CNS INFECTIONCNS INFECTION

Dr. Basu MDDr. Basu MD

CNS INFECTIONCNS INFECTION

Meningeal Infection: meningitisMeningeal Infection: meningitis

Brain parenchymal infection { encephalitis}Brain parenchymal infection { encephalitis}

How we will proceed ?How we will proceed ?Route of CNS infectionRoute of CNS infectionMeningitisMeningitis– Bacterial Bacterial – ViralViral– FungalFungalBrain parenchymal Infections.Brain parenchymal Infections.– Viral encephalitisViral encephalitis– Spongiform encephalopathySpongiform encephalopathy– AbscessAbscess– Rabies Rabies

How infection enter the CNS ?How infection enter the CNS ?

1.1. HAEMATOGENOUS SPREAD.HAEMATOGENOUS SPREAD.2.2. DIRECT IMPLANTATION DIRECT IMPLANTATION [ TRAUMA, [ TRAUMA,

NEURAL TUBE DEFECT].NEURAL TUBE DEFECT].3.3. LOCAL EXTENTION LOCAL EXTENTION [ [ MIDDLE EAR, MIDDLE EAR,

SINUS InfectionSINUS Infection]]4.4. VIA–VIA– PERIPHERAL NERVE : RABIESPERIPHERAL NERVE : RABIES

Meningitis Meningitis

LEPTOMENINGITIS [ Meningitis]LEPTOMENINGITIS [ Meningitis]Topics of individual diseasesTopics of individual diseases

1.1. EtiologyEtiology2.2. MorphologyMorphology

3.3. InvestigationInvestigation4.4. ClinicalClinical

LEPTOMENINGITIS [ Meningitis]LEPTOMENINGITIS [ Meningitis]Definition: Definition:

Inflammation of the LEPTOMENINGES AND Inflammation of the LEPTOMENINGES AND SUBARACHONOID SPACE (CSF).SUBARACHONOID SPACE (CSF).

Types:Types:1.1. ACUTE (PURULANT) MENINGITISACUTE (PURULANT) MENINGITIS2.2. ACUTE LYMPHOCYTIC ( VIRAL ) MENINGITISACUTE LYMPHOCYTIC ( VIRAL ) MENINGITIS3.3. Fungal Fungal 4.4. CHRONIC MENINGITISCHRONIC MENINGITIS

Lab diagnosis: CSFLab diagnosis: CSFInvestigationsInvestigations Pyogenic MeningitisPyogenic Meningitis Viral meningitisViral meningitis

Glucose Glucose Very lowVery low Normal Normal

Pressure Pressure increasedincreased Slightly increasedSlightly increased

Protein Protein HighHigh HighHigh

Cells Cells IncreasedIncreasedNeutrophilsNeutrophils

Moderately increasedModerately increasedLymphocytesLymphocytes

CultureCulture Often positiveOften positive NegativeNegative

ACUTE (PURULANT) MENINGITIS : ETIOLOGYACUTE (PURULANT) MENINGITIS : ETIOLOGY

1.1. NEONATS: NEONATS: Escherichia Coli, GROUP B Escherichia Coli, GROUP B STREPTOCOCI.STREPTOCOCI.

2.2. CHILDREN: > 6MONTHS = CHILDREN: > 6MONTHS = H. INFLUENZAE H. INFLUENZAE AND STREPTOCOCCUS PNEUMONIAEAND STREPTOCOCCUS PNEUMONIAE..

ACUTE (PURULANT) MENINGITIS : ETIOLOGYACUTE (PURULANT) MENINGITIS : ETIOLOGY

3.3. During Epidemics and most common in During Epidemics and most common in adults : adults : Neisseria meningitidis.Neisseria meningitidis.

4.4. Adult: S. pneumoniae, Listeria Adult: S. pneumoniae, Listeria monocytogenes.monocytogenes.

5.5. Following Surgery : Staphylococcus Following Surgery : Staphylococcus aureus.aureus.

Opaque meninges Opaque meninges due to exudatesdue to exudates

Neutrophil in Neutrophil in subarachonoid spacesubarachonoid space

Complications: sequelComplications: sequel

Edema can lead to herniation and death.Edema can lead to herniation and death.Resolution of infection may be followed by Resolution of infection may be followed by adhesive adhesive arachnoiditis: fibrosisarachnoiditis: fibrosis ( in ( in basal meningesbasal meninges): ): OObstructive bstructive hydrocephalushydrocephalus. . If cerebral meninges is involved: If cerebral meninges is involved: communicating communicating hydrocephalous occur.hydrocephalous occur.

CLINICAL SIGNSCLINICAL SIGNS

Clinical signs may include: Clinical signs may include: Headache, Headache, Neck stiffness (from irritation of spinal Neck stiffness (from irritation of spinal nerve roots), nerve roots), Fever, and clouded consciousness. Fever, and clouded consciousness.

TOPICTOPICViral EncephalitisViral Encephalitis

Viral Meningitis : Aseptic meningitisViral Meningitis : Aseptic meningitis

Meningoencephalitis : If Viral meningitis is Meningoencephalitis : If Viral meningitis is associated with parenchymal Infection.associated with parenchymal Infection.

Viral EncephalitisViral Encephalitis

CNS involvement may be localized or CNS involvement may be localized or Generalized.Generalized.

Clinical: Fever, head ache.Clinical: Fever, head ache.

Viruses that can cause encephalitisViruses that can cause encephalitis

Rabies virusRabies virusHerpes simplex I virus encephalitis: Herpes simplex I virus encephalitis: HIV encephalitisHIV encephalitis..Toxoplasmosis (infection)Toxoplasmosis (infection)

Eosinophilic Negri body, as seen here in a Purkinje Eosinophilic Negri body, as seen here in a Purkinje

cell in hippocampus.cell in hippocampus.

Rabies

Herpes simplex virus IHerpes simplex virus I

Produce hemorrhage and necrosisProduce hemorrhage and necrosisInvolve Involve temporal or frontal lobetemporal or frontal lobe

HIV INFECTION: SymptomsHIV INFECTION: Symptoms

Progressive DiseaseProgressive DiseaseAIDS-Dementia complexAIDS-Dementia complexVacuolar myelopathy of spinal cordVacuolar myelopathy of spinal cordMost common cause of Dementia In the Young Most common cause of Dementia In the Young adult (now-a-days) in the HIV endemic areas.adult (now-a-days) in the HIV endemic areas.

Micro: Multinucleated giant cells.Micro: Multinucleated giant cells.

Toxoplasma infectionToxoplasma infection

Can cause retinitis in new born. Can cause retinitis in new born.

Develop Develop calcificationcalcification in brain. in brain.

Can cause brain abscess.Can cause brain abscess.

Fungal meningitisFungal meningitis

Aspergillus: Vasculitis and hemorrhage.Aspergillus: Vasculitis and hemorrhage.

Cryptococcus: Involve Virchow robbins Cryptococcus: Involve Virchow robbins space---soap bubble lesion.space---soap bubble lesion.

Toxoplasmosis : ring lesionToxoplasmosis : ring lesionClassical for abscessClassical for abscess

Cryptococcus-soap Cryptococcus-soap bubble lesionbubble lesion

Chronic MeningitisChronic Meningitis

Caused by :Caused by :1.1. Mycobacterium TuberculosisMycobacterium Tuberculosis2.2. Cryptococcus NeoformansCryptococcus Neoformans3.3. Treponema pallidumTreponema pallidum4.4. Brucella.Brucella.

Mycobacterium TuberculosisMycobacterium Tuberculosis

Seen in AIDS with atypical mycobacterium Seen in AIDS with atypical mycobacterium Involve Involve basal surfacebasal surface of brain: basal of brain: basal meningitis.meningitis.

Meningeal SyphilisMeningeal Syphilis

May involve May involve spinal Meningesspinal Meninges: produce : produce thickening.thickening.Produce Produce meningeal fibrosismeningeal fibrosis and secondary and secondary Hydrocephalous.Hydrocephalous.

Brain AbscessBrain Abscess

Spread :Spread :A.A. HematogenousHematogenousB.B. ContiguousContiguousC.C. Direct : Face and nasal sinus, otitis Direct : Face and nasal sinus, otitis

media.media.D.D. Patient with Patient with Right to Left shuntRight to Left shunt are are

higher risk of Brain abscess.higher risk of Brain abscess.

Morphology of abscessMorphology of abscess

Localized collection of neutrophils.Localized collection of neutrophils.

Ring like shadow on CT

Clinical Features and ComplicationsClinical Features and Complications

FeverFeverIncreased Intracranial PressureIncreased Intracranial PressureFocal Neurological Deficit.Focal Neurological Deficit.

ComplicationsComplications1.1. Brain HerniationBrain Herniation2.2. Rupture of the abscess in the subarachnoid Rupture of the abscess in the subarachnoid

Space Space 3.3. Subdural EmpyemaSubdural Empyema

Thank you !!!Thank you !!!