Meningitis and Encephalitis Flashcards
Inflammation of leptomeningeal (pia mater + arachnoid) coverings of the brain
Meningitis
Inflammation of brain parenchyma (functional tissue, so inflam of the brain itself)
Encephalitis
Condition characterised by clinical and laboratory evidence for meningeal inflammation and negative routine bacterial cultures
Aseptic meningitis
Causative organisms meningitis
Bacteria - strep pneumoniae, neisseria meningitidis, haemophilus influenzae type B
Viruses
Fungi
Parasites
Non-infectious
Aseptic meningitis causative organisms
Pathogens - Enterovirus, mycobacteria, fungi, sprochetes
Autoimmune - sarcoidosis, Behcet’s, SLE
Malignancy - lymphoma, leukaemia, metastatic, carcinomas
Medication - NSAIDs, trimethoprim, azathioprine
Encephalitis causative organisms
Infectious and non-infectious causes
- main cause is herpesvirus
Meningitis symptoms
Photophobia
Neck stiffness
Headache
Fever
Encephalitis symptoms
Altered consciousness Seizures Personality changes Cranial nerve palsies Speech problems Motor/sensory deficit
Investigations for meningitis
LP for CSF
Management of meningitis
Empirical antimicrobial should be started promptly
- ceftriaxone
- vancomycin
Investigations for encephalitis
Blood cultures
Neuroimaging (MRI)
CSF analysis (LP)
Neonates - Extended labour, infection in previous pregnancy
Group B strep
Neonotes - Late neonatal infection
E. coli
Neonates - Do not forget
Listeria monocytogenes
Children/teenagers - Gram negative diplococci
Neisseria menigitides
Children/teenagers - unvaccinated
Haemophillus influenzae
Adults/elderly - gram positive cocci
Strep pneumoniae
Adults/elderly - elderly, cheese/unpasteurised milk, alcoholics
Listeria monocytogenes
Brudzinski’s sign
Meningitis
Severe neck stiffness causes patient’s hips and knees to flex when neck is flexed
Kernig’s signn
Meningitis
Severe hamstring stiffness causes inability to straighten the leg when hip is flexed to 90 degrees
Signs of infection in meningitis
Fever Tachycardia Hypotension Altered mental state Skin rash - petechiae = meningococcal septicaemia
Petechiae + meningitis
Meningococcal septicaemia
Meningitis investigations
Bloods (2 blood cultures)
Imaging (CT to exclude raised intracranial pressure)
LP (CSF for MCS+Gram-staining)
Indications for avoiding LP in meningitis
- Neurological signs suggesting raised ICP
- Superficial infection over LP site
- Coagulopathy
