Neurological infections Flashcards
What are the hallmark features of meningitis?
Photophobia, neck stiffness and rash
What is Kernig’s sign?
Attempt to flex the leg and extend the knee causes back pain
What is Brudzinki’s sign?
Movement of the neck causes move and raising of legs/ hip
What is encephalitis?
Inflammation of brain tissue •
Fever, headache, impaired GCS/confusion, seizures, focal neurology
• Viruses – HSV-1, VZV, EBV, CMV, WNV, JEV Rabies, HIV, enterovirus, HHV-6, TBE,
Other infections – Toxoplasma, syphilis, listeria, • Autoimmune
What is a brain abcess?
Pus within brain parenchyma • Fever, headache, low GCS, focal neurology, seizures, • Contiguous (Ear/Sinus/tooth) – Strep sp., Staph. aureus, H. influenzae. Bacteroides, Proteus • Haematogenous – Strep sp., Staph aureus • Direct spread (e.g. trauma) – Staph, Strep, Enterobacteriacae
What are the key findings when studying CSF?
Appearance - Bacterial (turbid), viral (clear), TB (clear or cloudy)
Cells - Bacteria >100 polymorphs, viral 5-1000 lymphocytes, TB -5-500 lymphocytes
Protein - bacteria high, viral normal, TB high
Glucose - low 50% of blood bacterial, normal, low 50% TB
What are some contraindications for CSF testing?
ICOBBS
Infection at LP site
Cardiorespiratory compromise
Ongoing seizure
Brain shift on neuroimaging
Bleeding disorder
Seizure
When should you always do a CT before LP?
GCS≤12 – Focal neurology – has – Papilloedema – Seizures
Great food has salt and pepper
What tests can you do for meningitis?
Diagnosis? – Meningitis • Investigations? – Blood cultures – LP – ?CT – Blood PCR/Throat culture/serum storage • Treatment? – IV Ceftriaxone 2g BD – IV Dexamethasone 10mg QDS
What is an appropriate treatment for bacterial meningitis?
How do you treat someone with strep meningitis?
Increasingly confused and agitated – ITU => Intubated • Blood culture positive Strep. pneumoniae • Ceftriaxone 2g bd 10 days • Dex 10mg qds 4 days • Gradual improvement, Extubation and ultimately discharg
How should neisseria meningitis be managed in a PH setting?
Close contacts N. meningitidis are at increased risk of disease (7 days - 4 weeks) post exposure – People who sleep in the same house, partners – HCW heavily exposed to airway secretions – Ciprofloxacin prophylaxis 500mg stat (alt rifampicin) – Vaccination could be used in outbreak
How are brain abcesses treated?
Neurosurgical emergency – discuss all cases • LP is usually contraindicated • CT with contrast or MRI best imaging • Treatment is combination of abx and surgery • Surgery can be aspiration via burr hole or debridment. Less neuro sequalae with former • Abx for 4-8 weeks • Outcome with treatment 10% mortality; coma poor prognostic sign. May have long-term seizures
How do you diagnose HSV encephalitis?
• CSF PCR 90-95% sensitive • CSF can occasionally be normal with negative PCR especially if <48h illness (5-10% cases) • If high suspicion, continue treatment and repeat LP after 24-48h. • MRI with contrast has good sens/spec (~90%) • EEG abnormal in ~80% (also identifies NCS)
