[Development of Alzheimer neurofibrillary changes in two autopsy cases of myotonic dystrophy]

Histopathological examination of two autopsy cases of myotonic dystrophy (MyD), a 65-year-old man (case 1) and a 61-year-old woman (case 2), revealed Alzheimer's neurofibrillary tangle (NFT) in the limbic system without concomitant presence of senile plaque as well as cavum septi pellucidi and thalamic inclusion body. The NFT were particularly abundant in the mesolimbic cortex. In addition to these, small traumatic scars were observed in the frontal lobe of case 1, who had clinically shown severe dementia. From these findings, it might be assumed that both premature aging and head trauma played an important role in the pathogenesis of NFT in these patients with MyD. The dementia of case 1 could be correlated well with abundance of NFT in the mesolimbic cortex.