CT before lumbar puncture

LP without CT is likely safe if:

1. History
   1. Age < 60
   2. Not immunocompromised
   3. No history of CNS disease
   4. No seizure within 1 week of presentation
2. Physical Exam
   1. No ALOC
   2. No inability to answer two consecutive questions successfully
   3. No inability to follow two consecutive commands successfully
   4. No gaze palsy
   5. No abnormal visual fields
   6. No facial palsy
   7. No arm drift
   8. No leg drift
   9. No abnormal language

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

CT before LP often results in longer average delay to abx

Source

NEJM 2001; 345; 1727-33