Medical Dictionary

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encephalitogenic (en-sef′a-li-to-jen′ik)
Producing encephalitis; typically by hypersensitivity mechanisms. See encephalitogen.

Encephalitozoon (en-sef′a-li-to-zo′on)
A genus of protozoan parasites, formerly considered part of the family Toxoplasmatidae, class Sporozoea, but now recognized as a member of the protozoan phylum Microspora, family Nosematidae. E. cuniculi is considered the primary microsporan parasite of mammals, commonly found in the brain and kidney tubules of rodents and carnivores and causing nosematosis in rabbits. [encephalitis + G. zoon, animal] E. cuniculi a common cryptic infection of most mammals and some birds, transmitted in urine-contaminated food and by transplacental transmission. Disseminated human infection has been reported among immunosuppressed individuals. Latent infection seen by serodiagnosis suggests widespread nonsymptomatic infection in tropical regions. E. hellem a species of E. described from human ophthalmic infections causing punctate keratopathy and corneal ulceration in AIDS patients. E. intestinale a diarrheogenic microsporidian described in HIV-infected patients; disease may be localized to the gastrointestinal tract or may disseminate intravascularly. E. intestinalis a species of E. described from human muscle; very few cases have been reported. Formerly called Septata intestinale.

encephalization (en-sef′a-li-za′shun)
SYN: corticalization.

encephalo-, encephal-
The brain. Cf.:cerebro-. [G. enkephalos, brain]

encephalocele (en-sef′a-lo-sel)
A congenital gap in the skull with herniation of brain substance. SYN: craniocele, cranium bifidum, bifid cranium. [encephalo- + G. kele, hernia] basal e. a defect in the skull floor with the herniation of brain tissue sometimes associated with coloboma of optic nerve.

encephalocystocele
SYN: hydrencephalocele.

encephaloduroarteriosynangiosis (en-sef′a-lo-door-o-ar-ter′e-o-sin-anj-e-o′sis)
SYN: duraencephalosynangiosis.

encephalodynia (en-sef′a-lo-din′e-a)
SYN: headache. [encephalo- + G. odyne, pain]

encephalodysplasia (en-sef′a-lo-dis-pla′ze-a)
Any congenital abnormality of the brain. [encephalo- + G. dys, bad, + plastos, formed]

encephalogram (en-sef′a-lo-gram)
The record obtained by encephalography. [encephalo- + G. gramma, a drawing]

encephalography (en-sef-a-log′ra-fe)
Obsolete technique of radiographic representation of the brain. See pneumoencephalography. [encephalo- + G. grapho, to write] gamma e. imaging of the encephalon by the administration of small amounts of gamma-emitting radiopharmaceuticals; term may be used to refer to any number of particular studies ( e.g., cerebral perfusion scintigraphy, cerebral neuroreceptor imaging) depending on the radiopharmaceutical used.

encephaloid (en-sef′a-loyd)
Resembling brain substance; denoting a carcinoma of soft, brainlike consistency, with reference to gross features. [encephalo- + G. eidos, resemblance]

encephalolith (en-sef′a-lo-lith)
A concretion in the brain or one of its ventricles. SYN: cerebral calculus. [encephalo- + G. lithos, stone]

encephalology (en-sef-a-lol′o-je)
The branch of medicine dealing with the brain in all its relations. [encephalo- + G. logos, study]

encephaloma (en-sef-a-lo′ma-la′she-a)
Herniation of brain substance. SYN: cerebroma.

encephalomalacia (en-sef′a-lo-ma-la′she-a)
Abnormal softness of the cerebral parenchyma often due to ischemia or infarction. SYN: cerebromalacia. [encephalo- + G. malakia, softness]

encephalomeningitis (en-sef′a-lo-men-in-ji′tis)
SYN: meningoencephalitis. [encephalo- + G. meninx, membrane, + -itis, inflammation]

encephalomeningocele (en-sef′a-lo-me-ning′go-sel)
SYN: meningoencephalocele. [encephalo- + G. meninx, membrane, + kele, hernia]

encephalomeningopathy (en-sef′a-lo-men-in-gop′a-the)
SYN: meningoencephalopathy.

encephalomere (en-sef′a-lo-mer)
SYN: neuromere. [encephalo- + G. meros, a part]

encephalometer (en-sef-a-lom′e-ter)
An apparatus for indicating on the skull the location of the cortical centers. [encephalo- + G. metron, measure]

encephalomyelitis (en-sef-a-lo-mi′e-li′tis)
Inflammation of the brain and spinal cord. [encephalo- + G. myelon, marrow, + -itis, inflammation] acute disseminated e. an acute demyelinating disorder of the central nervous system, in which focal demyelination is present throughout the brain and spinal cord. This process is common to postinfectious, postexanthem, and postvaccinal e.. acute necrotizing hemorrhagic e. a fulminating demyelinating disorder of the central nervous system that affects mainly children and young adults. Almost always preceded by a respiratory infection, characterized by the abrupt onset of fever, headache, confusion, and nuchal rigidity, soon followed by focal seizures, hemiplegia, or quadriplegia, brainstem findings, and coma; the CSF shows evidence of an inflammatory process; due to the massive destruction of the white matter of one or both hemispheres, often accompanied by similar destruction of the white matter of the brainstem and cerebellar peduncles; of unknown etiology. SYN: acute hemorrhagic leukoencephalitis, acute necrotizing hemorrhagic leukoencephalitis, Hurst disease. e. associated with carcinoma SYN: paraneoplastic encephalomyelopathy. benign myalgic e. SYN: epidemic neuromyasthenia. eastern equine e. (EEE) a form of mosquito-borne equine e. seen in the eastern U.S. and caused by the eastern equine e. virus, a species of Alphavirus, which belongs to the family Togaviridae; initial fever and viremia are followed by signs of central nervous system involvement (excitement, then somnolence, paralysis, and death); the incidence of clinical infection in humans is low but case fatality may be high. epidemic myalgic e. SYN: epidemic neuromyasthenia. equine e. an acute, often fatal, virus disease of horses and mules transmitted by mosquitoes and characterized by central nervous system disturbances; in the U.S., this disease is typically caused by one of three alphaviruses, and their resulting diseases are designated western equine, eastern equine and Venezuelan equine e.; these viruses belong to the family Togaviridae and can also cause neurologic disease in humans. SYN: equine encephalitis. experimental allergic e. a demyelinating allergic e. produced by the injection of brain tissue, usually with an adjuvant. SYN: experimental allergic encephalitis. granulomatous e. an e. in which granulomas occur. herpes B e. a frequently lethal disease of humans caused by infection with a normally latent monkey herpesvirus. mouse e. e. due to the mouse e. virus (a species of Enterovirus) which is not pathogenic in monkeys or in man, but attacks mouse colonies and causes a flaccid paralysis, usually of the hind limbs. postvaccinal e. a severe type of e. that can follow the rabies vaccination. SYN: postvaccinal encephalitis. Venezuelan equine e. (VEE) a form of mosquito-borne equine e. found in parts of South America, Panama, and Trinidad, caused by the Venezuelan equine e. virus (a species of Alphavirus in the family Togaviridae), and characterized by less central nervous system involvement than occurs in either eastern or western equine e.; fever, diarrhea, and depression are common; in humans, there is fever and severe headache after an incubation period of 2–5 days, and in a few cases there has been central nervous system involvement. viral e., virus e. an e. due to a neurotropic virus. western equine e. (WEE) an equine e. found in the western U.S. and parts of South America, transmitted by mosquitoes and caused by the western equine e. virus (a species of Alphavirus in the family Togaviridae); the infection is similar to but milder than eastern equine e. in humans and is, as a rule, inapparent, but some cases with central nervous system involvement have been fatal. zoster e. inflammation of the brain and spinal cord caused by varicella-zoster virus, a member of the family Herpesviridae.

encephalomyelocele (en-sef′a-lo-mi′e-lo-sel)
Congenital defect in the skull, usually in the occipital region, and cervical vertebrae with herniation of the meninges and neural tissue. [G. enkephalos, brain, + myelon, marrow, + kele, hernia]

encephalomyeloneuropathy (en-sef′a-lo-mi′e-lo-noo-rop′a-the)
A disease involving the brain, spinal cord, and peripheral nerves.

encephalomyelopathy (en-sef′a-lo-mi-e-lop′a-the)
Any disease of both brain and spinal cord. [G. enkephalos, brain, + myelon, marrow, + pathos, suffering] carcinomatous e. SYN: paraneoplastic e.. epidemic myalgic e. a disease superficially resembling poliomyelitis, characterized by diffuse involvement of the nervous system associated with myalgia. necrotizing e. [MIM*256000] SYN: Leigh disease. paracarcinomatous e. SYN: paraneoplastic e.. paraneoplastic e. an e. as a remote effect of carcinoma, most often oat cell carcinoma of the lung; characterized by extensive nerve cell loss, which may be diffuse, but often predominates in particular portions of the central nervous system, particularly the limbic lobes, medulla, cerebellum, and gray matter of the spinal cord. SYN: carcinomatous e., encephalomyelitis associated with carcinoma, paracarcinomatous e.. subacute necrotizing e. (SNE) a rare fatal disorder, primarily of children, being both acute and chronic in onset, manifested primarily as brainstem dysfunction, with ataxia, cranial nerve palsies, pseudobulbar palsy, hemi- or quadriplegia, mental deterioration, and involuntary movements; deficiencies of pyruvate dehydrogenase or cytochrome C oxidase have been found in some patients; pathologically, there is widespread symmetric necrosis involving much of the brainstem; these changes are similar to those seen with Wernicke encephalopathy.

encephalomyeloradiculitis (en-sef′a-lo-mi′e-lo-ra-dik′u-li-tis)
SYN: encephalomyeloradiculopathy.

encephalomyeloradiculopathy (en-sef′a-lo-mi′e-lo-ra-dik′u-lop-a-the)
A disease process involving the brain, spinal cord, and spinal roots. SYN: encephalomyeloradiculitis.

encephalomyocarditis (en-sef′a-lo-mi′o-kar-di′tis)
Associated encephalitis and myocarditis; often caused by a viral infection such as in poliomyelitis.

encephalon, pl .encephala (en-sef′a-lon, la) [TA]
That portion of the cerebrospinal axis contained within the cranium, composed of the prosencephalon, mesencephalon, and rhombencephalon. [G. enkephalos, brain, fr. en, in, + kephale, head]

encephalopathia (en-sef′a-lo-path′e-a)
SYN: encephalopathy.

encephalopathy (en-sef′a-lop′a-the)
Any disorder of the brain. SYN: cerebropathia, cerebropathy, encephalopathia, encephalosis. [encephalo- + G. pathos, suffering] bilirubin e. SYN: kernicterus. Binswanger e. SYN: Binswanger disease. bovine spongiform e. (BSE) a disease of cattle first reported in 1986 in Great Britain; characterized clinically by apprehensive behavior, hyperesthesia, and ataxia, and histologically by spongiform changes in the gray matter of the brain stem; caused by a prion, like spongiform encephalopathies of other animals ( e.g., scrapie) and human beings (Creutzfeldt-Jakob disease). See Creutzfeldt-Jakob disease. SYN: mad cow disease.In the middle 1990s, an unusual number of cases of Creutzfeldt-Jakob disease (CJD) were reported in persons under 30 years of age in Great Britain. These patients displayed typical clinical features but not the EEG changes characteristic of CJD, and autopsy specimens showed unusual amyloid plaques resembling those of kuru but not previously observed in CJD. These cases of variant Creutzfeldt-Jakob disease (V-CJD) were speculatively associated with an epizootic of bovine spongiform e. (mad cow disease) that killed more than 150,000 cattle in Britain between 1986 and 1996. Although the link between BSE and V-CJD cannot be confirmed on the basis of existing data, the mere possibility of such a link has already led to the development of recommendations to help reduce or prevent the occurrence of BSE in cattle worldwide. There is no evidence from U.S. surveillance activities or from scientific studies to indicate that BSE exists in the U.S. Since 1990, laboratory testing of brain specimens from cattle with CNS signs has shown no evidence of BSE. Since July 1989 the importation of cattle and cattle products from the U.K. has been banned by the U.S. Department of Agriculture. According to mortality statistics, the annual incidence of CJD in the U.S. remained stable at approximately 1 case per million persons between 1979 and 1994. WHO consultants have condemned the practice of feeding ruminant-derived meat-and-bone meal to cattle and urged the adoption of measures to ensure that no part of any animal that shows signs of a spongiform e. enters any human or animal food chain. Milk, dairy products, gelatin, and lard are considered safe. demyelinating e. extensive idiopathic loss of myelin sheaths in the brain, as occurs in leukodystrophy. hepatic e. SYN: portal-systemic e.. HIV e. SYN: AIDS dementia complex. hypernatremic e. subarachnoid and subdural effusions in infants with hypernatremic dehydration. hypertensive e. a metabolic e. caused by diffuse cerebral edema; follows an abrupt elevation of blood pressure in a long-term hypertensive patient. hypoxic-hypercarbic e. SYN: hypoventilation coma. hypoxic ischemic e. permanent brain injury due to a lack of oxygen or adequate blood flow to the brain. lead e. a metabolic e., caused by the ingestion of lead compounds and seen particularly in early childhood; it is characterized pathologically by extensive cerebral edema, status spongiosus, neurocytolysis, and some reactive inflammation; clinical manifestations include convulsions, delirium, and hallucinations. SEE ALSO: lead poisoning. SYN: lead encephalitis, saturnine e.. metabolic e. coma or its precursors resulting from a diffuse abnormality of cerebral neuronal or glial cell metabolism. Primary metabolic e. is due to any of the degenerative cerebral disorders that culminate in coma; secondary metabolic e. results when brain metabolism is disturbed by extracerebral disorders causing intoxication, electrolyte imbalances, or nutritional deficiencies, e.g., hepatic or renal disease or exogenous poisons. necrotizing e. SYN: Leigh disease. palindromic e. a relatively mild form that tends to recur. pancreatic e. a metabolic e. associated with extensive pancreatic necrosis. portal-systemic e. an e. associated with cirrhosis of the liver, attributed to the passage of toxic nitrogenous substances from the portal to the systemic circulation; cerebral manifestations may include coma. SYN: hepatic e.. progressive subcortical e. SYN: progressive multifocal leukoencephalopathy. pulmonary e. SYN: hypoventilation coma. recurrent e. [MIM*130950] a progressive form of e. occurring in young members of the same family; characterized by headache, vertigo, truncal ataxia, drowsiness and stupor, speech impairments, choreic-athetoid movements, and sometimes convulsions; probably autosomal dominant inheritance. saturnine e. SYN: lead e.. severe postanoxic e. SYN: delayed coma after hypoxia. spongiform e. an e. characterized by vacuolation within nerve and glial cells. subacute spongiform e. a form of spongiform e. that is associated with a “slow virus,” which to date has not been adequately described, is transmissible, and has a rapidly progressive, fatal course; e.g., Creutzfeldt-Jakob disease, kuru, Gerstmann-Sträussler syndrome, scrapie. See prion. subcortical arteriosclerotic e. SYN: Binswanger disease. thyrotoxic e. a metabolic e. arising in severe cases of thyrotoxicosis. traumatic e. an e. resulting from structural brain injury. traumatic progressive e. chronic progressive brain damage resulting from multiple brain injuries, e.g., dementia pugilistica. Wernicke e. SYN: Wernicke syndrome. Wernicke-Korsakoff e. See Wernicke syndrome, Korsakoff syndrome.

encephalopyosis (en-sef′a-lo-pi-o′sis)
Archaic term for purulent inflammation of the brain. [encephalo- + G. pyosis, suppuration]

encephalorrhachidian (en-sef′a-lo-ra-kid′e-an)
SYN: cerebrospinal. [encephalo- + G. rhachis, spine]

encephaloschisis (en-sef-a-los′ki-sis)
Developmental failure of closure of the rostral part of the neural tube. [encephalo- + G. schisis, fissure]

encephalosclerosis (en-sef′a-lo-skler-o′sis)
A sclerosis, or hardening, of the brain. SEE ALSO: cerebrosclerosis. [encephalo- + G. sklerosis, hardening]

encephaloscope (en-sef′a-lo-skop)
Any instrument used to view the interior of a brain abscess or other cerebral cavity through an opening in the skull. [encephalo- + G. skopeo, to view]

encephaloscopy (en-sef-a-los′ko-pe)
Examination of the brain or the cavity of a cerebral abscess by direct inspection.

encephalosis
SYN: encephalopathy.

encephalospinal (en-sef′a-lo-spi′nal)
SYN: cerebrospinal.

encephalotome (en-sef′a-lo-tom)
An instrument for use in performing encephalotomy.

encephalotomy (en-sef-a-lot′o-me)
Dissection or incision of the brain. [encephalo- + G. tome, incision]

enchondral (en-kon′dral)
SYN: intracartilaginous.

enchondroma (en-kon-dro′ma)
A benign cartilaginous growth starting within the medullary cavity of a bone originally formed from cartilage; enchondromas may distend the cortex, especially of small bones, and may be solitary or multiple (endochondromatosis). [Mod. L. fr. G. en, in, + chondros, cartilage, + -oma, tumor]

enchondromatosis (en-kon′dro-ma-to′sis) [MIM*166000 *225795]
A rare disorder characterized by hamartomatous proliferation of cartilage in the metaphyses of several bones, most commonly of the hands and feet, causing distorted growth in length and pathological fractures; chondrosarcoma may develop. When e. is associated with hemangiomas in the cutaneous or visceral regions, the condition is called Maffucci syndrome. Most cases are sporadic but a few instances demonstrate autosomal dominant inheritance with reduced penetrance. SYN: asymmetric chondrodystrophy, dyschondroplasia, hereditary deforming chondrodystrophy (2) , Ollier disease.

enchondromatous (en-kon-dro′ma-tus)
Relating to or having the elements of enchondroma.

enclave (en-klav, ahn-klahv′)
An enclosure; a detached mass of tissue enclosed in tissue of another kind; seen especially in the case of isolated masses of gland tissue detached from the main gland. [Fr. fr. L. clavis, key]

encoding (en-kod′ing)
The first stage in the memory process, followed by storage and retrieval, involving processes associated with receiving or briefly registering stimuli through one or more of the senses and modifying that information; a decay process or loss of this information (a type of forgetting) occurs rapidly unless the next two stages, storage and retrieval, are activated.

encopresis (en-ko-pre′sis)
The repeated, generally involuntary passage of feces into inappropriate places ( e.g., clothing). [G. enkopros, full of manure]

encranial (en-kra′ne-al)
SYN: endocranial.

encranius (en-kra′ne-us)
In conjoined twins, a form of fetal inclusion in which the smaller parasite lies partly or wholly within the cranial cavity of the larger autosite. [G. en, in, + kranion, skull]

encu
Acronym for equivalent normal child unit, that amount of information from any source (linkage analysis, parental, and collateral phenotypes, biochemistry of the carrier state, etc.) that will have the same impact on the probability as one usual progeny does that a consultand is a carrier for an autosomal dominant trait; e.g., each normal child contributes one e.. Cf.:ensu.

encysted (en-sis′ted)
Encapsulated by a membranous bag. [G. kystis, bladder]

encystment (en-sist′ment)
The condition of being or becoming encysted.

end
An extremity, or the most remote point of an extremity. acromial e. of clavicle [TA] the flattened lateral e. of the clavicle that articulates with the acromion and is anchored to the coracoid process by the conoid and trapezoid ligaments. SYN: extremitas acromialis claviculae [TA] , acromial extremity of clavicle. distal e. the posterior extremity of a dental appliance. SYN: heel (3) [TA] . fixed e. [TA] for a given movement, the e. of a bone that is held stationary (as a consequence of attachment or muscular fixation) while the other e. of the bone (the mobile e.) moves in response to muscle activity or gravity. SYN: punctum fixa [TA] . mobile e. [TA] for a given movement, the e. of a bone that moves in response to muscle activity or gravity while the other e. of the bone (the fixed e.) is held stationary (as a consequence of attachment or muscular fixation). SYN: punctum mobile [TA] . sternal e. of clavicle [TA] the enlarged medial e. of the clavicle that articulates with the manubrium sterni. SYN: extremitas sternalis claviculae [TA] , sternal extremity of clavicle.

end-
See endo-.

endadelphos (end′a-del′fos)
Unequal conjoined twins in which the parasitic member is included in the body of the host. [end- + G. adelphos, brother]

Endamoeba (end′a-me′ba)
A genus of amebae parasitic in invertebrates; originally described from cockroaches. [endo- + G. amoibe, change]

endangiitis, endangeitis (end-an-je-i′tis)
Inflammation of the intima of a blood vessel. SYN: endoangiitis, endovasculitis. [endo- + G. angeion, vessel, + -itis, inflammation] e. obliterans inflammation of the intima of a vessel with resulting occlusion of its lumen.

endaortitis (end′a-or-ti′tis)
Inflammation of the intima of the aorta. SYN: endo-aortitis.

endarterectomy (end-ar-ter-ek′to-me)
Excision of atheromatous deposits along with the diseased endothelium and media or most of the media of an artery so as to leave a smooth lining, mostly consisting of adventitia. [endo- + artery + G. ektome, excision] carotid e. excision of occluding material, including intima and most of the media, from the carotid a. coronary e. excision of occluding material, including intima and most of the media, from the coronary artery.

endarteritis (end′ar-ter-i′tis)
Inflammation of the intima of an artery. SYN: endoarteritis. bacterial e. implantation and growth of bacteria with formation of vegetations on the arterial wall, such as may occur in a patent ductus arteriosus or arteriovenous fistula. e. deformans e. with atheromatous patches and calcareous deposits. e. obliterans, obliterating e. an extreme degree of e. proliferans closing the lumen of the artery. SYN: arteritis obliterans, obliterating arteritis. e. proliferans, proliferating e. chronic e. accompanied by a marked increase of fibrous tissue in the intima.

endaural (end-aw′ral)
Within the ear. [endo- + L. auris, ear]

endbrain
SYN: telencephalon.

end-brush (end′brush)
SYN: telodendron.

end-bulb
See end bulb.

end-diastolic (end′di-a-stol′ik)
1. Occurring at the end of diastole, immediately before the next systole, as in e. pressure. 2. Interrupting the final moments of diastole, barely premature, as in e. extrasystole.

endectocide
A drug effective against both endoparasites and ectoparasites, e.g., the macrolide antibiotic avermectin. SEE ALSO: ivermectin. [endoparasite + ectoparasite + -cide]

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