CNS Infections

1. CNS Infections J. Ned Pruitt II Associate Professor of Neurology Medical College of Georgia

2. Case 1 A 35 yo man is brought to the ER after 5 days of fever and chills. His wife relates that he has been very confused today and she called 911 after a seizure. PMHx is unremarkable except for a splenectomy at age 14 after a traumatic injury. Meds – prn tylenol in the last week. NKDA Vaccinations are up to date.

3. Case 1 Exam – Ill appearing man. Temp 39 C. Lethargic and can answer simple questions but can give no meaningful history. Neck is stiff to flexion and extension. A fine petechial rash is on his chest and upper arms.

4. Case 1 – What next? More examination or history? Labs? Radiology? Medications?

5. CNS Infections Meningitis Bacterial, viral, fungal, chemical, carcinomatous Encephalitis Bacterial, viral Meningoencephalitis Abscess Parenchymal, subdural, epidural

6. CNS Infections Signs and symptoms Fever Headache Altered mental status -lethargy to coma Neck stiffness – meningismus – flex/ext Increased intracranial pressure – papilledema, nausea/vomiting, abducens palsies, bulging fontanelle in infants

7. Exam in suspected CNS Infection Mental Status Cranial nerve and fundiscopic exam Meningeal Signs General exam – rashes, lymphadenpathy Labs – CBCD, BMP, PT/PTT, bHCG, blood cultures, UA C&S Radiology – CT head - uncontrasted if no focal signs, contrast if mass suspected

8. LP Increased intracranial pressure is expected – but LP contraindicated if a mass is present or if epidural spinal abscess is suspected Left lateral decubitus position L3-L4 interspace or L4-L5 interspace Think about your studies before the LP

9. LP Tube #1 – glucose and protein Tube #2 – cell count and differential Tube #3 – gram stain and rountine culture, cyrptococcal antigen, AFB stain and culture Tube #4 – VDRL, or viral studies (PCR)

10. CSF Characteristics

11. Key CSF Features CSF is not liquid gold – get enough to get your answer CSF Glucose is 2/3 of serum glucose Important in diabetic patients Traumatic LPs – CSF pro increases by 1 for every 1000 rbcs Tube #1 and Tube#4 for rbcs when SAH is in the differential not as a routine Very high CSF Protein levels will make CSF yellow Send a full tube of CSF for cytology not just a few cc’s

12. Case 1 CT of head negative. LP - OP (opening pressure) 250mm, glucose 17, protein 92, Rbcs 3, Wbcs 280 with 89% pmns, 11% lymphocytes Gram stain - + for Gram neg organisms

13. Bacterial Meningitis Streptococcus pneumoniae Hemophilus influenzae Listeria moncytogenes Group B streptococcus Niesseria meningitidis

14. Bacterial Menigitis Age less than 3 months- Group B strep L. Monocytogenes E. coli Strep pneumoniae

15. Bacterial Meningitis 3 Months to 18 years – N. meningitidis S. pneumoniae H. influenzae

16. Bacterial Meningitis Age 18 to 50 years S. pneumoniae N. meningitidis H. influenzae

17. Bacterial Meningitis Over age 50 years S. pnemoniae L. monocytogenes Gram (-) bacilli

18. Treatment of Bacterial Meningitis PCN G or 3rd generation cephalosporin and consult ID Steroids – Dexamethasone IV q6 for 4 days

19. Viral Meningitis Very common Often caused by enteroviruses Treatment is supportive

20. Viral Encephalitis Encephalitis (Meningoencephalitis) Altered mental status and seizures Herpes Simplex virus – medial temporal lobe Acyclovir Management of seizures Very high morbidity and mortality PCR diagnosis of CSF West Nile, St Lousi E, EEE, CMV

21. Chronic Meningitis Immunocompromised patients Cryptococcus neoformans HIV M. tuberculosis M. avium Carcinomatous meningitis Lung, breast

22. Case 1 Meningitis caused by N. Meningitidis Treatment with 3rd generation cephalosporin for 10 days Dexamethasone Prophlaxis with Rifampin for contacts