Episode14–HeadachePearlsandPitfalls PreparedbyDr.LucasChartier
Migraine
POUNDmnemonicfordiagnosisofmigraine:Pulsatilequality,4‐72hOurs,Unilateralpain,Nausea,andDisablingintensity–4outof5featurespresentgivesapositivelikelihoodratioof24forthisheadachetobeamigraine(inastudybasedoutofGPclinics);photophobiaandphonophobiaarealsooftenpresent
Retinalandvitreousdetachmentproduceflashesorfloatersthatareunilateral,whiteincolorandproducea“curtaindescendingonthevision”phenomenon,asopposedtothemigraine‐associatedbilateral,colouredandtunnel‐visionsymptoms
SSNOOPmnemonicforredflags:Systemicsigns(fever,weightloss),Secondaryriskfactors(immuno‐compromisedstatus,HIV),Neurologicalsigns(speechdeficit,cranialnerveabnormalities),Onset–abrupt,Olderage(>40yo),Progressionofsymptoms
Tomakethediagnosisofmigraine,thepatientreallyshouldhavehadpriorrepeatedandsimilarsymptomsthathavebeendiagnosedasamigrainebyaphysician,notsimplyself‐diagnosis
EvidencebasedtreatmentintheED:
Dopamineantagonistsuchasmetoclopraminde(Maxeran©)orprochlorperazine(Stemetil©)inamini‐baginfusionover15min(notasaninjection),alongsideananticholinergicsuchasbenzatropine(Benztropine©)ordiphenhydramine(Benadryl©)todecreasetheextra‐pyramidalsymptomofakathisia(i.e.restlessness)–NNTof5forthesetwoadjuncts
RememberthatthemereimprovementoftheheadachewiththerapydoesNOTexcludeseriouspathology
Steroids(eg,dexamethasone10‐15mgIVorPO)atdischargemaybeusefultopreventreboundheadachewithin72hrsbydecreasingtheinflammationofthebloodvesselsinthebrain
Atdischarge,naproxen500mgPOhasbeenshowntobeasusefulasthe‘triptan’classofdrugs,whichshouldonlybeprescribedinpeoplewhohavehadresponsetotheminthepastandwhodonothavehypertensionorcardiovasculardisease
Subarachnoidhemorrhage(SAH)
SUMmnemonicfordiagnosisofSAH:Suddenonset,Unlikepreviousheadaches,Maximalatonset
Alsoconsiderriskfactorsoffamilyhistoryofcerebralaneurysm,SAHorpolycystickidneydisease,orcollagenvasculardiseases,hypertension,andbingedrinking,smokingoruseofcocaine,aswellasanelicitedhistoryofarecentsimilarheadache(i.e.sentinelbleed),onsetduringexertionorpre‐syncopeorsyncopeassociatedwiththisheadache
MigraineitselfisnotariskfactorforSAH,butrememberthatmigraine‐sufferersmayhaveSAHaswell!
ECGchangesin50‐100%ofpatientsduetoneurogenicmyocardialstunningandcoronaryvasospasm:deep,wideprecordialT‐waveinversion,bradycardia,andprolongedQT–bewareofanticoagulatingthesepatientsontheassumptionofacutecoronarysyndrome
StudybyPerryetal.iofsignsofSAH:
ThefollowingarestronglyandreliablyassociatedwithSAH:age>40,neckstiffnessorpain,onsetofheadacheonexertion,vomiting,witnessedlossofconsciousness,andelevatedBP>160/100
Alsoconsiderthefollowingsigns:stroke‐likesymptoms,seizureor3rdcranialnervepalsyfrommasseffect,6thcranialnervepalsywithdiplopia,orsubhyloidhemorrhage(i.e.denseredonfundoscopy,alsocalledTersonsyndrome–patientwilleventuallyneedreferraltoophthalmology),andevenmeningismus
WorkupofSAH:
CTscanofthehead–sensitivityofatleast95%infirst12hrsafteronset,butdecreasesto85%thenextdayand50%afteroneweek
Lumbarpuncture(LP)isthereforestillstandardofcare,despite25%risksofpost‐LPheadache,andthesmallrisksofneurologicaldamageandinfection
DoNOTwaitto12hrsafteronset(whenxantochromiabecomesreliablypresent)toperformLPaspatientswiththediseasewouldthereforebeputatriskofasubsequentfatalbleed
AtrueSAH‐positivetapmayhideina‘traumatictap’,socallatapa‘negativetap’ifandonly<5RBCsintube#4–adecreaseinatleast25%inthenumberofRBCsbetweentubes1and4shouldNOTbeusedatall
OpeningpressuresshouldALWAYSbedoneanddocumented,becauseitmightbeelevatedinSAH(willneverbeelevatedintraumatictap),andmayhelpdiagnosealternateconditions,suchasidiopathicintracranialhypertensionorcerebralvenousthrombosis
Post‐LPheadachesclassicallyoccur3dayslater,areworsewhennotsupine,andarearesultofCSFleakfromthedura–theyareminimizedbyusingsmaller(i.e.25G–tip:usea16Gneedleasatrocartopenetratethesofttissues,theninsertthe25Gneedleinsidethis),atraumatic(non‐cutting)blunttipneedles;bedrest,caffeineandhydrationhaveallbeenshowntoNOTbeeffectiveatreducingpost‐LPheadaches,andthedefinitivetreatmentinvolvesanautologousbloodpatchinsertedbyananesthetist
IfapatientrefusesanLPorthephysicianfailstoobtainCSFfluid,considerdoingaCT‐angiogram–thiswillexcludeaneurysmsthatcouldleadtobadoutcomesintheshortterm,butmayalsoleadtofalsepositive:2‐6%ofthepopulationhascerebralaneurysms,butCT‐Acannotidentifywhetherthisparticularaneurysmistheculpritfortheheadache,orevenifithasahighlikelihoodofrupturinginthefuture
EDtreatmentofSAH:
Topreventre‐bleeding,treathypertensiononlyifthemeanarterialpressureispersistentlyover100‐110forafewhours,andconsiderinvolvingyourconsultantneurosurgeononthetargetandmethodtodothis–labetalol20mgIVbolusfollowedbyaninfusionmaybeappropriate
Topreventvasospasmandresultantcerebralinfarct,nimodipine(calcium‐channelblocker)60mgPO/NGq4‐6hrsneedstobestartedwithin24hrsofpresentation
Topreventseizures,whichwilloccurin5‐20%ofpatientswithSAH,considerstartinganti‐epileptics
Spontaneouscervicalarterydissection
Oftenpresentafteratrivialtraumasuchashyperextensionoftheneckasaresultofshaving,checkingone’sblindspotwhiledriving,chiropracticmanipulation,rollercoasterride,boxing,orevencoughingorvomiting,especiallyinthesettingofconnectivetissuedisease
Carotidarterydissectionpresentswithunilateralfacial,neckorheadpainwithapartialHorner’ssyndrome(myosisandptosis,butnotanhydrosis),and1/3rdofpatientswillhaveretinalorcerebralTIAwithinoneweek(neurologicalsymptomslagbehindbecauseittakestimetohaveathrombusformedandthrownfromthesiteofdissection)
Vertebralarterydissectionpresentswithposteriorneckorocciputpainandposteriorcirculationsymptoms–ataxia,vertigo,dysarthria,diplopiaanddysphagia
DiagnosisismadebyCT‐Aoftheheadandneck(carotidDopplermaybeusedifCT‐Anotavailable,butitisnotasgoodandthereforeaCT‐Aisstilleventuallynecessary)
Treatmentincludesantiplateletoranticoagulationtherapy,exceptinthepresenceoflargeinfarctwithmasseffect,hemorrhagictransformationofaninfarct,orintracranialextensionofthedissection,butconsultantsshouldweighinbeforetreatmentisinitiated
Cerebralvenousthrombosis(CVT)ii
Maypresentasthreedifferententities:headache(fromthunderclaptosubacute),stroke‐likesymptoms,orseizures
ClinicalfeaturesassociatedwithCVTareriskfactorsassociatedwiththromboembolicdisease,aswellaspapilledema,youngerpatients(<40yo),orbitalchemosisandproptosisincavernousCVT,dilatedscalpveinsandscalpedemainsagitalCVT,andCNSorENTinfectionssuchassinusitis
D‐dimersarenotreliableinthediagnosisofCVT,eveninlow‐riskpatients(ifyouareconsideringthediagnosis,youneedtofullyinvestigateitwithneuro‐imaging)
GiventhattheoptimaltestMR‐Visnotreadilyavailable,diagnosiscanbemadewithplainCTheadinonly30%ofcases(deltasign,hemorrhagicinfarctatgray‐whitejunction,orhyperdensecorticalveinorduralsinus–imageontheleft)soCT‐venogrammustbedoneaswellifplainCTisnegative(CT‐Vsigns:emptydeltasign–imageontheright)
IfLPisperformed,openingpressuremaybeelevated;treatmentincludesunfractionatedheparinorLMWH(despitetheriskofhemorrhagictransformation,anticoagulationhasbeenshowntoreducedeathanddependency)
CVTisonthesamespectrumasidiopathicintracranialhypertension(IIH),whichpresentsasrefractoryheadachewithblurryvisionandvisualfielddefectsinyoung,obesewomenonoralcontraceptivepills;signsincludepapilledemaandVERYhighopeningLPpressureinthefaceofnormalCTscan;itistreatedwithdiuretics,notanticoagulation
Extracranialcausesofheadache
COpoisoning(thinkinthesettingofmultiplepatientsorwood‐bruningstove),acuteglaucoma(photophobia–doaneyeexam!),temporalarteritis(systemicsigns,andassociatedwithpolymyalgiarheumatica,jawclaudicationblurryvisionorretinalischemia–checktheESR!),andhypertensiveencephalopathy(alteredmentalstatuswithpapilledemaandend‐organdamageinthesettingofseverehypertension)
10seriouscausesofheadache
• LesiononCTscan(blood,pusortumor):
o Blood‐Subarachnoidhemorrhage,subduralhemorrhage,orstroke–hemorrhagicornot
o Pus‐meningitisorencephalitis
o Tumor‐tumor–1ryor2ry,benignormalignant
• Otherdiagnosesinthehead:
o Cervicalarterydissection–carotidorvertebral
o Hypertensiveencephalopathy
o Pre‐eclampsia(oreclampsia)
o Cerebralvenousthrombosisoridiopathicintracranialhypertension
o Glaucoma
o Temporalarteritis
• Thinking‘outsidethebox’:
o Carbonmonoxide(CO)poisoning
iPerryJJ,StiellIG,SivilottiMLA,etal.Highriskclinicalcharacteristicsforsubarachnoidhaemorrhageinpatientswithacuteheadache:prospectivecohortstudy.BMJ2010;341:c5204
iiSaposnikG,BarinagarrementeriaF,BrownRD,etal.DiagnosisandManagementofCerebralVenousThrombosis:AStatementforHealthcareProfessionalsFromtheAmericanHeartAssociation/AmericanStrokeAssociation.Stroke2011;42;1158‐1192
