A headache may follow intrathecal injection of drugs by 2 different mechanisms.
Mechanisms:
(1) direct effect of the injected drug
(2) chemical meningitis
Features in common:
(1) The headache is diffuse.
(2) The headache is present in the recumbent position.
(3) negative CSF cultures.
Parameter |
Direct Effect |
Chemical Meningitis |
onset after injection |
<= 4 hours |
5 - 72 hours |
duration |
<= 14 days |
|
CSF WBC changes |
usually unchanged |
pleocytosis |
Differential diagnosis:
(1) bacterial meningitis due to injection contamination
(2) cerebrospinal fluid fistula
(3) post-lumbar puncture headache
Specialty: Neurology