Meningitis

UNIVERSIDAD TCNICA DE AMBATOFACULTAD DE CIENCIAS DE LA SALUDCARRERA DE MEDICINAMENINGITIS

ALEX ARMIJOS1IntroduccinDefinicin:

Lameningitises unaenfermedad, caracterizada por lainflamacinde lasmeninges(leptomeninges). La causa ms frecuente de este tipo de inflamacin esviral.

2Introduccin3Meninges CerebralesDuramadreResistente2 capas: Peristica y MenngeaDivide en compartimientosSenos VenososAracnoidesGranulaciones aracnoideasLCRPiamadreInternoPlexos coroideos

Duramadre= PaquimeningitisPiamadre + Aracnoides= LeptomeningesDivisores compartimentales: Falx cerebral, Tentorium, hoz cerebelo4DefinicionesMeningitis: inflamacin de las leptomeninges del SNC por distintas causas, siendo la ms frecuente de causa viral.Meningitis Bacteriana Aguda: Es aquella meningitis con LCR de aspecto purulento por aumento de PMN y agente causal bacteriano.Meningitis Asptica: Inflamacin menngea de causa no bacteriana.Meningitis Simptica: Proceso sptico vecino al SNC que inflama las leptomeninges.Meningismo: Irritacin menngea (no inflamatoria).Meningitis Asptica: Viral y TBC

Meningismo. Se llama as a un sndrome menngeo en el que el examen del lquido cefalorraqudeo y, eventualmente, la autopsia, demuestran que no se trata de un proceso inflamatorio, sino de una reaccin serosa, con hipertensin intracraneal.5Fisiopatologa

Respuesta inflamatoria es la importanteReplicacin agente causal en LCRCambios en LCR (pH, lactato, protenas, glucosa y conteo celular)TNF-alpha, IL-1, IL-6,IL-8, NO, PGE2, PAFDao Pares Craneales e HTECTrombosis y Vasoespasmo cerebral por dao endotelialHipotensin sistmica secundariaMuerte por Shock Sptico o Trombosis SNC

Meninges como barrera al SIMenor severidad si no atraviesa la barrera pialEdema cerebral HTECHTEC contribuye a hipoperfusin cerebral y anaerobiosis (hipoglucorraquia)

Cuandoel cuerpo trata decombatir la infeccin, el problemapuede empeorar,vasos sanguneos se vuelvenpermeables ypermiten que las clulasblancas de la sangre, los fluidosy otras partculasque combaten la infeccinalentrar enlas meningesy el cerebro. Este proceso, a su vez,provocainflamacin del cerebro yeventualmentepuede resultaren la disminucindel flujo sanguneoapartes del cerebro, el empeoramiento delos sntomas de lainfeccin.

HTEC: por edema vasognico, inflamacin tejido cerebral (citotoxico) y bloqueo de flujo de LCR (edema interticial)6EtiologasBacteriasVirusHongosParsitosOtros

7PatogeniaHematgena: bacteria llega a los plexos coroideos y al LCRVecindad: proceso sptico intracranealDirecta: TEC abierto, fractura en base de craneo, etc. (meningitis a repeticin)

Inoculacin Inicial: piel, nasofaringe, pulmn, gastrointestinal, genitourinario, Va hematgena es la ms frecuente (inicia desde nasofaringe) neumococo y meningococoVecindad: OMC, Sinusitis, congnitas, tromboflebitis seno cavernoso, etc.La trombosis sptica de seno cavernoso describe un proceso tromboflebtico de las venas intracraneales de etiologa infecciosa, en donde se pueden vincular como entidades etiolgicas las infecciones de origen facial, de origen en senos paranasales (sinusitis), menos frecuente de infecciones otolgicas, infecciones odontognicas, farngeas, y focos spticos distantes.

8EpidemiologaLa mortalidad previo al uso de ATB era de 25% en su totalidad y casi de un 100% para las MBALa mortalidad por meningitis bacteriana es mayor en los extremos de la vidaRelacin directa entre VIH y meningitisLa vacunacin efectiva ha reducido factores contribuyentes al desarrollo de meningitisLa meningitis asptica es ms frecuente en pocas estivales

9Etiologas: Bacterias Grupo Edad

Age 18-50 yearsS pneumoniaeN meningitidisH influenzaeAge older than 50 yearsS pneumoniaeN meningitidisL monocytogenesAerobic gram-negative bacilli

Immunocompromised stateS pneumoniaeN meningitidisL monocytogenesAerobic gram-negative bacilli10Factores de RiesgoEdadDiabetesInsuficiencia RenalInmunosupresinVIHHacinamientoEsplenectomaAlcoholismoCirrosis

Infecciones contiguasExposicin a meningitisDrogas EVEndocarditis BacterianaDVPDeformidades cranealesDefectos Durales

Edad: 60 aosVIH y esplenectoma: predispone a grmenes encapsuladosDVP: derivacin Ventriculo-Peritoneal

11Clasificacin TemporalAguda 7d (>4 semanas con parmetros inflamatorios en LCR y sin mucha clnica)12Meningitis BacterianaSignos menngeos y pleocitosis neutroflicaClnica en 12horas40% han sido tratados anteriormente por MBAMeningitis Neumoccica

Coco gram +Meningitis ms frecuenteAsociado a fractura basilar, NAC, sinusitis, EB o colonizacin farngea

Meningitis por Haemophilus Influenzae

Cocobacilo gram Normal en la biota del Tracto Respiratorio Superior

Meningitis Agalactica

Coco gram +Causa el 70% de las meningitis en RNInfecta el 5-40% de los canales de partoMeningitis Meningoccica

Diplococo gram Grupo C es el ms frecuente en ChileAsociado a infecciones viralesAntecedentes de CTC, infecciones virales, tabaco, hacinamiento Meningitis por Lysteria monocitgenes

Bacilo gram +Tan solo el 8% de los casos, pero 22% mortalidadCasos transmitidos por alimentos contaminados

Meningitis Stafiloccica

Coco gram +Antecedentes: Neurocirugas, TEC, Shunts LCR, EB

Meningitis por Bacilos Gram Negativos

Bacilos gram Especies: Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosay Salmonella.Causas: Neurociruga, vejez, inmunosupresin, bacteremia por gram negativos.Necesita de un tratamiento rpido en intensivo con antimicrobianos en menos de 30 minutos desde la presencia del paciente al hospital.

Tipos: Meningitis Tuberculosa

Aerobic gram-negative bacilli includeEscherichia coli, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa,and Salmonellaspecies.TTO Gram negativos: Cefalosporinas de Tercera o Cuarta Generacin por 21 das, Dexametasona no ha mejorado resultados

Cefalosporinas de 4 Cefepime o Cefpirome

13Meningitis ViralSon meningitis aspticas a las cuales se les determina algn agente viralEtiologa AgudaEnterovirusCoxsackievirusEchovirusVirus herpex simplexCMVVEBPoliovirusVIH14Meningitis AspticaUna de las meningitis ms frecuentesInicio agudo generalmenteSin agente causal identificable55-70% son de causa viral (90% son enterovirus)Pleomorfismo LinfocticoIn patients with aseptic meningitis (CSF pleocytosis and normal CSF glucose, negative bacteria on Gram stain), the most common microorganisms are enteroviruses, human herpesvirus-2 (HHV-2), lymphocytic choriomeningitis virus (LCM), HIV, and other viruses.

Other etiologies include drugs (NSAIDs, metronidazole, IV immunoglobulin) and, rarely, leptospirosis. Manage by repeating LP if necessary to rule out partially treated bacterial meningitis.

Aseptic meningitisIn contrast to patients with bacterial meningitis, patients with aseptic meningitis syndrome usually appear clinically nontoxic, with no vascular instability. In many cases, a cause for meningitis is not apparent after initial evaluation and is therefore classified as aseptic meningitis. These patients characteristically have an acute onset of meningeal symptoms, fever, and cerebrospinal pleocytosis that is usually prominently lymphocytic.

15Meningitis CrnicaClnica y pleocitosis por >4 semanas de duracinAgentes causales:BrucellaM. tuberculosisT. pallidumC. neoformansCandida albicansAmebas

16Clnica: AnamnesisPerfil TemporalFiebre y convulsionesExposicin a infectadosSntomas gripales u otrosATB previos?Cirugas cranealesConductas sexuales riesgosasPaperasMordidas de animalesConsumo de lcteos no pasteurizados

Meningitis Tuberculosa, fngica, carcinomatosa o sifiltica= >1 semanas comienzan con sntoma o desde un mes antes con sntomas (TBC)Si se expuso a pactes con meningitisSntomas gripales u otros como exantemas, pericarditis, miocarditis, conjuntivitis, pleurodinia, herpangina, enfermedad mano-pie-bocaConductas sexuales riesgosas: VIH y VHSMordidas de animales pueden inducir meningitis asptica por rabiaLacteos sin pasteurizar: Lysteria y brucellosis17

Clnica: Examen FsicoTriada Clsica (85%)Estado de conciencia alteradoSntomas MenngeosRigidez de Nuca KernigBrudzinskiPapiledemaAfeccin PC aisladosFocos extracranealesOtros Sntomas GeneralesTriada Clsica: Fever + Dolor de Cabeza + Rigidez de nuca Fiebre se encuentra en 95% casos!!!!!!!!!!!!!!!!!!!!!!!Inexistencia de triada clsica + alteracin de conciencia tienen un 99-100% de VPNPapiledema en un 30% de los pacientes con MeningitisAfeccin PC aislados 25% (todos los motores oculares y el Facial)Focos extracraneales como: sinusitis, otitis, infeccin urinaria, artritis ante meningococo, faringitisNios pueden presentar: abombamiento de fontanelas, irritabilidad paradjica, llanto agudo, hipotona, anormalidades congnitasOtros Sntomas Generales: nauseas, vmito, fotofobia, somnolencia, confusin, irritabilidad, delirio y coma

18Clnica: Signos Meningeos

Approximately half of affected adults show signs of meningeal irritation, such as nuchal and/or spinal rigidity and a positive Kernig and/or Brudzinski sign.[9]The Kernig sign is determined in a supine patient by flexing the hip to 90 while the knee is flexed at 90; an attempt to further extend the knee produces pain in the hamstrings and resistance to further extension. The Brudzinski sign is determined by passively flexing the neck while the patient is in a supine position with extremities extended; this maneuver produces flexion of the hips in patients with meningeal irritation.Resistance to passive flexion of the neck is also a sign. Exacerbation of existing headache by repeated horizontal movement of the head, at a rate of 2-3 times per second, may also suggest meningeal irritation.19Clnica: Examen Fsico 2Incremento de PA y BradicardiaRushFocalidadComplicaciones Respiratorias (25% - 7d)Clnica atenuadaComorbilidades?Inmunocomprometidos? Meningitis Atpicas

Rush: meningococoFocalidad: por isquemia cerebral debido a la inflamacin cerebralClnica atenuada (parcialmente tratada?)Pacientes con comorbilidades de mayor edad pueden presentar tan solo como signos fiebre + letargia y sin signos menngeos

20Clnica: Meningitis CrnicaSemanas de evolucin (TBC?)PrdromoFiebre variableMalestarCefaleaAfeccin PCPrdromo: fiebre variable + Afeccin PC (oculres + Facial)The median incubation period before the appearance of symptoms in chronic syphilitic meningitis is 21 days (range 3-90 d)Patients with HIV have an increased risk of accelerated progression

21ExmenesTAC cerebralPuncin LumbarMedicin PresinConteo celularBioqumicoEstudio GramFondo de OjoRx TraxPCR agenteGenerales: Hemograma, bioquimico, ELP, BUN, Crea, coagulacin, cultivo, etc.VDRL

Acute bacterial meningitis is a medical emergency, and delays in instituting effective antimicrobial therapy result in increased morbidity and mortality.The cornerstone in the diagnosis of meningitis is examination of the CSF. The diagnosis of bacterial meningitis is made by culture to isolate the bacteria in the CSF sample. Other laboratory tests, which may include other culture of blood specimens, are needed to complement the CSF culture. These bacterial cultures are used for identification of the offending bacteria and occasionally its serogroup, as well as for determination of the organisms susceptibility to antibiotics.A computed tomography (CT) scan of the brain may be performed prior to lumbar puncture in some patient groups with a higher risk of herniation. These groups include those made up of patients with the following risk factors:As many as 50% of patients with pneumococcal meningitis also have evidence of pneumonia on initial chest radiograph.This association occurs in fewer than 10% of patients with meningitis caused byH influenzaeorN meningitidisand in approximately 20% of patients with meningitis caused by other organisms.

22ExmenesVDRL Tincin y cultivo de BAAR Montaje en fresco y tincin con tinta china para hongos Ag criptococcicoCultivo de bacterias y hongos de difcil crecimiento ECA ADA (puede estar elevado en TBC, linfoma, Brucella) Serloga a Borrellia, Brucella, Toxoplasma, Coxiella PCR a Micobacterias, Borrellia, VHS, VEB, CMV, VVZ, Toxoplama Bandas oligoclonales de Ig Citologa Citometra de flujo

El aumento del nivel de ECA en el LCR se observa aproximadamente en un 50% de los pacientes con neurosarcoidosis (13,14). Su eficacia en el diagnstico de neurosarcoidosis es controvertido, ya que su especificidad es baja. El nivel de ECA tambin se eleva en tumores enceflicos y meningitis bacteriana.

23Examenes: Puncin Lumbar

El proceso, que efectuado por profesionales entrenados, no implica ms que una pequea molestia en el momento de la colocacin de la anestesia cutnea, consiste en la insercin de una aguja, con un mandril en su interior(aguja de puncin lumbar) hueca entre las vrtebras lumbares L3/L4 o L4/L5 (lugares escogidos debido a las facilidades anatmicas que posee la columna a este nivel y a que la mdula termina entre L1 y L2 en adultos, y en infantes entre L2 y L3) hasta llegar al canal raqudeo (espacio subdural). El LCR fluye pasivamente gracias a la presin del mismo y no debe ser aspirado bajo ningn concepto. La cantidad de lquido recogido deber ser la mnima indispensable y depender del tipo de anlisis a realizar y de la enfermedad que se est investigando.Previo al proceso se desinfecta la zona de puncin con tintura de yodo.Despus, el paciente deber permanecer en posicin spina (boca arriba) durante 4 a 6 horas y beber mucho lquido para facilitar la recuperacin y evitar la ocurrencia de una de las complicaciones ms frecuente que es la cefalea post-puncin.24Examenes: Puncin LumbarContraindicaciones:Absolutas:Lesin intracraneal con efecto masa.Compresiones medulares agudas que pueden ser agravadas con la puncin lumbar.Lesiones cutneas, infeccin local u seas de la regin lumbar.Relativas:Alteraciones de la coagulacin adquiridas o congnitas.Trombocitopenia.Malformaciones arterio-venosas de la mdula espinal.

25Exmenes: Estudio LCR

CSF glucose studyIn bacterial meningitis, the CSF glucose (reference range is 40-70 mg/dL) is less than 40 mg/dL in 60% of patients. Obtain a simultaneous blood glucose determination for comparison purposes. Some patients may have elevated blood glucose levels as a result of underlying diabetes mellitus, and the predictive value of the CSF and blood glucose ratio may not be accurate in these circumstances.The CSF glucose level is usually within the reference range in viral meningitis, but some cases of LCM, HSV, mumps, and polio may cause low CSF glucose levels.In tuberculous meningitis, a characteristic hypoglycorrhagia (glucose < 40 mg/dL) is present, and the protein level is usually elevated, especially if a CSF block is present.CSF protein studyThe CSF protein level (reference range is 20-50 mg/dL) is usually elevated in bacterial meningitis. In viral meningitis, these levels are also usually elevated, although they can be within the reference range.In syphilitic meningitis, abnormal CSF protein levels (elevated) and CSF glucose levels (decreased) may be observed in 10-70% of cases.CSF Gram stain and acid-fast bacilli stainCSF Gram stain permits rapid identification of the bacterial cause in 60-90% of patients with bacterial meningitis. The presence of bacteria is 100% specific, but the sensitivity for detection is variable. The likelihood of detection is higher in the presence of a higher bacterial concentration and diminishes with prior antibiotic use.The demonstration of the acid-fast bacilli (eg, with auramine-rhodamine stain, Ziehl-Neelsen stain, Kinyoun stain) in the CSF is difficult and usually requires a large volume of CSF.

The diagnosis of cryptococcal meningitis relies on the identification of the pathogen in the CSF. The CSF is characterized by a lymphocytic pleocytosis (10-200 lymphocytes), a reduced glucose level, and an elevated protein level.26Examenes: TubosTubos necesariosGlucorraquia y ProteinorraquiaConteo Celular DiferencialGram, Cultivo LCR y VDRLRepeticin Conteo Celular u OtroCriterios Seupaul (alta S)

ndice Glucosa LCR/Sangre 500/uLLactato LCR > 31,5327ComplicacionesDisfuncin PCParlisisHipertonaAtaxiaConvulsiones (30%)Retardo MentalParlisis FocalHidrocefaliaAtrofia CerebralVentriculitisEmpiema SubduralCerebritisAbscesosAnemia HemolticaMuerteVentriculitis es un proceso inflamatorio ventricular, el cual involucra a las cuatro cavidades denominadas ventrculos, comnmente de aparente inaccesibilidad a la administracin sistmica de antibiticos. Asociado frecuentemente a las aracnoiditis, meningitis, cerebritis, encefalitis o encefalomielitis bacteriana e Hidrocefalia Secundaria.

CerebritisInflammation often extends along the perivascular (Virchow-Robin) spaces into the underlying brain parenchyma. Commonly, cerebritis results from direct spread of infection, either from otorhinologic infection or meningitis (including retrograde septicthrombophlebitis) or from hematogenous spread from an extracranial focus of infection. Parenchymal involvement, with edema and mass effect, may be localized or diffuse. Cerebritis can evolve to frank abscess formation in the gray matterwhite matter junction.

Subdural effusionIn children with meningitis who are younger than 1 year, 20-50% of cases are complicated by sterile subdural effusions. Most cases are transient and small to moderate in size. Of these effusions, 2% are infected secondarily and become subdural empyemas. In the empyema, infection and necrosis of the arachnoid membrane permits formation of a subdural collection.Risk factors include young age, rapid onset of illness, low peripheral WBC count, and high CSF protein. Seizures occur more commonly during the acute course of the disease, although long-term sequelae of promptly treated subdural effusions are similar to those of uncomplicated meningitis.

Empiema: dependiendo de la duracin de la infeccin, el empiema puede ser lquido o estar organizado y multiloculado. Puede localizarse a nivel intracraneal o espinal, constituyendo la primera localizacin el 13-23% de todas las infecciones intracraneales que se presentan como LOE, y siendo la segunda localizacin bastante ms rara.

VentriculomegalyVentriculomegaly can occur early or late in the course of meningitis and is usually transient and mild to moderate in severity. As a result of the subarachnoid inflammatory exudate, CSF pathways may become obstructed, leading to hydrocephalus. Exudates in the foramina of Luschka and Magendie can cause noncommunicating hydrocephalus, whereas exudates that accumulate in the basilar cisterns or over the cerebral convexity can develop into communicating hydrocephalus.28TratamientoEstabilizacin del pacienteTerapia EspecficaMonitorizacin de signos vitales

La Penicilina, ciertas Cefalosporinas (3 y 4), los Carbapenem, Fluoroquinolonas y Rifampicina proveen altos niveles de ATB en LCR.Aumento de germen penicilin resistente en el mundo enteroImipenem, Cefazolina y penicilinas disminuyen umbral convulsivo

29Tratamiento: AntibiticoDexametazona 15 mins previo dosis ATB 0.4 mg/kg q12h IV for 2 dCeftriaxona 50 aosCeftazidima + Ampicilina Inmunodeprimido

Ceftriaxona 2gr c/12 horas ev.Ampicilina 50mg/kg c/6 horas ev.*Vancomicina 1gr c/12 horas ev.

Vancomicina ante sospecha de neumococo penicilin resistente

most common types of bacterial meningitis should reduce the risk of death to less than 15%avoid imipenem, as it is proconvulsantCTC: The present understanding of the pathogenesis of bacterial meningitis has led to multiple therapeutic trials that involve the means to attenuate the detrimental effects of the hosts defenses (eg, inflammatory response to the bacterial products and the products of neutrophil activation) while eradicating bacteria with antibiotics. The use of steroids has been shown to improve the overall outcome of patients with certain types of bacterial meninigitis, such asH influenzae,tuberculous, and pneumococcal meningitis.A meta-analysis of 10 years of clinical trials confirmed that dexamethasone decreases morbidity, especially incidence and severity of neurosensory hearing loss, forH influenzaemeningitis and suggested comparable benefit forS pneumoniaemeningitis in childhood. No adequate adult studies exist, although the pathophysiology is presumably similar. Meta-analysis suggests that limiting dexamethasone therapy to 2 days may be optimal. Studies conducted in Europe have continued to support the use of dexamethasone in developed (as opposed to developing) countries, perhaps related to the relative incidence of TB meningitis.The timing of dexamethasone administration is crucial. If used, it should be administered before or with the first dose of antibacterial therapy. This is to counteract the initial inflammatory burst consequent to antibiotic-mediated bacterial killing. A more intense inflammatory reaction has been documented following the massive bacterial killing induced by antibiotics.

Neumococo10-14dResto 7dLysteria14-21

30Tratamiento: ViralVHSAcyclovir (10 mg/kg IV q8h) ?

CMVGanciclovir (induction dose of 5 mg/kg IV q12h, maintenance dose of 5 mg/kg q24h)

VIHHAARTMost viral meningitides are benign and self-limited. Often, they require only supportive care and do not require specific therapy. In certain instances, specific antiviral therapy may be indicated, if available.Some experts do not advocate antiviral therapy unless associated encephalitis is present, because the condition is usually benign and self-limitedHIV meningitis that occurs during an acute seroconversion syndrome.31Tratamiento: Meningitis CrnicaTuberculosaAntituberculosos tradicionales a dosis normales (por 1 a 2 aos)Corticoides (etapa 2 a 3) por 6 semanas

Criptoccica y C. albicansAmphotericin B (0.7-1 mg/kg/d IV) for at least 2 weeks, with or without flucytosine (100 mg/kg PO) in 4 divided doses32Diagnsticos DiferencialesInfeccin por VHSTU CerebralHSAConvulsionesMeningitis no InfecciosaCarcinomatosis Meningea

Vasculitis SNCIctusEncefalitisAlteracin MentalEmpiema SubduralLeptospirosisAbsceso CerebralDelirium Tremens

33PronsticoNivel de conciencia alterado (secuelas)Convulsiones (mortalidad; secuelas)Edema cerebral e infarto cerebral (mal pronostico)MB con