Symptom profiles in patients with Alzheimer’s disease with and without concomitant cerebrovascular disease: an observational study

Abstract

Background: Diagnostic criteria of Alzheimer’s disease (AD) and vascular cognitive impairment (VCI) describe different cognitive profiles. AD patients often have concomitant cerebrovascular disease (CVD) and these patients could therefore be expected to display symptoms of both AD and VCI. AD patients with concomitant CVD display symptoms of cognitive impairment with less AD pathology than those without CVD. Medial temporal atrophy (MTA) on magnetic resonance imaging (MRI) is a biomarker of neurodegeneration in AD, and we would expect less MTA in AD patients with CVD. The first aim was to examine whether there were differences in the results of cognitive tests for memory, executive function, and processing speed, or in depressive symptoms, between AD patients with and without CVD. Secondly, to assess whether MTA on MRI is more pronounced among AD patients without CVD. Methods: A total of 192 AD patients with amnestic mild cognitive impairment or mild dementia underwent cognitive assessment and depression screening. Cerebral MRIs were assessed for MTA, white matter hyperintensities, and lacunar and cortical infarcts. CVD was defined as the presence of white matter hyperintensities Fazekas scale ≥2 or any infarct. To study the effect of CVD, several multiple linear regression analyses were carried out using CVD adjusted for age and sex as the independent variable, and cognitive test scores, depression scores, and MTA as dependent variables. Results: Mean age was 72.2 (SD 8.3) years. The number of AD patients with and without concomitant CVD was 121 and 71, respectively. The group with CVD scored significantly lower on tests of attention, executive function and immediate recall compared with the group without CVD. In analyses controlled for age and sex, concomitant CVD was not associated with significant differences in any cognitive test nor in depressive symptoms. A statistically significant association between AD with concomitant CVD and more pronounced MTA was identified. Conclusions: The results indicate that cognitive test profiles, depressive symptoms, and MTA scores cannot be used to distinguish AD patients with and without CVD.