老年痴呆症：阿尔茨海默病疾病

AndI'mBobDoughty.TodaywetellaboutAlzheimer'sdisease（阿尔茨海默病）.Onecenturyafteritsdiscovery,thediseaseisstilldestroyingpeople'sbrains.Thecauseremainsunknown.知识扩展：阿尔茨海默病疾病描述

是一组病因的原发性退行性脑变性疾病。多起病于老年期，潜隐起病，病程缓慢且不可逆，临床上以智能损害为主。病理改变主要为皮质弥漫性萎缩，沟回增宽，脑室扩大，神经元大量减少，并可见老年斑（SP），神经原纤维结（NFT）等病变，胆碱乙酰化酶及乙酰胆碱含量显著减少。起病在65岁以前者旧称老年前期痴呆，或早老性痴呆，多有同病家族史，病情发展较快，颞叶及顶叶病变较显著，常有失语和失用。

AUnitedStatesSenatecommitteemetlastmonthtodiscusstheissueofAlzheimer'sdisease.TheSenateSpecialCommitteeonAgingheardfromseveralspeakers,includingretiredSupremeCourtJusticeSandraDayO'Connor.SheurgedCongresstosupportanaggressivecampaignagainstthedisease.

MizO'ConnorwasthefirstwomantoserveonAmerica'shighestcourt.Butsheleftthecourtintwothousandsix.HerhusbandJohnsuffersfromAlzheimer's.Sheneededtimetomovehimtoanassistedcarecenter.

AboutfivehundredthousandpeopleintheUnitedStatesalonehavethisheartbreakingdisease.Millionsmoreareexpectedtohaveitinyearstocome.

DoctorsdescribeAlzheimer'sasaslowlyincreasingbraindisorder.Itaffectsmemoryandpersonality--thosequalitiesthatmakeapersonanindividual.Thereisnoknowncure.Victimsslowlylosetheirabilitiestodealwitheverydaylife.Atfirst,theyforgetsimplethings,likewheretheyputsomethingoraperson'sname.

Astimepasses,theyforgetmoreandmore.Theyforgetthenamesoftheirhusbands,wivesorchildren.Thentheyforgetwhotheyare.Finally,theyremembernothing.Itisasiftheirbraindiesbeforetheotherpartsofthebody.VictimsofAlzheimer'sdodiefromthedisease,butitmaytakemanyyears.

Alzheimer'sdiseaseisthemostcommondisabilityormentalsicknesscalleddementia.Dementiaisthelossofthinkingabilitythatissevereenoughtointerferewithdailyactivities.Itisnotadiseaseitself.Instead,dementiaisagroupofsignsofsomeconditionsanddiseases.

Somekindsofdementiacanbecuredorcorrected.Thisisespeciallytrueiftheyresultfromdrugs,infection,sightorhearingproblems,headinjury,andheartorlungproblems.Otherkindsofdementiacanbecorrectedbychanginglevelsofhormonesorvitaminsinthebody.However,braincellsofAlzheimer'svictimsdieandarenotreplaced.

Victimscanbecomeangryandviolentastheabilitytothinkandrememberdecreases.Oftentheyshoutandmovewithnopurposeorgoal.Mediareportsoftentellaboutolderadultsfoundwalkinginplacesfarfromtheirhomes.Theydonotknowwheretheyareorwheretheycamefrom.Generally,thesepeoplearesufferingfromAlzheimer'sdisease.

Alzheimer'sgenerallydevelopsdifferentlyineachperson.Yetsomeearlysignsofthediseasearecommon.Often,thevictimsmaynotrecognizechangesinthemselves.Othersseethechangesandstruggletohidethem.

Probablythemostcommonearlysignisshort-termmemoryloss.Thevictimcannotremembersomethingthathappenedyesterday,forexample.Also,victimsofthediseasehaveincreasingdifficultylearningandstoringnewinformation.Slowly,thinkingbecomesmuchmoredifficult.Thevictimscannotunderstandajoke,orcannotcookameal,orperformsimplework.

AnothersignofAlzheimer'sdiseaseisdifficultysolvingsimpleproblems.Alzheimer'spatientsmightnotknowwhattodoiffoodonastoveisburning.Also,peoplehavetroublefollowingdirectionsorfindingtheirwaytonearbyplaces.

Anothersignisstrugglingtofindtherightwordstoexpressthoughtsorunderstandwhatisbeingdiscussed.Finally,peoplewithAlzheimer'sseemtochange.Quietpeoplemaybecomenoisyandaggressive.Theymayeasilybecomeangryandlosetheirabilitytotrustothers.

Alzheimer'sdiseasenormallyaffectspeoplemorethansixty-fiveyearsold.Butrarecaseshavebeendiscoveredinpeopleyoungerthanfifty.

Alzheimer'sisidentifiedinonlyabouttwopercentofpeoplewhoaresixty-five.Buttheriskincreasestoabouttwentypercentbyageeighty.Byninety,halfofallpeoplearefoundtohavesomesignsofthedisease.

Alzheimer'saffectspeopleofallracesequally.Yetwomenaremorelikelytodevelopthediseasethanmen.Thisispartlybecausewomengenerallylivelongerthanmen.

Thereisnoone,simpletesttoshowifsomeonehasAlzheimer'sdisease.Socialworkersandmentalhealthexpertssometimestestformemoryandjudgment.Patientsmaybeaskedtoidentifysmellssuchassmoke,naturalgasorfruits.Somescientistssayaweakenedabilitytoidentifysmellsmaybeinvolved.TheybelieveitmightshowpossibledevelopmentofAlzheimer's.

MedicaldoctorswhosuspectapatienthasAlzheimer'smusttestthepersonformanyotherphysicalproblemsfirst.Alzheimer'sisconsideredifthetestsfailtoshowtheexistenceofotherproblems.TheonlywaytobesureapersonhasAlzheimer'sistoexaminethevictim'sbrainafterdeath.

PeoplewhocareforAlzheimer'spatientsmaybecomeextremelytiredphysicallyandemotionally.Familiesoftencangetadviceandemotionalsupportfromlocalgroups.TheAlzheimer'sDiseaseEducationandReferralCenterandTheAlzheimer'sAssociationprovideinformationandsupport.

Patientscannotfullyrecoverfromthedisease.Butmanycanbehelpedbymedicine.Thatisespeciallytrueifthediseaseisfoundearly.

America'sFoodandDrugAdministrationhasapprovedseveraldrugstotreatsignsofthedisease.Thedrugsareoftwokinds.Adoctormustorderthesemedicinesforpatients.

Mostarecalledcholinesteraseinhibitors.Cholinesteraseinhibitorsmayworkbyprotectingachemicalmessengerneededforbrainactivities.Theyaremeanttotreatmemory,thinking,language,judgmentandotherbrainactivity.Theyareusedformildtomoderatecasesofthedisease.

Thesecondkindofdrughasalongname.Itisrepresentedbythedrugmemantine.Thismedicineseemstoworkbygoverningtheactivityofachemicalinvolvedininformationprocessing,storageandmemory.IttreatspatientswithmoderatetosevereAlzheimer's.

BritishwriterIrisMurdochdiedofAlzheimer'sdisease.Shesaiditwasadarkandterribleplace.

Thetwothousandsevenfilm,"AwayfromHer"tellswhathappenstoonemarriagewhenapartnersuffersfromAlzheimer'sDisease.JulieChristiewasnominatedfortheAcademyAwardforBestActressforplayingthepatient.Listenasshedescribesthepainofhermentalcondition.

IthasbeenmorethanacenturysinceaGermandoctor,AloisAlzheimer,toldaboutadementiapatientwhosebrainwasstudiedafterdeath.Herbrainhadstickystructuresandnervecellsthatappearedtobemixedtogether.Laterstudiesshowedthesenervesaremadeofaproteincalledtau.Thetauproteinchangessothatitstickstogetheringroups.Thestickystructureswereshowntobeamyloidplaques.

ScientistsarestillnotsurewhatcausesAlzheimer'sdisease.Theleadingtheoryblamesamyloidplaques.

NotallscientistsaresurethatamyloidplaquescauseAlzheimer's.Somesaytheplaquescouldbeaneffectofthedisease,notthecause.ReportssaysomepeoplewhodieofAlzheimer'sdonothaveanyplaquesintheirbrains.Otherswhohavethestickystructuresshowednosignsofthedisease.

Otherpossibilitiesaresometimesnoted.Theseincludestudiesofenzymesthatactonproteinstoproducetheplaques,andusingantibodiesagainstamyloid.Yetamyloidandenzymesareimportantforhealth.Scientistsdonotwanttodestroythemcompletely.

OtherscientistsareworkingwithagenecalledapoE4.Researchersfoundinnineteenninety-threethatitspresenceincreasesthechanceofdevelopingAlzheimer'sdisease.

ManymorestudiesarebeingdonetofindthecauseandtreatmentsforAlzheimer's.Itisadiseasethatcontinuestoaffectmillionsofpeoplearoundtheworld.

ThisSCIENCEINTHENEWSprogramwaswrittenbyJerilynWatson.OurproducerwasBriannaBlake.ThisisBobDoughty.

AndthisisFaithLapidus.Readandlistentoourprogramsatwww.en8848.com.JoinusagainnextweekformorenewsaboutscienceinSpecialEnglishontheVoiceofAmerica.