As patients with GAD65 encephalitis frequently present with inflammatory CSF, possibly reflecting meningeal inflammation, but without contrast enhancement on MRI, hence, we defined “meningoencephalitis” by the presence of patchy or diffuse contrast enhancement in the leptomeninges, supporting an inflammatory process disrupting the blood–brain barrier in these sites, with or without clinical or neuroimaging findings of brain parenchyma inflammation. The gene discussed is GAD2; the disease is meningoencephalitis.