Nystagmus is involuntary eye movement that can be part of the vestibulo-ocular reflex (VOR), with the eyes moving first in the direction of the lesioned side (slow phase) followed by a quick correction (fast phase) to the opposite side or away from the lesioned side. The direction of nystagmus is defined by the direction of its quick phase (e.g. a right-beating nystagmus is characterized by a rightward-moving quick phase). The oscillations may occur in the vertical, horizontal or torsional planes, or in any combination. The resulting nystagmus is often named as a gross description of the movement, e.g. downbeat nystagmus, upbeat nystagmus, seesaw nystagmus, periodic alternating nystagmus. These descriptive names can be misleading however, as many were assigned historically, solely on the basis of subjective clinical examination, which is not sufficient to determine the eyes' true trajectory. Over the past forty years, however, objective eye movement recording techniques have been applied to the study of nystagmus, and the results have led to a greater accuracy and understanding of the condition. The term symptom (from the Greek meaning chance, mishap or casualty, itself derived from συμπιπτω meaning to fall upon or to happen to) has two similar meanings in the context of physical and mental health: Strictly, a symptom is a sensation or change in health function experienced by a patient. ... In medicine, a sign is a feature of disease as detected by the doctor during physical examination of a patient. ... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... // H00-H59 - Diseases of the eye and adnexa (H00-H06) Disorders of eyelid, lacrimal system and orbit (H00) Hordeolum and chalazion (H000) Hordeolum and other deep inflammation of eyelid (H001) Chalazion (H01) Other inflammation of eyelid (H010) Blepharitis (H011) Noninfectious dermatoses of eyelid (H02) Other disorders of eyelid (H020) Entropion... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... An eye is an organ that detects light. ... Figure 3 Three-neuron arc, during a head movement to the right. ...

Nystagmus is not to be confused with other superficially similar-appearing disorders of eye movements (saccadic oscillations) such as opsoclonus or ocular flutter that are composed purely of fast-phase eye movements, while nystagmus is characterised by the combination of a slow eye movement that usually act to take the eye off the point of regard, interspersed with the fast movement that serves to bring the eye back on target. Without the use of objective recording techniques, it may be very difficult to distinguish between these conditions. Opsoclonus refers to a uncontrolled movement of the eyes. ... Ocular flutter is an opsoclonic disorder in which the eyes incontinuously saccadically moves around the point of fixation in the field of vision. ...

In medicine, the presence of nystagmus can be benign, or it can indicate an underlying visual or neurological problem. Over forty types of nystagmus have been classified. medicines, see medication and pharmacology. ...

In police work, testing for horizontal gaze nystagmus is one of a battery of field sobriety tests used by officers in the field to determine whether a suspect is driving under the influence of alcohol. The test involves observation of the suspect's pupil as it follows a moving object, noting (1) lack of smooth pursuit, (2) distinct and sustained nystagmus at maximum deviation, and (3) the onset of nystagmus prior to 45 degrees. A general rule of thumb is that a person's blood alcohol concentration can be estimated by subtracting the angle of onset from 50 degrees. Therefore, a person with an angle of onset of nystagmus at 35 degrees has a blood alcohol concentration of approximately 0.15%. While there is some scientific basis behind this observation, in practice the test is fatally flawed, for it relies on subjective examination and interpretation of eye movements, and estimation of gaze angles, which are notoriously inaccurate. This article or section does not cite its references or sources. ... Functional group of an alcohol molecule. ...

Pathological nystagmus

Nystagmus is a relatively common clinical condition, affecting one in every 5,000 to 10,000 individuals.^{[citation needed]} One survey in Oxfordshire, England identified one in every 670 children by the age of two as manifesting nystagmus. (American Nystagmus Network) The cause for pathological nystagmus may be congenital, idiopathic, secondary to a pre-existing neurological disorder or may be induced temporarily by certain drugs (alcohol and other central nervous system depressants and stimulants, such as lithium salts, phenytoin and ecstasy). Nystagmus generally causes a degree of vision impairment, although the severity of such impairment varies widely. Sometimes it is the other way round — many blind people have nystagmus, which is one reason that some wear dark glasses.[1] A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ... Idiopathic means arising spontaneously or from an obscure or unknown cause. ... Neurology is a branch of medicine dealing with disorders of the central and peripheral nervous systems. ... A psychoactive drug or psychotropic substance is a chemical substance that acts primarily upon the central nervous system where it alters brain function, resulting in temporary changes in perception, mood, consciousness and behavior. ... Functional group of an alcohol molecule. ... A diagram showing the CNS: 1. ... Lithium salts are chemical salts of lithium used as mood stabilizing drugs, primarily in the treatment of bipolar disorder, depression, and mania; but also in treating schizophrenia. ... Phenytoin sodium (marketed as Dilantin® in the USA and as Epanutin® in the UK, by Parke-Davis, now part of Pfizer) is a commonly used antiepileptic. ... MDMA (3,4-methylenedioxymethamphetamine), most commonly known by the street names ecstasy or XTC (for more names see the full list), is a synthetic entactogen of the phenethylamine family, whose primary effect is believed to be the stimulation of secretion as well as inhibition of re-uptake of large amounts... Visual impairment is the functional loss of vision. ... Blindness is the condition of lacking visual perception due to physiological or psychological factors. ...

If the pathologic nystagmus is based in the central nervous system (CNS), such as with a cerebellar problem, the nystagmus can be in any direction including horizontal. Purely vertical nystagmus is usually central in origin. Vestibular nystagmus usually combines a rotational component with vertical or horizontal eye movements and may be spontaneous or positional. Spontaneous vestibular nystagmus is nystagmus that occurs randomly, regardless of the position of the patient's head. Positional nystagmus is different from spontaneous nystagmus in that it occurs when a persons head is in a specific position (e.g., benign paroxysmal positional vertigo; BPPV). (See a video of Nystagmus associated with BPPV) A diagram showing the CNS: 1. ... The cerebellum (Latin: little brain) is a region of the brain that plays an important role in the integration of sensory perception and motor output. ...

Diseases presenting nystagmus

Some of the diseases which present nystagmus as a pathological sign are:

• Head trauma (the most common cause in young people)
• Stroke (the most common cause in older people)
• Ménière’s disease and other balance disorders
• Multiple sclerosis
• Brain tumors
• Wernicke-Korsakoff syndrome
• Encephalopathy
• Lateral medullary syndrome
• Aniridia
• Optic nerve hypoplasia
• Albinism
• Noonan syndrome
• Pelizaeus-Merzbacher disease

Head injury is a trauma to the head, that may or may not include injury to the brain (see also brain injury). ... A stroke, also known as cerebrovascular accident (CVA),[1] is an acute neurological injury in which the blood supply to a part of the brain is interrupted. ... Ménières disease (or syndrome, since its cause is unknown) was first described by French physician Prosper Ménière in 1861. ... Balance is the result of a number of body systems working together. ... A brain tumor is any intracranial tumor created by abnormal and uncontrolled cell division, normally either found in the brain itself (neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells), lymphatic tissue, blood vessels), in the cranial nerves (myelin-producing Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland... Wernicke-Korsakoff syndrome is a combination of Korsakoffs syndrome, which is characterized by confusion, severe anterograde and retrograde amnesia and confabulation; and Wernickes encephalopathy, which is characterized by nystagmus, ophthalmoplegia, coma and, if untreated, death. ... Encephalopathy is a container term for various conditions affecting the brain. ... Lateral medullary syndrome (also called Wallenbergs syndrome) is a disease in which the patient has difficulty with swallowing or speaking or both owing to one or more patches of dead tissue (known as an infarct) caused by interrupted blood supply to parts of the brain. ... Aniridia is a rare congenital condition characterized by the underdevelopment of the eyes iris. ... Optic nerve hypoplasia is a medical condition that results in underdevelopment of the optic nerves. ... Albinism (from Latin albus, meaning Bobby Herrick; extended etymology at Wiktionary), more technically hypomelanism or hypomelanosis, is a form of hypopigmentary congenital disorder, characterized by a lack of melanin pigment in the eyes, skin and hair (or more rarely the eyes alone). ... Noonan Syndrome (NS) is a relatively common congenital genetic condition which affects both males and females. ... Pelizaeus-Merzbacher disease (PMD) is a rare central nervous system disorder in which coordination, motor abilities, and intellectual function are delayed to variable extents. ...

Causes

Congenital nystagmus occurs more frequently than acquired nystagmus, is not associated with other disorders (such as refraction errors or diplopia) and is usually mild and non-progressive. The affected persons are not aware of their spontaneous, small-amplitude eye movements. Refraction error is an error in the focussing of light by the human eye. ... Diplopia, commonly known as double vision, is the perception of two images from a single object. ...

• Congenital

• Infantile:

• Idiopathic
• Albinism
• Aniridia
• Leber's congenital amaurosis
• Bilateral optic nerve hypoplasia
• Bilateral congenital cataracts
• Rod monochromatism
• Optic nerve or macular disease
• Persistent hyperplastic primary vitreous

• Latent nystagmus
• Nystagmus blockage syndrome

• Acquired

• Visual loss (e.g. dense cataract, trauma, cone dystrophy)
• Toxic/metabolic (e.g. alcohol intoxication, lithium, barbiturates, phenytoin(Dilantin), salicylates, benzodiazepines, phencyclidine, other anticonvulsants or sedatives, Methylenedioxymethamphetamine, Wernicke's encephalopathy, thiamine deficiency)
• Central nervous system disorders (e.g. thalamic hemorrhage, tumor, stroke, trauma, multiple sclerosis)
• Vestibular Pathology (Meniere's, BPPV, Labyrinthitis)
• Non-physiologic

Idiopathic means arising spontaneously or from an obscure or unknown cause. ... Albinism (from Latin albus, meaning Bobby Herrick; extended etymology at Wiktionary), more technically hypomelanism or hypomelanosis, is a form of hypopigmentary congenital disorder, characterized by a lack of melanin pigment in the eyes, skin and hair (or more rarely the eyes alone). ... Aniridia is a rare congenital condition characterized by the underdevelopment of the eyes iris. ... Lebers congenital amaurosis is a rare inherited eye disease that appears at birth or in the first few months of life, typically characterized by nystagmus, sluggish or no pupillary responses, and severe vision loss or blindness. ... Achromatopsia is a medical condition (also called maskun or rod monochromatism) characterized by a low cone cell count or lack of function in cone cells; these are the light receptors responsible for colour perception. ... Visual loss results in the absence of vision where it existed before, which can happen either acutely or over a long period of time. ... Human eye cross-sectional view, showing position of human lens. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ... MDMA (3,4-methylenedioxy-N-methylamphetamine), most commonly known today by the street name ecstasy, (often abbreviated to E, X, or XTC ) is a semisynthetic entactogen of the phenethylamine family, whose primary effect is believed to be the stimulation of secretion—as well as inhibition of re-uptake—of large... Wernickes encephalopathy is a severe irreversible syndrome characterised by loss of short-term memory. ... For the similarly-spelled nucleic acid, see Thymine Thiamine or thiamin, also known as vitamin B1, is one of the B vitamins. ... Tumor or tumour literally means swelling, and is sometimes still used with that meaning. ... A stroke, also known as cerebrovascular accident (CVA),[1] is an acute neurological injury in which the blood supply to a part of the brain is interrupted. ...

Diagnosis

Nystagmus can be clinically investigated by using a number of non-invasive standard tests. The simplest one is to irrigate an external auditory meatus with warm or cold water. The temperature gradient provokes the stimulation of the vestibulocochlear nerve and the consequent nystagmus. The resulting movement of the eyes may be recorded and quantified by special devices called electronystagmograph (ENG), which is a form of electrooculography (an electrical method of measuring eye movements using external electrodes) or even less invasive devices called videoonystagmograph (VNG), which is a form of videooculography(VOG) (a video-based method of measuring eye movements using external small cameras built into head masks). Special swinging chairs with electrical controls are also used in this test to induce rotatory nystagmus. The term non-invasive in medicine has two meanings: A medical procedure which does not penetrate or break the skin or a body cavity, i. ... Bat ears come in different sizes and shapes The ear is the sense organ that detects sound. ... The vestibulocochlear nerve (also known as the auditory or acoustic nerve) is the eighth of twelve cranial nerves, and is responsible for transmitting sound and equilibrium (balance) information from the inner ear to the brain. ... Electronystagmography (ENG) is a diagnostic test to record involuntary movements of the eye caused by a condition known as nystagmus. ... Electrooculography (EOG) is a medical technique for measuring the resting potential of the retina, the resulting signal is called electrooculogram. ... Alternative meanings: There is also an Electric-type Pokémon named Electrode. ...

Congenital nystagmus has traditionally been viewed as non-treatable, but medications have been discovered in recent years that show promise in some patients. In 1980, researchers discovered that a drug called baclofen could effectively stop periodic alternating nystagmus. Subsequently, gabapentin, an anticonvulsant, was found to cause improvement in about half the patients who received it to relieve symptoms of nystagmus. Other drugs found to be effective against nystagmus in some patients include memantine, levetiracetam, 3,4-diaminopyridine, 4-aminopyridine, and acetazolamide.^[1] Several therapeutic approaches, such as contact lenses, drugs, surgery, and low vision rehabilitation can also be used in order to improve visual function. Baclofen (brand names Kemstro® and Lioresal®) is a derivative of gamma-aminobutyric acid, and is an agonist specific to mammalian but not fruit fly (Drosophila) GABAB receptors[1][2]. It is used for the treatment of spastic movement, especially in instances of spinal cord injury, spastic diplegia and multiple sclerosis. ... Gabapentin (brand name: Neurontin®) was initially synthesized to mimic the structure of GABA for the treatment of epilepsy. ... Memantine is the first in a novel class of Alzheimers disease medications acting on the glutamatergic system. ... Levetiracetam (brand name: Keppra®) is an anticonvulsant medication used to treat epilepsy. ... 4-Aminopyridine or 4-pyridinamine is a potassium channel blocker. ... Acetazolamide, sold under the trade name Diamox®, is a carbonic anhydrase inhibitor that is used to treat glaucoma, epileptic seizures, benign intracranial hypertension and altitude sickness. ... A soft contact lens A contact lens (also known as contact, for short) is a corrective or cosmetic lens placed on the cornea of the eye atop the iris. ... A cardiothoracic surgeon performs a mitral valve replacement at the Fitzsimons Army Medical Center. ... Low vision is alternatively a general term used to describe lowered visual acuity, and a specific legal term in Canada and the United States used to designate someone with vision of 20/70 or less in the better eye with correction. ... Rehabilitation of sensory and cognitive function typically involves methods for retraining neural pathways or training new neural pathways to regain or improve neurocognitive functioning that has been diminished by disease or traumatic injury. ...

Nystagmus is very noticeable, but little recognised.