Table 1.

Clinical forms of MBS and their differentials [1].

Clinical form of MBS	Predominant symptoms	Clinical differentials and their MRI findings
Acute MBS	Mental confusion, disorientation, neurocognitive deficits, and seizures	(1) Wernicke encephalopathy  Symmetric involvement of medial thalami, mammillary bodies, tectal plate, and periaqueductal grey matter; hypointense on T1WI; hyperintense on T2W and FLAIR images. Few cases with cortical involvement restricted to motor and premotor areas.
Chronic MBS	Chronic dementia	(1) Alzheimer disease  Extreme hippocampal and medial temporal lobe atrophy, severe global atrophy in end-stage disease.   (2) Multi-infarct dementia   (i) Diffuse white matter disease with large confluent lesions (hypointense on T1WI and hyperintense on T2W and FLAIR images) affecting at least 25% of white matter, mainly in the periventricular regions. (ii) Multiple lacunar infarcts in frontal white matter, thalami, and basal ganglia. (iii) Strategic infarcts: involving Parieto-temporo-occipital association areas, angular gyrus (middle cerebral artery territory), paramedian thalamic, and inferior medial temporal lobe (posterior cerebral artery territory).   (3) Frontotemporal lobar degeneration (Pick's) disease:   Pronounced atrophy of frontal and/or temporal lobes.