Parent Support for Children with Challenges - Definitions

A B C D E F G H I J K L M N O P Q R S T U V W XYZ

NAD: See National Association for the Deaf.
NAGC: See National Association for Gifted Children.
NAPI&FI: See Neurological Assessment of the Preterm Infant and Full-term Infant.
narcolepsy: An uncontrollable desire to sleep or periodic attacks of deep sleep.
nasal bridge: The portion of the nose lying directly between the eyes. A low (deep-set) nasal bridge contributes to the appearance of a saddle nose; a high nasal bridge leads to a beaked nose.
nasion: Root of the nose; where the nose meets the frontal bone or forehead.
nasogastric tube: A feeding tube that goes through the nose into the stomach. It is intended for short-term usage; if prolonged tube feeding is anticipated, a gastrostomy will be considered.
nasopalpebral reflex: Nose-eyelid reflex; an infant reflex in which a tap on the bridge of the nose (stimulus) produces bilateral blinking (response).
NASW: See National Association of Social Workers.
National Association for the Deaf (NAD): Founded in 1980, the NAD is open to all adults with profound hearing impairment and other interested individuals. The organization is active in legislative advocacy for the protection of civil rights of people with profound hearing impairments in such areas as employment, communication, and citizenship. The NAD maintains a speakers bureau and a legal defense fund and also offers educational, therapeutic, and vocational services to its members. It provides training in communication and publishes newsletters and educational materials. The NAD is affiliated with the World Federation of the Deaf.
National Association for Gifted Children (NAGC): Founded in 1954, the NAGC pursues improved education of the gifted (those who have superior general intellectual ability) and sponsors programs to enhance such children's creative potential and capacity for individual thought. The NAGC publishes Gifted Child Quarterly.
National Association of Social Workers (NASW): The national professional organization of social workers whose function is to promote the professional development of social work and social workers, establish and maintain professional standards of practice, promulgate and administer professional ethics boards, and certify advanced level practice competency. The Academy of Certified Social Workers (ACSW) is a suborganization within the NASW for social workers who achieve advanced practice competencies. The Diplomate in Clinical Social Work denotes the highest competency level. The NASW publishes the journal Social Work.
National Center for Learning Disabilities (NCLD): Formerly the Foundation for Children with Learning Disabilities, the NCLD promotes public awareness of learning disabilities, neurological disorders, and related impairments that can be a barrier to literacy. founded in 1977, the NCLD provides resources and referrals on a national level to volunteers, parents, and professionals. The NCLD is active in grant making, legislative advocacy, training seminars, and dissemination of information to the public about learning disabilities. The center publishes Their World, an annual magazine describing true life stories about ways individuals cope with learning disabilities; a parent list of recommended readings and other resources; and various training materials.
National Down Syndrome Congress (NDSC): A national organization of parents and professionals that disseminates information and assists in referrals with regard to Down syndrome. The group's newsletter, Down Syndrome News, is published 10 times yearly; many local Down syndrome family associations are affiliated with this organization.
National Education Association (NEA): The National Education Association is the largest professional organization in the United States for teachers at all levels of education. The primary focus of the organization is the rights and welfare of teachers; it functions predominantly as a teachers' union. Founded in 1857 as the National Teacher Association, the organization changed its name to the National Education Association in 1876. The NEA does advocate for improved education for all people, including those with disabilities, maintains a governmental relations unit and a political action network, and endorses candidates for national office.
National Institute of Mental Health (NIMH): A federal agency-part of the National Institutes of Health-that provides a national focus for federally funded teaching and research efforts to prevent and treat mental illness and promote mental health. It also provides technical assistance to state and local mental health agencies.
National Institutes of Health (NIH): A federal agency that supports and conducts research into the causes and prevalence of diseases and furnishes information to health professionals and to the public. It is composed of 13 research institutes and eight other components. The research institutes include the National Institute of Child Health and Human Development (NICHD), the National Institute on Deafness and Other Communication Disorders (NIDCD), and the National Institute of Neurological Disorders and Stroke (NINDS).
natural fool: Term used in the Middle Ages to describe a person with mental retardation. It was recognized that such a person's intellectual capacities had never progressed beyond those of childhood. Natural fool was later replaced in common usage by the word idiot. Contrast with persona non compos mentis.
natural language: Children's attempts to produce adult words. These attempts are not random with respect to approximation or error but seem to follow distinct processes. Innate limitations are hypothesized to prevent the correct production of the adult speech model. These limitations (physical, mental, and experiential) lessen as a child matures and develops increased mental operational abilities. The term natural language is also used to describe oral communication in the daily life experiences of a child.
natural proportion: The element of full inclusion that requires students with disabilities to be placed in general classrooms at a rate consistent with the incidence rate of the disability within the general population.
NBAS: See Brazelton Neonatal Behavioral Assessment Scale.
NCLD: See National Center for Learning Disabilities.
NCV: See Nerve conduction velocity.
NDA: See neurodevelopmental assessment.
NDSC: See National Down Syndrome Congress.
NDT: See neurodevelopmental therapy.
NEA: See National Education Association.
NEC: See necrotizing enterocolitis.
neck extensor hypertonia: Increased resistance on repeatedly flexing the head in infants under 6 months of age; this may be an early sign of later motor disability.
neck righting: Log rolling; nuchal righting; a primitive reflex in which turning the head to one side (stimulus) causes the body to follow along as though it were a log or all of one piece (response). This pattern must break up into a segmental rolling response before voluntary rolling over can emerge. Persistent neck righting can accompany severe hypertonia (increased muscle tone) and related neuromotor disorders.
necrotizing enterocolitis (NEC): A condition that occurs commonly in preterm infants, in which parts of the bowel become ischemic (blood supply deficiency), potentially leading to paralysis (ileus), perforation, and peritonitis (massive infection). Surgical treatment may include colectomy or colostomy. A history of NEC suggests a complicated neonatal course.
negative practice: A form of punishment that requires the individual to perform or engage in a maladaptive behavior so many times that it becomes aversive to him or her. For example, if a child plays with matches, one can have the child light several hundred matches in succession.
negative reinforcement: Encouraging a behavior by the removal of an aversive consequence (e.g., not losing recess if classwork is completed).
Nellhaus chart: Composite international and interracial head circumference graphs for boys and girls from birth to 18 years of age. The name derives from Gerhard Nellhaus, who pooled data from numerous other studies to produce this chart.
neologism: Word substitutions or mispronunciations that may indicate underlying language problems. They may be structural (coptiheler for helicopter), phonological (brad/bread), or semantic (pull on/boots). Structural neologisms usually occur along with other difficulties in organizing semantic relations; semantic neologisms often reflect a problem in understanding perceptual and functional attributes of words; and phonological neologisms occur frequently with auditory misperceptions. Phonological neologisms are not so much an indication of extensive language difficulties as are structural and semantic neologisms.
Neomullsoy: See chloride-deficient formula.
neonatal: Pertaining to the first 28 days of life after birth; that part of the perinatal period after birth.
Neonatal Behavioral Assessment Scale (NBAS): See Brazelton Neonatal Behavioral Assessment Scale.
neonatal intensive care unit (NICU): A designation applied to a range of regionalized hospital-based services to diagnose and treat perinatal problems. There are three levels of NICU. Level I provides for resuscitation, observation, and stabilization; relatively uncomplicated deliveries and normal newborns are accommodated at such hospitals. Level III centers have the ability to handle complicated deliveries and the pediatric subspecialty staff to support severely premature babies; teaching and research are usually carried out at such centers. Level II hospitals are intermediate between Levels I and III with regard to the services available.
Neonatal Neurological Examination (NNE): A brief qualitative assessment, developed by Lilly and Victor Dubowitz, of habituation, movement, tone, reflexes, and neurobehavioral items in preterm and full-term newborn infants, with items scored in terms of maturity and normality.
Neonatal Oral-Motor Assessment Scale (NOMAS): A brief 42-item semiquantitative scale that rates tongue and jaw responses during nonnutritive and nutritive sucking in newborns.
neonatal seizures: Seizures occurring during the neonatal period (the first 28 days of life). Manifestations of seizures in neonates may he subtle and include lip smacking, eye deviation, or blinking; or they may have more motor involvement, such as pedaling movements ("bicycling") or tonic (increased muscle tone) extension of the extremities (arms or legs) (similar to stretching). Tonic seizures have a poorer prognosis, as they arc often associated with intraventricular hemorrhage (bleeding). Neonatal seizures may also be caused by hvpoxic-ischemic encephalopathy (brain damage due to lack of oxygen), hypoglycemia (low blood sugar level), hypocalcemia (low blood calcium), infection (e.g., meningitis [inflammation of the spinal cord and brain membranes]), drug withdrawal, or abnormal formation of the brain. The outcome of neonatal seizures is related to the underlying etiology (cause), with reversible problems such as hypocalcemia having a better developmental outcome than meningitis or intraventricular hemorrhage.
neonate: Newborn.
nerve block: A procedure in which a liquid is injected into a nerve or the muscle surrounding the nerve. This liquid can be an anesthetic agent that causes local or regional anesthesia (numbness) in the area supplied by the nerve. Another use for such an anesthetic agent occurs in the obturator nerve (in the hip) block in a child with cerebral palsy. The function of the obturator nerve is blocked to simulate the effect of an adductor tenotomy and hip flexor release. If too much function is lost, then the surgery may be contraindicated. Another type of nerve block, the phenol block (named for the compound injected into the nerve), produces a temporary reduction in hypertonia (increased muscle tone) and spasticity by damaging the involved nerve. Although nerve regeneration makes this effect temporary, the period of decreased tone can be used to stretch the tendons and thus postpone, or obviate, the need for surgical lengthening.
nerve conduction study: A measurement of the velocity of the conduction of a nervous impulse. It is performed by stimulating a nerve in two locations and measuring the difference between the stimulus and time for muscle contraction. Nerve conduction velocities (NCVs) are reduced in diseases that damage the myelin (fatty insulation material) sheath (e.g., Cockayne syndrome). They are normal in muscular diseases.
nerve conduction velocity: (NCV) A neurophysiological measure of the speed with which electrical impulses travel along the path of specific nerves; this measure is used to help distinguish muscle disorders due to peripheral nerve problems from those due to muscle disorders.
nervous breakdown: A nonmedical, nonspecific term for a mental disorder. In the family history of children with developmental disabilities, it is not unusual to find a history of "nerves" or "nervous breakdowns" in extended family members often spanning several generations. This anecdotal observation may weakly support the familial transmission of neurological disorders manifesting as both psychological and learning problems.
nervous system: The body's communication network. It consists of two divisions (the central nervous system and the peripheral nervous system) that function by responding to the environment outside the body in a coordinated manner.
NESS: See Neurological Examination of Subtle Signs.
networking: The use of formal and informal linkages of people and resources for the purpose of facilitating access to services, skills, contacts, and knowledge.
neural tube: The brain and the spinal cord in early fetal development. Neural cells migrate to form folds that fuse together and create the neural tube, leading to development of the brain and spinal cord. Defects in production of the neural tube occur early in gestation and produce a range of neural tube defects (NTDs) such as anencephaly (no brain or absent top of skull) and myelomeningocele (protuberance of both the spinal cord and its lining) in the head-to-tail direction and holoprosencephaly (forebrain deficiency) and craniospinal rachischisis (congenital spinal column fissure) from front to back. These result in various forms of developmental disabilities (e.g., mental retardation, learning disabilities) and medical problems (e.g., neurogenic bladder).
neurodevelopmental assessment (NDA): A nonstandardized clinical evaluation performed by a developmental pediatrician to diagnose the presence, etiology (cause), and severity of a developmental disability. The assessment battery includes a medical and developmental history, a physical examination (including dysmorphic [atypical] features), an expanded neurological examination (including, for example, primitive reflexes and signs of minor neurological dysfunction), and evaluation of developmental levels. The NDA may be the sole battery conducted in a preschool-age child, but in a school-age child it is almost always supplemented by psychological and educational testing.
neurodevelopmental therapy (NDT): A system of physical therapy for the treatment of cerebral palsy. Devised by Berta Bobath (a physical therapist) and Karl Bobath (a physician), the approach interprets the abnormal tone, movement, and posture of cerebral palsy as secondary to a failure of primitive reflexes to disappear; postural and balance reactions are facilitated. NDT is the most popular form of physical therapy for cerebral palsy. Training and certification are available to physical and occupational therapists, but the approach can be used by parents, teachers, and anyone who handles and interacts with children with motor impairment. Sometimes referred to as the Bobath method.
neurofibromatosis (NF): von Recklinghausen disease; elephant man disease. A genetic syndrome that includes cafe au lait spots (more than five coffee-with-milk colored skin patches of at least 1.5 centimeters in diameter), neurofibroma(ta) (tumors of the skin, brain, optic and auditory nerves), and hone lesions. Axillary (armpit) freckling may occur; the number of cafe au lait spots, neurofibromata, and secondary symptoms all tend to increase with age. Lisch nodules (pigmented specks) in the iris (the colored part of the eye that surrounds the pupil) on ophthalmological examination can help to clarify the diagnosis. Mental retardation occurs in less than 5% of cases, but seizures are more common (20% of cases), and learning and attention problems may be even more frequent. The orthopedic, visual, and auditory complications of this syndrome suggest that routine follow-up in a multidisciplinary specialty (NF) clinic may be advisable for many people with NF. Incidence is 1 in 3,000. The gene for NF is localized to chromosome 17. Inheritance is autosomal dominant with a high occurrence of spontaneous mutations (50%); recurrence risk is 50%. There are two genetic subtypes: NF1 is classical NF; NF2 is severe bilateral acoustic neurofibromatosis. Named after the German pathologist Friederich von Recklinghausen (1833-1910).
neuroleptic malignant syndrome: An idiosyncratic response to neuroleptic drugs (phenothiazines, butyrophenones, and thioxanthenes) that includes rigidity, fever, sweating, hypertension (high blood pressure), and altered consciousness, with a 20% mortality rate.
neuroleptics: Major tranquilizers; a broad class of antianxiety, antipsychotic, mood-stabilizing drugs that includes phenothiazines, butyrophenones, and thioxanthenes. In people with developmental disabilities, these drugs are often used to treat agitation and depression and may cause tardive dyskinesia (slow, rhythmic, automatic movements), constipation, sedation, and cataracts.
neurolinguistics (NLP): A communication model of behavior and therapy based on human channels of perceiving, and processing information. Neurolinguistic programming assesses the way information is received through the five senses, the organization of the data through verbal and nonverbal linguistic channels, and the output of information and its ultimate impact on communication.
neurological assessment: Examination of the nervous system of the body, including a systematic evaluation of the function of each component of the central and peripheral nervous systems. The following are assessed: 1) cranial nerves, 2) motor function, 3) sensory function, 4) reflexes, 5) cerebellum, and 6) mental status and speech. Abnormalities may indicate an etiology (cause) for a developmental problem and suggest necessary additional testing. A neurological examination can be done by any physician. An evaluation more specific to a child with developmental disabilities should be performed by a developmental pediatrician or a child neurologist. All children with developmental disabilities or suspected developmental disabilities should have neurological assessments.
Neurological Assessment of the Preterm Infant and Full-term Infant (NAPI&FI): A standardized clinical assessment used to document changes in the neurological examination in the newborn period to evaluate the impact of the perinatal environment on the baby.
Neurological Examination of Subtle Signs (NESS): A National Institutes of Health/National Institute of Mental Health (NIH/NIMH) research battery of soft neurological signs that allows comparisons of children at different ages.
neurometrics: Computerized mapping and analysis of auditory evoked response potentials that can visually display (using, for example, brain electrical activity mapping [BEAM]) diagnostic brain activity patterns. This research approach to brain localization is being applied to a variety of cognitive and psychiatric disorders.
neuromuscular: Pertaining to the joint functioning of muscles and nerves; neuromotor.
neuromuscular reflex therapy: See patterning.
neuron: The nerve cell that comprises a cell body and a "tail" called the axon. Within a nerve cell, the message is passed from the cell body to the axon by a change in electrical potential that stimulates the release of the chemicals (neurotransmitters) responsible for passing the message from neuron to neuron. When killed, nerve cells do not regenerate.
neuron-specific enolase: A biochemical marker for brain injury; increased levels of NSE in the cerebrospinal fluid (CSF) correlate with neuronal (gray matter) damage.
neuropathy: Disease of the peripheral nerves (those outside the brain and spinal cord).
neuropsychological battery: A group of tests of distinct brain processes for the purpose of localizing brain damage and dysfunction and discriminating those higher cortical dysfunctions secondary to central nervous system damage from those that are not. The Halstead-Reitan neuropsychological batteries must be administered with the age-appropriate Wechsler intelligence scale and the Wide Range Achievement Test-Revised (WRAT-R); the Luria-Nebraska Neuropsychological Battery does not include these measures. These tests are frequently used with adults and teenagers with acquired brain injury; their ability to localize brain dysfunction in the more plastic brains of younger children with developmental disabilities remains unproven.
neurotransmitter: A chemical released by the nerve cell axon that transmits a message from one nerve cell to another. Many substances are clearly neurotransmitters (e.g., dopamine, acetylcholine), and others are thought to be. Neurotransmitters are specific to certain areas of the nervous system (e.g., acetylcholine in the parasympathetic [cholinergic] system regulating breathing and heart rate). They can be inhibitory or excitatory and often work in conjunction with each other to control body movement and function.
nevus flammeus: See port-wine stain.
nevus sebaceus of Jadassohn: A skin lesion, usually on the face or scalp, with linear yellow/orange/tan stripes that become increasingly greasy and verrucous (warty) over time. It is sometimes associated with seizures and mental retardation; See Schimmelpenning-Feuerstein-Mims syndrome.
newborn intensive care unit: See neonatal intensive care unit.
NF: See neurofibromatosis.
NICU: See neonatal intensive care unit; newborn intensive care unit.
Niemann-Pick disease: A group of disorders characterized by deficiencies in lysosomal enzymes that break down sphingomyelin, a chemical in the body. This results in a buildup or storage of sphingomyelin in the reticuloendothelial system (cells that ingest matter). These disorders, termed lysosomal storage diseases, are generally inherited in an autosomal recessive manner. Neurological svmptoms including hypotonia (decreased muscle tone), dvstonia (impaired muscle tone), developmental arrest, cerebellar ataxia (unsteady gait), or seizures may be seen in types A, C, or D; type B has no neurological symptoms. Treatment with anticancer drugs has been unsuccessful; however, since the buildup is in the reticuloendothelial system, it is thought that bone marrow transplant may prove an effective therapy.
NIH: See National Institutes of Health.
NIMH: See National Institute of Mental Health.
Nine Diagnostic Points: A clinical checklist devised in Great Britain to define childhood schizophrenia; in this preliminary instrument no distinction was made between autism and schizophrenia. The nine descriptors included impairment of relationships with people, unawareness of one's personal identity, preoccupation with objects, resistance to environmental changes, abnormal perceptual experiences, acute anxiety, delay or absence of speech development, distorted motility (spontaneous movement), and mental retardation. It is only of historical interest.
9p monosomy: 9p-; monosomy of the short arm of chromosome 9. A chromosomal disorder with mental retardation, craniosynostosis (premature fusion of skull sutures) with trigonocephaly (triangularly shaped head), a peculiar fades, and congenital heart disease.
NLP: See neurolinguistics.
NNE: See Neonatal Neurological Examination.
no: The infant's receptive language ability to respond to the verbal command "no" emerges at around 1 year of age; the child's expressive language use of "no" emerges at around 2 years of age and is, from an ego psychology perspective, the child's first word; and, from a behavioral perspective, part of the phase known as the "terrible twos."
nociceptive: Relating to the perception of pain.
noise: Sound that distorts a signal or message; the level of background, or ambient, noise can affect the ability of a person with (or without) a hearing impairment to successfully discriminate sounds.
NOMAS: See Neonatal Oral-Motor Assessment Scale.
nondisabled: Descriptive term for people without disabilities that is often used in speech or writing. Use of the term nondisabled avoids the more subjective term normal, which implies that people with disabilities are not "normal" on the basis of their disabilities. The preferred term in the disabilities field, however, is people without disabilities.
nondisjunction: A failure of two homologous chromosomes (those that are paired with the same number) to separate during meiosis or mitosis. This can result in two chromosomes from one parent and one chromosome from the other parent being passed on to the child, producing a trisomy (an individual with three chromosomes of the same number). This is how Down syndrome commonly occurs.
nondominant: The side of the body (usually left) innervated by the contralateral (opposite) brain hemisphere (usually right) that is not specific for language; the nondominant side of the body is usually very slightly weaker, smaller, and less coordinated.
nonexclusionary discipline: Those disciplinary practices that do not remove a student from the school environment and thus allow for continued implementation of individualized education program (IEP) goals; nonexclusionary discipline includes loss of recess and other privileges, detention, time-out, and in-school suspension. Because some states and many school districts do not prohibit corporal punishment, the IEP should specify accepted disciplinary procedures as part of the behavior management plan.
nonnutritive sucking: Sucking when not feeding.
nonverbal: Without oral language.
nonvocal: Describes individuals who have not developed functional oral communication skills. Individuals with hearing impairment, mental retardation, autism, tracheostomy tubes, or other severe physical impairments may be nonvocal. The terms nonvocal or nonverbal are preferred to mute or dumb because the latter suggest that mental incapacitation accompanies hearing loss or the inability to speak.
Noonan syndrome: Turner-like syndrome, Turner phenotype. A syndrome with many features identical to those in Turner syndrome (e.g., short stature, webbed neck, low posterior (back) hairline, shieldlike chest, cubitus valgus [lateral deviation of the forearm], and abnormalities of the pinnae [earlobes]), except that it occurs in both sexes and has normal chromosomes. In Turner syndrome the cardiac defect is left-sided (coarctation of the aorta); in Noonan syndrome it is right-sided (valvular pulmonic stenosis). Mental retardation is rare in Turner syndrome but occurs in over half of people with Noonan syndrome. Menstrual cycles arc normal in females with Noonan syndrome. Incidence is 1 in 1,000 severely affected and perhaps as many as 1 in 100 mildly affected. Three quarters of cases are parent-to-child transmission, suggesting autosomal dominance with markedly variable expressivity. The term male Turner syndrome reflects incorrect usage. Named after the American pediatrician Jacqueline Noonan (b. 1921).
nootropic: A class of psychoactive drugs that are purported to selectively improve the efficiency of higher cortical functions; an example of such a drug is piracetam, which has been claimed to selectively improve reading ability.
normalization: The philosophy and principle of making available to all people with developmental disabilities-regardless of the severity of those disabilities-daily experiences and activities that are culturally normative and as close as possible to the prevailing patterns of mainstream society. Wolf Wolfensberger is recognized as an originator and major proponent of the normalization movement in the United States.
norm-referenced test: A test in which an examinee's performance is compared with the performance of a specific group. A norm provides a typical performance of the specified group. Raw scores are converted into derived scores, which indicate the examinee's standing relative to the norm group. Most intelligence tests are examples of norm-referenced tests. In contrast, criterion-referenced tests measure levels of mastery compared with established levels, rather than with the performance of other individuals.
Norrie syndrome: Oculoacousticocerebral degeneration; a genetic syndrome with visual loss progressing to blindness, progressive mental retardation, and nonprogressive sensorineural (involving the inner ear or the auditory nerve) hearing loss. Inheritance is X-linked recessive. Named after the Danish ophthalmologist Gordon Norrie(1855-1941).
Northwestern Syntax Screening Test (NSST): A language test for children 3-8 years of age: a picture-pointing task measures receptive language and a delayed-imitation task measures expressive language.
nosology: Systematic or scientific classification of disease; especially concerned with the criteria to define and distinguish subtypes from one another.
NSE: See neuron-specific enolase.
NSST: See Northwestern Svntax Screening Test.
nuchal righting: See neck righting.
nuchal rigidity: Stiff neck; a finding on physical examination that raises the suspicion of meningitis (inflammation of the spinal cord and brain membranes) in young children.
nuclear family: A separately housed family unit consisting of parents and their dependent children.
nucleotides: The component parts of the nucleic acids that form the genetic material of all living cells.
nursemaid elbow: Pulled elbow; dislocation of the proximal radial head (forearm near the elbow) bv excessive traction; a common injury in preschool children.
nutritive sucking: Sucking during feeding.
nyctalopia: Night blindness.
nystagmus: A rhythmic back and forth movement of the eyes that consists of at least a slow phase in the horizontal plane. Optokinetic nystagmus, which is elicited in infants by rotating a drum with alternating dark and light stripes, can be used to detect vision in a young child. Nystagmus in far lateral gaze can be a normal variant. Congenital nystagmus can be inherited and may be associated with decreased vision. Occasionally, nystagmus accompanied by a head tilt and titubation (bobbing and nodding) can be indicative of a central nervous system disturbance, such as a tumor or a postinfectious encephalopathy (brain damage due to lack of oxygen). Nystagmus can be induced by drugs like antidepressants, anticonvulsants, or tranquilizers. It can also occur during seizures and in some degenerative disorders or ischemic (blood supply deficiency) disorders. Treatment is specific to the characteristics of the nystagmus and the underlying cause.