Meningitis

1. Meningitis Gary R. Skankey, MD, FACP

2. Causes of Meningitis • Bacteria • Community-acquired - S. pneumoniae, N. meningitidis, gp B streptococcus • Post-op or hospital acquired – MRSA, Ps. Aeruginosa • In the very young and very old Listeria monocytogenes • Viruses • Enterovirus, coxsackie virus, echovirus, HSV-2, etc • Fungi • Coccidioides, cryptococcus • TB

3. Clincal Presentation • Acute meningitis • Abrupt or rapid onset • “flu-like” prodrome – myalgias • Fever • Headache • Nucal stiffness • Altered sensorium (meningo-encephalitis) • Rash

4. Clinical Presentation • Chronic meningitis • Insidious, gradual onset • Weeks of headache • Low grade fever • Sweats, chills • Weight loss

5. Acute Meningitis

6. Physical Exam • Koenig-Brudzinski’s sign – uncommon • Nucal rigidity – common • Photophobia – common • Rash - uncommon

9. Lab • CT head – r/o cerebritis, brain abscess, brain edema • Lumbar puncture • Pleocytosis • High protein • Low glucose (CSF:serum glucose < 50%) • Bacterial antigens – more sensitive in children • Gram stain and culture

11. Treatment • Ceftriaxone 2 gm IV Q 12, or Cefotaxime 2 gm IV Q 4, plus • Vancomycin 1.5 gm IV Q 12 • In the very young or very old add Ampicillin 2 gm IV Q 4 • If pcn allergic, ask for details: • Rash : use cephalosporin • Anaphylactic : use Aztreonam 2 gm IV Q 8

12. IN The ER • 1st step – Give antibiotics ASAP • 2nd step – draw labs • 3rd step – CT head • 4th step - LP

13. Prevention • Vaccines • Pneumovax • Meningicoccal vaccine • Both should be administered to any asplenic patient • Exposure to meningococcus • Rifampin 600 mg PO BID x 4 doses • Only for intimate contacts: spouse, boyfriend/girlfriend, household contacts • Not needed for: classmates, co-workers, HCWs (ER personnel, EMTs, etc)

14. Viral Meningitis • 75% caused by enteroviruses • Enterovirus • Coxsackie virus • Echo virus • Other viruses • HSV2 (HSV1 causes encephalitis) • HIV • Lymphocytic choriomeningitis virus • Mumps • Varicella Zoster

15. Viral Meningitis • Cannot distinguish initially from bacterial meningitis • Severe HA, photophobia, nucal rigidity, fever • May be preceded by a few weeks by viral gastroenteritis • Ask pt is he/she had the “stomach flu” some time in the past couple weeks • Almost never involves brain (meningoencephalitis) • Pt never obtunded, no Hx of seizure • Disease is self-limited, resolves after 7 to 10 days without treatment • No serious sequelae

16. CSF • Low numbers of WBCs : 10 to 500 • PMNs predominate early, Monos or Lymphocytes later • CSF to serum glucose ratio usually = 50% • Protein may be high • Gram stain, culture and bacterial antigens negative • Enteroviral PCR positive about 70% of time

17. Approach to Viral Meningitis • Treat like bacterial meningitis until the 72 hr culture comes back negative, or… • Enteroviral PCR comes back positive • Consider acyclovir if CSF HSV PCR positive • HSV meningitis is self-limited

18. Chronic Meningitis

19. Causes • Cryptococcus • Coccidioides immitis • Mycobacterium tuberculosis • Other fungal – histoplasmasma, blastomyces, sporotrix • Other bacteria – brucella, francisella, nocardia, borellia • Non-infectious – Wegener’s, sarcoid, malignanacy

20. Presentation • Insidious onset • Low grade fever if any • Persistant, worsening headache • Photophobia and nucal rigidty usually absent • Symptoms have usually lasted several weeks by the time diagnosis is made

21. Diagnosis • History • Exposure to bird droppings (crypto) • Travel to Arizona, Central Valley California, Desert Southwest (cocci) • Contacts with TB pts • CSF • Modest pleocytosis • Glucose may be normal, but protein usually high (very high if coccidioma causes CSF obstruction)

22. Diagnosis • TB • CSF AFB smear usually negative • AFB culture takes 6 weeks • Positive PPD or quantiFERON may suggest diagnosis • CSF PCR not standardized yet, but may be helpful; • Cryptococcus • India ink • Cryptococcal Ag in CSF

23. Diagnosis • Coccidioidomycosis • Difficult diagnosis to make • CSF fungal smear and cultures usually negative • Titers have high false negativity rate even from CSF • Cocci CF titer from serum may give clue. • Any pt with history of pulmonary cocci who develops HA with pleocytosis should be treated for cocci meningitis

24. Treatment • TB • Treat like pulmonary TB: INH, Rif, Eth, PZA for two months, then INH, Rif to comlete 12 months • Steroids – improves mortality, reduces adverse events (infarcts) • Crytpococcus • Amphotericin plus flucytosine for 6 weeks followed by fluconazole to complete 6 months • High toxicity rate (renal failure, pancytopenia) • High dose fluconazole (400 to 800 mg QD) if can’t tolerate ampho + 5FC • Serial LPs to reduce CSF pressure and assure clearing of infection • In AIDS pts – continue Fluconazole until CD4 >100

25. Treatment • Coccidioidomycosis • Intrathecal amphotericin now rarely used • Chemical arachnoiditis • High dose fluconazole (800 to 1200 mg QD) • Serial LPs to assure improvement of infection • Incurable – symptoms may resolve, but patient can never stop fluconazole • Taper down to no lower than 400 to 600 mg QD

26. Recurrent meningitis • Mollaret’s meningitis • Most common cause is HSV2 • Many other poorly defined causes as well • Leaking arachnoid cyst • Cryptogenic • May respond to acyclovir

27. Conclusion • Acute bacterial meningitis is most commonly caused by viruses, then bacteria • Chronic meningitis can be caused by fungi and TB • Recurrent meningitis – Malloret’s • Call ID when pt has meningitis