医药临床护理Musculardiseasesppt课件

MusculardiseasesMyastheniagravisDefinition:Myastheniagravisiscausedbyadefectofneuromusculartransmissionduetoanantibody-mediatedattackuponnicotinicacetylcholinereceptors(AChR).ClinicalCharacter:FluctuatingweaknessImprovedbyinhibitorsofcholinesteraseEtiologyandPathogenesisRelatedtodestructiveeffectsofautoantibodiestoAChREvidence:1.Experimental immunization of animalswith purified AChR from an electric fish,induces high titers of antibody to thereceptor.2.HumanserumantibodiesthatreactwithhumanAChRwerefoundinMGpatients3.Electrophysiologic features of MG wereproducedbypassivetransferofhumanIgGtomice.4.Plasmapheresisreducedplasmalevelsofanti-AChR and ameliorated myasthenicsymptomsandsigns.Howtheautoimmunedisorderstartsisnotknown.InhumanMG,hyperplasiaofthethymusabout15%ofcasesisathymoma.AChRantibodiesaresynthesizedbyBcellofhyperplasticthymusgland.Whenhumanmyasthenicthymuswastransplantedintomice,theanimalproducedantibodiestoAChRthatboundtotheirownmotorend-plates.A.Primarilyinthethymus.1.70%ofthymusglandfromadultMGpatientsarenotinvoluted.2.Thethymusweighmorethannormal.3.The thymus glands show lymphoidhyperplasia.4.Immunocytochemical:germinalcenterscontainBcells,plasmacells,andTcells.Pathology5.10%of myasthenic thymus glandscontainthymomas.B.Loss of synaptic folds and widenedcleftsC.Somenerveterminalsaresmallerthannormal.D.On residual synaptic folds show Y-shapedantibody-likestructures,IgG.Clinicalfeatures1.Incidence:0.4/100,000.Prevalence:5/100,000.Beforeage40,Male:female3:12.Symptoms:Threeclinicalcharacteristics.1)Thefluctuatingnature:Theweaknessvaries in a single day;day to day;or overlongerperiods.(remissionsorexacerbations).Crisis:When an exacerbation involvesrespiratorymuscles2)Thedistributionofweakness:A.Ocularmusclesareaffectedfirstinabout40%ofthecases(Ptosisanddiplopia).B.Affected facial oropharyngeal muscles(dysarthria,dysphagia and limination offacialmovements).C.Limbandneckweakness.Crisis:occurin:oropharyngealrespiratorymuscleweakness.provokedby:respiratoryinfectionsurgicalproceduresemotionalstresssystemicillness3).Thethirdcharacteristicistheclinical response to cholinergicdrugs.Thisoccurssouniformlythatithasbecomepartofthedefinition.3.Signs:(1)The vital signs and general physicalexamination are normal limits,unless thepatientisincrisis.(2)Weakness of the facial and levatorpalpabraemusclesproducesacharacteristicexpressionlessfaceswithdroopingeyelids.(3).Completeophthalmoplegiainoneorbotheyes(diplopia).Thepupilisneverinvolved.(4).Weakness of oropharyngeal or limbmuscles,andrespiratorymuscle.(5).Sensationisnormalandthereflexesarepreserved.1.Classification:(1)Group1.About14%ofpatientshaveocularmyastheniaonly.(2)GroupIIA.Mildgeneralizedmyastheniawithocularsigns.(3)Group IIB.Moderately severe generalizedmyasthenia,with mild bulbar and ocularinvolvement.(4)Group III.Acute severe myasthenia,withbulbarandrespiratory complications.Tracheostomyisrequired.(5)GroupIV.Lateseveremyasthenia,usuallydevelopingfromothergroupswithin2years.1.Routineexaminationsofblood,urine,andCSFarenormal.2.EMG:90%patients have progressivedecrementintheamplitudeofmuscleactionpotentialsevokedbyrepetitivenervestimulationat3to5Hz.Laboratorytests3.AchRAntibodiestoarefoundin90%ofpatientsofallages.Thetiterdosenotmatchtheseverityofsymptoms.4.CTscansofthemediastinumdemonstrates thymomas,especially inthoseolderthan40.Diagnosis1.Characteristichistoryandphysicalexamination.2.Jollytest3.Edrophonium(Tension)tests.4.Neostigminetest:0.04mg/kg,IM,reachesitsmaximum activity in 1-2 hours.Theeffectisgoneat3-4hours.5.EMG.6.AntibotiestoAchRtest.7.CT scans of thymus.Hyperplasia orthymoma.Differentialdiagnosis:1.Botulism:presynapticblockerofacetylcholinereleasecausedbycontaminatefoodsprogressivemuscleweaknessBeginning:extraocularpharyngealmusclesTreatment:trivalentantitoxinguanidinehydrochloride2.Lambert-Eatonsyndrome(LEMS):Myasthenia-likesyndromeoccurswithcarcinomaGeneralizedmuscleweaknessThe EMG is helpful in differentiating thesyndromefromtruemyastheniagravis.Treatment with removal of the tumor andguanidinehydrochloride.Treatment1.Anticholinesterasetherapy:Anticholinesterase drug should be given assoonasthediagnosisismade.i.Pyridostigmine60mgqidii.Neostigminebromide15mgqidiii.Ifthepatientshavedifficultyeating,dosescanbetakenabout30minutesbeforeameal.2.Corticosteroidtherapy(1).High-dosecoticosteroidtherapy1).Prednisone,60-100mgdaily.Improvementbeginsatabout12days.2).Dexamethasone,20mgdailyIVfor10days.3).Prednisononmethel,480-1000mgdailyIVfor3-5days.(2).Low-dosecorticosteroidtherapy:prednisone25mg,qod,graduallyincreasingthedosageby12.5mgeveryweekuntilthetotal dosage reaches 100 mg on alternatedays.3.Immunotherapy(1).Azathioprine,50-100mg,twiceaday.(2).Cyclophophamide100mg,twiceaday.3.Thymectomy:About80%ofpatientswithoutthymomabecomeasymptomaticorgotocompleteremissionafterthymectomy.4.Plasmapheresis:Toremovetheharmfulantibody.6.Treatmentofcrisis(1).Myastheniccrisis:needassistedventilationabout10%ofmyasthenicpatientsoccur,occur in patients with dysarthria,dysphagia,respiratorymuscleweakness,respiratoryinfection,andmajorsurgerycausedbylessanticholinesterasedrugsdosage.(2).Cholinergiccrisis:overdosageofanticholineserasedrugscholinergicsideeffects,excessiveanticholinesterasetherapy.(3).Brittlecrisis:Chronic anticholinergic drugs damages thesynapse,somepatientsbecomerefractorytothemedication.Crisisisanemergency.The patients respiratory function must bemaintainedsameasrespiratoryfailuretreatmentCholinergicdrugdiscontinuedinafewdaysorweeks.The therapeutic goal is to maintain vitalfunctionsandtoavoidortreatinfection.3.DrugsofavoidedDrugsthathavemildneuromuscularblockingeffectsandsedatives,arecontraindicated.Quinine,Quinidine,Procainamide,Propranolol,Lidocaine,Aminoglycosideantibiotics,Polymyxin,Viomycin,Colistin,Morphine,Bubiurates,andothertranquilizers.8.Amongthetreatment,anticholinesterasegrugtherapyandplasmapheresisaresymptomatictreatmentsthymectomy,steroids,andotherimmunosuppressivedrugsmayalterthecourseofthedisease.Periodicparalysischaracterizedboutsoflimbweakness.someformshavebeenmappedtothegeneforthe apha subunit of the sodium channel ofmuscleregardas“channelopathies.”Thetwomaintypeswerefirstseparatedbythelevelofserumpotassium.HypokalemicperiodicParalysisThe potassium content decreases in aspontaneousattacktovaluesof3.0mEq/Lorlower.Attacksmaybeinduced:injectonofinsulin,orglucose,ingestionofamealhighincarbohydrates.Incidence:Male:female,3:1autosomedominantheredityThefirstattackusuallyoccursatpuberty,butitmayoccurastheageof4ordelayedtothesixthdecade.SymptomsandSigns:attackusuallybeginsafterrest.ItcommonlydevelopsduringthenightparalysisvariesfromslightweaknessofthelegtocompleteparalysisTheoropharyngealandrespiratorymusclesareusuallyspared.Theremayberetentionofurineandfecesduringasevereattack.Attackvariesfromafewhoursto24hours.Theintervalbetweenattacksmaybeoneyear,oroneormoreattacksmayoccurdaily.Weaknessisespeciallybepresentonthemorningaftertheingestionofahigh-carbohydratemealbeforeretiringonthepreviousnight.Intervalbetweenattacks,patientsarestrongandserumpotassiumnormal.In a mild attack,tendon reflexes and electricalreactionsarediminished.Insevereattacks,tendonandcutaneousreflexesare absent and muscles do not respond toelectricalstimulation.Cutaneoussensationisnotdisturbed.Fatalities are rare,but death may occur fromrespiratoryparalysis.Diagnosis:transientattacksofweakness.confirmed by finding low potassium,highsodiumcontentintheserumduringanattack,orbyinducinganattackwithIVglucose(100g)andregularinsulin(20units).Treatment1.Acute attacks,rapidly terminated byingestionof20to100mEqofpotassiumsalts.Thebasisoftherapyisoraladministrationofacetazolamide,250to1000mgdaily.Thisregimenpreventsattacksinabout90%2.spironolactonepromoteretentionpotassium.Patientswiththyrotoxicperiodicparalysisarespontaneousorinducedattacksduringtheperiodofhyperthyroidism.Glucoseandinsulinareusefulintheinterimbetweentreatmentofhyperthyroidismbydrugsorradioiodine,beforetheeuthyroidstatereturns.HyperkalemicPeriodicParalysisCharacterizedonsetbeforeage10attackstooccurinthedaytimeandtobeshorterandlesssevereMyotoniaisdemonstrablebyEMGMyotonic lid-lag is the sole clinicalevidenceofthetrait.The serum and urinary potassium contentmaybeincreasedduringanattack,thismaybeduetoleakageofpotassiumfrommuscle.The attacks tend to be precipitated byhunger,rest,andcoldandbyadministrationofpotassiumchoride.Attacksmaybeterminatedbyadministrationofcalciumgluconate,glucose,andinsulin.Acetazolamide,250 mg to 1000 mg daily,hasbeeneffectiveinreducingthenumberofattacksorinabolishingthemaltogether.ProgressiveMuscularDystrophiesDefinition:A muscular dystrophy has fiveessentialcharacteristics.1.defined by clinical,histologic,and EMGcriteria.No signs of denervation or sensory loss,unlessthereisaconcommitantandseparatedisease.2.symptoms include limb or cranial muscleweakness.(Theheartandvisceralmusclesmayalsobeinvolved.)3.Symptomsbecomeprogressivelyworse.4.Histologicchangesimplydegenerationandregeneration of muscle,but no abnormalstorageofmetabolicproductisevident.5.This disease is recognized as heritable,even if there are no other cases in theparticularfamily.Classification.Therearefourmaintypes:Duchennemusculardystrophy(DMD)Facioscapulohumeralmusculardystrophy(FSHD)limb-girdlemusculardystrophy(LGMD)myotonicmusculardystrophyEachtypediffersfromtheothersinageatonset,distributionofweakness,rateofprogression,presenceorabsenceofcalfhypertrophy,highserumlevelsofCK,andpatternofinheritance.LaboratoryDiagnosisEMGmusclebiopsyDNAanalysisSerumCKECGDuchenneMuscularDystrophyX-linkedrecessivetrait.Femalecarrythegenearecarriers.incidenceis1in3,500malebirths.nogeographic,ethnicvariation.onethirdarenewmutations;lifespanofDMDisshortened,about20-30y.prevalenceisless(1to18,000males).ClinicalFeatures1.Evident at birth if serum enzymes aremeasured.2.Thesymptomsdonotbeginuntilage3to5 years,but that may be a measure ininfants.3.Walkingdelayedandtheboysneverrunnormally;Soon toe-walking and waddinggait.4.Progresses,overt difficulty walking,climbingstairs,andrisingfromchairs.5.An exaggerated lordosis is assumed tobalance.6.Theboystendtofalleasily,andtheyhavedifficultyrisingfromtheground.(Gowerssign)7.Asthediseaseprogresses:thearmsandhandsareaffectedswallowing,ocularmovementsaresparedIliotibialcontractureslimithipflexionheelcordcontracturescausetoe-walking8.Atage9-12,theboynolongerwalksandenters a wheelchair;scoliosis may becomeserious;contributetodisability.9.Byaboutage20,respirationiscompromised and mechanical ventilation isneeded.10.heartissparedclinically,butECGisabnormal:increasedR-Samplitude,anddeep,narrowQwaves.congestivefailuremaysuperveneinafewcases.gastrointestinalsystemissparedbutacutegastricdilatationinafewcases.MentalretardationaffectaboutonethirdofboyswithDMD.BeckerMuscularDystrophy(BMD)resemblesDMDinessentialcharacteristics:X-linked,calf hypertrophy,weakness isgreatestproximally,andserumCKlevelsarehigh.EMGandmusclehistologyaresame.Thetwodifferenceareageatonset(usuallyafterage12)andrateofprogression(stillwalkingafterage20,oftenlater).Diagnosis1.The clinical diagnosis of DMD is evident fromclinicalfeatures.In sporadic,atypical cases,spinal muscularatrophy might be mistake for DMD fasciculationand EMG denervation,identify the neurogenicdisorder.2.SerumCKlevelofDMDandBMDareusuallyatleast20timesnormal3.Dystrophingeneandproteinanalysiscanmakethecorrectdiagnosis.TreatmentThere is no specific drug therapy for DMDandBMD.Prednisonetherapywasbetterthanplaceboincontrolledtrials.Bracingmaypreventscoliosisinwheelchair-boundpatients.Surgical correction of spinal and limbdeformitiestomaintainambulationaslongaspossible.Facioscapulohumeral(FSH)MuscularDystrophyautosomaldominantfashion.characteristicdistributionofweakness:thefaceisalwaysaffected.Progressionisslow;evenbeasymptomatic.Onsetinadolesence,occasionallydetectedinchildren.Serumenzymelevelsarenormal.FSHDgenemapsto4q35-qter.ClinicalManifestations1.Facialweakness,Patientshaveneverbeenabletowhistleorblowupaballoon.2.Scapularwingingisprominent.3.The shoulder girdle has a characteristicappearance.cannotraisethearmslaterallytoshoulderlevel.4.Weaknessinthelegsmayaffectproximalmuscles.Laboratorystudies:EMG and muscle biopsy show amyopathicpattern.Thehistologicchangesaremild.Serumenzymevaluesareusuallynormalortriviallyelevated.ECGisnormal.Diagnosis:Accordingtotheclinicalfeatures,autosomaldominantfashion,serumCKlevel,andEMG.Management:Treatmentissymptomatic.Limb-GirdleMuscularDystrophy(LGMD)LGMDisamyopathicsyndromesofproximallimbweaknessthatareusuallyslowlyprogressive.Clinicalmanifestations1.Onsetinadolescenceoradult,andinheritance:autosomaldominantorrecessive.2.The legs are usually affected first,withdifficultyclimbingstairsandrisingfromchairs.3.Awaddinggait.risingthearmsdifficult,andwingingofthescapula4.Kneejerkstendtolostbeforetheanklejerks.Cranial muscles are usually spared.Progressionisslow.5.EMGandmusclebiopsyshowmyopathicchanges.SerumCKmaybeelevatedbutlesssothaninDMD.Diagnosis:According to the clinical features andexclusiontoincludesyndromesthatdidnotmeetcriteriaforDMD,FSHD,ormyotoniccategorise.Management:Treatmentissymptomatic.同学们来学校和回家的路上要注意安全同学们来学校和回家的路上要注意安全