Objective: To investigate loss of neurons in the nucleus basalis (NB) of Meynert in patients with subcortical ischemic vascular disease (SIVD) compared with healthy controls, patients with Alzheimer disease (AD), and patients with mixed AD and SIVD.
Design: Autopsied cases drawn from a longitudinal observational study of patients with SIVD, patients with AD, and healthy controls.
Setting: Multi center, university-affiliated, program project neuropathology core.
Patients: Patients with pathologically defined SIVD (n = 16), AD (n = 20), and mixed AD and SIVD (n = 10) and healthy controls matched by age and educational level (n = 17) were studied.
Main outcome measures: The NB neuronal cell counts in each group and their correlation with the extent of magnetic resonance imaging white matter lesions and Clinical Dementia Rating (CDR) scores closest to death.
Results: No significant loss of neurons was found in SIVD patients compared with age-matched controls in contrast to the AD and mixed groups, who had significant neuronal loss. A significant inverse correlation between NB neurons and CDR scores was found in the AD group but not in the SIVD and mixed groups. The NB cell counts were not correlated with either the extent of white matter lesions or cortical gray matter volume in the SIVD or AD groups.
Conclusions: These findings inveigh against primary loss of cholinergic neurons in SIVD patients but do not rule out the possibility of secondary cholinergic deficits due to disruptions of cholinergic projections to cerebral cortex.