According to Miller, “It has been speculated that general anesthesia and surgery may increase the risk for aggravation of MS. At present, there is no general consensus on this matter, and patients should therefore be informed of the potential for aggravated symptoms in the postoperative period” (p 1172), and “There has been no documented association with the type of anesthetic or particular anesthetic agents and exacerbation of disease” (p 1031-21). According to Stoelting’s Co-Existing Disease, the suggested reason that spinals (and not epidurals) have been implicated in exacerbation is that CNS demyelination may render the spinal cord overly sensitive to local anesthetics – epidural anesthestics result in lower concentrations of LA in the white matter.
These patients may be taking Interferon-β (treatment of choice for relapsing-remitting disease), which may lead to influenza-like symptoms, increases in aminotransferase concentrations, leukopenia, or anemia. Glatiramer acetate (mimics myelin basic protein) is generally reserved for patients resistant to IF-β. Mitoxantrone is an immunosuppressant with severe cardiac toxicity. Azathioprine is an immunosuppressant as is methotrexate. Some patients will present on long term corticosteroid therapy.
Volatile agents are the most commonly used anesthetic agents. Note that these patients may be at increased risk for hyperkalemia following SCh, and both increased and decreased sensitivity to non-depolarizing NMBDs have been described.
Multiple Sclerosis: Anesthetic Drugs
- Volatile Agents: most commonly used anesthetic agent
- Local Anesthetics: avoid intrathecally (no reported problems given epidurally)
- Succinylcholine: may lead to hyperkalemia
- Non-Depolarizing NMBDs: both increased and decreased sensitivity have been reported
- Steroids: may need to be continued perioperatively