CNS Infections Flashcards
Common organisms
Haemophilus
Meningococcus
Pneumococcus
Diagnosis
- LP: if good then probably not bacterial
- CT
- MRI
Risk factors
Sickle cell
Asplenic
Complement deficiency
Manifestations
Fever & Neurologic signs (mostly infectious)
Neurologic:
headache, meningitis, convulsion, focal signs, kernig & brudzinski, confusion, agitation,…
Non-specific signs
- Fever
- Low appetite
- Poor feeding
- Headaches
- Myalgia
Specific signs
- Nuchal rigidity + backache
- Kernig
- Brudzinski
- Mental state change (Bacterial=progressive, viral=swings)
- Convulsion
CNS infection other specific signs
- Cranial neuropathy (6,4,3)
- Mental change, CSF glucose decrease
- Photophobia
- Mostly positive B/C
- Mottling (mostly sign of organ failure)
LP & CSF results
-
Pleocytosis > 1000 or 250
<20 normal if lymphocyte or monocyte
Bacterial: first 12h lymphocytic, then maybe neutrophils -
Low Glucose & High Protein
Viral: neutrophil then lymphocyte - Normal Glucose & Bit high protein
LP Contraindications
- High ICP
- Altered Consciousness
- Focal Signs
- Lesions and Abscesses
- Neutropenia
- Coagulation disorder
- Thrombocytopenia
- History of CNS diseases
Meningitis Treatment
ICU if altered consciousness
- Empiric: Ceftriaxone (100mg/kg) in 2dose or Cefotaxime + Vancomycin (60mg/kg) in 4dose
- If Gram-Negative, Imipenem instead of cephalosporine
- Listeria: Ampicillin 300
Treatment Duration
- Meningococcus: 5-7d
- Haemophilus: 7-10d
- Pneumococcus: 10-14d
- Gr (-): 2-3w after sterilization
- Staph: 4-6w
Dexamethasone
Decreases side effects specially ototoxicity
- 1-2h before Ab
- 0.15 mg/kg QID / 4d
Other doses: amikacin, ampicillin, Ceftriaxone, meropenem, vanco
Amikacin 15mg/kg/d TDS
Ampicillin 150mg/kg/d
Ceftriaxone 100mg/kg
Meropenem 40mg/kg/dose
Vancomycin 60mg/kg/d in 4dose
Meningitis causes:
1- Hearing loss
2- Convulsions
3- Focal signs
4- Obstructive thrombosis
5- Hyponatremia
Hearing Loss
- Sensorineural
- Test in every meningitis
- ABR test
- Pneumococcus has worse hearing loss
Focal Signs
- Increased ICP
- Hernia
- Hydrocephalus (stays in under 2yr olds)
Obstructive thrombosis etiology
Less if treated fast or not meningococcus
Meningococcus: fast thrombosis & gangrene
Hyponatremia
- Late treatment because of SIADH
- Can cause convulsions
- ~20%
Meningococcal Prophylaxis
-
Rifampin
Children 10mg/kg BID / 2d
Adults 600mg BD / 2d -
Ciprofloxacin
Adults only 500mg single -
Ceftriaxone
Children 125mg IM single
Adults 250mg IM single
Haemophilus Prophylaxis
Rifampin
Children 20mg/kg daily
Adults 600mg daily
4 days
Vaccines
- Meningococcus: 11-12y & 16-18y
For those in danger - Haemophilus: 2-4-6m
Viral
- Seasonal
- More common:
Enterovirus, Varicella, Herpes -
Rash specially in Enteroviruses & Herpes Viruses
Fever + Neurologic + Rash: check viral meningoencephalitis - Cerebellar ataxia
Viral Treatment
Only for Herpes encephalitis:
Acyclovir 10-20mg/kg TID
