Here's a good article about LDN if you're not familiar with it:

http://ms.about.com/b/2009/04/20/low...-sclerosis.htm

Excerpt from above article:

In case you have not yet gotten caught up in the talk surrounding LDN, here is the lowdown: Naltrexone is an opiate agonist, and at the usual dosage of 50 to 100 mg, is used to help people stop abusing alcohol or narcotics (opioid drugs). Low dose naltrexone refers to the “off-label” use of naltrexone at a fraction of the usual dose, which is thought to help MS through a possible variety of mechanisms, including increasing sensitivity to endorphins, reducing inflammation and/or reducing production of free radicals. This has the following (reported) results among people with MS:

* stops progression of multiple sclerosis disability,
* prevents relapses, and
* reduces MS symptoms.