meningitis cns infection, infectious diseases of Central nervous system

Harrison 2022

1. M eningitis

2. Bacterial meningitis An acute purulent infection within the SAS

3. Epidemiology The most common form of suppurative CNS infection Community-acquired bacterial meningitis: - S .pneumoniae - N.meningitides (causative organism of recurring epidemics) -GBS - L.monocytogens -Hib

4. Etiology S.pneumonia 20y/o RFx : Pneumococcal pneumonia Pneumococcal sinusitis OM Alcoholism DM Splenectomy Hypogamma Complement deficiency Head trauma with basilar skull fx & csf rhinorrhea

5. Cont. N.meningitidis (gr-cocci) Petechial or purpuric skin lesions( bx is needed) Vaccination?

6. Cont . Gr- bacilli DM Cirrhosis Alcoholism UTI Gram-negative meningitis can also complicate neurosurgical procedures, particularly craniotomy, and head trauma associated with CSF rhinorrhea or otorrhea

7. Cont . L.mono Neonates Pregnant women Elderly >60 Immunocompromised Infections with L. monocytogenes follow ingestion of contaminated food that contains the bacteria at high concentrations

8. Cont. H.influenza Unvaccinated children Elderly Non Hib is an emerging pathogen

9. Cont. Cecil: Gram-negative meningitis is rare; it usually affects debilitated persons and those with a breach in the meninges as a result of trauma or neurosurgical procedures. Staphylococcus aureus meningitis is usually found in the early period after neurosurgery or trauma, in those with CSF shunts, or in patients with underlying conditions such as diabetes mellitus, alcoholism, chronic kidney disease requiring hemodialysis, injection-drug use, and malignancies. Staphylococcus epidermidis is the most common cause of meningitis in patients with CSF shunts.

10. Pathophysiology

11. Cont. Initial step: lysis of bacterial cell wall Immune response Vascular permeability CSF flow obstruction Vasculitis Thrombosis (why not anticoagulants??)

12. Clinical presentation Headache Fever Nuchal rigidity

13. Cont . Decreased level of consciousness-variable Nausea&vomiting Photophobia Neck stiffness-pathognomonic, tests Seizures-focal or generalized Raised ICP- csf opening p>180 in 80%, >400 in 20%

14. ICP Consciousness Papilledema Pupils Sixth nerve palsy Cushing reflex Cerebral herniation

15. Diagnosis Tx with suspicion LP if … CSF findings

16. D Dx Viral meningoencephalitis HSV encephalitis Ricketsial dis-RMSF Focal lesions- subdural & epidural empyema & brain abscess Non-infectious CNS conditions- SAH, tumors, SLE, Bechet’s , …

17. Treatment?? Dexa+3 rd or 4 rd caphalo ( ceftriaxone,cefotaxim,cefepime )+ vanco+acyclovir+Doxy (tick season) + Ampicillin- L.mono + Metronidazole-gr-anaerobes- otitis,sinusitis,mastoiditis + VANCO+ceftazidime or meropenem -subs for ceftriaxone or cefotaxime in HAM

18. Specific Antimicrobial therapy

19. ICP rise tx ICU admission elevation of the patient’s head to 30–45° intubation and hyperventilation (Paco2 25–30 mmHg) mannitol

20. Prognosis H.infl , N.menin , GBS 3-7% L.mono 15% S.pneumo 20% Mortality: decreased level of consciousness on admission onset of seizures within 24 h of admission signs of increased ICP young age (infancy) and age >50 the presence of comorbid conditions including shock and/or the need for mechanical ventilation delay in the initiation of treatment

21. Cont.

22. Viral meningitis Headache-invariably present-frontal or retroorbital -photophobia-pain on moving the eyes Fever Meningeal irritation Nuchal rigidity-mild Malaise, myalgia, anorexia, nausea, vomiting, abdominal pain and/or diarrhea

23. Etiology Enterovirus( echovirus,coxsackivirus ) VZV HSV(HSV2>HSV1) Arbovirus 2/3 of aseptic meningitis cases are viral

24. Diagnosis CSF exam Pleocytosis -Lymph- pmn in 48h in echovirus9,WNV,EEE,mumps Pr NR or slightly elevated 0.2-0.8 Gluc NR- in mumps or LCMV(also csf cell counts up to thousands) As a rule, a lymphocytic pleocytosis with a low glucose concentration should suggest fungal or tuberculous meningitis, Listeria meningoencephalitis , or noninfectious disorders (e.g., sarcoid , neoplastic meningitis ).

25. CSF PCR PCR amplification has become the single most important method for diagnosing CNS viral infections . In both enteroviral and HSV infections of the CNS, CSF PCR has become the diagnostic procedure of choice and is substantially more sensitive than viral cultures. HSV CSF PCR is also an important diagnostic test in patients with recurrent episodes of “aseptic” meningitis

26. Lab studies CBC diff LFT RFT ESR CRP Electrolytes, glucose, ck , adolase , amylase, lipase

27. Neuroimaging studies ? Altered consciousness Seizures Focal signs Atypical CSF profile Immunocompromising condition

28. DDx untreated or partially treated bacterial meningitis early stages of meningitis caused by fungi, mycobacteria, or Treponema pallidum ( neurosyphilis ), in which a lymphocytic pleocytosis is common, cultures may be slow growing or negative, and hypoglycorrhachia may not be present early meningitis caused by agents such as Mycoplasma, Listeria spp., Brucella spp., Coxiella spp., Leptospira spp., and Rickettsia spp parameningeal infections neoplastic meningitis meningitis secondary to noninfectious inflammatory diseases, including medication-induced hypersensitivity meningitis, SLE and other rheumatologic diseases, sarcoidosis, Behçet’s syndrome, and the uveomeningitic syndromes

29. probability of bacterial meningitis is 0.3% or less if …

30. Treatment Symptomatic: Analgesic Antipyretic Antiemetic Outpt or inpt ? Accyclovir No therapy for WNV Vaccination