Difference between revisions of "CT before lumbar puncture"

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

Revision as of 22:02, 17 November 2014

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
    • No ALOC
    • Ability to answer two consecutive questions successfully
    • Ability to follow two consecutive commands successfully
    • Normal neurologic 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

Source

  1. *NEJM 2001; 345; 1727-33
  2. Emergency Radiology: Case Studies Schwartz