Neuronal and glial inclusions in frontotemporal dementia with or without motor neuron disease are immunopositive for p62.

We examined the immunoreactivity of p62 in five cases of frontotemporal dementia (FTD) with ubiquitin-positive, tau-negative inclusions. Only one case had clinical features suggestive of motor neuron disease (MND). In all cases, ubiquitin-positive neuronal inclusions and neurites in the hippocampal region and cerebral neocortex were immunohistochemically positive for p62. Moreover, in the temporal region of a case of FTD with MND, many oligodendrocytes and some astrocytes were positive for p62. These results suggest that the degenerative process involves p62 in FTD and that the process takes place not only in neurons but also in glial cells.