Background: Measurement of regional atrophy of the corpus callosum and cortical grey matter may differentiate between primary loss of intracortical projecting neurons and primary fibre degeneration in Alzheimer's disease (AD) and vascular dementia (VD).
Methods: The regional corpus callosum area and cortical grey matter volumes were measured in 30 patients with the clinical diagnosis of probable AD, 20 patients with the clinical diagnosis of probable VD and 24 healthy elderly control subjects using MRI in two centers in Munich and Amsterdam.
Results: Patients with AD showed significantly reduced volumes of cortical grey matter in all cerebral lobes and atrophy of anterior and posterior corpus callosum areas. In VD patients only occipital lobe grey matter volume and anterior corpus callosum area were significantly reduced. In AD patients reduction of cortical grey matter volumes was significantly correlated with regional reductions of corpus callosum areas, but not in VD patients or controls.
Conclusion: These findings support the notion that measurement of the corpus callosum and cortical grey matter atrophy may identify the underlying causes of cortical disconnection in AD and VD and may be helpful to differentiate between both conditions.