Neuropathobiology of multiple sclerosis

Axonal loss contributes to the permanent neurologic disability experienced by patients who have multiple sclerosis (MS). The steady progression of permanent neurologic symptoms occurs once a threshold of axonal loss is reached and the compensatory capacity of the CNS is surpassed. Although the exact mechanisms of axonal damage are unknown, current evidence suggests axonal loss during relapsing-remitting MS is mediated by inflammation, whereas axonal loss during secondary progressive MS may be initiated by compensatory responses to chronic demyelination. To prevent and delay disability, early aggressive treatment with anti-inflammatory drugs in combination with neuroprotective therapies should be provided to patients who have MS.