《垂体前叶功能减退》PPT课件

垂体前叶功能减退解放军总医院内分泌科窦京涛,垂体解剖,Functionsofthepituitarygland:Eachlobeofthepituitaryglandproducescertainhormones.anteriorlobe:growthhormoneprolactin-tostimulatemilkproductionaftergivingbirthACTH(adrenocorticotropichormone)-tostimulatetheadrenalglandsTSH(thyroid-stimulatinghormone)-tostimulatethethyroidglandFSH(follicle-stimulatinghormone)-tostimulatetheovariesandtestesLH(luteinizinghormone)-tostimulatetheovariesortestesintermediatelobe:melanocyte-stimulatinghormone-tocontrolskinpigmentationposteriorlobe:ADH(antidiuretichormone)-toincreaseabsorptionofwaterintothebloodbythekidneysoxytocin-tocontracttheuterusduringchildbirthandstimulatemilkproduction,HypopituitarismHypopituitarismisageneraltermthatreferstoanyunderfunctionofthepituitarygland.Thisisaclinicaldefinitionusedbyendocrinologistsandisinterpretedtomeanthatoneormorefunctionsofthepituitaryaredeficient.Thetermmayrefertobothanteriorandposteriorpituitaryglandfailure.CausesofhypopituitarismDeficientpituitaryglandfunctioncanresultfromdamagetoeitherthepituitaryortheareajustabovethepituitary,thehypothalamus.Thehypothalamuscontainsreleasingandinhibitoryhormoneswhichcontrolthepituitary.Sincethesehormonesarenecessaryfornormalpituitaryfunction,damagetothehypothalamuscanalsoresultindeficientpituitaryglandfunction.Injurytothepituitarycanoccurfromavarietyofinsults,includingdamagefromanenlargingpituitarytumor,irradiationtothepituitary,pituitaryapoplexy,traumaandabnormalironstorage(hemochromatosis).Withincreasingdamagethereisaprogressivedecreaseinfunction.Thereappearstobeapredictablelossofhormonalfunctionwithincreasingdamage.Theprogressionfrommostvulnerabletoleastvulnerableisusuallyasfollows:firstisgrowthhormone(GH),nextthegonadotropins(LHandFSHwhichcontrolsexual/reproductivefunction),followedbyTSH(whichcontrolthyroidhormonerelease)andfinallythelasttobelostistypicallyACTH(whichcontrolsadrenalfunction).SheehansSyndromeSheehanssyndromeisaconditionthatmayoccurinawomanwhohasasevereuterinehemorrhageduringchildbirth.Theresultingseverebloodlosscausestissuedeathinherpituitaryglandandleadstohypopituitarismfollowingthebirth.DeficiencyofACTHandcortisolDeficiencyofACTHresultingincortisoldeficiencyisthemostdangerousandlifethreateningofthehormonaldeficiencysyndromes.Withgradualonsetofdeficiencyoverdaysorweeks,symptomsareoftenvagueandmayincludeweightloss,fatigue,weakness,depression,apathy,nausea,vomiting,anorexiaandhyperpigmentation.Asthedeficiencybecomesmoreseriousorhasamorerapidonset,(Addisoniancrisis)symptomsmayincludeconfusion,stupor,psychosis,abnormalelectrolytes(lowserumsodium,elevatedserumpotassium),andvascularcollapse(lowbloodpressureandshock)whichcanbefatal.Treatmentconsistsofcortisoladministrationoranothersimilarsteroid(likeprednisone).Forpatientswithacuteadrenalinsufficiency(Addisoniancrisis),rapidintravenousadministrationofhighdosesteroidsisessentialtoreversethecrisis.,DeficiencyofTSHandthyroidhormoneDeficiencyofthyroidhormonecausesasyndromeconsistingofdecreasedenergy,increasedneedtosleep,intoleranceofcold(inabilitytostaywarm),dryskin,constipation,muscleachinganddecreasedmentalfunctions.Thisconstellationofsymptomsisveryuncomfortableandisoftenthesymptomcomplexthatdrivespatientswithpituitarydiseasetoseekmedicalattention.Replacementtherapyconsistsofadailypillcalledthyroxine(Synthroid,Levothyroxineetc).Thecorrectdoseisdeterminedthroughbloodtests.DeficiencyofLHandFSH(HypogonadotropicHypogonadism)Womendevelopovariansuppressionwithirregularperiodsorabsenceofperiods(amenorrhea),infertility,decreasedlibido,decreasedvaginalsecretions,breastatrophy,andosteoporosis.Bloodlevelsofestradiolarelow.EstrogenshouldbereplacedandcanbegivenorallyasPremarinorestrace,orcanbegivenasapatchappliedtwiceweekly.Womentakingestrogenalsoneedtotakeprogesteronereplacement(unlesstheyhaveundergoneahysterectomy).Annualpapsmearsandmammogramsaremandatory.Mendeveloptesticularsuppressionwithdecreasedlibido,impotence,decreasedejaculatevolume,lossofbodyandfacialhair,weakness,fatigueandoftenanemia.Ontesting,bloodlevelsoftestosteronearelowandshouldbereplaced.IntheUnitedStates,testosteronemaybegivenasabi-weeklyintramuscularinjection,apatchform,oragelpreparation.Inothercountries,oralpreparationsoftestosteroneareavailable.GrowthHormoneDeficiencyGrowthhormoneisnecessaryinchildrenforgrowth,butalsoappearsnecessaryinadultstomaintainnormalbodycomposition(muscleandbonemass).Itmayalsobehelpfulformaintaininganadequateenergylevel,optimalcardiovascularstatusandsomementalfunctions.SymptomsofGHdeficiencyinadultsincludefatigue,poorexerciseperformanceandsymptomsofsocialisolation.GHisonlyavailableininjectableformandmustbegiven6-7timesperweek.AntidiureticHormonedeficiencycausingdiabetesinsipidusThisproblemarisesfromdamagetothepituitarystalkortheposteriorpituitarygland.Itmayoccurtransientlyaftertranssphenoidalsurgerybutisrarelypermanent.Patientswithdiabetesinsipidushaveincreasedthirstandurination.Replacementofantidiuretichormoneresolvesthesesymptoms.Antidiuretichormone(ADH)iscurrentlyreplacedbyadministrationofDDAVP(alsocalledDesmopressin)asynthetictypeofADH.DDAVPcanbegivenbysubcutaneousinjection,intranasalspray,orbytablet,usuallyonceortwiceaday.,主要原因,一、原发、垂体缺血性坏死：产后大出血（Sheehan)综合征、糖尿病、颞动脉炎、子癫等、垂体区肿瘤：原发于鞍内的肿瘤，如嫌色细胞瘤、颅咽管瘤；鞍旁肿瘤：脑膜瘤、视神经胶质瘤。、垂体卒中：一般与垂体瘤有关、医源性鼻烟部或蝶鞍区放射治疗后、手术创伤毁坏、免疫性疾病、感染性疾病、海绵窦血栓形成及原发性空泡蝶鞍,主要原因,继发性、垂体柄破坏性外伤、肿瘤或动脉瘤压迫及手术创伤、下丘脑或其他中枢神经系统病变创伤、恶性肿瘤、类肉瘤、异位松果体瘤及神经性厌食等,机理,缺血破坏,临床表现,一、垂体前叶机能减退1、PRL和GH分泌不足：PRL和GH分泌不足是产后大出血最先出现的垂体激素分泌受损表现PRL产后无乳、乳房不胀GH血糖2、促性腺激素不足：产后闭经、性欲减退、阴毛脱落、乳房萎缩及内外生殖器萎缩和不育,临床表现,促甲状腺激素分泌不足:表情淡漠、反应迟钝、怕冷、健忘、面色苍白、眉毛头发稀少、心率慢、可有或无黏液性水肿促肾上腺皮质激素分泌不足：无力、食欲不振、不耐饥饿、体重减轻、心界缩小、心音低、血压低、抵抗力差,危象,危象前期：某些诱因作用精神、神志症状：严重软弱无力、精神萎靡、表情淡漠、嗜睡、消化系统症状：厌食、恶心、呕吐，进食或饮水既吐，合并中上腹痛，持续2-4周消瘦、脱水心血管系统：收缩压80-90mmHg，脉压差小，体位性低血压体温正常或高热高热伴恶心，呕吐，短时进入危象服镇静或安眠药可无上述表现,危象,出现严重低血糖、昏迷、休克1、低血糖及低血糖昏迷神志改变、嗜睡、朦胧或烦躁、呻吟，面部或四肢肌肉抽动，交感神经兴奋症状，既而昏迷2、感染诱发昏迷高热、厌食、呕吐、神志朦胧，血压下降3、其他原因引起昏迷镇静、安眠药物水中毒：呕吐、淡漠、嗜睡、癫痫发作低体温：冬季、黏液性水肿病人,危象,4、休克：与上述有重叠面色苍白、厌食、恶心、烦躁、反应迟钝、脉率快、冷汗血压下降为明显指标、末梢紫绀等原因：多原因肾上腺皮质功能低失水低血钠感染低血糖5、精神病样发作：发病快、无前期、多因劳累、未进食或停止治疗后烦躁不安、自言自语、幻听、幻视、喊叫、狂躁4小时昏迷,三、诱因感染、劳累、停止治疗、服用镇静剂感染：占70%呼吸道感染消化道感染泌尿道感染,实验室检查,1、垂体前叶激素测定基础水平症状体征及单次血不能判断时行LHRH,TRH,低血糖试验，以判断垂体功能危象时不能等结果，抽血待测2、血糖、电解质、肾功能血糖可低至1.12mmol/L(20mg/dl)50%有低血钠少数有低血钾50%以上BUN升高,诊断及鉴别诊断,重点：病史、症状、体征有生育史妇女如有昏迷、休克、精神样发作、低血糖考虑垂体前叶功能低下体检毛发稀少、皮肤色素淡支持诊断鉴别诊断胰岛细胞瘤：昏迷前无恶心、厌食肝病：有肝病史、肝功异常原发肾上腺皮质功能低减：有典型皮肤色素沉着,ReplacementtherapyHypopituitarismandpanhypopituitarismaretreatedbyreplacementofappropriatehormones.Sincemostoftheanteriorpituitaryhormonesareproteinsorglycoproteinsreleasedinpulsatilepatterns,whosefunctionsaretoinducesecretionofsmallermoleculehormones(thyroidhormonesandsteroids),itissimplerandlessexpensiveformostpurposestosimplyreplacethetargetglandhormones.Thereareafewexceptions,suchasfertilityinduction.GHisreplacedwithgrowthhormone.TSHisreplacedwiththyroxine.ACTHisusuallyreplacedwithhydrocortisonebutanyglucocorticoidmaybeused.LHandFSHaremostoftenreplacedbysupplyingtheappropriatesexsteroids(e.g.,testosteroneorestrogenandprogestin).VirtuallyallpeoplewhoneedTorE2replacementforhypopituitarismrarelyhavespontaneous,effectivespermatogenesisorfollicularmaturation.BothGnRHbysubcutaneouspumpandgonadotropins(Pergonal)bydailysubcutaneousinjectionshavebeenusedeffectivelytoinducefertility.Prolactinisnotusuallyreplaced,asinfantformulaisreadily