Infections of the nervous system Flashcards
What is meningitis?
Inflammation/infection of the meninges
What is encephalitis?
Inflammation/infection of brain substance
What is myelitis?
Inflammation/infection of the spinal cord
What is the classical triad of meningitis presentation?
Fever
Neck stiffness
Altered mental status
What is meningism?
Neck stiffness
Photophobia
Nausea
Vomiting
What is a petechial skin rash?
Petechiae are tiny purple, red, or brown spots on the skin. They usually appear on your arms, legs, stomach, and buttocks
Won’t go pale if you press them; a normal rash would
What are some bacterial causes of meningitis?
Neisseria meningitidis
Streptococcus pneumoniae
Haem influenzae
What are some viral causes of meningitis?
Enteroviruses
How may encephalitis present?
Flu-like prodrome
Progressive headache with associated fever
Progressive cerebral dysfunction including but not limited to confusion and memory disturbance
Seizures
What are the 2 important antibodies associated with auto-immune encephalitis?
Anti-voltage gated potassium channel (Anti-VGKC)
Anti-NMDA receptor
What would be some of the signs of auto-immune encephalitis associated with Anti-VGKC?
Frequent seizures
Amnesia
Altered mental state
What would be some of the signs of auto-immune encephalitis associated with Anti-NMDA receptor?
Flu like prodrome
Prominent psych features
Altered mental state
Seizures
What are some useful investigations for meningitis?
Blood cultures
Lumbar puncture
No need for imaging if LP is feasible
What are some useful investigations for encephalitis?
Blood cultures
CT/MRI
LP
EEG
What may contraindicate a lumbar puncture?
Focal symptoms suggesting a brain mass
Reduced conscious level suggesting raised ICP
How would CSF composition change in bacterial meningitis?
Increased opening pressure
High cell count (neutrophils)
Reduced glucose
High protein
How would CSF composition change in viral meningitis and encephalitis?
Normal/increased opening pressure
High cell count (lymphocytes)
Normal glucose
Slightly increased protein
What is the most common cause of encephalitis in Europe?
Herpes Simplex
How is herpes simplex encephalitis diagnosed ?
PCR
CSF for viral DNA
How is herpes simplex encephalitis treated?
Aciclovir
Through which route are enteroviruses usually spread?
Faecal-oral
What is a common cause of viral encephalitis in other parts of the world? (Significant if patient is well travelled)
Arbovirus encephalitides
How are brain abscesses managed?
Surgical drainage if possible
Penicillin to cover streps
Meronidazole for anaerobes
What is cryptococcal meningitis caused by?
Cryptococcus neoformans
Which bacteria causes Lyme Disease?
Borrelia burgoferi
Which bacteria causes Syphilis?
Treponema pallidum
Which bacteria causes leptospirosis?
Leptospira interrogans
What are some useful tests in Lyme disease?
CSF lymphocytosis
PCR of CSF
MRI
EMG
What is used to treat Lyme disease?
Prolonged antibiotic treatment
IV ceftriaxone
Oral doxycycline
What are some viral causes of poliomyelitis?
Poliovirus types 1,2,3
All enteroviruses
How is Rabies transmitted to humans?
By bite or salivary contamination of an open lesion
Which bacteria causes tetanus?
Clostridium tetani
