Meningitis Flashcards
(37 cards)
what are the features of meningism?
headache
stiff neck
photophobia
vomiting
what are the causes of meningism?
meningitis
SAH
infection accompanied by bacteraemia
severe viral infections i.e. influenza can also cause meningitism
what is characteristic of the neck stiffness in meningism?
stiffness on passive flexion (looking down to the feet)
what is neck stiffness with lateral or rotational movements indicate?
local cause in the cervical joints
by what mechanism does molecules pass through the blood brain barrier?
active transport
lipid solubility
what are the 5 steps of the pathogenesis of meningitis?
attachment to mucosal epithelial cells transgression of the mucosal barrier survival in the blood stream entry into CSF production of infection in the meninges with or without brain infection (encephalitis)
what are the bacterial causes of meningitis?
neisseseria meningitidis
streptococcus pneumoniae
e.coli
group B strep
what are the common organisms responsible for meningitis in neonates?
e.coli
group B streptococci
listeria monocytogenes
what are the viral causes of meningitis?
enteroviruses;
- cocksackie A and B
- polio
- echoviruses
- parechoviruses
mumps
HSV
what is aseptic meningitis?
non-infective meningitis
usually caused by tumour cells in the CSF which cause an elevated lymphocyte and protein count
no organism is cultures or detected
what cranial nerves palsies may occur with meningitis?
VI, VII, VIII
what are risk factors for meningitis?
recent skull trauma
alcoholism
diabetes
if the presentation of meningitis is acute and rapidly progressive what is the most likely cause?
meningococcal
what is Kernig’s sign?
with the hip flexed, the patient leg cannot be straightened due to hamstring spasm in meningism
if FBC shows a low white cell count (leucopenia) what does this indicate?
septicaemia or disseminated intravascular coagulation
= poor prognosis
(the infection should cause it to rise)
what is the predominant cell types in bacterial and viral meningitis in the CSF?
bacterial - neutrophils
viral - lymphocytes
what antibiotics are used to treat meningitis?
benzylpenicillin given 4 hourly
or ceftriaxone
what strain of meningococcal meningitis is most common?
groups B and C
ratio 3:2
what strain of meningococcal meningitis is there a vaccine for?
group C
what are the features of fulminant meningococcal septicaemia?
sudden onset of symptoms with rapid deterioration of consciousness, renal failure, disseminated intravascular coagulation, fever and septicaemic shock
what is the mortality rate for fulminant meningococcal septicaemia?
50% die within first 24 hours of illness
what are bad prognostic markers of meningitis?
DIC metabolic acidosis absence of polymorph leukocytosis delay in instigation of therapy extremities of age purpuric lesions shock with absence of signs of meningism hyperpyrexia
what is the most common organism that causes meningitis in adults?
streptococcus pneumoniae
what are predisposing factors for pneumococcal meningitis?
alcoholism splenomegaly head trauma endocarditis sinusitis pneumonia
