Hippocampal atrophy, whole brain volume, and white matter lesions in older hypertensive subjects.
ABSTRACT To determine the potential role of whole brain atrophy, hippocampal atrophy, or both, and small vessel disease/white matter lesions as mechanisms underlying the cognitive impairment associated with hypertension.
Using MRI scanning the authors determined hippocampal volumes, whole brain volumes, and location and severity of white matter lesions, using Scheltens scale, in 103 hypertensive (166 +/- 8/88 +/- 7 mm Hg, 54 female) and 51 normotensive (132 +/- 12/74 +/- 7 mm Hg, 21 female) subjects age > or = 70 years.
Compared to normotensive subjects, older hypertensive subjects had significantly smaller whole brain volumes (887 +/- 109 vs 930 +/- 97 cm3, p = 0.02) and nonsignificantly reduced hippocampal volumes (5.39 +/- 1.60 vs 5.67 +/- 1.80 cm3, p = 0.33). Hypertensive subjects had an increased burden of periventricular lesions: bands (p = 0.03), frontal caps (p = 0.08), occipital caps (p = 0.07), and total periventricular hyperintensities (p = 0.02). They also had higher scores in subcortical areas: frontal (p = 0.04), temporal (p = 0.03), and deep white matter areas (p = 0.05). A correlation was found between whole brain volumes and systolic blood pressure (r = -0.19, p = 0.02). No correlation was seen between whole brain volumes and white matter lesion burden.
Moderate hypertension in non-impaired older subjects is associated with smaller whole brain volume and an increased burden of subcortical and periventricular white matter lesions.
- SourceAvailable from: Caterina Rosano[show abstract] [hide abstract]
ABSTRACT: Maintaining brain health promotes successful aging. The main determinants of brain health are the preservation of cognitive function and remaining free from structural and metabolic abnormalities, including loss of neuronal synapses, atrophy, small vessel disease and focal amyloid deposits visible by neuroimaging. Promising studies indicate that these determinants are to some extent modifiable, even among adults seventy years and older. Converging animal and human evidence further suggests that inflammation is a shared mechanism, contributing to both cognitive decline and abnormalities in brain structure and metabolism. Thus, inflammation may provide a target for intervention. Specifically, circulating inflammatory markers have been associated with declines in cognitive function and worsening of brain structural and metabolic characteristics. Additionally, it has been proposed that older brains are characterized by a sensitization to neuroinflammatory responses, even in the absence of overt disease. This increased propensity to central inflammation may contribute to poor brain health and premature brain aging. Still unknown is whether and how peripheral inflammatory factors directly contribute to decline of brain health. Human research is limited by the challenges of directly measuring neuroinflammation in vivo. This review assesses the role that inflammation may play in the brain changes that often accompany aging, focusing on relationships between peripheral inflammatory markers and brain health among well-functioning, community-dwelling adults seventy years and older. We propose that monitoring and maintaining lower levels of systemic and central inflammation among older adults could help preserve brain health and support successful aging. Hence, we also identify plausible ways and novel experimental study designs of maintaining brain health late in age through interventions that target the immune system.Aging and disease. 02/2012; 3(1):16-33.
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ABSTRACT: Late onset Alzheimer’s disease (AD) is the most common cause of progressive cognitive dysfunction and dementia. Despite considerable progress in elucidating the molecular pathology of this disease, we are not yet close to unraveling its etiopathogenesis. The hippocampus is at the epicenter of cognition being associated with learning and memory. A battery of neurotoxic modifiers has been delineated that may unleash deleterious heterogeneous pathologic impacts. Synergistically they target hippocampus causing its neuronal degeneration, gray matter volume atrophy, and progressive cognitive decline. The neurotoxic factors include aging, stress, depression, hypoxia/hypoxemia, hypertension, diabetes, obesity, alcohol abuse, smoking, malnutrition, and polypharmacy—to name a few. Addressing “upstream pathologies” due to these multiple and heterogeneous neurotoxic modifiers vis-a-vis hippocampal dysfunction is of paramount importance. The downstream-generated inflammatory cytokines, mitochondrial dysfunction, oxidative stress, hypoperfusion, excitotoxicity, amyloid beta, and neurofibrillary tangles may then trigger and sustain neurocognitive pathology. The failure of clinical trials in AD is due in part to this complex multifactorial neurotoxic–pathophysiological labyrinth. The key is to employ appropriate preventive and treatment strategies prior to significant hippocampus damage and its dysfunction. Prevention/reversal of the diverse neurotoxic impacts, delineated here, should be an integral part of therapeutic armamentarium, in order to ameliorate hippocampus dysfunction and to enhance memory in aging, mild cognitive impairment, and AD. Throughout, the paper highlights both the challenges presented by the ever present neurotoxic onslaught, and the opportunities to overcome them. Hence, arresting AD pathogenesis is achievable through early intervention. A targeted approach may ameliorate neurocognitive pathology and attenuate memory deterioration.Neurotoxicity Research 07/2013; · 2.87 Impact Factor
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ABSTRACT: High blood pressure (BP) levels may be associated with brain volume reduction and may contribute to brain atrophy in key brain regions involved in cognition and susceptible to neurodegeneration in Alzheimer's disease. The purpose of this work was to systematically review and quantitatively synthesize the association of BP levels with brain volume reduction in humans. An English Medline, Cochrane Library and PsycINFO search was conducted in June 2012 using the Medical Subject Heading terms 'Blood pressure', 'Hypertension', 'Brain mapping' and 'Brain atrophy'. Of the 609 screened abstracts, 28 studies (4.6%) were included in the qualitative analysis. Twenty-six studies (92.9%) showed a significant association of higher BP levels and/or hypertension with total and/or regional brain volume reduction, the frontal and temporal lobes being particularly affected. In addition, four other studies reported an association between lower BP levels and brain volume reduction. Due to the heterogeneity of methodology and outcomes, random-effects meta-analyses of the mean difference of brain volume could be performed on only seven studies, with a total of 709 cases with hypertension and 1001 controls without hypertension. The findings showed no between-group difference regarding the whole-gray matter volume (summary mean difference = 2.42 cm [95% confidence interval (CI): -2.13 to 6.96]). Conversely, cases with hypertension exhibited lower hippocampus volume compared with controls [summary mean difference = -0.10 cm (95% CI: -0.17 to -0.02)]. These findings provide evidence that high BP levels lead to brain volume reduction, specifically in hippocampus, and may be an important factor that contributes to neurodegeneration in Alzheimer's disease.Journal of hypertension 06/2013; · 4.02 Impact Factor