Studies show thyroid disorders cause cognitive impairment, with proposed mechanisms including Tau hyperphosphorylation, neuronal reduction, DNA hypermethylation, hippocampal shrinkage and neuron death, altered brain bioelectricity, decreased Na-K-ATPase activity, impaired brain metabolism and glucose uptake, altered neural activity, increased Aβ levels, inflammation, oxidative stress, cell death, altered gene expression, changes in synaptic plasticity, and reduced cerebral blood flow [1]. The gene discussed is MAPT; the disease is thyroid gland disorder.