We also compared total protein in CSF from PRES to PML (as highly relevant differential diagnosis) and MS patients (as a classical neuroinflammatory disorder), observing no difference between PRES and PML or MS (median in mg/l (IQR); PRES 419 (362.5), PML 599 (379), p = 0.09, MS 472 (392), p = 0.78). Here, PML is linked to progressive multifocal leukoencephalopathy.