1. Meningitis Acute bacterial meninigitis Definition Aetiology
Meningitis is a clinical syndrome characterized ________ of the meninges, the three layers of membranes that enclose the brain and spinal cord. Can be ______ or ______.
Meningitis is primarily involving the meninges
Encephalitis is primarily involving the__________
The layers which enclose the brain and spinal cord are as following:
_________ - A tough outer membrane
_________ – A lacy, web like middle membrane
_________ – A delicate, fibrous inner layer that contains many of the blood vessels that feed the brain and spinal cord.
Aetiology
Types of meningitis
Bacterial
Viral
Fungal
Parasites
Drugs
Bacterial, fungal and parasitic infections can cause chronic meningitis. The most common cause of a chronic bacterial infection is ___________ ____________ (TB!)
Viral meningitis is more common and is usually more benign than bacterial meningitis
Acute bacterial meninigitis
Meningococcal meningitis
Most common type of bacterial meningitis in children and young adults
Caused by _________ _________
Often found in nasopharynx of otherwise healthy individuals.
Thought that recent viral infections disrupt the epithelial surface and facilitate invasion by ________ __________.
Causes the typical non-blanching rash.
Pneumoncoccal meningitis
Most common type of bacterial meningitis
Caused by __________________.
Present in 5-10% of healthy adults.
Haemophilus Influenza meningitis
Meningitis is the most serous acute manifestations of systemic infection with H influenza.
In the past was a major cause of meningitis and the type __ strain accounted for the majority of these cases.
However since the introduction of the _________ vaccine in the 1990 the overall incidence of H influenza meningitis has decreased by 35%
_________accounts now for less than 9.4% of the H influenza cases
Pathophysiology
Most cases of meningitis are caused by an infectious agent that has colonized or established a localised infection elsewhere in the host.
The pathogen can then gain access to the CNS by one of the following main pathways
Most commonly, _________-> haematogenous seeding of the CNS
A retrograde _________pathway via olfactory or peripheral nerves
Direct _________spread (eg. Sinusitis, otitis media, trauma etc)
Signs & symptoms
Acute bacterial meningitis presents with a classical triad of
_________
(+ altered mental state)
Other symptoms of meningitis include
Nausea and Vomiting
Photophobia
Sleepiness
Confusion
Irritability
Delirium
Coma
Notably these symptoms will be similar for any cause that will cause inflammation of meninges. For example, _________ _________.
Sepsis
Meningococcal disease is the leading infectious cause of death in early childhood. It can present as bacterial meningitis (meningococcal meningitis) or as septicaemia . However it most commonly presents as both.
The SIRS criteria is useful in diagnosis sepsis, two or more of the following with a source of infection indicates sepsis.
Temperature _________
Heart Rate _________
Respiratory Rate _________
WBC __________________

2. Lumbar puncture Investigations Complications Management
Indications
_________(enceph/mening)
_________
__________________ (sarcoid/MS)
__________________ (GBS/CIDP)
___________________________
__________________
____________________________________
Contraindications:
S+S of ICP without negative imaging
Focal neuro signs without negative imaging
Local infection (skin, bone, pustular acne)
Clotting disorders (INR>1.5 or platelets…)
CONSENT:
‘Lumbar puncture with CSF sampling’
 Aid further diagnosis and management
RISKS =
Pain
Headache
Bleeding
Infection
Failure of procedure
Anesthetic
Damage to surrounding structures (temp/perm)
Elevated protein – very high (ie >2gl)
Guillain-Barre
Spinal block
TB meningitis
Fungal meningitis
Malignant meningitis
Elevated protein – high (>1g/L)
Bacterial meningitis
Viral encephalitis
Cerebral abscess
Neurosyphilis
Subdural haematoma
Low CSF glucose
Mumps meningitis
HSV encephalitis
SAH (sometimes)
Polymorphs
Lymphocytes
Viral encephalitis/meningitis
Partially-treated meningitis
Bechet syndrome, SLE, CNS vasculitis
HIV-assoc
Lymphoma, leukaemia
Lyme disease
Oligoclonal bands MS
Neurosarcoidosis
CNS lymphoma
SLE
Subacute sclerosing panencephalitis (rare, late comp of measles)
Neurosyphillis
Complications
Immediate
Increased intracranial pressure
Coma
Septic shock
Seizures
Delayed
Decreased hearing,
Cranial nerve dysfunction
Multiple seizures
Focal paralysis
Subdural effusions
Waterhouse-friderichsen syndrome
(adrenal gland failure due to bleeding into the adrenal glands.)
Management
ABC!
Treat causative organism
Treat complications.
Acute bacterial meningitis
Initial “blind” treatment must be started immediately (IM benzylpenicillin)
Guide with microbiological diagnosis
If septic use the sepsis 6