Hi White matter Hyper intensities(WMH) of brain indicate either ischaemia or dementia.They usually represent small vessel disease.They are also useful to assess effectiveness of treatment They are associated with frontal hypometabolism and executive dysfunction.WMH have a stronger effects on glucose metabolism in that region and cortical atrophy, Frontal WMH was associated with memory dysfunction in nondemented subjects. They are more likely to occur in bipolar disorder and major depressive disorder. So I hope this answers your query and if you have any further queries ,you can ask us.