Previous studies reported elevated concentrations of MMP-9 and/or a high MMP-9/TIMP-1 ratio in the serum of patients with central nervous diseases, such as intracerebral hemorrhage, traumatic brain injury, multiple sclerosis, and febrile convulsive disorders, including FS and acute encephalitis or encephalopathy [7,9,11,26,27]. Here, MMP9 is linked to Feingold syndrome.