CNS Infection ST1 Lecture - Dr Dave Partridge - Yorkshire and the ...

Meningitis
and other CNS infections
A practical guide
Dave Partridge
SpR in Infectious Diseases
and Microbiology

Infective CNS disease.
• CNS disease is most frequently an
uncommon complication of common
organisms.
• Infection usually originates in another
system prior to CNS involvement.
• Disease can be the result of direct
invasion or be postinfectious or
parainfectious phenomena.

Definitions
• Myelitis
– Spinal cord involvement – localised or multifocal.
– May occur in conjunction with encephalitis +/- meningitis.
– May affect a specific neuronal type e.g. poliomyelitis.
• Meningitis
– Inflammation of the meninges!
• Encephalitis
– Infection of the brain substance.
– Involvement of particular areas of brain may occur with specific
pathogens.
• Encephalopathy
– Diffuse disease of brain substance.
– Usually non-infective but must be distinguished from encephalitis

Aims of lecture
• To be confident in the diagnosis and
initial management of adults with:
– meningitis
– meningococcal septicaemia
– brain abscess
– encephalitis

Aims of lecture
• In relation to meningitis in adults:
– to know empirical antibiotic therapy
to give in different patient groups
– to know when to give adjuvant
steroids
– to understand indications and
contraindications to lumbar puncture
– to understand indications for brain
imaging prior to lumbar puncture

Clinical Case One

A referral from A&E…
• 18 year old first year university student
• 12 hour history of severe headache and
fever
• Temp 38.5, BP 100/60 P110
• Photophobia, neck stiffness, GCS 15/15
• No papilloedema or focal neurology
• No rash
• Normal FBC and clotting
…What do you do next?

What do you do next?
1. Proceed immediately to lumbar puncture
2. Take blood cultures and then give empirical
cefotaxime 2g IV
3. Take blood cultures and then give empirical
cefotaxime 2g IV and aciclovir 10mg/kg IV
4. Take blood cultures and then give
dexamethasone 0.15mg/kg and then give
cefotaxime 2g IV
5. Do a CT head, if normal proceed to lumbar
puncture

CT or not CT?

When to CT before LP
• Age more than 60
• Immunocompromised
• History of CNS disease
• New onset seizures
• Decreased conscious level
– GCS

NEVER delay antibiotics
whilst awaiting CT

Lumbar puncture
• Written consent
• Measure opening pressure
• Take at least 5ml CSF, and at least 10ml
if sending for AAFB
– CSF protein/glucose
– microscopy, culture, sensitivities
– viral PCR (enterovirus/HSV/VZV)
– bacterial PCR/antigen tests
• Send simultaneous blood glucose
• Telephone lab

If LP to be delayed by more
than 30 minutes, give
empirical antibiotics prior
to procedure

Median time from presentation to
03:43
lumbar puncture
Medicine via GP ID via GP Neuro via GP Medicine via A+E ID via A+E
05:56
07:00
13:10
13:20

LP done. What next?
1. Give empirical cefotaxime 2g IV
2. Give empirical cefotaxime 2g IV and
aciclovir 10mg/kg IV
3. Give dexamethasone 0.15mg/kg and then
give cefotaxime 2g IV
4. Give dexamethasone 0.15mg/kg IV,
cefotaxime 2g IV and amoxicillin 2g IV
5. Defer therapy pending LP results

Which antibiotics?
• Cefotaxime 2g qds
– Chloramphenicol as alternative if severe betalactam
allergy
• Consider resistant pneumococci
(vancomycin) in recent travellers
• Add amoxicillin 2g four hourly if:
– Age > 55
– Immunocompromised
– Alcohol

ALWAYS send blood
cultures before starting
antibiotics
Also send:
Throat swabs
EDTA blood for PCR

When to give steroids
• Any adult with suspected bacterial
meningitis? Or those in whom pneumococcal
disease is most likely?
• Give with or before first dose of antibiotics
• Dexamethasone 10mg or 0.15mg/kg IV qds
for four days
• Stop steroids if CSF does not show bacterial
meningitis
de Gans, J. and van de Beek, D. NEJM 2002;347:1549-1556
Fitch, M. and van de Beek, D. The Lancet Infectious Diseases 2007;7:191-200

Steroids and meningitis
de Gans, J. and van de Beek, D. NEJM 2002;347:1549-1556

Meningitis in England and
Wales – HPA reports

Meningococcal meningitis
van de Beek D, de Gans J, McIntyre P, Prasad K, The Cochrane Library 2008, Issue 4

Lumbar puncture results
• OP 22 cmH 20
• Protein 0.90 g/L
• Glucose 1.7/6.0
• RBC

Lumbar puncture results
• OP 22 cmH 20
• Protein 0.90 g/L
• Glucose 4.1/6.0
• RBC

Interpretation of CSF results
Bacterial
meningitis
White cells/uL 1000-10,000
(10,000)
Viral
meningitis

Non-viral causes of lymphocytic
meningitis
• Partially treated bacterial meningitis.
• Para-meningeal focus of infection
• Listeria monocytogenes
• Tuberculosis
• Lyme disease
• Leptospirosis
• Syphilis

Meningitis management
• Recognise meningitis
• Cannulate and take bloods (cultures,
PCR) and throat swab
• Resuscitate
• Give antibiotics
• Consider steroids
• If no contraindication, LP
• Notification and contact prophylaxis

Meningitis audit 2006 STH
Investigation Performed Not performed
FBC 24 0
Coagulation 22 2
Throat swab 14 10
Blood cultures 19 5
Meningococcal PCR 15 9
Serum save 12 12
Paired glucose with CSF 12 5

Meningitis audit 2006
• Appropriate antibiotics given in 21/24 cases
– Amoxicillin not given to patients aged >50 in 4/6 cases
– One patient received cefotaxime only despite recent travel to
area with high incidence of pneumococcal resistance.
• Dosage and durations of antibiotics used always correct.
• Median time to receipt of antibiotics from presentation –
03:38.
• Median time to receipt of antibiotics in those with confirmed
bacterial disease – 3:15 (0:10-4:48)
• 7 patients received steroids.
– 2 with first dose, 5 after.
– Included all those with subsequently confirmed pneumococcal or
tuberculous disease.

Clinical Case Two

Another referral from A&E...
• 67 year old man
• 5 day history of fever, headache
• 24 hours decreased consciousness
• Has now become ataxic.
• History of CLL, splenomegaly
• Temp 39, GCS 8/15, BP 170/100 P120

Gram Stain

Listeria monocytogenes
• Gram positive bacillus.
• Food-borne followed by bacteraemia.
• May be isolated from stool of 5% healthy
persons at any time.
• Usually seen on Gram film +/- grown in cultures
of CNS or blood.
• More frequent cause of disease in the elderly or
immunocomprmised.
• Intrinsic resistance to cephalosporins.

Clinical Case Three

Patient referred to MAU by GP
• 18 year old first year university student
• 12 hour history of severe headache and
fever
• Temp 38.5, BP 100/60 P110
• Photophobia, neck stiffness, GCS 15/15
• No papilloedema or focal neurology
• Petechial non-blanching rash
…What do you do next?

What do you do next?
1. Proceed immediately to lumbar puncture
2. Take blood cultures and then give empirical
cefotaxime 2g IV
3. Take blood cultures and then give empirical
cefotaxime 2g IV and aciclovir 10mg/kg IV
4. Take blood cultures and then give
dexamethasone 0.15mg/kg and then give
cefotaxime 2g IV
5. Do a CT head, if normal proceed to lumbar
puncture

Meningococcal septicaemia
• Non-blanching petechial/purpuric rash
– Differential: enteroviruses
• Rash is late feature, may be absent
• Severe muscle pain and thirst
• LP not necessary!
• Give antibiotics as soon as possible
after blood cultures/PCR/throat swab
• Resuscitate if signs of shock
• ICU referral

Clinical Case Four

Patient referred by GP
• 56 year old male
• Normally fit and well
• Wife noticed patient increasingly
lethargic over past one week
• Initially complaining of headache, now
intermittently confused
• Temp 38.5, GCS 12/15 (E4 V3 M5)
• No focal neurological signs
...What do you do next?

What do you do next?
1. Proceed immediately to lumbar puncture
2. Give empirical dexamethasone 0.15mg/kg
and then cefotaxime 2g IV + amoxicillin 2g
3. Give empirical aciclovir 10mg/kg IV
4. Give cefotaxime 2g IV + amoxicillin 2g +
aciclovir 10mg/kg
5. Arrange an urgent CT head + contrast

CT head normal. Do LP:
• OP 22 cmH 20
• Protein 1.05 g/L
• Glucose 3.8/5.0
• RBC

Encephalitis
• Most commonly caused by HSV in UK
• Commoner in immunocompromised
• Insidious onset (days), can be abrupt
• Fever + headache + lethargy + behavioural
change
• Progression to focal signs, seizure, coma
• CSF – lymphocytosis (usually).
• Characteristic neuroradiological changes
often. EEG may help.
• If suspect, treat: 10mg/kg aciclovir IV tds

Arboviral encephalitides
• Japanese Encephalitis Virus.
• West Nile Virus.
• Toscana virus.
• Tick borne encephalitis.
• Many, many others.
• Louping Ill.

Other things not to forget in the
• Malaria
• Typhoid
•HIV
• Trypanosomiasis
• Typhus
• Rabies
• Discuss with ID.
travelled patient

DON’T FORGET HIV

Questions?