VOLUME 31 • NUMBER 22 November1,2009 This article is the first of two parts. Anatomy Thetemporalbone,whichformsanimportantpartof thelateralskullbase,housesthehearingapparatusand allowsthepassageofcriticalstructuressuchastheinter- nalcarotidarteryandcranialnervesV,VI,VII,andVIII. Theduraandthesigmoidvenoussinusareincloseprox- imity.Theboneisvariablypneumatized,dependingon developmentandeustachiantube(ET)function.Theair cellsofthetemporalbone,includingallthemastoidaircells, communicatewitheachotherandultimatelydrainintothe middleear.TheETconnectsthemiddleeartothenasophar- ynx.Themiddleearcavityisthemostcommonsourceof infectioninthetemporalbone.Suchaninfectionhasthe potentialtoinvolveanyoftheanatomicstructuresdescribed and,ultimately,invadetheintracranialcavity. PartIofthisarticlediscussessomeoftheseinfections; PartIIwilladdressthemanagementofcerebrospinalfluid (CSF)leakfromtheearandencephalocelesinthisregion. ContributingFactors Severalfactorsplayaroleindeterminingtheaggres- sivenessofinfectionsofthetemporalboneand,especially, theirintracranialspread.Thesefactorsincludediabetesmel- litus,immunocompromise,malnutrition,smoking,andpre- viousradiationorchemotherapy.Multiplepreviousear surgeriesandchronicinfections,especiallyinveryyoung andveryoldpatients,aresignificantfactors.Somecon- genitalanomaliesandtraumaalsomayplayarole.The InfectionsoftheTemporalBoneWithSpecialEmphasis OntheManagementofTemporalEncephaloceles:PartI RajMurali,MD,ChristopherLinstrom,MD,DhruveJeevan,MD,and D.RyanOrmond,MD Learning Objectives: After participating in this activity, the neurosurgeon should be better able to: 1. Describe the anatomy of the temporal bone. 2. List the various types of temporal bone infection. 3. Discuss the management of intracranial complications associated with temporal bone infections. ABIWEEKLYPUBLICATIONFORCLINICALNEUROSURGICAL CONTINUINGMEDICALEDUCATION Category: Skull base KeyWords: Temporalboneanatomy,Earinfections,Tegmendefects, Cholesteatoma, Cerebrospinal fluid leaks,Temporal encephaloceles Dr.MuraliisProfessorandChairman,Dr.JeevanisResident,and Dr.OrmondisResident,DepartmentofNeurosurgery,Munger Pavilion,3rdFloor,NewYorkMedicalCollege,Valhalla,NY10595, E-mail:raj_murali@nymc.edu;andDr.LinstromisProfessorofOto- laryngology,NewYorkMedicalCollege,andChiefofNeurotology, NewYorkEyeandEarInfirmary,NewYork,NY. Unlessotherwisenotedbelow,eachfaculty’sspouse/lifepartner (ifany)hasnothingtodisclose. Theauthorshavedisclosedthattheyhavenosignificantrela- tionshipswithorfinancialinterestsinanycommercialorganiza- tionspertainingtothiseducationalactivity. AllstaffinapositiontocontrolthecontentofthisCMEactivityhavedis- closedthattheyhavenofinancialrelationshipswith,orfinancialinter- estsin,anycommercialcompaniespertainingtothiseducationalactivity. LippincottCMEInstitutehasidentifiedandresolvedallfacultyand staffconflictsofinterestregardingthiseducationalactivity. LippincottContinuingMedicalEducationInstituteisaccreditedbytheAccreditationCouncilforContinuingMedicalEducationto providecontinuingmedicaleducationforphysicians. LippincottContinuingMedicalEducationInstitutedesignatesthiseducationalactivityforamaximumof1.5 AMA PRA Category 1 Credits™. Physiciansshouldonlyclaimcreditcommensuratewiththeextentoftheirparticipationintheactivity.TheAmericanAssociationofNeurological Surgeonsatteststhatthiseducationalactivityhasbeenrecognizedforco-sponsored/endorsementfor1.5Category1CMEcreditsoftheAmerican AssociationofNeurologicalSurgeon’sContinuingEducationAwardinNeurosurgery. ThisactivityexpiresonOctober31,2010. CNE22.qxd:Layout 1 10/18/09 8:37 PM Page 1