Difference between revisions of "CT before lumbar puncture"

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==LP without CT is likely safe if==
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{{CT before LP}}
# History
 
## Age < 60
 
## Not immunocompromised
 
## No history of CNS disease
 
## No seizure within 1 week of presentation
 
# Physical Exam
 
## No ALOC
 
## No inability to answer two consecutive questions successfully
 
## No inability to follow two consecutive commands successfully
 
## No gaze palsy
 
## No abnormal visual fields
 
## No facial palsy
 
## No arm drift
 
## No leg drift
 
## No abnormal language
 
 
If none of the above, chance of normal ct is 97%; none of the patients herniated
 
 
 
== CT findings that prohibit LP ==
 
#Midline shift
 
##Look for unequal pressures between the 3 cerebral compartments (left/right supretentorial compartments, posterior fossa)
 
##Look for intracerebral masses not causing midline shift
 
#Obstructive [[Hydrocephalus]]
 
##Look for enlargement of ventricles prox to lesions and normal ventricles distal (especially 4th ventricle)
 
#Basilar cisterns compressed
 
##Lateral/3rd ventricles may be small due to diffuse cerebral edema or enlarged due to obstr. hydroceph. +/- shift
 
#Posterior fossa mass
 
##Look for displacement/compression of 4th ventricle
 
  
 
==See Also==
 
==See Also==
 
*[[Lumbar Puncture]]
 
*[[Lumbar Puncture]]
  
==Source==
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==References==
*NEJM 2001; 345; 1727-33
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<references/>
*Emergency Radiology: Case Studies Schwartz
 
  
[[Category:Neuro]]
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[[Category:Neurology]]
 
[[Category:Procedures]]
 
[[Category:Procedures]]
[[Category:Rads]]
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[[Category:Radiology]]

Latest revision as of 16:50, 25 June 2016

LP without CT is likely safe if:[1]

  • History
    • Age < 60
    • Not immunocompromised
    • No history of CNS disease
    • No seizure within 1 week of presentation
  • Physical Exam

If none of the above, chance of normal ct is 97%; none of the patients herniated

CT findings that prohibit LP:[2]

  • Midline shift
    • Unequal pressures between the 3 cerebral compartments (left/right supretentorial compartments, posterior fossa)
    • Intracerebral masses not causing midline shift
  • Obstructive Hydrocephalus
    • Enlargement of ventricles prox to lesions and normal ventricles distal (especially 4th ventricle)
  • Basilar cisterns compressed
    • Lateral/3rd ventricles may be small due to diffuse cerebral edema or enlarged due to obstr. hydroceph. +/- shift
  • Posterior fossa mass
    • Displacement/compression of 4th ventricle

See Also

References

  1. Computed Tomography of the Head before Lumbar Puncture in Adults with Suspected Meningitis. NEJM 2001; 345; 1727-33
  2. Emergency Radiology: Case Studies Schwartz