Chapter14

智力遲鈍與兒童自閉癥

MentalRetardation

andChildhoodAutismOutlineMentalRetardationChildhoodAutismTeachingPlan

Knowtheetiology,symptoms,classificationandclinicalmanagementsofmentalretardation

Understandthesymptomsofchildhoodautism

MentalRetardation1st

OverviewDefinitionAperson’soverallintellectualfunctioningiswellbelowaverage,withanintelligencequotient(IQ)around70orless.Haveasignificantlyimpairedabilitytocopewithcommonlifedemandsandlacksomedailylivingskillsexpectedofpeopleintheiragegroupandculture,e.g.,learning,communication,self-care,independentliving,socialinteraction,play,work,andsafety.Theageofonsetisinchildhood,beforeage18.EpidemiologyPrevalence:20‰inUS,2.84‰inChina.Sex:amale-to-femaleratioofapproximately2:1.Socialclass:TheMildiscommoninthelow,theothersareequallycommonamongallsocialclasses(US).2ndEtiologyGeneticCausesFragileXsyndrome(脆性X綜合征)

Downsyndrome(先天愚型、21染色體三體綜合征)

Inbornerrorsofmetabolism(先天性代謝障礙)

Phenylketonuria(PKU)(苯丙酮尿癥)

Galactosemia

（半乳糖血癥）Homocystinuria

（高胱氨酸尿）Maplesyrupurinedisease（槭糖尿?。〣iotinidasedeficiency（生物素酰胺酶缺乏癥）GeneticCausesDownsyndromeExternalCausesProblemsduringawoman’spregnancyMalnutrition(營養(yǎng)不良)

Amother’suseofalcoholordrugsEnvironmentaltoxinsLead(鉛)

Mercury(汞)

ViralinfectionsRubella(風(fēng)疹)

Cytomegalovirus(巨細(xì)胞病毒)

UntreateddiseasesDiabetesmellitus.(糖尿病)

ExternalCausesFetalAlcoholSyndromeFetalalcoholsyndrome(FAS)isasetofbirthdefectscausedbyheavyconsumptionofalcoholduringpregnancy.Childrenwiththisconditiontypicallyhaveamisproportioned

(不對稱)

head,facialdeformities(畸形),mentalretardation,andbehavioralproblems.FASistheleadingknowncauseofmentalretardationintheWesternHemisphere.1993-2003MicrosoftCorporation.Allrightsreserved.ExternalCausesProblemsduringbirthPrematurebirth(早產(chǎn))

Verylowbirthweight(低體重兒)

Stressestothefetussuchasdeprivationofoxygen(缺氧)

ExternalCausesProblemsafterbirthInfectiousdiseasesEncephalitis(腦炎)

Meningitis(外傷)

BraindamageAccidentalblowstotheheadneardrowning(溺死)

Severechildabuse(虐待)

exposuretosuchtoxinsasleadandmercuryPovertyandlackofstimulationduringinfancyandearlychildhood3rdClinicalFindingsMildIQ:50~69Compriseabout85percentofpeoplewithretardation.Oftencannotbedistinguishedfromnormalchildrenuntiltheyattendschool.Althoughtheylearnmoreslowly,peoplewithmildretardationusuallycandevelopacademicskillsequivalenttothesixth-gradelevel.Asadults,theycanworkandliveinthecommunityifhelpedwhentheyexperienceunusualsocialoreconomicstress.Somemaymarryandhavechildren.ModerateIQ:35~49About10percentofpeoplewithmentalretardationaremoderatelyretarded.Theycanprogresstoaboutthesecond-gradelevelinacademicskills.Byadolescence,theyusuallyhavegoodself-careskills—suchaseating,dressing,andgoingtothebathroom—andcanperformsimpletasks.Asadults,mostcanworkatunskilledorsemiskilledjobswithsupervision.SevereIQ:20~34Affects3to4percentofmentallyretardedindividuals.Maylearntotalkduringchildhoodanddevelopbasicself-careskills.Inadulthoodtheycanperformsimpletaskswithclosesupervision.Oftenliveingrouphomesorwiththeirfamilies.ProfoundIQ:<20About1to2percentofretardedpeoplehaveprofoundmentalretardationandrequireconstantcare.Profoundlyretardedindividualscanunderstandsomelanguage,buttheyhavelittleabilitytotalk.Theyoftenhaveaneurologicalconditionthataccountsfortheirretardation.4thDiagnosisandDifferentialDiagnosis(A)DiagnosisTheageofonsetisbeforeage18.IQ<70.Thepatientshavevariousdegreesofdifficultiesinthesocialfunctions.(B)DifferentialDiagnosisChildhoodAutismADHDHellersyndromeChildhoodschizophrenia5thClinicalManagementandPreventionTreatmentandCare

EducationEmploymentOpportunitiesLivingArrangementsMedicationChildhoodAutismA.EpidemiologyandEtiologyEpidemiology

Relativelyrare,arateofabout5casesin10,000childrenMorecommoninmalesthaninfemales,witharatioof3:1or4:1GeneticStudiesTendstoruninfamilies.Theconcordancerateinmonozygotictwinshasbeenestimatedat36%to0indizygotictwins.A“fragileX(脆性X)”chromosomehasbeennotedinasmallnumberofautisticpatients.Likelylocationsforautism-relatedgeneswerefoundonchromosomes2,7,16and17.NeroanatomicalStudies

Thetotalbrainvolumewaslarger.Thegreatestaveragepercentageincreaseinsizeoccurredintheoccipital(枕葉),parietal(頂葉)andtemporal(顳葉)lobes.BiochemicalStudies

Highplasmaserotoninconcentration.Highconcentrationofhomovanillicacid(themajordopaminemetabolite)incerebrospinalfluid(CSF).OtherStudiesImmunologicalincompatibility(不相容)(I.e.,maternalantibodiesdirectedatthefetus)maycontributetoautisticdisorder.Ahigher-than-expectedincidenceofperinatal

(圍產(chǎn)期的)

complicationsseemstooccurininfantswhoarelaterdiagnosedwithautisticdisorder.B.ClinicalFindingsAn

OverviewTheonsetusuallyoccursinearlychildhood,andproblemsaretypicallynotedduringthe2ndor3rdyearoflife.Achronic,lifelongdisorderwithpoorprognosis.Threetypicalsymptoms:impairedsocialinteractions,impairedabilitytocommunicate,arestrictedrepertoireofactivitiesandinterests.Withinthefirst3–6monthsofthelife,maynotdevelopanormalpattern(模仿)

ofsmilingorrespondingtocuddling(擁抱).

Donotprogressthroughdevelopmentalmilestones(重要事件)

suchaslearningtosaywordsorspeaksentences.Seemaloof(冷淡),withdrawn(孤僻)anddetached(獨(dú)立),mayengageinself-stimulatingbehaviorsuchasrockingorheadbanginginsteadofrelatingwarmlytotheirparents.ProgressionoftheDisorderAloofness(冷淡)

/lackofinterestinparentsorothers,(inmildercases,thechildmaydisplayssomeinteraction,butlackswarmthandsensitivity).Lackofimaginationandimitation(模仿)skills,doesnotparticipateinpretend(假扮)playwithothers.Nodisplaysofloveandaffectionandnoresponsetosuchdisplaysfromothers.LackofdesiretocommunicatewithothersUsuallywillnotseekcomfortwhenhurt.ImpairedReciprocalSocialInteractions

-TypicalLanguagedevelopmentseverelydelayedormayneverdevelop.Ifdeveloped,speechisoftenecholalic

(模仿言語),rote(生搬硬套)and“robotic”sounding.Voicesoftenhigh-pitched(高音).Receptivelanguageoftenpoor(maylearnbetterwithvisualcues).Bodylanguagecommunicationsareusuallyabsent(eyecontact,facialexpressions,gestures(手勢)

).CommunicationImpairments–TypicalDesireforsameness,definitelyresistchange.Obsessiverituals(儀式),adherence(堅(jiān)持)toroutines.Mayhaveintenseattachmenttounusualobjects–pieceofstring.Oftenfocusonpartsofatoy(wheels,shiningsurfaces).Stereotypedmovements(handflapping(拍打),spinning(旋轉(zhuǎn)),toe(腳尖)walking,headbanging).BehavioralAbnormalities

–TypicalAbout75%ofthechildrenwithautisticdisorder

havementalretardation;about30%functionin

themildtomoderaterangeand45–50%are

severelytoprofoundmentallyretarded.

About25%ofthemhavenormalintelligence;

andsomemayhavespecifictalentsorabilities,

particularlyinareasofmusicormathematics.IntelligenceUnusualresponsestosensoryinput,bothpositive(敏感)

andnegative(遲鈍).Sle