Combined Alzheimer's disease and cerebrovascular staging explains advanced dementia cognition

The absence of a consensus system for full neuropathological evaluation limits clinicopathological studies and comparability between laboratories. Combined staging for Alzheimer's type and cerebral vascular pathology may allow a better classification of cases for clinical and cognitive correlation.

Cognitive and postmortem neuropathological data were obtained from 70 brains donated to the Tissue Bank of the Centro de Investigación de Enfermedades Neurológicas (CIEN) Foundation according to recently developed staging schemes for Alzheimer's type and vascular pathology. Subjects belonged to a cohort of institutionalized patients with moderate or severe dementia and a mean follow-up period of 7 years.

Cases were classified into three groups: Alzheimer's predominant (64.1%), vascular predominant (6.3%) and mixed pathology (29.6%). Significant differences were observed in Severe Mini-Mental State Examination and verbal fluency between the vascular predominant and the other groups of patients.

The combination of scales measuring cerebral vascular and Alzheimer's type pathology allowed a classification of patients that reveals differences between groups in premortem cognitive features.