TARDBP and Alzheimer disease: From a pathological standpoint, AD‐TDP pathology was limited to the amygdala in 43%, involved the limbic system (entorhinal and hippocampal regions) in 25%, and extended into extra‐limbic regions (basal ganglia, brainstem, frontal neocortex) in 32% of the TDP‐43(+) cases.