GAD1 and Autoimmunity: The underlying pathophysiology of hyperglycemic HC/HB is not completely understood, although many theories have been proposed including metabolism of gamma-aminobutyric acid (GABA) as an alternate energy source, ischemic injury, deposition of metalloproteins, hemorrhagic injury, derangements in dopamine or estrogen function, autoimmune, anti-glutamic acid decarboxylase (anti-GAD)-mediated autoimmunity or neurodegeneration of myelinated axons [40].