Resource Center

Glossary

A-D E-H I-L M-P Q-Z

A-D

Absence Seizures

A non-convulsive generalized seizure when a person may appear to be staring into space with or without jerking or twitching movements of the eye muscles. These seizures may last for seconds, or even tens of seconds, with full recovery of consciousness and no confusion. People experiencing absence seizures sometimes move from one location to another without any purpose.

Abstract Thinking

Being able to apply abstract concepts to new situations and surroundings.

Acceleration

To increase speed and/or change velocity.

Alopecia

A condition of a loss of hair or baldness.

Amnesia

A loss of memory. Amnesia can be caused by brain injury, shock, fatigue, repression, illness and sometimes anesthesia.

Angiogram

A procedure in which a dye is injected through a thin tube into a blood vessel. Special x-ray pictures are taken, allowing your health care provider to view the blood vessels of the brain, heart or other part of the body. Also called an arteriogram for arteries or venogram for veins.

Anorexia

A loss of appetite, especially when prolonged over time.

Anosmia

The decrease or loss of the sense of smell.

Anoxia

Absence of oxygen supply to an organ.

Anoxic Brain Injury

Injury to the brain due to severe lack of oxygen. This usually happens when blood is unable to flow to the brain due to certain injuries, bleeding, or cardiac arrest.

Apraxia

The loss or impairment of the ability to perform complex coordinated movements despite having the desire and the physical ability to perform the movements.

Arthralgia

Joint pain or stiffness in a joint.

Ataxia

The inability to coordinate the movement of muscles. Ataxia may affect the fingers, hands, arms, legs, body, speech, or eye movements.

Axons

Also known as nerve fibers, an axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma. Axons are the primary transmission lines of the nervous system.

Basal Ganglia

The deep brain structures that help start and control voluntary movements and postures.

Bipolar Disorder

Also known as manic-depressive illness, bipolar disorder is a brain disorder that causes unusual shifts in a person’s mood, energy, and ability to function.

Blast Injuries

Injuries that result from the complex pressure wave generated by an explosion. The explosion causes an instantaneous rise in pressure over atmospheric pressure that creates a blast over pressurization wave. Injuries to organs surrounded by fluid, such as the brain and air filled organs such as the ear, lung and gastrointestinal tract are common.

Brain

The main organ of the central nervous system (CNS). It is divided into the cerebrum, brainstem, and cerebellum. The brain regulates virtually all human activity.

Brain Stem

The lower extension of the brain where it connects to the spinal cord. Neurological functions located in the brainstem include those necessary for survival (breathing, heart rate) and for arousal (being awake and alert).

Cerebellum

The portion of the brain (located in the back) that helps coordinate movement.

Cerebral Hypoxia

The inadequate oxygen supply to brain tissue. Mild or moderate cerebral hypoxia is sometimes known as diffuse cerebral hypoxia. It can cause confusion and fainting, but its effects are usually reversible.

Cerebral Spinal Fluid

A colorless fluid that is found around and inside the brain and spinal cord, offering some protection and cushioning the brain.

Cerebrum

The largest part of the brain. It is divided into two hemispheres, or halves. It controls motor, sensory, and higher mental functions, such as thought, reason, emotion, and memory.

Chronic Subdural Hematoma

An "old" collection of blood and blood breakdown products between the surface of the brain and its outermost covering (the dura).

Closed Head Injury

Injury to structures within the skull or the brain that do not result in an opening in the, such as a direct blow to the head or a blast. Injuries may range from a mild concussion to potentially fatal.

Coma

A state of unconsciousness from which the person is not aware of the environment nor able to perform voluntary actions.

Computerized Axial Tomography, or CT or CAT Scan

A painless procedure in which x-rays are passed through the affected area at different angles, detected by a scanner, and analyzed by a computer. CT scan images show bones and blood collections more clearly than conventional x-rays. The computer can combine individual images to produce a three-dimensional view.

Concussion

A blow, jarring, shaking or other non-penetrating injury to the brain which causes a temporary decrease in normal brain activity.

Consciousness

The state of awareness of the self and the environment.

Contusion

A bruise. In terms of brain injury, a contusion refers to bruising of the brain tissues.

Coup-Contrecoup

An injury to the brain that occurs when an impact or violent motion brings the head to a sudden stop, causing injury to the impact site and the opposite side of the brain. This is also known as an acceleration/deceleration injury.

Cranium

Skull.

Deceleration

To reduce speed or go more slowly.

Diffuse

Widely spread.

Diffuse Axonal Injury, or DAI

Widespread injury of large nerve fibers (axons covered with myelin).

Diffuse Brain Injury

Injury to cells in many areas of the brain rather than in one specific location.

Diplopia

Seeing two images of a single object; double vision.

Dura Mater

The outermost of three membranes protecting the brain and spinal cord. It is tough and leather like.

Dysarthria

Difficulty in forming words or speaking them because of weakness of the muscles used in speaking. Tongue movements are usually labored and the rate of speaking may be very slow. Voice quality may be abnormal, usually excessively nasal; volume may be weak; drooling may occur.

Dyskinesia

Involuntary movements most often seen in the arms or legs.

E-H

Electroencephalograph, or EEG

A test that measures electrical activity of the brain that is recorded from electrodes placed on the scalp.

Epidural Hematoma

Bleeding into the area between the skull and the dura mater.

Euphoria

An exaggerated or abnormal sense of well-being not based on reality.

Executive Functions

The ability to formulate and carry out plans effectively. These functions are essential for independent, creative and socially constructive behavior.

Expressive Aphasia

also known as Broca’s aphasia. A difficulty in expressing oneself in speech and writing. Characterized by knowing what one wants to say but being unable to find the words to say what is being thought. There is lack of spontaneous speech, words are often labored over and sentences are short and incomplete.

Focal Brain Injury

Damage confined to a small area of the brain. The focal damage is most often at the point where the head hits an object or where an object, such as a bullet, enters the brain.

Frontal Lobe

The front part of the brain; involved in planning, organizing, problem solving, selective attention, personality and a variety of "higher cognitive functions."

Generalized Tonic-Clonic Seizures

A seizure involving the entire body. It is also called a grand mal seizure. Such seizures usually involve muscle rigidity, violent muscle contractions, and loss of consciousness.

Glasgow Coma Scale

A scale used for measuring level of consciousness. Scoring is determined by three factors: eye opening ability, verbal responsiveness, and motor responsiveness. The scores range from lowest level of responsiveness a 3 to highest level of responsiveness a 15.

Hematoma

A collection of blood caused by the rupture or tearing of blood vessels.

Herniation/Herniated

Compression of brain tissue caused by high pressure inside the skull that can lead to death if not aggressively treated.

Hypertension

The medical term for high blood pressure.

Hypotension

The medical term for low blood pressure.

Hypoxia

Decreased oxygen levels in an organ, such as the brain.

I-L

Intracranial Pressure (ICP) Monitor

A monitoring device used to determine the pressure within the brain. It is used to assess potential complications resulting from increased pressure exerted on the brain.

Impaired Initiation

The diminished ability to take the first step in beginning an action.

Improvised Explosive Devices, or IEDs

An IED can be almost anything with any type of material and initiator. It is a “homemade” device that is designed to cause death or injury by using explosives alone or in combination with toxic chemicals, biological toxins, or radiological material. IEDs can be produced in varying sizes, functioning methods, containers, and delivery methods. IEDs can utilize commercial or military explosives, homemade explosives, or military ordinance and ordinance components.

Intracerebral Hematoma

Collection of blood inside the brain tissue.

Intracerebral Hemorrhage

A subtype of intracranial hemorrhage that occurs within the brain tissue itself. Intracerebral hemorrhage can be caused by brain trauma, or it can occur spontaneously in hemorrhagic stroke.

Intracranial Pressure, or ICP

The amount of pressure inside the skull resulting from the brain tissue, cerebrospinal fluid and blood volume. This pressure normally ranges from 0-10 mm Hg.

Limbic System

A group of structures deep within the brain that are associated with emotion and motivation.

Lobe

A part of the brain located in each of the two hemispheres. Each hemisphere of the cerebrum is divided into four sections known as the frontal lobe, the parietal lobe, the occipital lobe, and the temporal lobe.

M-P

Magnetic Resonance Imaging, or MRI

A test that uses a powerful magnet linked to a computer to make detailed pictures of soft tissues inside the body.

Meninges

The covering of the brain that consists of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.

Mild Traumatic Brain Injury, or mTBI

Also referred to as a concussion, mTBI involves a disruption of brain function caused by trauma. This disruption is characterized by, but not limited to, a loss of consciousness for less than thirty minutes, and posttraumatic amnesia lasting for less than 24 hours, and a Glasgow Coma Scale of 13 – 15.

Military Acute Concussion Evaluation, or MACE

A standardized mental status exam that is used to evaluate concussion in theater. This screening tool was developed to evaluate a person with a suspected concussion.

Myalgia

Pain in one or more muscles.

Neurocognitive

Of, relating to, or involving the brain and the ability to think, remember or process thoughts.

Neurons

A nerve cell that can receive and send information by way of connections with other nerve cells.

Neuropsychology

A science that combines the study of the brain’s structures and functions with psychological processes and human behaviors.

Neuroradiological Tests

Tests using computer-assisted brain scans. These tests allow providers to visualize the brain. Tests may include: CT Scan, MRI, Angiogram, EEG, SPECT Scan, PET Scan, DTI Scan.

Neurotransmitters

Chemicals found within the brain that are released from a neuron which transmit signals from neuron to neuron across gaps called synapses. These chemicals either excite or inhibit specific reactions, such as in motor neurons, the neurotransmitter causes contraction of muscles through stimulation of muscle fibers.

Nystagmus

Involuntary, usually rapid movement of the eyeballs (side to side or up and down).

Occipital Lobe

The occipital lobes are found at the back of the brain. These lobes receive signals from the eyes, process those signals, allow people to understand what they are seeing, and influence how people process colors and shapes.

Ocular

Relating to the eye.

Open Head Injury

Trauma to the brain that occurs from a skull fracture or penetrating injury.

Parietal Lobe

The part of the brain that is involved with movement, and with the processing of signals received from other areas of the brain such as vision, hearing, motor, sensory and memory.

Penetrating Head Injury

A brain injury in which an object pierces the skull and enters the brain tissue.

Perseveration

The repeated and uncontrollable use of the same words or actions regardless of the situation.

Photophobia

An intolerance to light; or a painful sensitivity to strong light.

Positron Emission Tomography, or PET Scan

a specialized imaging technique that uses an injection of a short-lived radioactive substance and special CT scans. PET scanning provides information about the body's chemistry not available through other procedures. Unlike other imaging techniques that look at structures of the brain, PET looks at the energy use of different parts of the brain.

Post Deployment Health Assessment, or PDHA

The military’s global health screening that occurs when a unit or service member returns from an overseas deployment. The purpose of this screening is to review each service member's current health, mental health or psychosocial issues commonly associated with deployments, special medications taken during the deployment, possible deployment-related occupational/environmental exposures, and to discuss deployment-related health concerns.

Post Deployment Health Reassessment, or PDHRA

A second assessment used three to six months following redeployment or return of service members from overseas deployment. PDHRA extends the continuum of care for deployment related heath concerns and provides education, screening, assessment and access to care.

Post Traumatic Stress Disorder, or PTSD

A condition where memories of traumatic events are re-lived after the fact.

Post-traumatic Amnesia, or PTA

The inability to remember things following a traumatic event. Memory loss caused by brain damage or severe emotional injury.

Q-Z

Rancho Los Amigos Scale of Cognitive Functioning

A scale used to follow the recovery of the TBI survivor and to determine when he or she is ready to begin a structured rehabilitation program.

Receptive Aphasia

Also known as Wernicke’s aphasia characterized by difficulty understanding spoken words. The aphasic individual themselves have difficulty interpreting and categorizing sounds and speak in what is referred to as a “word salad” with random words put together unintelligibly to form sentences.

Seizure

Uncontrolled electrical activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms. Seizures fall into two main groups. Focal seizures, also called partial seizures, happen in just one part of the brain. Generalized seizures are a result of abnormal activity throughout the brain.

Seizures

A sudden or severe change in behavior due to excessive electrical activity in the brain. Many types of seizures cause loss of consciousness with twitching or shaking of the body. Occasionally, seizures can cause temporary abnormal sensations or visual disturbances.

Shaken Baby Syndrome

A severe form of head injury that occurs when an infant or small child is shaken forcibly enough to cause the brain to bounce against the skull, causing brain injury.

Single-photon Emission Computed Tomography, or SPECT Scan

Test that uses the injection of a weak radioactive substance into a vein, followed by pictures taken with special cameras. This test is similar to a PET scan and provides information on the energy being used by the brain.

Skull Fracture

A break, split or crack in the skull.

Subdural Hematoma

Bleeding confined to the area between the outer-most covering of the brain (dura) and the brain.

Temporal Lobes

Temporal lobes are located at about ear level, and are the main memory center of the brain, contributing to both long-term and short-term memories. The temporal lobe is also involved with understanding what is heard, and with the ability to speak. An area on the right side is involved in visual memory and helps people recognize objects and faces. An area on the left side is involved in verbal memory and helps people remember and understand language. The back area of the temporal lobes helps people interpret the emotions and reactions of others.

Thalamus

A part of the brain that is primarily responsible for relaying sensory information from other parts of the brain to the cerebral cortex.

Tinnitus

“Ringing in the ears" or another noise that seems to originate in the ears or head.

Traumatic Brain Injury, or TBI

An injury to the brain as the result of trauma to the head.

Whiplash

An injury to the neck caused when the head is violently thrown back and forth such as in a rear end car collision.