Meningitis and other Intracranial Infections

Question 1

Risk factors for meningitis

Answer 1

Advanced age

Crowding

Exposure to pathogens

Immunocompromised

Cranial anatomical defects/ventriculoperitoneal shunt

Cochlear implants

Sickle cell disease

Question 2

Common causative pathogens in meningitis

Answer 2

Streptococcus pneumoniae (pneumococcus)

Neisseria meningitidis (meningococcus)

Haemophilus influenzae

Listeria monocytogenes (often in patients at extremes of age)

Question 3

Clinical features of meningitis

Answer 3

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

Question 4

Most common meningitis-causing pathogens in 0-3 months

Answer 4

Group BStreptococcus(most common cause in neonates)

E. coli

Listeria monocytogenes

Question 5

Most common meningitis-causing pathogens in 3 months - 6 years

Answer 5

Neisseria meningitidis

Streptococcus pneumoniae

Haemophilus influenzae

Question 6

Most common meningitis-causing pathogens in 6 years - 60 years

Answer 6

Neisseria meningitidis

Streptococcus pneumoniae

Question 7

Most common meningitis-causing pathogens in >60s

Answer 7

Streptococcus pneumoniae

Neisseria meningitidis

Listeria monocytogenes

Question 8

Most common meningitis-causing pathogens in immunocompromised

Answer 8

Listeria monocytogenes

Question 9

Investigations in meningitis

Answer 9

Bloods (FBC, U+E, clotting, glucose)

ABG

Blood cultures

CT Head

Lumbar puncture (if no signs of raised ICP)

Question 10

Antibiotic choice in meningococcal meningitis

Answer 10

IV benzylpenicillin or cefotaxime (or ceftriaxone)

Question 11

Antibiotic choice in pneumococcal meningitis

Answer 11

IV cefotaxime (or cefrtiaxone)

Question 12

Antibiotic choice in meningitis caused by Haemophilus influenzae

Answer 12

IV cefotaxime (or cefrtiaxone)

Question 13

Antibiotic choice in meningitis caused by Listeria

Answer 13

IV amoxicillin (or ampicillin) + gentamicin

Question 14

Acute management of meningitis

Answer 14

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

Question 15

Post-exposure prophylaxis in meningitis

Answer 15

Close prolonged contact within 7 days prior to onset

Single doseciprofloxacin - ASAP and ideally within 24hrs of initial diagnosis

Question 16

Complications of meningitis

Answer 16

Hearing loss

Seizures and epilepsy

Cognitive impairment and learning disability

Memory loss

Focal neurological deficitssuch as limb weakness or spasticity

Question 17

Common causes of viral meningitis

Answer 17

HSV

Enterovirus

VZV

Question 18

Define encephalitis

Answer 18

Inflammation of brain parenchyma

Question 19

Aetiology of encephalitis

Answer 19

HSV1 most common

Question 20

Clinical features of encephalitis

Answer 20

Fever

Headache

Psychiatric symptoms

Seizures

Vomiting

Focal features e.g. aphasia (temporal sign)

Question 21

Investigations in encephalitis

Answer 21

CSF: lymphocytosis, elevated protein

PCR for HSV

CT/MRI: medial temporal and inferior frontal changes

EEG pattern: lateralised
periodic discharges at 2 Hz

Question 22

Management of encephalitis

Answer 22

IV aciclovir