What is the efficacy of epidural or intrathecal injection of steroids to help with MS exacerbations in non-progressive patients? Would this be a better targeted therapy than systemic oral, IV, or IM steroids?
This subject was hotly debated in the 1970s and 1980s with limited data from a few small case-control series (with the control typically consisting of IV or oral systemic steroids). These limited studies did not suggest superiority of intrathecal steroid over systemic administration. Much of the literature argued the point of serious complications of the intrathecal route (aseptic meningitis, calcified pachymeningitis, etc).
While the thought of intrathecal steroid administration is interesting, I would also point out that 1) IV steroid does penetrate the central nervous system with good effect (and arguably with less side effect than intrathecal administration), 2) there is peripheral immune system activation the does occur in MS that then moves into the nervous system (so targeting steroids solely to the CNS space likely is not a robust strategy), and 3) steroids can speed recovery of neurologic deficit but has not shown the ability to actually modify the underlying disease course.
Currently, there appears to be some research groups looking into intrathecal steroid administration for progressive forms of MS (a different topic not asked in your question). At present, there isn't enough data to comment on that topic.
A. Scott Nielsen MD MMSc
Neurologist and MS Specialist at Kaiser Permanente