Добавил:

Sekretar kiopkiopkiop18@yandex.ru t.me/Prokururor I Вовсе не секретарь, но почту проверяю Опубликованный материал нарушает ваши авторские права? Сообщите нам.

Вуз:

Ростовский Государственный Медицинский Университет

Предмет:

Медицина общая

Файл:

Книга_186_библиотеки_им_акад_М_И_Перельмана

.pdf

Скачиваний:

Добавлен:

30.08.2026

Размер:

51 Мб

Скачать

☆

<<< < Предыдущая 9 10 11 12 13 14 15 16 17 18 19 2021 / 5021 22 23 24 25 26 27 28 29 30 31 32 33 > Следующая >>>

Lateralmedullarysyndrome(orWallenbergsyndrome),causedbyposteriorinferiorcerebellarartery (PICA)occlusion,classicallypresentswithvertigoaswellasahostofotherneighborhoodsignsand symptomsincludinghoarseness,dysphagia,nystagmus,Hornersyndrome,andhemisensoryloss(see page68).Whitearrowispointingtothelateralmedullaryinfarct.(CourtesyofCarlosTorres,MD.)

Box5.5

Whenneurologistshearapatientdescribetheirsymptomsas“acuteonset,”thefirstthing thatcomestomindisvascularpathology:ischemicorhemorrhagicstroke.Thisisan absolutelyappropriateresponse,butitiscertainlyworthpointingoutthat“acute-onset” vertigoshouldnotswayyouinexorablytowardacentraletiology.Bothperipheralandcentral vertigocan(andoftendo)presentacutely.

Box5.6DisembarkmentSyndrome(maldedebarquement)

Haveyoueverhadatransientsenseofimbalance—likeyouarestillfloatingup-and-downon thewaves—whenyoustepoffaboatontodryland?Thatunpleasantsenseofdisequilibrium mayoccurwithyourfirststeponshoreorseveralminutestohoursafterabandoningthehigh seas.Thissensationisnormalifitisbrief(lastingminutestohours),butifitbecomes persistentitisreferredtoasdisembarkmentsyndrome.Formaldiagnosticcriteriainclude

https://t.me/med1917

persistent,non-spinningvertigo(patientsoftendescribeasensationofswayingorrocking) lastingmorethan48hours,withonsetlessthan48hoursfromexposure.Re-exposureto passivemotionshouldtransientlyrelievesymptoms.Disembarkmentsyndromecanlast weekstoyears.Disablingfatigueandcognitivedifficultiescanalsooccur.Theetiologyis unknown,andtreatmentisdifficult.Scopolamine,meclizine,anticonvulsants,anddiuretics havenotbeenfoundtobereliablyeffective.Somepatientsmayexperiencesomebenefit fromabenzodiazepineorselectiveserotoninreuptakeinhibitor.Vestibularrehabilitationhas notbeenfoundtobeconsistentlybeneficial.

ABriefWordonSyncope

Syncopeisthetransientlossofconsciousnessduetoinadequatebloodflowtothebrain.Patientspresent withalossofmuscletoneandsubsequentcollapse,followedbyarelativelyquickreturntobaseline. Precedinglightheadednessiscommon.Brieftonicormyoclonicmovementscanalsooccur;thisisknown asconvulsivesyncopeandisacommonandbenignsyncopalvariant(seepage165).Presyncopeshould beevaluatedthesameastruesyncope,asthecauses—bothbenignandserious—arethesame.

Thereare,forourpurposes,threemajortypesofsyncope:

1.  Reflex syncope is very common. It is caused by a sudden drop in blood pressure or heart rate due to alterations in autonomic activation, either increasedparasympathetic or decreased sympathetic tone. Vasovagal syncope isthe most commontype of reflex syncopeandclassicallypresentswithprodromallightheadedness,diaphoresis,pallor,palpitations,nausea,and/orblurringordarkeningof visionpriortothelossofconsciousness.Ifyoususpectvasovagalsyncopebut,forwhateverreason,arenotcertain,tilttabletestingcan behelpfultoconfirmthediagnosis.Situationalsyncopeisanothertypeofreflex syncopeand referstosyncopeduetoanidentifiable triggersuchasurination(referredtoasmicturitionsyncope)orcoughing.

2.  Syncope due to cardiopulmonary dise ase . Since this isa book about neurology,we won’t expoundonthis topic. Causes include arrhythmias and structural cardiopulmonary diseases, such as aortic stenosis or hypertrophic cardiomyopathy with significant left ventricular outflow obstruction. From a neurologic perspective, it is important to have a low threshold to refer to cardiology when patientspresentwithotherwiseunexplainedsyncope.Concurrentneurologicandcardiacevaluationsareoftenideal.

3. OrthostaticSyncope.Orthostatichypotensionisdefinedasadecreaseinsystolicbloodpressureofatleast20mmHgoradecrease indiastolicbloodpressureofatleast10mmHgwithin3minutesofstanding.Therearethreemaincauses:

Volum edeple tion.Signif icantvolum ede pletioncanbe duetovom iting,bleeding,orj ustdehy dration,am ongm a ny otherpotentialc auses.

Medic ations.Thislistisalongonea ndincludesm edic ationsthatcause vasodilation,volume depletion,anda utonomicdy sr egulation.

Autonomicfailure.Autonom icfa ilurec an bedue toneur odege nera tivedisea ses( sucha sPa rkinsondise ase or Multiple Sy stem Atrophy ;se eChapte r13) ora utonomic neur opathy (c ause dm ostoftenby  diabete s,butdon’tforget toconsiderthem a ny otherpote ntialetiologiesincludingamy loidosis,connec tivetissuediseases,vitam indef iciencie s,andva riousinfec tions;seeChapter11) .

Areyouwonderingwhytransientischemicattacks(TIAs)arenotonthislistofcausesofsyncope?It’s acommonmisperceptionthatTIAsfrequentlypresentwithsyncope.VertebrobasilarTIAscancauseloss ofconsciousnessifthalamicstructuresareinvolved,butforthistooccurinisolation,withoutanyother neurologicdeficits,isveryrare.TheAmericanAcademyofNeurologyrecommendsagainstcarotidartery imagingforsyncopewithoutthepresenceofotherneurologicsymptoms;occlusivecarotidarterydisease resultsinischemiaofbraintissuesuppliedbytheophthalmic,anteriorandmiddlecerebralarteries,as wediscussedinChapter2,andcausesfocaldeficitssuchasweakness,numbness,andvisualfieldcuts, butitdoesnotcausesyncope.

https://t.me/med1917

YourPatient’sFollow-up:AlthoughKyle’svertigoisimproving,youorderanMRIbecause you’vefoundconvincingfocalityonhisexamination.Thenystagmusishardtosee—thisis notunusual!—butyouthinkit’sthere,andyouareconfidentabouttheleftupperextremity dysmetria.NowthatyouknowabouttheHINTStest,you’vealsonotedanegativehead impulsetestandpositivetestofskew,bothconcerningforacentraletiology.Hissymptoms areallbutresolvedbythetimetheMRIiscompleted,butthescanisnotableforasmall acuteinfarctintheleftcerebellum.Youadmithimforastrokeevaluationand,onreviewing histelemetrythefollowingmorning,noteabout30minutesofatrialfibrillation.He’ssoon dischargedonanticoagulationandisgratefulforyourhelp.

Younowknow:

1. Thatacutedizzinesscanmeaneitherlightheadednessorvertigo.Lightheadednessismostoftennotaprimarilyneurologiccomplaint;it is moreoftenthe resultofdehydrationor,lesscommonlybutimportantly,underlyingcardiacdisease.Vertigoisaneurologicsymptom andrequiresacarefulhistoryandexaminationtoappropriatelymanageandtreat.Disequilibriumisanothertypeofvertigo—chronic,as opposedtoacute—that’smostoftenseenintheelderly.

2. Vertigo doesnotalwaysmeanspinning!Vertigoisdefined as the false sensationofmovement,orthesensationofmovement when

nothingisactuallymoving.

3. BPPV, Meniere disease, and vestibular neuritis are common causes of peripheral vertigo. If the history is straightforward and the examinationconsistent,anMRI is notneeded.Butifyouare unsure,orifyourexaminationisconcerningfor central etiology,getan MRI.

4. Centralvertigoismostoftencausedbyischemicorhemorrhagicstrokewithinthebrainstemorcerebellum.Multiplesclerosislesionsin thesameregionscanalsopresentwithvertigo.Suspectcentralvertigowhen“neighborhood”signsorsymptomsarepresent.

5. Syncope can be divided into reflex syncope, syncope due to cardiopulmonary disease, and orthostatic syncope. TIAs rarely cause syncope.Iftheydo,itistheposteriorcirculation(i.e.,vertebrobasilarsystem)thatisresponsibleandnottheanteriorcirculation.Carotid dopplersarenotrecommendedforpatientswhopresentwithsimplesyncopewithoutotherassociatedneurologicfindings.

Menierediseasewaspreviouslybelievedtobetheresultofexcessendolymphwithinthesemicircularcanals,butthecurrentconsensusis thatso-calledendolymphatichydropsismorelikelyamarkerfordiseaseinsomepatientsratherthanthecause;itisn’tevidentinallpatients, andmanypatientswithhydropsdonothaveclinicalevidenceofMenieredisease.

Itisthoughtthatmigrainousvertigoisatypeofcentralvertigopredominantlybecauseevaluationforperipheralcauses(i.e.,earornerve dysfunction)comesupnegative.

https://t.me/med1917

6Seizures

Inthischapter,youwilllearn:

1. Howtoclassifyanddistinguishamongdifferenttypesofseizures

2. Howtomanageafirst-timeseizureinanurgentsetting

3. Howtosortthroughandmakesenseoftheantiepilepticmedications

4. Howtodefine,classify,andtreatstatusepilepticus

5. Howtodiagnoseandmanagepsychogenicnonepilepticseizures(PNES)

CASE6

https://t.me/med1917

YourPatient:Carlton,a58-year-oldaccountantwithnoknownmedicalhistory,isbrought

intotheemergencydepartment(ED)byemergencymedicalservices(EMS)afterhewas foundonthegroundinasupermarketparkinglot.EMStellsyouthatawitnessatthescene sawseveralminutesoffull-bodyshaking,butthishadresolvedbythetimeEMSarrived.The patient’svitalsarestableandhisfingerstickglucoseiswithinnormallimits.Heappears sleepy,butwhenheopenshiseyes,younoticethathe’slookingpreferentiallytotheleft. Youdon’tnoticeanyabnormalshakingmovements.Hewon’tfollowcommandsbutseemsto withdrawhisrightarmandleglessbrisklythanhislefttonoxiousstimuli.Whatisthefirst stepinyourmanagement?

Seizuresaresuddenburstsofabnormalelectricalactivityoccurringwithinthecerebralcortex.Because theycanhappeninanyareaofthecortex,seizurescancausealmostanyneurologicmanifestationyoucan imagine,fromdramaticmotoreventswithlossofconsciousnesstosubtlesensoryorbehavioral abnormalities.Sometimesyoucanevenfindelectricalactivityonanelectroencephalogram(EEG) indicativeofaseizurewithoutanyassociatedclinicalmanifestationsatall.Seizuresareamongthemost commonandtreatableconditionsinallofneurology.

Epilepsy

Noteveryonewhohasaseizurehasepilepsy.Asmanyas1in20peoplewillhaveasingleseizurein theirlifetime,butonlyapproximately1in50willbediagnosedwithepilepsy.Thediagnosisofepilepsy requires:

https://t.me/med1917

Atleasttwounprovokedseizuresoccurringmorethan24hoursapart

One unprovoked seizure, plus the probability of further seizures must be similar to the risk of recurrenceaftertwounprovokedseizures(atleast60%)—don’tworry,wewillexplainthisinjusta moment

Thediagnosisofaspecificepilepsysyndrome(seepage170)

ProvokedVersusUnprovokedSeizures

AccordingtotheInternationalLeagueAgainstEpilepsy(ILAE)guidelines,a“provoked”seizureisa seizurethatisdirectlycausedbyanacute,symptomatic1condition.Sepsis,hypo-orhyperglycemia,and alcoholwithdrawalarecommoncausesofprovokedseizures.Otherconditions—stroke,traumaticbrain injury,intracranialsurgery,andpostanoxicencephalopathy—areconsideredacute,symptomatic conditionsonlyiftheseizureoccurswithinthefirst7daysfollowingtheinsult.

An“unprovoked”seizureisaseizureofunknownetiologyoraseizurerelatedtoapreexistingbrain lesionorpreexistingdisorder(i.e.,a“remote,symptomatic”condition2).Suchlesions—anoldstroke, forinstance,orabraintumor—canactasseizure“niduses”inthattheycancreateirritablebraintissue thatispronetoseize.Butwhy,forexample,doesapatientwithastrokethatoccurredmanyyearsago seizeforthefirsttimetoday?Theanswerisoftenelusive;thus,intheabsenceofanacute,symptomatic condition,thatseizureisconsideredunprovoked.

WhatConditionsIncreasetheRiskofRecurrenceAfteraSingleSeizure?

Let’sgobacktothatseconddefinitionofepilepsyforamoment:oneunprovokedseizure,plusthe probabilityoffurtherseizuressimilartothegeneralrecurrenceriskaftertwounprovokedseizures.

Thechanceofseizurerecurrenceislowfollowingasingleseizurebutincreasessignificantlyaftera secondseizure.So,whatfactorsincreasethisriskafterjustasingleseizuresuchthattheriskishigh enoughtopotentiallywarrantthediagnosisofepilepsy?Thereareonlyahandfulofthings:

AnabnormalEEG.AnEEGthatis“irritable”or“epileptiform”showsabrainthatisnotactively seizingbuthasthepotentialtoseize.Itisthereforenotsurprisingthatspecific“irritable”featureson anEEG(the details of this are beyond thescope of this book)are associatedwith a significantly increasedriskoffurtherseizures.

https://t.me/med1917

AnabnormalEEGshowinghigh-amplitudegeneralizedfast4-to-6Hzandslowwavesinateenagerwith myoclonicandgeneralizedtonic-clonicseizuresuponawakening,characteristicofjuvenilemyoclonic

https://t.me/med1917

epilepsy(seepage173).(ReprintedfromWyllieE,CascinoGD,GidalBE,GoodkinHP.Wyllie’sTreatment ofEpilepsy.5thed.WoltersKluwer;2012.)

Remote,symptomaticseizures.Althoughanoldstrokeorknownbraintumordoesnot“count”asan acute, provokingfactor, theselesionscanrepresenta locus ofirritable braintissue. Patients with theselesionshaveanincreasedriskforfurtherseizures.

https://t.me/med1917

Achronicleftmiddlecerebralartery(MCA)distributioninfarctonCTthatcouldserveasthesourceof seizureactivity.(ReprintedfromWeinerWJ,GoetzCG,ShinRK,LewisSL.NeurologyfortheNon- Neurologist.6thed.WoltersKluwer;2010.)

https://t.me/med1917

<<< < Предыдущая 9 10 11 12 13 14 15 16 17 18 19 2021 / 5021 22 23 24 25 26 27 28 29 30 31 32 33 > Следующая >>>

Соседние файлы в папке Библиотека им академика М.И. Перельмана

#
29.08.202697 Мб0Книга_181_библиотеки_им_акад_М_И_Перельмана.pdf
#
29.08.202683 Мб0Книга_182_библиотеки_им_акад_М_И_Перельмана.pdf
#
29.08.202680 Мб0Книга_183_библиотеки_им_акад_М_И_Перельмана.pdf
#
30.08.202659 Мб0Книга_184_библиотеки_им_акад_М_И_Перельмана.pdf
#
30.08.202657 Мб0Книга_185_библиотеки_им_акад_М_И_Перельмана.pdf
#
30.08.202651 Мб0Книга_186_библиотеки_им_акад_М_И_Перельмана.pdf
#
30.08.202648 Мб0Книга_187_библиотеки_им_акад_М_И_Перельмана.pdf
#
30.08.202647 Мб0Книга_188_библиотеки_им_акад_М_И_Перельмана.pdf
#
30.08.202647 Мб0Книга_189_библиотеки_им_акад_М_И_Перельмана.pdf
#
30.08.202661 Мб0Книга_19_библиотеки_им_акад_М_И_Перельмана.pdf
#
31.08.202640 Мб0Книга_190_библиотеки_им_акад_М_И_Перельмана.pdf