Encephalitis Brain Abscess

1. EncephalitisBrain Abscess Reşat Özaras, MD, Prof. Infection Dept.

2. A 37-year-old male • Headache, stupor, tendency to sleep, fever, unaware to recognise the time and the place...

4. Acute Encephalitis • The inflammation of the parenchyma of the brain especially that of the cerebral cortex

5. The inflammation of the CNS • Encephalitis… the parenchyma...mostly due to viral infections • Meningitis… the meninges... mostly due to bacterial infections

6. Fever Headache Mental changes Confusion Hallucinations Personality changes Diplopia Fatigue Tremors Rash Loss of consciousness Symptoms

7. Acute Encephalitis • Mostly due to viral inf. • Herpes simplex virus (HSV) (the most common etiology of acute sporadic encephalitis) • Arboviruses – arthropod-borne virus (outbreaks in summer time…mosquitos and ticks) • Varicella zoster virus (VZV) (immunosuppressed patients)

8. HSV-1 • The most common etiology of acute sporadic encephalitis • HSV-1 • acquired in childhood period, • re-activates after years

9. Primary infection; On the mucosa of oropharynx, mostly asymptomatic fever, pain, dysphagia 2-3 weeks Following primary infection, a latent infection in trigeminal ganglion HSV-1

10. Inferior and medial temporal lobe Orbito-frontal lobe Limbic structures HSV-1 Inflammation necrotizing lesions Hemorrhagic necrosis in herpes encephalitis especially when remains untreated.

11. HSV-1 Widespreadedemaandsubarachnoidhemorrhageareas in medialtemporalandorbitofrontalregions

12. HSV-1 • Fever • Unilateral or generalized headache • Mental changes • Focal seizures • Focal neurological deficits • Dysphasia • Hemiparesis

13. VZV • Primary infection… chickenpox • Latent infection thereafter • The commonest reactivation… herpes labialis • Chickenpox, herpes labialis and zona may be complicated with encephalitis

14. Epstein Barr Virus • Causes infectious mononucleosis • May cause encephalitis • Direct invasion of CNS or immune mechanisms • Cortex, brain stem, basal ganglia, temporal lobe

15. CMV • Encephalitis in both immunocompetent and immunosuppressed • Risk is higher • immunosuppressed, • organ transplanted • HIV-infected patients • Organ transplantation, highest risk… CMV (-) donor to CMV (+) recipient

16. HIV • In 10-50% of AIDS patients, HIV infection in CNS • Multinuclear giant cells in gray matter and central white matter are pathognomonic.

17. Rabies • Lyssavirus • Acute progresive fatal encephalitis. • Transmitted with infected saliva of the animal • Incubation period: 5 days-6 mo.(20-60 days) • III, IV and IXth canial nerve palsies • Prodromal period, neurological disease period, paralysis, coma, and death.

18. Mumps • The commonest complication; inflammation in CNS • A pleocytosis in CSF in half of the cases • In 5-30%: headache, vomiting, neck stiffnes

19. History PE Neck stiffness CBC Biochemistry Culture Imaging Serology CSF analysis Clinical Evaluation

20. Season Localisation Travel Occupational exposure Exposure to animals Immunization Immune status of the patient History

21. Lab • CBC • Renal and hepatic tests • Coagulation studies • Plain chest X-ray Nonspecific Maindiagnosticmethods • CSF analysis • Cranial imaging

22. Cranial Imaging MRI Less sensitive than MRI CT • Sensitive for early period HSV encephalitis • Edema in orbitofrontal and temporal regions

23. Herpes simplex encepalitis CT(A) and MRI (B-F) temporal lobe involvement

25. CSF Analysis • Cell count: 10-2000 cells/mm3 • Mostly <500 cell/mm3 • Lymphocyte predominance • Erythrocytes (in 80% of the cases) • Normal CSF findings in 10% • Glucose (mg/dl): normal or low • CSF glucose/serum glucose: normal (>0.6) or low • Protein (mg/dl): >50 • Gram staining: no microorganisms • Culture: none

26. Microbiology • HSV PCR: For the first 24-48 hours, detecting HSV DNA by PCR in CSF: • specific (100%) and • sensitive (75-98%)

27. Herpes simplex encephalitis; Neurons including Cowdry A type intranuclear inclusion bodies. Hematoxylen-Eosin, X400.

28. Treatment • If shock/hypotension exists, crystaloid infusion • If unconscious, provide airway/breathing • Seizure, lorazepam 0.1 mg/kg, IV

29. Treatment • For encephalitis, give acyclovir

30. Treatment • Acyclovir IV, 14 – 21 days • HSV encephalitis • VZV encephalitis

31. Some keys • Atypical lymphocytes on peripheral smear… IMN • High amylase … Mumps

32. Complications Acute period Chronic period Chronic fatigue Depression Personality changes Gait disorders Memory disorders Speech disorders Visual problems Mental retardation Hemiplegia Seizure • Seizure • Inappropriate ADH synd. • Intracranial pressure inc. • Resp. arrest • Coma • Death

33. Prognosis • The virulence of the virus • Patient’s; • previous health status • immune status (chemotherapy, transplantation, AIDS) • age(<1, and >55 years) • any neurological symptoms

34. Prognosis • Being in coma on prsentation: severe inflammation in the brain, poor prognosis • Treated • Mortality… 20% • Morbidity… 40% • Untreated • Mortality … 50-75% • Morbidity… 100%

35. Brain Abscess • Focal collection in the brain parenchyma due to • Infection • Trauma • Surgery

36. Pathogenesis • Hematogenous: multiple abscess • Chronic pulmonary inf. (lung abscess, empyema…) • Skin inf. • Pelvic inf. • Intraabdominal inf. • Bacterial endocarditis • Cyanotic congenital heart dis.

37. Direct transmission • Subacute or chronic otitis media, mastoiditis (inferior temporal lobe and cerebellum) • Frontal or ethmoid sinusitis (frontal lobes) • Dental infections (frontal lobes)

38. Early lesion (first 1-2 weeks): • The borders are not clearly defined, localised edema • Inflammation, no necrosis • “Cerebritis” • After 2-3 weeks, necrosis • A fibrous capsule

39. Etiology • Aerobs+Anaerobs

40. Signs&Symptoms • Headache • Fever • Neck stiffness • Mental changes • Nausea, vomiting

41. Warning • LP is contraindicated!

42. Diagnosis • Imaging • MRI • CT

43. Treatment • Intervention • Antibiotics • Ceftriaxone + metronidazole Mortality 0-30 %

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