Meningitis and other Intracranial Infections Flashcards
Risk factors for meningitis
Advanced age
Crowding
Exposure to pathogens
Immunocompromised
Cranial anatomical defects/ventriculoperitoneal shunt
Cochlear implants
Sickle cell disease
Common causative pathogens in meningitis
Streptococcus pneumoniae (pneumococcus)
Neisseria meningitidis (meningococcus)
Haemophilus influenzae
Listeria monocytogenes (often in patients at extremes of age)
Clinical features of meningitis
Headache
Fever
Neck stiffness
Photophobia
Nausea and vomiting
Focal neurology
Seizures
Reduced conscious level
Features of overwhelming sepsis (including the often reported non-blanching petechial rash of impending DIC)
Eponymous clinical signs such as Kernig’s and Brudzinski’s are insensitive, but specific for meningitis
Most common meningitis-causing pathogens in 0-3 months
Group BStreptococcus(most common cause in neonates)
E. coli
Listeria monocytogenes
Most common meningitis-causing pathogens in 3 months - 6 years
Neisseria meningitidis
Streptococcus pneumoniae
Haemophilus influenzae
Most common meningitis-causing pathogens in 6 years - 60 years
Neisseria meningitidis
Streptococcus pneumoniae
Most common meningitis-causing pathogens in >60s
Streptococcus pneumoniae
Neisseria meningitidis
Listeria monocytogenes
Most common meningitis-causing pathogens in immunocompromised
Listeria monocytogenes
Investigations in meningitis
Bloods (FBC, U+E, clotting, glucose)
ABG
Blood cultures
CT Head
Lumbar puncture (if no signs of raised ICP)
Antibiotic choice in meningococcal meningitis
IV benzylpenicillin or cefotaxime (or ceftriaxone)
Antibiotic choice in pneumococcal meningitis
IV cefotaxime (or cefrtiaxone)
Antibiotic choice in meningitis caused by Haemophilus influenzae
IV cefotaxime (or cefrtiaxone)
Antibiotic choice in meningitis caused by Listeria
IV amoxicillin (or ampicillin) + gentamicin
Acute management of meningitis
Admit to hospital
Empiric antibiotic therapy:
2g of IV ceftriaxone BD
Additional IV amoxicillin in young/old patients to better cover listeria
IV aciclovir if viral encephalitis suspected
Penicillin allergic: chloramphenicol
Community: IM benzylpenicillin may be given pending hospital transfer if there is a non-blanching rash
Post-exposure prophylaxis in meningitis
Close prolonged contact within 7 days prior to onset
Single doseciprofloxacin - ASAP and ideally within 24hrs of initial diagnosis
Complications of meningitis
Hearing loss
Seizures and epilepsy
Cognitive impairment and learning disability
Memory loss
Focal neurological deficitssuch as limb weakness or spasticity
Common causes of viral meningitis
HSV
Enterovirus
VZV
Define encephalitis
Inflammation of brain parenchyma
Aetiology of encephalitis
HSV1 most common
Clinical features of encephalitis
Fever
Headache
Psychiatric symptoms
Seizures
Vomiting
Focal features e.g. aphasia (temporal sign)
Investigations in encephalitis
CSF: lymphocytosis, elevated protein
PCR for HSV
CT/MRI: medial temporal and inferior frontal changes
EEG pattern: lateralised
periodic discharges at 2 Hz
Management of encephalitis
IV aciclovir
