth, and dejection.

dopa decarboxylase - an enzyme present in the body that converts levodopa to dopamine.

dopamine - a chemical substance, a neurotransmitter, found in the brain that regulates movement, balance, and walking.

dyskinesia - an involuntary movement including athetosis and chorea.

dysphagia - difficulty in swallowing.

Dysthymia (Also known as dysthymic disorder.) - classified as a type of affective disorder or mood disorder that often resembles a less severe, yet more chronic form of major (clinical) depression. However, persons with dysthymia may also experience major depressive episodes at times.

dystonia - a slow movement or extended spasm in a group of muscles.

dystrophin - a protein; a chemical substance made by muscle fibers.

top

 

Eating disorders - abnormal eating behaviors.

Electroconvulsive therapy (ECT) - a procedure causing a brief convulsion by passing an electric current through the brain; used to treat some mental disorders.

electrodiagnostic tests (i.e., electromyography and nerve conduction velocity) - studies that evaluate and diagnose disorders of the muscles and motor neurons. Electrodes are inserted into the muscle, or placed on the skin overlying a muscle or muscle group, and electrical activity and muscle response are recorded.

electroencephalogram (EEG) - a procedure that records the brain's continuous, electrical activity by means of electrodes attached to the scalp.

electroencephalogram (EEG) - a procedure that records the brain's continuous, electrical activity by means of electrodes attached to the scalp.

electromyogram (EMG) - a test that measures the electrical activity of a muscle or a group of muscles. An EMG can detect abnormal electrical muscle activity due to diseases and neuromuscular conditions.

embolus - a "wandering" blood clot.

encephalitis - a condition characterized by inflammation of the brain. This condition causes problems with the brain and spinal cord function.

encephalitis - a viral infection of the brain.

epilepsy - a condition in which there is a problem with the brain that causes long-term seizures in the child.

epilepsy (also called seizure disorder) - a brain disorder involving recurrent seizures.

Euphoria - a feeling of elation or well-being that is not based on reality and is commonly exaggerated.

euphoria - a feeling of well-being or elation; may be drug-related.

evoked potentials - procedures that record the brain's electrical response to visual, auditory, and sensory stimuli.

extensor muscle - any muscle that causes the straightening of a limb or other part.

extrapyramidal system - system consisting of nerve cells, nerve tracts, and pathways that connects the cerebral cortex, basal ganglia, thalamus, cerebellum, reticular formation, and spinal neurons that is concerned with the regulation of reflex movements such as balance and walking.

top

 

Factitious disorders- pretending to have physical or psychological symptoms for a secondary gain, such as assuming a sick role in order to eliminate responsibilities.

festination - walking with a series of quick, small, shuffling steps as if hurrying forward to keep balance.

flexor muscle - any muscle that causes the bending of a limb or other body part.

fractures - a partial or complete break in the bone.

top

 

ganglion - a cluster of nerve cells.

Generalized anxiety disorder (GAD) - a mental disorder that causes its sufferers chronic and exaggerated worry and tension that seem to have no substantial cause. Persons with generalized anxiety disorder often worry excessively about health, money, family, or work, and continually anticipate disaster.

genetic studies - diagnostic tests that evaluate for conditions that have a tendency to run in families.

gray matter - the darker-colored tissues of the central nervous system; in the brain, the gray matter includes the cerebral cortex, the thalamus, the basal ganglia, and the outer layers of the cerebellum.

Guillain-Barr - A disorder in which the body's immune system attacks part of the nervous system.

Guillain-Barr - A reversible condition that affects the nerves in the body. GBS can result in muscle weakness, pain, and even temporary paralysis of the facial, chest, arm, and leg muscles. Paralysis of the chest muscles can lead to breathing problems.

top

 

hallucinations - a strong perception of an event or object when no such situation is present; may occur in any of the senses (i.e., visual, auditory, gustatory, olfactory, or tactile).

head injury - a broad term that describes a vast array of injuries that occur to the scalp, skull, brain, and underlying tissue and blood vessels in the child's head. Head injuries are also commonly referred to as brain injury, or traumatic brain injury (TBI), depending on the extent of the head trauma.

headache - pain or discomfort in the head or face area. Headaches can be single or recurrent in nature, and localized to one or more areas of the head and face.

headache (primary) - includes tension (muscular contraction), vascular (migraine), and cluster headaches not caused by other underlying medical conditions.

headache (secondary) - includes headaches that result from other medical conditions. These may also be referred to as traction headaches or inflammatory headaches.

histrionic personality disorder - persons with this disorder are overly conscious of their appearance, are constantly seeking attention, and often behave dramatically in situations that do not warrant this type of reaction. The emotional expressions of persons with histrionic personality disorder are often judged as superficial and exaggerated.

hydrocephalus - the lack of absorption, blockage of flow, or overproduction of the cerebral spinal fluid (CSF) that is found inside of the ventricles (fluid-filled areas) inside of the brain. This may result in a buildup of fluid, which may cause the pressure inside of the head to increase and the skull bones to expand to a larger-than-normal appearance.

top

 

Illusions - a false perception; the mistaking of something for what is not.

Impulse control disorders - a lack of judgment in the ability to control one's behavior. Examples include kleptomania (stealing), pyromania (fire starting), trichotillomania (pulling out one's hair), and pathologic gambling.

incontinence - involuntary voiding of the bladder or bowel.

intracranial pressure (ICP) - the pressure inside the skull.

top

 

ketogenic diet - a diet very high in fat (about 90 percent of the calories come from fat). Protein is given in amounts to help promote growth. A very small amount of carbohydrate is included in the diet. This very high-fat, low-carbohydrate diet causes the body to make ketones. Ketones are made by the body from protein. They are made for energy when the body does not get enough carbohydrates for energy. If your child eats too many carbohydrates, then his/her body may not make ketones. The presence of ketones is important to the success of the diet. The diet is sometimes used to assist in the control of seizures.

top

 

Learning disorders - seen in childhood; also identified in adulthood. Reading, writing, and mathematical calculations are challenging to understand and express. May interfere with social, work, and academic progression.

levodopa (L-dopa) - the single most effective anti-Parkinson drug; it is changed into dopamine in the brain.

Lewy body - A pink-staining sphere, found in the bodies of dying cells, that is considered to be a marker for Parkinson's disease.

lordosis (also called sway-back) - an exaggeration of the forward curve of the lower part of the back.

lumbar puncture (also called spinal tap) - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes your child's brain and spinal cord.

lumbar puncture (also called spinal tap) - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord.

top

 

magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

Major depression (Also known as clinical depression or unipolar depression.) - classified as a type of affective disorder or mood disorder that goes beyond the day's ordinary ups and downs, becoming a serious medical condition and important health concern in this country.

Mania - a mood disorder which may be characterized by extreme elation, impulsivity, irritability, rapid speech, nervousness, distractibility, and/or poor judgment.

Manic depression (Also known as bipolar disorder.) - classified as a type of affective disorder or mood disorder that goes beyond the day's ordinary ups and downs. Manic depression is characterized by periodic episodes of extreme elation, elevated mood, or irritability (also called mania) countered by periodic, classic depressive symptoms.

meningitis - an inflammation of the meninges, the membranes that cover the brain.

metabolic tests - diagnostic tests that evaluate the absence or lack of a specific enzyme (i.e., amino acids, vitamins, carbohydrates) that are necessary to maintain the normal chemical function of the body.

microcephaly - a condition, present at birth, in which the head is much smaller than normal for an infant of that age and gender.

micrographia - a change in handwriting with the script becoming smaller and more cramped.

monoamine oxidase (MAO) - an enzyme that breaks down dopamine. There are two types of MAO "A" and "B." In Parkinson's disease, it is beneficial to block the activity of MAO B.

Mood disorder (Also known as affective disorder.) - a category of mental health problems which includes depressive disorders.

multiple sclerosis (MS) - a disease of the central nervous system that is an unpredictable condition that can be relatively benign, disabling, or devastating, leaving the patient unable to speak, walk, or write.

muscular dystrophy - the name given to a group of diseases that are, for the most part, genetically determined and cause gradual wasting of muscle with accompanying weakness and deformity.

myasthenia gravis (MG) - a life-long condition in which the body's immune system fights its own body. This causes problems with the nerves that provide communication to the muscles resulting in muscle weakness. This disease affects the voluntary muscles of the body that include the eyes, face, neck, chest, arms, and legs.

myelodysplasia (also called spina bifida) - a condition, present at birth, that can affect the development of the back bones, spinal cord, surrounding nerves, and the fluid-filled sac that surrounds the spinal cord. This neurological condition can cause a portion of the spinal cord and the surrounding structures to develop outside, instead of inside, the body. The sac-like lesion can occur anywhere along the spine.

myelogram - a procedure that uses dye injected into the spinal canal to make the structure clearly visible on x-rays.

myoclonus - jerking, involuntary movements of the arms and legs; may occur normally during sleep.

top

 

Narcissistic personality disorder - persons with this disorder present severely overly-inflated feelings of self-worth, grandiosity, and superiority over others. Persons with narcissistic personality disorder often exploit others who fail to admire them, and are overly sensitive to criticism, judgment, and defeat.

neurocutaneous syndromes - a broad term that describes a group of neurological (brain) disorders. These diseases are life-long conditions that cause tumors to grow inside the brain, spinal cord, organs, skin, and skeletal bones. The most common symptoms in children with these diseases are the unique changes that can be found on the skin. The three most common types of neurocutaneous syndromes are tuberous sclerosis, neurofibromatosis (NF), and Sturge-Weber disease.

neuron - a cell specialized to conduct and generate electrical impulses and to carry information from one part of the brain to another.

neurosonography - a procedure that uses ultra high-frequency sound waves that enable the physician to analyze blood flow in cases of possible stroke.

neurotransmitters - chemical substances that carry impulses from one nerve cell to another; found in the space (synapse) that separates the transmitting neuron's terminal (axon) from the receiving neuron's terminal (dendrite).

Neurotransmitters - chemicals in the brain that regulate other chemicals in the brain.

nigral - of or referring to the substantia nigra.

norepinephrine - a neurotransmitter found mainly in areas of the brain that are involved in governing autonomic nervous system activity, especially blood pressure and heart rate.

top

 

Obesity - a generalized accumulation of body fat.

Obsessive-compulsive disorder (OCD) - an anxiety disorder in which a person has an unreasonable thought, fear, or worry that he or she tries to manage through a ritualized activity to reduce the anxiety. Frequently occurring disturbing thoughts or images are called obsessions, and the rituals performed to try to prevent or dispel them are called compulsions.

Obsessive-compulsive personality disorder - persons with this disorder are inflexible to change and bothered by a disrupted routine due to their obsession for order. Thus, they experience anxiety and have trouble completing tasks and making decisions. Persons with obsessive-compulsive personality disorder often become uncomfortable in situations that are beyond their control and have difficulty maintaining positive, healthy interpersonal relationships as a result.

on-off effect, on-off phenomena - a change in the patient's condition, with sometimes rapid fluctuations between uncontrolled movements and normal movement, usually occurring after long-term use of levodopa and probably caused by changes in the ability to respond to this drug.

orthostatic hypotension - a large decrease in blood pressure upon standing; may result in fainting.

top

 

pallidotomy - a surgical procedure in which a part of the brain, called the globus pallidus, is cut in order to reduce symptoms of tremor, rigidity, and bradykinesia.

palsy - paralysis of a muscle or group of muscles.

Panic disorder - characterized by chronic, repeated, and unexpected panic attacks - bouts of overwhelming fear of being in danger when there is no specific cause for the fear. In-between panic attacks, persons with panic disorder worry excessively about when and where the next attack may occur.

Paranoid personality disorder - persons with this disorder are often cold, distant, and unable to form close, interpersonal relationships. Often overly, yet unjustifiably, suspicious of their surroundings, persons with paranoid personality disorder generally cannot see their role in conflict situations and often project their feelings of paranoia as anger onto others.

Paraphilias - a cluster of psychosexual disorders which include sexual behaviors that include suffering and humiliation directed towards a nonconsenting partner.

parkinsonism - the name given to a group of disorders with similar features - four primary symptoms (tremor, rigidity, postural instability, and bradykinesia) that are the result of the loss of dopamine-producing brain cells.

Parkinson's disease (PD) - The most common form of parkinsonism; a slowly progressing, degenerative disease that is usually associated with the following symptoms, all of which result from the loss of dopamine-producing brain cells: tremor or trembling of the arms, jaw, legs, and face; stiffness or rigidity of the limbs and trunk; bradykinesia (slowness of movement); postural instability, or impaired balance and coordination.

peristalsis - wavelike contractions that move food through the digestive tract.

Phobia - an uncontrollable, irrational, and persistent fear of a specific object, situation, or activity.

positron emission tomography (PET) scan - a computer-based imaging technique that provides a picture of the brain's activity rather than its structure by measuring levels of injected glucose which are labeled with a radioactive tracer.

Post-traumatic stress disorder (PTSD) - a debilitating condition that often follows a terrifying physical or emotional event causing the person who survived the event to have persistent, frightening thoughts and memories, or flashbacks, of the ordeal. Persons with PTSD often feel chronically, emotionally numb. Once referred to as "shell shock" or "battle fatigue."

Psychiatric nurse - may have a Master's degree in psychiatric mental health nursing. An advanced practicepsychiatric nurse is educationally and clinically trained in psychopathology, individual, group, family therapy, and crisis intervention. They may also be licensed to prescribe psychotropic medications.

Psychiatrist - licensed physicians (M.D. or D.O.) who specialize in the evaluation, diagnosis, and treatment of mental disorders. Their medical and psychiatric training prepares them to treat adults and children either individually, as part of and involving the family unit, and/or in a group setting. Psychiatrists can prescribe medications, if needed.

Psychologist - a specialist in the study of the structure and function of the brain and related behaviors or mental processes. A psychologist may provide psychological evaluation, assessment, testing, and treatment, but may not prescribe medications.

Psychosis - a loss of contact with reality

Purging - persons with bulimia nervosa engage in a destructive pattern of ridding their bodies of the excess calories (to control their weight) by vomiting, abusing laxatives or diuretics, taking enemas, and/or exercising obsessively - a process called purging.

pyramidal pathway - a collection of nerve tracts that travel from the cerebral cortex through the pyramid of the medulla oblongata in the brainstem to the spinal cord. Within the pyramid of the medulla, fibers cross from one side of the brain to the opposite side of the spinal cord; the pyramidal pathway is intact in Parkinson's disease.

top

 

range of motion - the extent that a joint will move from full extension to full flexion.

resting tremor - a tremor of a limb that increases when the limb is at rest.

retropulsion - the tendency to step backwards if bumped from the front or upon initiating walking; usually seen in patients who tend to lean backwards because of problems with balance.

Reye syndrome - A condition that affects the brain, liver, and kidney function. It has a very rapid onset that can cause the child to go into a coma, or can result in death within hours of the symptoms.

rigidity - increased resistance to the passive movement of a limb.

top

 

Schizoid personality disorder - persons with this disorder are often cold, distant, introverted, and have an intense fear of intimacy and closeness. Persons with schizoid personality disorder are often too absorbed in their own thinking and daydreaming that they exclude themselves from attachment with persons and reality.

Schizophrenia - one of the most complex of all mental health disorders; involves a severe, chronic and disabling disturbance of the brain.

Schizotypal personality disorder - similar to schizoid personality disorder, persons with this disorder are often cold, distant, introverted, and have an intense fear of intimacy and closeness. Yet, with schizotypal personality disorder, persons also exhibit disordered thinking, perception, and ineffective communication skills. Many symptoms of schizotypal personality disorder resemble schizophrenia, but are less mild and intrusive.

Seasonal affective disorder (SAD) - a mood disorder characterized by depression related to a certain season of the year - especially winter.

seizure - occurs when part(s) of the brain receives a burst of abnormal electrical signals that temporarily interrupts normal electrical brain function.

seizure - occurs when part(s) of the brain receives a burst of abnormal electrical signals that temporarily interrupts normal electrical brain function.

Self-esteem - feelings about one's self.

serotonin - a chemical necessary for communication between certain nerve cells.

Sexual dysfunctions - a cluster of disorders, including problems with pain, arousal dysfunctions, and organ achievement not related to medication or a medical condition.

sialorrhea - drooling.

Sleep disorders - a cluster of sleep problems, ranging from difficulty falling asleep to sleeping too long. Also includes sleepwalking, night terrors, and sleep apnea.

Social phobia - an anxiety disorder in which a person has significant anxiety and discomfort related to a fear of being embarrassed, humiliated, or scorned by others in social or performance situations.

somatostatin - a chemical necessary for communication between certain nerve cells.

spasm - a condition in which a muscle or group of muscles involuntarily contract.

Specific phobia - a type of phobia characterized by extreme fear of an object or situation that is not harmful under general conditions.

spina bifida (also called myelodysplasia) - a condition that is present at birth. It can affect the development of the back bones, spinal cord, surrounding nerves, and the fluid-filled sac that surrounds the spinal cord. This neurological condition can cause a portion of the spinal cord and the surrounding structures to develop outside, instead of inside, the body. The sac-like lesion can occur anywhere along the spine.

spinal cord - a bundle of nerves that carries messages between the brain and the rest of the body.

spinal cord - a bundle of nerves that carries messages between the brain and the rest of the body.

spinal muscular atrophy - a degenerative problem that affects the spinal cord and nerves, resulting in muscle wasting and weakness.

spinal tap (also called a lumbar puncture) - a special needle is placed into the lower back, into the spinal canal, which is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes your child's brain and spinal cord.

spinal tap (also called a lumbar puncture) - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord.

striatum - part of the basal ganglia, it is a large cluster of nerve cells, consisting of the caudate nucleus and the putamen, that controls movement, balance, and walking; the neurons of the striatum require dopamine to function.

stroke (also called brain attack) - happens when brain cells die because of inadequate blood flow to the brain.

subarachnoid hemorrhage - a brain attack that occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull (but not into the brain itself).

Substance abuse disorder - includes alcohol and drug misuse and abuse. Problems extend into the social, family, and occupational functions of the affected person. Any drug, including alcohol, that is used in excess of legal limits or prescription directions is considered abusive. Intoxication and withdrawal are common problems in the abusing population.

substantia nigra - a small area of the brain containing a cluster of black-pigmented nerve cells that produce dopamine which is then transmitted to the striatum.

Suicidal behavior - actions taken by one who is considering or preparing to cause their own death.

Suicidal ideation - thoughts of suicide or wanting to take one's life.

Suicide - the intentional taking of one's own life.

Suicide attempt - an act focused on taking one's life that is unsuccessful in causing death.

sustention (postural) tremor - a tremor of a limb that increases when the limb is stretched.

synapse - a tiny gap between the ends of nerve fibers across which nerve impulses pass from one neuron to another; at the synapse, an impulse causes the release of a neurotransmitter, which diffuses across the gap and triggers an electrical impulse in the next neuron.

top

 

thrombus - a blood clot.

Tourette's syndrome (TS) - A tic disorder characterized by repeated involuntary movements and uncontrollable vocal sounds. This disorder usually begins during childhood or early adolescence.

tremor - a rhythmical shaking of a limb, head, mouth, tongue, or other part of the body.

tyrosine - the amino acid from which dopamine is made.

top

 

white matter - nerve tissue that is paler in color than gray matter because it contains nerve fibers with large amounts of insulating material (myelin). The white matter does not contain nerve cells. In the brain, the white matter lies within the gray layer of the cerebral cortex.

top

 

x-ray - a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

top