Anti-GAD positive stiff-person syndrome and cerebellar ataxia: two treatable conditions that clinicians should be aware of Síndrome de pessoa-rígida e ataxia cerebelar com teste anti-GAD positivo: duas condições clínicas tratáveis as quais o médico deve permanecer atento

. In re-cent years, most cases of SPS and its variants have been tested positive for serum antibodies and for glutamic acid decarboxylase 65 kD isoform (anti-GAD). GAD has a selective expres-sion on central nervous system neurons, secreting gamma-aminobutyric acid (GABA), and on Langerhans beta cells of pancreas