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Medical Dictionary


meningitis, pl .meningitides (men-in-ji′tis, -jit′i-dez; -jit′i-dez)
Inflammation of the membranes of the brain or spinal cord. SEE ALSO: arachnoiditis, leptomeningitis. SYN: cerebrospinal m.. [mening- + G. itis, inflammation] basilar m. m. at the base of the brain, due usually to tuberculosis, syphilis, or any low-grade chronic granulomatous process; may result in an internal hydrocephalus. cerebrospinal m. SYN: m.. eosinophilic m. SYN: angiostrongylosis. epidemic cerebrospinal m. SYN: meningococcal m.. epidural m. SYN: pachymeningitis externa. external m. SYN: pachymeningitis externa. internal m. SYN: pachymeningitis interna. listeria m. SYN: listeriosis. meningococcal m. an acute infectious disease of children and young adults, caused by Neisseria meningitidis characterized by fever, headache, photophobia, vomiting, nuchal rigidity, seizures, coma, and a purpuric eruption; even in the absence of m., meningococcemia can induce toxic phenomena such as vasculitis, disseminated intravascular coagulation, shock, and Waterhouse-Friderichsen syndrome due to adrenal hemorrhage; late complications include paralysis, mental retardation, and gangrene of extremities. SYN: cerebrospinal fever, epidemic cerebrospinal m..Approximately 2500 cases of invasive meningococcal disease occur annually in the U.S., with a case fatality rate of 10–15%. The incidence of endemic meningococcal disease peaks between late winter and early spring. Attack rates and case fatality rates are highest among children aged 6–12 months. Household exposure to tobacco smoke is a risk factor for meningococcal disease in children. Organisms are spread from person to person by direct contact and in saliva and respiratory secretions. The epidemiology of meningococcal disease is poorly understood. The nasopharyngeal carriage rate in the general population is 5–10%. This asymptomatic carrier state can persist for months or years and may confer protection against invasive disease. During epidemics of meningococcal m., the carrier rate can approach 95%, yet fewer than 1% may develop the disease. Diagnosis is established by the finding of meningococci in cerebrospinal fluid or blood. Because meningococcemia can progress fulminantly to an irreversible stage, intravenous penicillin G, ampicillin, or chloramphenicol is begun as soon as the diagnosis is suspected, usually before laboratory confirmation. Intensive support of vital functions is crucial during the acute phase. Close contacts of known cases are treated prophylactically with rifampin or ciprofloxacin; mass prophylaxis may be appropriate in a confirmed institutional outbreak. A quadrivalent vaccine has been effective in preventing meningococcal disease due to serogroups A, C, W-135, and Y. Shortcomings of the vaccine are that it does not protect against serogroup B, which causes 30–40% of meningococcal disease in the U.S.; does not interrupt the carrier state; does not induce immunity quickly enough to protect a person already infected; and protects for only 4–5 years. Routine immunization is recommended only for military recruits, travelers to endemic areas, and others known to be at long-term high risk. A major objection to infant vaccination has been the poor induction of immunity in this age group to serogroup C, which causes 45% of m. in the U.S. Use of a meningococcal C vaccine conjugated to protein has yielded high initial titers of anticapsular and bactericidal antibody in infants and toddlers, as well as more prolonged protection and better response to booster doses. Mollaret m. a recurrent aseptic m.; febrile illness accompanied by headaches, malaise, meningeal signs, and cerebrospinal fluid monocytes. neoplastic m. infiltration of subarachnoid space by neoplastic cells, typically medulloblastoma or metastatic carcinoma. SYN: neoplastic arachnoiditis. occlusive m. leptomeningitis causing occlusion of the spinal fluid pathways. otitic m. infection of the meninges secondary to otitis media or mastoiditis. serous m. acute m. with secondary external hydrocephalus. tuberculous m. inflammation of the cerebral leptomeninges marked by the presence of granulomatous inflammation; it is usually confined to the base of the brain (basilar m., internal hydrocephalus) and is accompanied in children by an accumulation of spinal fluid in the ventricles (acute hydrocephalus). SYN: cerebral tuberculosis (1) .

meningo-, mening-
The meninges. [G. meninx, membrane]

meningocele (me-ning′go-sel)
Protrusion of the membranes of the brain or spinal cord through a defect in the skull or spinal column. [meningo- + G. kele, tumor] spurious m. an extracranial or extraspinal accumulation of cerebrospinal fluid, due to meningeal tear. SYN: traumatic m.. traumatic m. SYN: spurious m..

meningococcemia (me-ning′go-kok-se′me-a)
Presence of meningococci (N. meningitidis) in the circulating blood. acute fulminating m. rapidly moving systemic infection with Neisseria meningitidis, usually without meningitis, characterized by rash, usually petechial or purpuric, high fever, and hypotension. May lead to death within hours.

meningococcus, pl .meningococci (me-ning′go-kok′us, -kok′si)
SYN: Neisseria meningitidis. [meningo- + G. kokkos, berry]

meningocortical (me-ning′go-kor′ti-kal)
Relating to the meninges and the cortex of the brain. SYN: meningeocortical.

meningocyte (me-ning′go-sit)
A mesenchymal epithelial cell of the subarachnoid space; it may become a macrophage. [meningo- + G. kytos, cell]

meningoencephalitis (me-ning′go-en-sef′al-i′tis)
An inflammation of the brain and its membranes. SYN: cerebromeningitis, encephalomeningitis. [meningo- + G. enkephalos, brain, + -itis, inflammation] acute primary hemorrhagic m. SYN: acute epidemic leukoencephalitis. biundulant m. SYN: tick-borne encephalitis (Central European subtype). chronic progressive syphilitic m. SYN: paretic neurosyphilis. eosinophilic m. a disease caused by infection with the rat lungworm, Angiostrongylus cantonensis, whose larvae, ingested with infected slugs or land snails (or some unidentified transport host), migrate from intestine to the meninges of the brain where the disease is produced; it is usually mild, of short duration, and characterized by fever, eosinophilia, and white blood cells (rarely nematode larvae) in the spinal fluid. herpetic m. a severe form of m. caused by herpesvirus type 1 and associated with a high mortality rate. mumps m. a usually benign nervous system infection arising during the active phase of clinical mumps parotiditis. primary amebic m. an invasive, rapidly fatal cerebral infection by soil amebae, chiefly Naegleria fowleri, found in humans and other primates and experimentally in rodents; the disease is characterized by a high fever, neck rigidity, and symptoms associated with upper respiratory infection such as cough and nausea; although organisms have been cultured from various organs, the brain is the primary focus, especially the olfactory lobes and cerebral cortex, which are first attacked by the amebae that enter from nasal mucosa through the cribriform plate; death usually occurs two to three days after onset of symptoms. syphilitic m. a secondary or tertiary stage manifestation of syphilis; rarely fatal.

meningoencephalocele (me-ning′go-en-sef′a-lo-sel)
A protrusion of the meninges and brain through a congenital defect in the cranium, usually in the frontal or occipital region. SYN: encephalomeningocele. [meningo- + G. enkephalos, brain, + kele, hernia]

meningoencephalomyelitis (me-ning′go-en-sef′a-lo-mi-e-li′tis)
Inflammation of the brain and spinal cord together with their membranes. [meningo + G. enkephalos, brain, + myelos, marrow, + -itis, inflammation]

meningoencephalopathy (me-ning′go-en-sef-a-lop′a-the)
Disorder affecting the meninges and the brain. SYN: encephalomeningopathy. [meningo- + G. enkephalos, brain, + pathos, suffering]

meningomyelitis (me-ning′go-mi′e-li′tis)
Inflammation of the spinal cord and of its enveloping arachnoid and pia mater, and less commonly also of the dura mater. [meningo- + G. myelos, marrow, + -itis, inflammation]

meningomyelocele (me-ning-go-mi′e-lo-sel)
Protrusion of the spinal cord and its membranes through a defect in the vertebral column. SYN: myelocystomeningocele, myelomeningocele. [meningo- + G. myelos, marrow, + kele, tumor]

meningo-osteophlebitis (me-ning′go′os-te-o-fle-bi′tis)
Inflammation of the veins of the periosteum.

meningoradicular (me-ning′go-ra-dik′u-lar)
Relating to the meninges covering cranial or spinal nerve roots. [meningo- + L. radix, root]

meningoradiculitis (me-ning′go-ra-dik-u-li′tis)
Inflammation of the meninges and roots of the nerves.

meningorrhachidian (me-ning′go-ra-kid′e-an)
Relating to the spinal cord and its membranes. [meningo- + G. rhachis, spine]

meningorrhagia (me-ning′go-ra′je-a)
Hemorrhage into or beneath the cerebral or spinal meninges. [meningo- + G. rhegnymi, to burst forth]

meningosis (men′ing-go′sis)
Membranous union of bones, as in the skull of the newborn. [meningo- + G. -osis, condition]

meningovascular (me-ning′go-vas′ku-lar)
Concerning the blood vessels in the meninges; or the meninges and blood vessels.

meninguria (men-ing-goo′re-a)
The passage of membraniform shreds in the urine. [meningo- + G. ouron, urine]

meninx, gen. meningis, pl .meninges (me′ninks, -jez; men′ingks; me-nin′jes) [TA]
Any membrane; specifically, one of the membranous coverings of the brain and spinal cord. SEE ALSO: arachnoid mater, dura mater, pia mater, leptomeninx. [Mod. L. fr. G. m., membrane] m. fibrosa rarely used term for dura mater. m. primitiva SYN: primitive m.. primitive m. the embryonic loose mesenchymatous tissue surrounding the brain and spinal cord; from it the three definite meninges (arachnoid mater, dura mater, and pia mater) are derived. SYN: m. primitiva. m. tenuis SYN: leptomeninx. vascular m. rarely used term for pia mater. SYN: m. vasculosa. m. vasculosa SYN: vascular m..

meniscectomy (men′i-sek′to-me)
Excision of a meniscus, usually from the knee joint. [G. meniskos, crescent (meniscus) + ektome, excision]

menisci (me-nis′si)
Plural of meniscus.

meniscitis (men′i-si′tis)
Inflammation of a fibrocartilaginous meniscus. [G. meniskos, crescent (meniscus), + -itis, inflammation]

meniscocyte (me-nis′ko-sit)
SYN: sickle cell. [G. meniskos, a crescent, + kytos, a hollow (cell)]

meniscopexy (me-nis′ko-pek-se)
Surgical procedure anchoring the medial meniscus to its former attachment. SYN: meniscorrhaphy. [menisco- + G. pexis, fixation]

meniscorrhaphy (men-is-kor′a-fe)
SYN: meniscopexy. [menisco- + G. rhaphe, suture]

meniscotome (me-nis′ko-tom)
An instrument used in the removal of a meniscus. [G. meniskos, crescent (meniscus) + tome, incision]

meniscus, pl .menisci (me-nis′kus, me-nis′si)
1. SYN: m. lens. 2. [TA] A crescent-shaped intraarticular fibrocartilage found in certain joints. 3. A crescent-shaped fibrocartilaginous structure of the knee, the acromio- and sternoclavicular and the temporomandibular joints. [G. meniskos, crescent] articular m. SYN: m. lens. m. articularis SYN: m. lens. converging m. a convexoconcave lens in which the power of the convexity exceeds that of the concavity. SYN: positive m.. diverging m. a convexoconcave lens in which the power of the concavity exceeds that of the convexity. SYN: negative m.. lateral m. [TA] crescent-shaped intraarticular cartilage of the knee joint attached to the lateral border of the upper articular surface of the tibia, occupying the space surrounding the contacting surfaces of the femur and tibia. SYN: m. lateralis [TA] , external semilunar fibrocartilage. m. lateralis [TA] SYN: lateral m.. medial m. [TA] crescent-shaped intraarticular cartilage of the knee joint attached to the medial border of the upper articular surface of the tibia occupying the space surrounding the contacting surfaces of the femur and tibia. SYN: m. medialis [TA] , falciform cartilage, internal semilunar fibrocartilage of knee joint. m. medialis [TA] SYN: medial m.. negative m. SYN: diverging m.. periscopic m. SYN: aplanatic lens. positive m. SYN: converging m.. tactile m. a specialized tactile sensory nerve ending in the epidermis, characterized by a terminal cuplike expansion of an intraepidermal axon in contact with the base of a single modified keratinocyte. SYN: m. tactus, Merkel corpuscle, Merkel tactile cell, Merkel tactile disk, tactile disk. m. tactus SYN: tactile m..

John H., U.S. neurologist, *1928. See M. syndrome.

The menses, menstruation. [G. men, month]

menocelis (men-o-se′lis)
A dark macular or petechial eruption sometimes occurring in cases of amenorrhea. [meno- + G. kelis, spot]

menometrorrhagia (men′o-me-tro-ra′je-a)
Irregular or excessive bleeding during menstruation and between menstrual periods. [meno- + G. metra, uterus, + rhegnymi, to burst forth]

menopausal (men′o-paw-zal)
Associated with or occasioned by the menopause.

menopause (men′o-pawz)
Permanent cessation of the menses; termination of the menstrual life. [meno- + G. pausis, cessation] premature m. failure of cyclic ovarian function before age 40. SYN: premature ovarian failure.

menophania (men-o-fa′ne-a)
First sign of the menses at puberty. [meno- + G. phaino, to show]

Menopon (men′o-pon)
A genus of biting lice (family Menoponidae, order Mallophaga) found on birds; it includes important pests that infect domestic fowl, such as M. gallinae (M. pallidum), the shaft louse of poultry, a light yellow louse about 1.7 to 2.0 mm long, found on barnyard fowl, ducks, and pigeons.

menorrhagia (men-o-ra′je-a)
SYN: hypermenorrhea. [meno- + G. rhegnymi, to burst forth]

menorrhalgia (men-o-ral′je-a)
SYN: dysmenorrhea. [meno- + G. algos, pain]

menotropins (men-o-tro′pinz)
Extract of postmenopausal urine containing primarily the follicle-stimulating hormone. SEE ALSO: human menopausal gonadotropin, urofollitropin.

menouria (men-o-u′re-a)
Menstruation occurring through the urinary bladder as a result of vesicouterine fistula. [meno- + G. ouron, urine, + -ia, condition]

menoxenia (men-o-ze′ne-a, men′ok-se′ne-a)
Any abnormality of menstruation. [meno- + G. xenos, strange]

menses (men′sez)
A periodic physiologic hemorrhage, occurring at approximately 4-week intervals, and having its source from the uterine mucous membrane; usually the bleeding is preceded by ovulation and predecidual changes in the endometrium. SEE ALSO: menstrual cycle. SYN: menstrual period. [L. pl. of mensis, month]

menstrual (men′stroo-al)
Relating to the menses. [L. menstrualis]

menstruant (men′stroo-ant)

menstruate (men′stroo-at)
To undergo menstruation. [L. menstruo, pp. -atus, to be menstruant]

menstruation (men-stroo-a′shun)
Cyclic endometrial shedding and discharge of a bloody fluid from the uterus during the menstrual cycle. [see menstruate] anovular m. menstrual bleeding without recent ovulation; also occurs in subhuman primates. SYN: anovulational m., nonovulational m.. anovulational m. SYN: anovular m.. nonovulational m. SYN: anovular m.. retained m. SYN: hematocolpos. retrograde m. a flow of menstrual blood back through the fallopian tubes; it sometimes carries with it endometrial cells. supplementary m. bleeding from the navel or urinary tract due to endometriosis occurring at the time of m.. suppressed m. nonappearance of menstrual bleeding from whatever cause. vicarious m. bleeding from any surface other than the mucous membrane of the uterine cavity, occurring periodically at the time when the normal m. should take place.

menstruum, pl .menstrua (men′stroo-um, -stroo-a)
Old term for solvent. [Mediev. L. menstrual fluid, thought to possess certain solvent properties, ntr. of L. menstruus, monthly]

mensual (men′soo-al, -shoo-al)
Monthly. [L. mensis, month]

mensuration (men-soo-ra′shun)
The act or process of measuring. [L. mensuratio, fr. mensuro, to measure]

1. Relating to the mind. [L. mens (ment-), mind] 2. Relating to the chin. SYN: genial, genian. [L. mentum, chin]

mentalis (men-ta′lis)
See m. (muscle). [L.]

mentality (men-tal′i-te)
The functional attributes of the mind; mental activity.

mentation (men-ta′shun)
The process of reasoning and thinking.

Maud L., Canadian pathologist in U.S., 1879–1960. See Michaelis-M. constant, Michaelis-M. hypothesis.

Mentha (men′tha)
A genus of plants of the family Labiatae. M. piperita is peppermint; M. pulegium, pennyroyal; M. viridis, spearmint. SYN: mint. [L.]

menthane (men′than)
The monocyclic terpene parent of alcohols such as menthol and terpin.

An alcohol obtained from peppermint oil or other mint oils, or prepared synthetically; used as an antipruritic and topical anesthetic, in nasal sprays, cough drops, and inhalers, and as a flavoring agent. SYN: peppermint camphor. camphorated m. a liquid obtained by triturating equal parts of camphor and m.; was used locally as a counterirritant and (diluted) as a spray in rhinitis and pharyngitis.

menthyl salicylate
Used as a sunscreen to filter out ultraviolet light in preparations to protect the skin from sunburn.

mentolabialis (men′to-la-be-a′lis)
The mentalis and depressor labii inferioris considered as one muscle. [L.]

In cephalometrics, the lowermost point in the symphysial shadow as seen on a lateral jaw projection. [L. mentum, chin]

mentoplasty (men′to-plas-te)
Plastic surgery of the chin, whereby its shape or size is altered. [L. mentum, chin, + G. plastos, formed]

mentum, gen. menti (men′tum, -ti) [TA]
SYN: chin. [L.]


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