Neuroglossary
Terms used in brain injury, spinal cord injury and other neurotrauma treatment and rehabilitation
necrosis - Cell death. The apparent changes indicative of cell death that are caused by the progressive degradative action of enzymes and that may affect groups of cells or part of a structure of an organ. Necrotic tissue refers when a tissue is dead. A common example is when a patient develops gangrene in one of the extremities. That part of the extremity has no circulation, the color is black, and by naked eye looks dead and is called necrotic. Amputation is normally required. Examination of the body after death is necropsy, autopsy, or post mortem examination.
nerve - Bundle of nerve fibers, grouped together like a cord and visible to the naked eye. The nerve fibers are covered by a membrane. The nerves and the membrane are part of the nerve.
nerve conduction velocity (NCV) studies - Motor and sensory nerves are stimulated and recorded by surface electrodes in this procedure. Motor nerves are stimulated at distal and proximal points and the compound muscle action potential (CMAP) is recorded from the muscle, to find out the maximum motor conduction velocity. Mixed/sensory nerves are stimulated at a distal point and the sensory nerve action potential (SNAP) is recorded antidomically by surface electrodes from the nerve at a more distal site or from the skin area supplied by the nerve, to find out the maximum sensory nerve conduction velocity. Late responses (H-response and F-response) are also obtained to find out the conduction in proximal segments of sensory and motor fibers. Also referred to as Nerve Conduction Studies (NCS).
nerve impulse or action potential - The spread of an impulse along the nerve.
neural spinal canal - See vertebral canal.
neurapraxia - The first level of nerve injury. The large motor fibers are predominately affected and anatomic continuity of the nerve is preserved. The prognosis for recovery is excellent and usually complete within a few days to weeks.
neurilemma - Membrane covering the nerve fiber; also called Schwannﾒs membrane.
neuro- - Combining form denoting relationship to a nerve or nerves, or to the nervous system.
neurocytes - One of the four types of tissue, neurocytes are the nerves and nervous system cells.
neuro-development - The physical process wherein the brain undergoes anatomical changes involving the size, number, and efficiency of interconnections which provide the substrate for virtually all other developmental changes.
neuroendocrine - Pertaining to neural and endocrine influence, and particularly to the interaction between the nervous and endocrine systems.
neurogenic symptoms - Symptoms that indicate spinal nerves are affected in some way.
neurogenic tonus - Tonic contraction of the muscle due to stimuli received through the nervous system.
neuroglia - Supportive or connective structure of the nervous system; also called glia.
neurolemma - A covering or wrapper of a nerve. Also called neurilemma, this thin membrane enwraps the myelin layers of some myelinated nerve fibers, especially peripheral ones, or the extensions of certain unmyelinated nerve fibers.
neuroma - Tumor or new growth largely made up of nerve cells and nerve fibers; a tumor growing from a nerve.
neuron - A nerve tissue cell consisting of the cell body and extensions of the nerve called axons and dendrites.
neuropathy - Related to damage or disturbance in the nervous system.
neuropraxia - Function of a neuron as opposed to structure.
neuropsychiatrist - A medical specialist dealing with the evaluation and treatment of disorders deriving from impaired brain functioning and the concurrent behavioral and emotional changes.
neuropsychologist - A clinical psychologist who conducts testing to quantify and localize impaired brain functioning.
neurosis - A psychogenic disorder of the emotions based upon a fundamental anxiety where origin is usually beyond conscious awareness. Neuroses are characterized by disturbed interpersonal relationships and a sense of chronic psychological discomfort.
neurotmesis - The most severe form of nerve injury. There is complete disruption within the nerve and/or an actual severing of the nerve. This injury needs surgical repair. There is wallerian degeneration of the nerve distal to the site of the injury and the prognosis for recovery is far poorer than in the case of neurapraxia or axonotmesis (the other 2 classes of nerve injuries). A nerve may not always have only one type of injury. It is possible to have combined types of injuries within a given nerve.
neurotransmitter - A chemical synthesized within the nerve cell body, characteristic for this type of nerve, and stored at the nerves in pods as granules. Release of these chemicals into the synaptic cleft between axons facilitates nerve transmissions.
neurovascular - Pertains to both nervous and vascular elements; also pertains to nerves that control the caliber of blood vessels.
newton - The SI unit of force, which, when applied in a vacuum to a body having a mass of 1 kilogram, accelerates it at the rate of 1 meter per second (symbol, N).
nociceptive input - A period of extreme stress and increased pain perception through affective processes.
nociceptor - Receptor responding to stimuli that produce pain.
noncontained - Refers to a herniation of the intervertebral disc that has disrupted the posterior annular fibers.
nonviable - Until the twentieth to twenty-fourth week, the fetus is considered nonviable, or unlikely to survive outside the uterus. An infant is viable at about twenty to twenty-four weeks of gestation.
notch - Indentation at the edge of a bone.
noto- Combining form meaning related to the back.
notochord - In embryology, a rod-shaped body of cells that is the center of development of the axis of the skeleton; also called chorda dorsalis.
nsaid - Nonsteroidal anti-inflammatory drug. Aspirinlike drug that reduces pain and inflammation arising from injured tissue.
nuclear medicine scanning tests - Imaging processes whereby radioactive chemicals are introduced into the body, and various organs absorb them, giving off gamma rays that are captured by an image-producing device called a gamma camera.
nucleic acid - Complex organic acids found in the nucleus of all living cells that contain the genetic code essential to life.
nucleus - Central portion of the cell that contains chromosomes and positive protons; a general term used to designate a group of nerve cells usually found located within the central nervous system and bearing a direct relationship to the fibers of a particular nerve; the central portion of the cell contains chromosomes and positive protons.
nucleus pulposus - Innermost gelatinous core of the intervertebral disc. It acts like a shock absorber for axial forces and like a semi-fluid ball bearing during flexion, extension, rotation, and lateral flexion of the vertebral column.
nystagmus - A jerking of the eyeballs in extreme directions of gaze. May be a normal variant or indicative of brain tissue or balance apparatus malfunctioning.
