Cerebral white matter disorders affecting behavior and cognition are reviewed from the University of Colorado School of Medicine, and Denver VA Medical Center. Diffuse white matter pathology disrupts attentional systems, frontal lobe function, visuospatial skills, and emotional status, while sparing language abilities. White matter behavioral disorders have a greater capacity for recovery than gray matter disorders, possibly related to remyelination. However, a pure white matter disorder is uncommon, and gray matter is frequently implicated. The prototype white matter disease, multiple sclerosis, is frequently complicated by cognitive and emotional dysfunction. Other white matter disorders asociated with dementia include metachromatic leukoencephalopathy, toluene-abuse leukoencephalopathy, AIDS dementia complex, traumatic brain injury, and hydrocephalus. Most white matter disorders are diffuse but some are focal, resulting in aphasia, alexia, agraphia, apraxia, agnosia, or akinetic mutism. The MRI and diffusion-weighted MRI may identify new examples of white matter involvement in behavioral disorders. 
COMMENT. The neurobehavioral disorder characteristic of white matter dementia is defined by deficits in sustained attention, memory retrieval, visuo-spatial skills, frontal lobe function, and emotional status, with preserved language and extrapyramidal function. Deficits in right frontal lobe function are explained by the relatively greater amounts of white matter in the right compared to left hemispheres.