Meningitis

Question 1

Define meningitis

Answer 1

Inflammation of the inner meningeal/leptomeningeal (pia mater and arachnoid) coverings of the brain, most commonly due to infection

Question 2

What is the most common cause of meningitis

Answer 2

Viral causes
Enteroviruses (coxsackie A/B)
Mumps
HSV
VZV
HIV

Question 3

Aetiology of bacterial meningitis

Answer 3

Neonates: Group B streptococci, E. coli, Listeria monocytogenes
Children: Haemophilus influenzae (Hib), Neisseria meningitidis, S. Pneumoniae
Teenagers: Neisseria meningitides (Hib if unvaccinated)
Adults: S. pneumoniae, Neisseria meningitidis, TB
Elderly: S. pneumoniae, Listeria monoyctogenes

Question 4

Risk factors for meningitis

Answer 4

Young age
Winter season (bacterial)
Close communities e.g. dormitories, military barracks
Contiguous infection: Sinusitis, otitis media, Mastoiditis, pneumonia
Immunodeficiency: HIV, chemotherapy, leukaemia, lymphoma
Alcoholism, smoking
Basal skull fracture
Incomplete immunisation
Absent/non-functioning: Splenectomy
Sickle cell anaemia
CSF shunts
Intracranial surgery
Recent travel and exposure (rodents, ricks, mosquitos, sexual activity)

Question 5

What are the symptoms of meningitis

Answer 5

Meningism: (1) headache (2) neck stiffness (3) photophobia
Rash: non-blanching petechial (meningococcal)
Fever
Neck or backache
GI: N&V, diarrhoea, abdominal pain/distension
Seizures

Question 6

What are the signs of meningitis on examination

Answer 6

Obs: fever, tachycardia, hypotension

General exam:
Rash
- non-blanching petechial rash (meningococcal)
- Darker skin: check the soles/palms/conjunctivae/palate (i.e. paler areas)
Altered mental state (reduced GCS)
Prolonged CRT
Cold extremities

Meningitis specific:
Kernig’s sign = pain/resistance on passive knee extension with hips flexed
Brudzinski’s sign = flexing the neck causes automatic flexion of the hips and knees
Meningism: photophobia, neck stiffness

Question 7

What investigations should be done for meningitis

Answer 7

(Initiate sepsis 6)

Bedside: ?petechial scraping
Bloods: Blood cultures, Blood gas, FBC, CRP , glucose, coagulation screen, PCR for meningococcal disease, U&Es, LFTs
Other: Lumbar puncture (Confirm diagnosis)

Question 8

What results will you see for bacteral, viral, TB, and cryptococcal meningitis on lumbar puncture

Answer 8

Bacterial: Turbid/cloudy, high neutrophils (polymorphs), low glucose, high protien

Viral: clear, high lymphocytes (mononuclear), normal glucose, normal/high protein

TB: Fibrin web, high lymphocytes (mononuclear), low glucose, high protein

Cryptococcus: stains with india ink

Question 9

When is a LP contraindicated

Answer 9

Raise ICP (reduced consciousness, bradycardia + HTN, focal neurologicla signs, unequal/unreponsive pupils, papilloedema)
Overlying skin infection
Extensive/spreading purpura (indicator of coagulopathy, DIC)
Shock

Question 10

What is the management for bacterial meningitis in primary care (+doses)

Answer 10

IV/IM benzylpenicillin + Call for ambulance for urgent hospital referral
<1yo - 300mg
1-9yo - 600mg
>10yo - 1200mg

If there is no non-blanching rash → do NOT give Abx, call for hospital

Question 11

What is the management of bacterial meningitis in secondary care

Answer 11

1. ABCDE: Give oxygen, check airways, crystalloid fluids,
   a. Fluid bolus of normal saline
2. Take blood cultures
3. IMMEDIATE empirical IV/IM antibiotics
4. Dexamethasone 10mg IV shortly before or with the first dose of antibiotics
5. If severe → ITU admission

+ notify public health England (notifiable disease)
+ follow up + hearing test

Question 12

What antibiotics are indicated for meningitis

Answer 12

<3 months: cefotaxime + amoxicillin/ampicillin
>3 months: IV ceftriaxone
Meningococcal: Benzylpeniciliin
Listeria: ampicillin/amoxicillin IV
?encephalitis: Acyclovir
Penicillin and cephalosporin resistant pneumococci: vancomycin and rifampicin
Penicillin allergic: Ceftaxime
Travel Hx/prolonged Abx exposure: add vancomycin

Question 13

What is the management for viral meningitis

Answer 13

conservative management (self-limiting with good prognosis)

Question 14

What is the prophylaxis for close contacts for meningitis

Answer 14

Ciprofloxacin for 2 days and vaccination
given to everyone who has had prolonged close contact with the case in a household-type setting during the 7 days BEFORE onset of illness

Question 15

What are the complications of meningitis

Answer 15

Septicaemia, shock, DIC
Neuro: cerebral infarction, hearing loss, seziures, cognitive impairment, motor deficits, visual impairment, cerebral oedema
Clotting: DVT, peripheral gangrene
Hydrocephalus, learning difficulties
Water-house-Friderichsen syndrome

Question 16

What is the prognosis for meningitis

Answer 16

Outcome is excellent with prompt and adequate antimicrobial and supportive therapy
Prognosis depends on age, presence of comorbidity, causative pathogen and severity at presentation
Mortality rate for bacterial meningitis is 10-40%

Question 17

What results on LP indicate the need for steroids and when are steroids contraindicated

Answer 17

Frankly purulent CSF
WBC > 1000/microlitre
Raised WBC with protein concentration >1g/L
Bacteria on Gram stain

<3months, high dose CI in meningococcal disease

Question 18

Management for chronic meningitis

Answer 18

Seen with TB, syphillis, cryptococcus
Lower mortality

Cryptococcus → ambisome ± flucytosine

Question 19

What is seen on MRI in TB meningitis

Answer 19

Leptomeningeal enhancement
Basal cistern enhancement
Dilatation of ventricles