see: [RCH meningitis](https://www.rch.org.au/clinicalguide/guideline_index/Meningitis_encephalitis/)
See also: [[Encephalopathy|Encephalitis]]
#infectious_diseases
> [!key points]
> - ceftriaxone is conraindicated in neonates recieving calcium-containing IVF; can cause precipitant in lungs and kidneys, increases bilirubin. **cefotaxime is an alternative**
# paediatric meningitis
| Age | organisms | Abx | ?dexamethasone|
|---|---|---|---|
|<2 months| GBS, E coli, listeria (rare)| benpen 60mg/kg IV + cefotaxime 50mg/kg| no|
|≥ 2 months| N meningitis, HiB, s pneumo | ceftriaxone 50mg/kg +/- vanc| 0.15mg/kg IV Q6H|
# Causes
| organism | notes |
| ------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| streptococcus pneumoniae | - common in adults and children<br>- pneumococcal vaccines ↓ incidence<br>- gram +ve diplococcus<br>- pneumonia may *also* be present (in other words, in a confused patient with pneumonia on CXR, do not assume that their confusion is just from the pneumonia!)<br>- blood and CSF cultures usually positi |
| neisseria meningitis | - gram negative aerobic diplococci<br>- group B more common than group C in immunised groups<br>- nasopharynx site where meningococci transmitted by aerosol or secretions to others<br>- sudden onset headache, fever, neck stiffness. nausea, vomiting, photophobia, ALOC. abdo + extremity pains<br>- petechial [[Rash]] → present in ==only 40%== . may take 6-12 hours to develop<br>- acute adrenal haemorrhage (waterhouse Freidrichsen syndrome) may occur<br>- meningococcaemia associated risk of vascular compromise to extremities requiring amputation<br>- associated with severe depression in protein C levels (↑ risk of [[thrombophilia]]) |
| other bacterial | - e coli and group B strep important in neonates and infants < 3 months<br>- listeria in newborns → now very rare; occurs mostly in immunocompromised <br>- h influenzae B in non-vaccinated children<br>- [[#Mycobacterial tuberculosis]]<br>- mycoplasma<br>- treponema pallidum [[Syphilis]]<br>- [[Brucellosis]] |
| Viral | - mumps, coxsackie, echoviruses<br>- herpes, EBV<br>- enteroviruses<br>- [[HIV]]<br>- CMV |
| Fungi and parasites | - [[#Cryptococcal meningitis]]<br>- [[#Toxoplasmosis\toxolasma gondii]]<br>- cysticerosis |
| others | - drugs (eg NSAIDS, sulfamethoxazole, AZT)<br>- [[Sarcoidosis]], SLE, Wegner's |
# hiv meningitis
## Cryptococcal meningitis
Cryptococcus neoformans most common cause of CNS fungal infection in immunocompromised patients
> most patients have have increased ICP (↑ [[Lumbar puncture#Opening pressure|opening pressure]] during LP)
***clinical findings***
- headache
- ALOC
- +/- meningeal signs
- most patients have ↑ ICP
- CSF: WBC lower than 500 microL, ↓ glucose, ↑ protein
- india ink preparations positive in 50% of cases
- if pt has HIV, CSF less likely to have abnormal cell counts and chemistries
***Treatment:*** amphoteracin. No dex
## Toxoplasmosis
toxoplasma gondii is an intracellular protazoan
*Nb* that HIV encephalitis is likely toxoplasmosis. See [[HIV]]
cerebral toxoplasmosis usually accompanied by acute or subacute development of focal disease, including [[Seizures]]. Chronically can have confusion, memory loss, lethargy similar to AIDS-dementia
CSF non-specific: ↑ protein, mononuclear pleocytosis (<100 cells/microL), and rarely, ↓ glucose. serum and CSF serology may be positive or negative and does not help make a diagnosis, although patients with encephalitis usually have detectable IgG antibiodies
Dx usually clinical and imaging responses to antibiotics (pyrimethamine or sulfadiazine).
> can be difficult to differentiate from CNS lymphoma
## Mycobacterial tuberculosis
see: [[Tuberculosis]]
- infection typically in setting of disseminated TB
- atypical mycobacterium infection in HIV-infected individuals uncommonly affects CNS
***clinical manifestation:***
- meningitis involving *basal cisterns*
- [[Encephalopathy|Encephalitis]]
- abscess formation
***CSF:***
- 100 - 400 cells/microL with lymphocytic predominance
- 30% of cases may show predominance of neutrophils early in the course
- ↓ CSF glucose
- ==absence of visible growth== is not negative until 8 weeks; may need to treat for TB on spec if epidemiological risks and reasons to suspect this looking at CSF (eg encephalitis, high lymphocytes, high opening pressure, etc)
# related questions
## meningitis
- [x] 11Q: [Meningitis](x-devonthink-item://C1DDA3AB-2DA2-4922-A8A6-F597AB7E2558?page=14) -- [Answer](x-devonthink-item://A10DE51E-92FA-42D1-8AA0-7AE68C2FA743?page=17) -- [prop](x-devonthink-item://B864660E-6598-4555-ACA9-B87F41ED4C3A?page=11)