5- Neurology (Emergencies: Meningitis, Encephalitis, Spinal cord compression)) Flashcards
Meningitis background
- Inflammation of the meninges
- Usually due to bacterial (more common) or viral (less serious) infection
cause of meningitis
- Neisseria meningitidis- ‘meningococcus’- gram negative diplococcus bacteria
->11-17 yo - Streptococcus pneumoniae – ‘pneumococcus’
-> All other ages - Group B strep
-> Neonates
typical presentation of meningitis
o Fever
o Neck stiffness
o Vomiting
o Headache
o Photophobia
o Altered consciousness/ seizure
presentation of meningococcal septicaemia
non-blanching rash
presentation of meningitis in babies
Non specific: hypotonia, poor feeding, lethargy, hypothermia and bulging fontanelle
special tests for meningitis
o Kernig’s test
o Brudzinski’s
investigations for meningitis
- Bloods
o Meningococcal ~PCR - Lumbar puncture in all children
o <1month presenting with fever
o 1 to 3 months with fever and are unwell
o under 1yo with unexplained fever and other serious illness
lumbar puncture procedure
L3-L4
(spinal cord ends at L1-2)
samples are send for bacterial culture, viral PCR< cell count, protein and glucose
(blood glucose should be sent at the same time to compare to CSF)
bacterial vs viral CSF findings
meningococcal infections
- Meningococcal septicaemia
- Meingococcal meningitis
Meningococcal septicaemia
refers to the meningococcus bacterial infection in the bloodstream. Meningococcal refers to the bacteria and septicaemia refers to infection in the blood stream. Meningococcal septicaemia is the cause of the classic “non-blanching rash” that everybody worries about. This rash indicates the infection has caused disseminated intravascular coagulopathy (DIC) and subcutaneous haemorrhages.
Meningococcal meningitis
is when the bacteria is infecting the meninges and the cerebrospinal fluid around the brain and spinal cord.
viral meningitis causes
- Herpes simplex virus (HSV)
- Enterovirus
- Varicella zoster virus (VZV).
Management
Viral meningitis
tends to be milder than bacterial and often only requires supportive treatment.
- Aciclovir can be used to treat suspected or confirmed HSV or VZV infection.
management of bacterial meningits in the community
o Urgent stat injection (IM or IV) benzylpenicillin prior to transfer to hospital
management of bacterial meningits in the hospital
- Lumbar puncture prior to antibiotics (unless acutely deteriorating)
- Antibiotics
- Steroids if bacterial -> reduce severity of hearing loss and neurological damage
o Dexamethasone 4x daily for 4 days
antibiotics used in bacterial meningitis
Under 3 months – cefotaxime plus amoxicillin (the amoxicillin is to cover listeria contracted during pregnancy)
Above 3 months – ceftriaxone
o +- vancomycin if risk of penicillin resistant pneumococcal infection e.g. foreign travel or prolonged antibiotic exposure
Post exposure prophylaxis (meningococcal infection)
- Highest risk for people that have had close prolonged contact within 7 days to the onset of the illness
- Risk decreases 7 days after exposure (if no symptoms have developed 7 days after exposure they are unlikely to develop illness)
- Management: single dose of ciprofloxacin – give stat
pathophysiology of cauda equina syndrome
Pathophysiology
- The cauda equina is a collection of nerve roots that travel through the spinal canal after the spinal cord terminates around L2/L3
- Spinal cord tapers down at the end in a section called the conus medullaris
- The nerve roots exit either side of the spinal column at their vertebral level (l3, L4, L5,S1, S2,S3,S4,S5,Co)
- The nerves of the cauda equina supply
classification of cauda equina syndrome
investigations for cauda equina
- PR examination for anal tone
- Emergency Lumbar-sacral spine MRI – gold standard
