ENO2 and myalgic encephalomeyelitis/chronic fatigue syndrome: NSE neuron-specific enolase, VEGF vascular endothelial growth factor, S-100B S-100 calcium binding protein B, CRP C-reactive protein, GFAP glial fibrillary acidic protein, VEN viral encephalitis, PGE primary generalized epilepsy, CFS complex febrile seizures