WordNet

become tight or as if tight; "Her throat constricted" (同)constringe, narrow
the contractile aperture in the center of the iris of the eye; resembles a large black dot
young of any of various canines such as a dog or wolf (同)whelp
especially tense; especially in some dialects
drawn together or squeezed physically or by extension psychologically; "a constricted blood vessel"; "a constricted view of life"

PrepTutorEJDIC

〈物など〉'を'締めつける,圧縮する
(一般にschoolに学ぶ)『生徒』;(個人指導を受けている)生徒,門下生,弟子
ひとみ,瞳孔(どうこう)
=puppy / (キツネ・オオカミ・アザラシなどの)子 / 〈雌犬が〉子犬を生む

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/03/15 11:20:01」(JST)

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Not to be confused with meiosis, mitosis, or myositis.

Miosis (or myosis, from Ancient Greek μύειν, mūein, "to close the eyes") is a term with various definitions, which generally include constriction of the pupil.

The opposite condition, mydriasis, is the dilation of the pupil. Anisocoria is the condition of one pupil being more dilated than the other.

Definitions[edit]

Definitions of miosis include:

Constriction of the pupil that is excessive,^[1] which may potentially be interpreted as being relative to what would be expected by the amount of light the pupil receives
Constriction of the pupil to a diameter of less than two millimeters^{[not in citation given]}^[2]^[3]
Constriction of the pupil with causes including both abnormal and physiological ones.^{[not in citation given]}^[4]
Pupillary constriction by abnormal causes.^{[not in citation given]}^[5]

Physiology of the photomotor reflex[edit]

Light entering the eye strikes three different photoreceptors in the retina: the familiar rods and cones used in image forming and the more newly discovered photosensitive ganglion cells. The ganglion cells give information about ambient light levels, and react sluggishly compared to the rods and cones. Signals from photosensitive ganglion cells have multiple functions including acute suppression of the hormone melatonin, entrainment of the body's circadian rhythms and regulation of the size of the pupil.

The retinal photoceptors convert light stimuli into electric impulses. Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurons send axons to neurons of the Edinger-Westphal nucleus whose visceromotor axons run along both the left and right oculomotor nerves. Visceromotor nerve axons (which constitute a portion of cranial nerve III, along with the somatomotor portion derived from the Edinger-Westphal nucleus) synapse on ciliary ganglion neurons, whose parasympathetic axons innervate the iris sphincter muscle, producing miosis. This occurs because sympathetic activity from the ciliary ganglion is lost thus parasympathetics are not inhibited. Image

Causes[edit]

Age[edit]

senile miosis (a reduction in the size of a person's pupil in old age)

Diseases[edit]

Horner's syndrome
Hemorrhage into pons (intracranial hemorrhage)
Hereditary disorders
Cluster Headaches with ptosis
Iridocyclitis
Fatal familial insomnia

Drugs[edit]

Opioids such as fentanyl, morphine, heroin and methadone (the notable exception being demerol/pethidine)
Antipsychotics, including haloperidol, thorazine, olanzapine, quetiapine and others
Cholinergic agents such as acetylcholine
Some cancer chemotherapy drugs, including camptothecin derivatives
Mirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA)
Trazodone
Some MAO Inhibitors.
In some rare cases, when exposed to mustard gas.
Organophosphates

References[edit]

^ Farlex medical dictionary citing:
- Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition.
- Saunders Comprehensive Veterinary Dictionary, 3 ed.
^ Seidel, Henry M.; Jane W. Ball, Joyce E. Dains, G. William Benedict (2006-03-29). Mosby's Guide to Physical Examination. Mosby. ISBN 978-0-32-303573-6. Cite uses deprecated parameters (help)
^ Farlex medical dictionary citing: Millodot: Dictionary of Optometry and Visual Science, 7th edition.
^ Farlex medical dictionary citing: The American Heritage Medical Dictionary. Copyright 2007
^ Farlex medical dictionary citing: Mosby's Medical Dictionary, 8th edition.

External links[edit]

FP Notebook
-1254817782 at GPnotebook

UpToDate Contents

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1. 緊張性瞳孔 tonic pupil
2. 瞳孔不同患者へのアプローチ approach to the patient with anisocoria
3. 成人における急性オピオイド中毒 acute opioid intoxication in adults
4. 成人における詳細な神経学的検査 the detailed neurologic examination in adults
5. ブドウ膜炎：病因、臨床症状、および診断 uveitis etiology clinical manifestations and diagnosis

English Journal

Tournay's description of anisocoria on lateral gaze: Reaction, myth, or phenomenon?

Robert MP, Plant GT.Author information From the Service d'Ophtalmologie (M.P.R.), Hôpital Universitaire Necker-Enfants Malades, AP-HP, Paris; Centre d'Étude de la Sensori-Motricité (M.P.R.), CNRS UMR 8194, Université Paris Descartes, Sorbonne Paris Cité, France; Neuro-ophthalmology Department (G.T.P.), National Hospital for Neurology and Neurosurgery, Queen Square, London; Neuro-ophthalmology Department (G.T.P.), Moorfields Eye Hospital, London; and Ophthalmology Department (G.T.P.), St Thomas' Hospital, London, UK.AbstractThe year 1917 witnessed the opening of a great debate in neuro-ophthalmology, with Tournay's description of a phenomenon thought to be universal: anisocoria in lateral gaze, due to mydriasis of the abducting pupil and a minor miosis of the fellow one. Through many publications, this phenomenon was soon assessed and confirmed to be physiologic, while the cause of the pupil reaction in lateral gaze was extensively discussed. Cases of abolition and reversal of the phenomenon were also reported in specific clinical situations, such as neurosyphilis, and its study became part of the neuro-ophthalmologic examination. Publications on the phenomenon declined after 1934, with only one publication appearing between 1934 and 1974 (1957). In 1974, the demise of the Tournay phenomenon was secured after 2 pupillographic studies showed it to be rare and marginal. This story is reviewed. Hypotheses are proposed in order to help unfold the controversy; anisocoria in lateral gaze should not be regarded as a myth, nor does it-or only rarely-correspond to a pupil reaction, or noumenon: it can usually be accounted for by a specific optical distortion (apparent without real anisocoria) and hence fits the Kantian definition of a phenomenon. An understanding of Tournay phenomenon is therefore of current relevance to the examination of the pupils to avoid misinterpretation of observed changes in the pupil.
Neurology.Neurology.2014 Feb 4;82(5):452-6. doi: 10.1212/WNL.0000000000000089.
The year 1917 witnessed the opening of a great debate in neuro-ophthalmology, with Tournay's description of a phenomenon thought to be universal: anisocoria in lateral gaze, due to mydriasis of the abducting pupil and a minor miosis of the fellow one. Through many publications, this phenomenon was s
PMID 24491971

Recommendations for the Management of Cerebral and Cerebellar Infarction With Swelling: A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association.

Wijdicks EF, Sheth KN, Carter BS, Greer DM, Kasner SE, Kimberly WT, Schwab S, Smith EE, Tamargo RJ, Wintermark M; on behalf of the American Heart Association Stroke Council.AbstractBACKGROUND AND PURPOSE: There are uncertainties surrounding the optimal management of patients with brain swelling after an ischemic stroke. Guidelines are needed on how to manage this major complication, how to provide the best comprehensive neurological and medical care, and how to best inform families facing complex decisions on surgical intervention in deteriorating patients. This scientific statement addresses the early approach to the patient with a swollen ischemic stroke in a cerebral or cerebellar hemisphere.
Stroke; a journal of cerebral circulation.Stroke.2014 Jan 30. [Epub ahead of print]
BACKGROUND AND PURPOSE: There are uncertainties surrounding the optimal management of patients with brain swelling after an ischemic stroke. Guidelines are needed on how to manage this major complication, how to provide the best comprehensive neurological and medical care, and how to best inform fam
PMID 24481970

Accidental mushroom poisoning mimicking stroke. A case report and literature review.

Comelli I, Lippi G, De Blasio A, Cervellin G.Author information Emergency Department, University Hospital of Parma, Parma, Italy. gcervellin@ao.pr.it.AbstractWe describe here a paradigmatic case of mushroom poisoning mimicking a stroke. A 64-year old male was referred to the emergency department (ED) for a car accident. He was found diaphoretic, hypotensive, bradycardic, and slightly confused at presentation. No signs of trauma were observed on physical examination. The patient had weakness of the right limbs and bilateral severe myosis. The lab tests were normal, except for leukocytosis, mild hyperglycemia, mild hyperazotemia and moderate hypokalemia. The clinical picture, with the exception of miosis, was thereby suggestive for a stroke, which was also considered the cause of the car accident. The patients' wife, who was brought later to the ED, reported that the husband had suffered a stroke 4 years earlier, with residual right hemiparesis. She also referred that the patient showed signs of diaphoresis and confusion, and the car was intentionally driven into the ditch. Among other details, she referred that the husband ate mushrooms that she had personally collected 2 hours before taking the drive. Two mg of atropine, intravenous rehydration and potassium were hence administered in the suspicion of a cholinergic toxydrome, and complete clinical remission was rapidly obtained. Among the mixture of mushrooms eaten by the patient, a mycologist identified Armillaria Mellea (an edible mushroom) and notably Inocybe Fastigiata, a toxic muscarine-containing mushroom, easily confounded with Armillaria. After observation and oral rehydration, the patient was discharged.
Acta bio-medica : Atenei Parmensis.Acta Biomed.2014 Jan 23;84(3):229-33.
We describe here a paradigmatic case of mushroom poisoning mimicking a stroke. A 64-year old male was referred to the emergency department (ED) for a car accident. He was found diaphoretic, hypotensive, bradycardic, and slightly confused at presentation. No signs of trauma were observed on physical
PMID 24458168