Figure 1.

Diagram integrating immune signaling and metabolic pathways, which together explain the symptomatic similarities between both multiple sclerosis (MS) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Shared pathways are dysfunctions in intracellular signaling pathways, for example, nuclear factor κB (NFκB); immunoinflammatory pathways, for example, T helper (Th) and T regulatory (Treg) cells, cyclo-oxygenase 2 (COX2), and proinflammatory cytokines (PICs); and oxidative and nitrosative stress (O+NS) pathways. These in turn may induce increased damage by O+NS to proteins and lipids, secondary autoimmune responses and mitochondrial defects. There is evidence that these dysfunctions together with brain disorders are associated with the onset of ME/CFS symptoms, which appear in ME/CFS and MS. PEM = post-exertional malaise.