Blood pressure and drug treatment in clinically diagnosed Lewy body dementia and Alzheimer's disease

Pathogenesis and research progress in leukoaraiosis

Leukoaraiosis is a common imaging marker of cerebral small vessel disease. In recent years, with the continuous advances in brain imaging technology, the detection rate of leukoaraiosis is higher and its clinical subtypes are gradually gaining attention. Although leukoaraiosis has long been considered an incidental finding with no therapeutic necessity, there is now growing evidence linking it to, among other things, cognitive impairment and a high risk of death after stroke. Due to different research methods, some of the findings are inconsistent and even contradictory. Therefore, a comprehensive and in-depth study of risk factors for leukoaraiosis is of great clinical significance. In this review, we summarize the literature on leukoaraiosis in recent years with the aim of elucidating the disease in terms of various aspects (including pathogenesis, imaging features, and clinical features, etc.).

Small vessel disease to subcortical dementia: a dynamic model, which interfaces aging, cholinergic dysregulation and the neurovascular unit

BACKGROUND

Small vessels have the pivotal role for the brain's autoregulation. The arteriosclerosis-dependent alteration of the brain perfusion is one of the major determinants in small vessel disease. Endothelium distress can potentiate the flow dysregulation and lead to subcortical vascular dementia (sVAD). sVAD increases morbidity and disability. Epidemiological studies have shown that sVAD shares with cerebrovascular disease most of the common risk factors. The molecular basis of this pathology remains controversial.

PURPOSE

To detect the possible mechanisms between small vessel disease and sVAD, giving a broad vision on the topic, including pathological aspects, clinical and laboratory findings, metabolic process and cholinergic dysfunction.

METHODS

We searched MEDLINE using different search terms ("vascular dementia", "subcortical vascular dementia", "small vessel disease", "cholinergic afferents", etc). Publications were selected from the past 20 years. Searches were extended to Embase, Cochrane Library, and LILIACS databases. All searches were done from January 1, 1998 up to January 31, 2018.

RESULTS

A total of 560 studies showed up, and appropriate studies were included. Associations between traditional vascular risk factors have been isolated. We remarked that SVD and white matter abnormalities are seen frequently with aging and also that vascular and endothelium changes are related with age; the changes can be accelerated by different vascular risk factors. Vascular function changes can be heavily influenced by genetic and epigenetic factors.

CONCLUSION

Small vessel disease and the related dementia are two pathologies that deserve attention for their relevance and impact in clinical practice. Hypertension might be a historical problem for SVD and SVAD, but low pressure might be even more dangerous; CBF regional selective decrease seems to be a critical factor for small vessel disease-related dementia. In those patients, endothelium damage is a super-imposed condition. Several issues are still debatable, and more research is needed.

Blood Pressure Trajectories in the 20 Years Before Death

IMPORTANCE

There is mixed evidence that blood pressure (BP) stabilizes or decreases in later life. It is also unclear whether BP trajectories reflect advancing age, proximity to end of life, or selective survival of persons free from hypertension.

OBJECTIVE

To estimate individual patient BP for each of the 20 years before death and identify potential mechanisms that may explain trajectories.

DESIGN, STUDY, AND PARTICIPANTS

We analyzed population-based Clinical Practice Research Datalink primary care and linked hospitalization electronic medical records from the United Kingdom, using retrospective cohort approaches with generalized linear mixed-effects modeling. Participants were all available individuals with BP measures over 20 years, yielding 46 634 participants dying aged at least 60 years, from 2010 to 2014. We also compared BP slopes from 10 to 3 years before death for 20 207 participants who died, plus 20 207 birth-year and sex-matched participants surviving longer than 9 years.

MAIN OUTCOMES AND MEASURES

Clinically recorded individual patient repeated systolic BP (SBP) and diastolic BP (DBP).

RESULTS

In 46 634 participants (51.7% female; mean [SD] age at death, 82.4 [9.0] years), SBPs and DBPs peaked 18 to 14 years before death and then decreased progressively. Mean changes in SBP from peak values ranged from -8.5 mm Hg (95% CI, -9.4 to -7.7) for those dying aged 60 to 69 years to -22.0 mm Hg (95% CI, -22.6 to -21.4) for those dying at 90 years or older; overall, 64.0% of individuals had SBP changes of greater than -10 mm Hg. Decreases in BP appeared linear from 10 to 3 years before death, with steeper decreases in the last 2 years of life. Decreases in SBP from 10 to 3 years before death were present in individuals not treated with antihypertensive medications, but mean yearly changes were steepest in patients with hypertension (-1.58; 95% CI, -1.56 to -1.60 mm Hg vs -0.70; 95% CI, -0.65 to -0.76 mm Hg), dementia (-1.81; 95% CI, -1.77 to -1.87 mm Hg vs -1.41; 95% CI, -1.38 to -1.43 mm Hg), heart failure (-1.66; 95% CI, -1.62 to -1.69 mm Hg vs -1.37; 95% CI, -1.34 to -1.39 mm Hg), and late-life weight loss.

CONCLUSIONS AND RELEVANCE

Mean SBP and DBP decreased for more than a decade before death in patients dying at 60 years and older. These BP decreases are not simply attributable to age, treatment of hypertension, or better survival without hypertension. Late-life BP decreases may have implications for risk estimation, treatment monitoring, and trial design.

Effects of centrally acting ACE inhibitors on the rate of cognitive decline in dementia

OBJECTIVES

There is growing evidence that antihypertensive agents, particularly centrally acting ACE inhibitors (CACE-Is), which cross the blood-brain barrier, are associated with a reduced rate of cognitive decline. Given this, we compared the rates of cognitive decline in clinic patients with dementia receiving CACE-Is (CACE-I) with those not currently treated with CACE-Is (NoCACE-I), and with those who started CACE-Is, during their first 6 months of treatment (NewCACE-I).

DESIGN

Observational case-control study.

SETTING

2 university hospital memory clinics.

PARTICIPANTS

817 patients diagnosed with Alzheimer's disease, vascular or mixed dementia. Of these, 361 with valid cognitive scores were included for analysis, 85 CACE-I and 276 NoCACE-I.

MEASUREMENTS

Patients were included if the baseline and end-point (standardised at 6 months apart) Standardised Mini-Mental State Examination (SMMSE) or Quick Mild Cognitive Impairment (Qmci) scores were available. Patients with comorbid depression or other dementia subtypes were excluded. The average 6-month rates of change in scores were compared between CACE-I, NoCACE-I and NewCACE-I patients.

RESULTS

When the rate of decline was compared between groups, there was a significant difference in the median, 6-month rate of decline in Qmci scores between CACE-I (1.8 points) and NoCACE-I (2.1 points) patients (p=0.049), with similar, non-significant changes in SMMSE. Median SMMSE scores improved by 1.2 points in the first 6 months of CACE treatment (NewCACE-I), compared to a 0.8 point decline for the CACE-I (p=0.003) group and a 1 point decline for the NoCACE-I (p=0.001) group over the same period. Multivariate analysis, controlling for baseline characteristics, showed significant differences in the rates of decline, in SMMSE, between the three groups, p=0.002.

CONCLUSIONS

Cognitive scores may improve in the first 6 months after CACE-I treatment and use of CACE-Is is associated with a reduced rate of cognitive decline in patients with dementia.