Impact of cerebrovascular pathology on behavioural and neuropsychiatric symptoms in patients with Alzheimer's dementia: findings from a retrospective, naturalistic study.

Aim: Cerebrovascular disease (CVD) has been associated with depression and a host of neuropsychiatric conditions including dementia. This study assessed the relationship between cerebrovascular findings reported on MRI brain scans and neuropsychiatric symptoms (NPS) and behavioural problems in patients with Alzheimer's disease (AD).

Methods: Medical notes were retrospectively reviewed in patients undergoing brain MRI following referral for cognitive impairment to a memory clinic between January 2004 and June 2008. Patients with AD were graded into four categories of CVD severity based on neuroradiology reports and assessed for behavioural and NPS and activities of daily living using Neuropsychiatric Inventory (NPI), Geriatric Depression Scale (GDS) and Bristol Activities of Daily Living (BADL). Frontal lobe symptoms and parkinsonian features were also evaluated.

Results: Of the initial 232 patients who underwent MRI 72% were diagnosed with AD. 89% of AD patients had CVD findings reported on MRI. Moderate-to-severe CVD was present in 47% of patients. None of the AD patients satisfied a diagnosis of vascular dementia. There was no significant relationship observed between level of MRI CVD findings and scores on NPI (p = 0.57), GDS (p = 0.26) and BADL (p = 0.46). The level of CVD severity did not appear to influence frontal lobe and parkinsonian assessments (p = 0.60).

Conclusion: The contribution of CVD to the pathogenesis of various NPS is still debated. Our study, based on patients diagnosed with AD in a memory clinic setting, suggests that there is no relationship between the extent of CVD pathology and neuropsychiatric and behavioural measures in AD patients. Further prospective quantitative studies are needed to assess the role of CVD, if any, in neuropsychiatric and behavioural symptoms in AD. It is possible that the relatively small pathological contribution of CVD to the development of these symptoms is obscured by the effect of the wider neurodegeneration encountered in AD.