Meningitis

  • CNS infection should be considered in all patients with a headache, neck stiffness, fever, altered sensorium, or diffuse or focal neurological findings.
  • pneumoniae is one of the two leading causes of bacterial meningitis in adults. Mortality from S. pneumoniae is 30%.
  • pay close attention to cranial nerves 2, 3, 4, and 6
  • Altered mental status in a patient with suspected meningitis can be a sign of increased ICP or encephalitis.
  • You’ve got to get the LP! Only true way to assess for meningitis
  • Early initiation of empirical antimicrobial therapy is recommended in cases of suspected acute CNS infection. Antibiotic administration should not be delayed for CSF analysis or performance of neuroimaging studies.
  • Antibiotic chemoprophylaxis should be assured for close contacts of patients with meningitis resulting from N. meningitidis or H. in uenza.
  • Concomitant CNS infection should be strongly considered in any symptomatic patient with another severe systemic infection, such as urinary tract infection or pneumonia.
  • First line treatment for bacterial meningitis is ceftriaxone plus vancomycin.
  • Acyclovir is recommended for patients with suspected meningoencephalitis.
  • Dexamethasone is recommended prior to treatment with antibiotics in adults (controversial)

 

CT before LP?

  • If you think CT will show a cause for the headache, do a CT
  • If a CT is indicated for other reasons (depressed conscious level, focal neurology), do a CT
  • If a GCS 15 patient is to undergo LP for suspected (or to rule out) meningitis, and they have a normal neurological exam (including fundi), and are not elderly or immunosuppressed, there is no need to do a CT first.
  • If you’re seriously worried about meningitis and are intent on getting a CT prior to LP, don’t let the imaging delay antimicrobial therapy.

 

CT for Subarachnoid Hemorrhage

Subarachnoid Haemorrhage

A negative head CT in a neurologically normal patient, with a thunderclap headache presentation, a clear time of onset, and a modern CT scanner performed within 6 hours of onset read by an attending radiologist results in a post test risk of SAH of 1 – 2/1000 patients. A shared decision strategy should be used to balance the risk and benefits of performing a lumbar puncture versus a negative CT within 6 hours being sufficient to rule out SAH.

A Thunderclap Headache

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A thunderclap headache is defined as a very severe headache that reaches its maximum intensity within 1 minute. One of the most common causes is subarachnoid hemorrhage, but what else can cause a it?