Why do frontal lobe symptoms predominate in vascular dementia with lacunes?

We studied 30 necropsy cases of vascular dementia with a lacunar state. Manifestations included dementia, lack of volition, emotional lability, small-stepped gait, dysarthria, urinary incontinence, grasp reflex, pyramidal signs, paraplegia in flexion, and akinetic mutism. Pathologically, there was diffuse incomplete softening of white matter in all cases. Both lacunes and diffuse softening were found predominantly in the frontal lobes. The prominent clinical features were therefore frontal lobe symptoms, with good correlation between the symptoms and the distribution of pathologic lesions.