Neural antibodies (anti-NMDA-R; anti-AMPA-R, anti-VKCC; LGI1/VGKC, anti-Yo, anti-Ri, anti-Hu, anti-CV2, anti-GABA-A/B, anti-MAG, and anti-Tr), and anti-thyroid antibodies (thyroperoxidase-TPO, thyrotropin-receptor-TRAK, thyroglobulin-TAK) were negative, as were mitochondrial diagnostics, including Sanger Sequencing for m.3243A>G (“MELAS”), m.8344A>G (“MERFF”) mitochondrial DNA point mutations, and of the entire POLG and FXN (Friedreich's ataxia) genes. Here, TPO is linked to Friedreich ataxia.