TREM2 and dementia: Perivascular cell densities of the recently described TREM2 (triggering receptor expressed on myeloid cells‐2) cells with the morphology of monocytes and macrophages rather than classic process‐bearing morphology of microglia [25] were also assessed in the expectation that their contribution might explain aberrations in the gliovascular and inflammatory processes associated with WM disease in dementia.