Define meningitis
Inflammation of the pia and arachnoid mater. Oft caused by organisms infecting the CSF.
Define meningism
A set of symptoms indicative of some kind of meningitis, not necessarily of an infective cause (e.g. chemical meningitis/post-surgical)
Symptoms of infective meningitis
Causes of infective meningitis
Bacterial (notifiable):
Listeria affects extremes of age, immunocompromised (including pregnant women + DM)
Viral more common, bacterial more severe
Define encephalitis
Inflammation of cerebral cortex
Symps of encephalitis
Combined with meningism = meningo-encephalitis
Causes of encephalitis
Usually viral:
Occassionally - toxoplasma gondii from cats
Lab investigations for meningitis/encephalitis
MRI HEAD for Encephalitis (unilateral inflam) - do first to check ICP
CSF obtained via LUMBAR PUNCTURE - ‘gin-clear’, pressure <15cm of H2O (fast - analysed within couple of hours)
- analysed for:
- CONTRAINDICATED in raised ICP due to risk of tentorial herniation/coning
Blood - cultures + PCR for S pneum + N mening
Nose + throat swabs - blood/chocolate agar + PCR for enterovirus
Stool PCR for Enterovirus
CSF lab findings consistent with bacterial infection
Empirical treatment for bacterial meningitis
IV cefotaxime/ceftriaxone (3rd gen cephalosporins)
+ IV DEXAMETHASONE (corticosteroid) adjuvent therapy (ie simultaneously)
If Immunocomp give AMOXICILLIN - covers Listeria
If Px presents to GP with non-blanching, purpuric rash -> give IM BENZYLPENICILLIN + immediate hospital referral
Antibiotic therapy for Listeria monocytogenes CSF infection
IV AMOXICILLIN - HIGH DOSE + FREQUENCY
- 2g every 4-6hrs
May add IV GENTAMICIN as adjunctive Abx
When is a lumbar puncture not required in diagnosing bacterial meningitis
If the patient presents with the carachterisitc haemorrhagic rash + meningism -> strong clinical suspicion of MENINGOCOCCAL SEPTICAEMIA + meningitis
What actions should be taken if a patient is confirmed to have meningococcal meningitis
CSF lab findings consistent with viral meningitis/encephalitis
Treatment for encephalitis
IV ACICLOVIR for HSV or VZV
If enterovirus -> self limiting, no antiviral needed just supportive measures where necessary
Define Transient Ischaemic Attack
Sudden onset neurological Deficit that lasts for less than 24hrs, caused by focal brain, spinal cord or retinal ISCHAEMIA WITHOUT EVIDENCE OF ACUTE INFARCTION
Epidemiology of TIA
Causes of TIA
CAROTID THROMBO-EMBOLI
- thrombosis
- emboli (fat from atheroma or thrombus, typically from heart) - remember AFib = risk factor for stroke!
RFx for TIA
Almost same as IHD/stroke
Also:
Presentation of TIA
Focal neurology - sudden onset; typically lasts 5-15mins, can last up to 24hrs:
Dx of TIA
Clinical - same as stroke
Tx of TIA
Don’t drive till seen by specialist
- If High risk need to be assessed within 24hrs
Classification of ischaemic stroke
TOAST classification (subtypes of ischaemic stroke):
Define iscahemic stroke
Episode of NEUROLOGICAL DYSFUNCTION caused by FOCAL cerebral, spinal or retinal INFARCTION (lasting more than 24 hrs)