A previously well, 19 year old female presents with fever, headache, photophobia and neck stiffness.
a). List three (3) clinical features that would indicate the need for a brain CT scan prior to lumbar puncture in this patient?
b) A lumbar puncture is performed. The initial results reveal:
|
Red blood cells |
356 x 106/L |
(0-5 x 106/L) |
|
Polymorphs |
3180 x 106/L |
(0-5 x 106/L) |
|
Mononuclear cells |
206 x 106/L |
(0.15 – 0.40 g/L) |
|
Glucose |
0.4 mmol/L |
(2.5 – 5.6 mmol/L) |
What are the three (3) most likely causative organisms?
c) After 24 hours of appropriate therapy she develops new onset of generalised tonic-clonic seizures. List three (3) likely intracranial causes.
a). List three (3) clinical features that would indicate the need for a brain CT scan prior to lumbar puncture in this patient?
New onset seizures Immunocompromised state Abnormal level of consciousness
Focal neurological signs (signs suspicious of a space occupying lesion)
History of CNS disease (mass lesion, stroke, focal infection) Papilloedema
b)
Neisseria meningitidis
Streptococcus pneumoniae
Haemophilus influenzae
c) After 24 hours of appropriate therapy she develops new onset of generalised
tonic-clonic seizures. List three (3) likely intracranial causes.
Raised intracranial pressure
Cerebritis
Cerebral abscess
Septic venous thrombosis
The first part of this question closely resembles Question 25.1 from the second paper of 2009. The question is really asking, "what are the features of increased intracranial pressure in the presence of a space-occupying lesion?"
Then, the college tells you that the CSF is essentially pus, with numerous polymorphs and monocytes. Three causes of bacterial meningitis are asked for.
The main culprits are:
Seizures in meningitis are a signs of terrible intracranial processes. Either the brain itself is inflamed (cerebritis), or the patient has developed a cerebral venous sinus thrombus, or there is increased intracranial pressure, or an abscess has formed.
Tunkel, Allan R., et al. "Practice guidelines for the management of bacterial meningitis." Clinical infectious diseases 39.9 (2004): 1267-1284.
Oh's Intensive Care manual: Chapter 54 (pp. 597) Meningitis and encephalomyelitis by Angus M Kennedy