Neurology: Inherited Alzheimer's disease, microhemorrhage in the brain indicates an increased risk of dementia

Cerebral microhemorrhages (CMHs), which are small brain hemorrhages, are common in the elderly, especially those with dementia.
These lesions are usually associated with hypertension, Alzheimer's disease (AD) or cerebral amyloid vascular disease (CAA) related vascular β- amyloid (A [beta]), or as amyloid-associated bleeding abnormalities image (ARIA- Part of H), currently in AD clinical trials, the condition is often improved by improving Aβ.

The presence of CMHs at baseline may predict additional CMHs in the general population and AD in the future.
Therefore, in trials of Aβ alteration therapy, the US FDA recommends monitoring CMHs and excluding participants with 5 or more CMHs.

Because elderly participants usually have mixed pathologies, it is difficult to distinguish or determine which of these three factors is the cause of CMHs, especially in treatment trials.
Evaluating a young cohort, such as individuals with dominant inherited AD (DIAD), who have relatively normal blood pressure and are not receiving treatment, may help describe the natural history of CMHs uniquely associated with AD.
This may provide a better understanding of the impact of CMHs when individuals with DIAD are observed in treatment trials, and potentially help evaluate other AD cohorts.

In this way, Nelly Joseph-Mathurin and others of the University of Washington in the United States explored the inherent clinical risks associated with the presence of cerebral microhemorrhages (CMHs) or cerebral microhemorrhages, and determined hemorrhagic amyloid-related imaging abnormalities (ARIA-H) The characteristics of high-risk individuals of the same time were evaluated longitudinally in families with dominant inherited Alzheimer’s disease (DIAD).

They included mutation carriers (n = 310) and non-carriers (n = 201) for neuroimaging, including gradient echo MRI sequences to detect CMHs, as well as neuropsychological and clinical evaluations.
Cross-sectional and longitudinal analyses assessed the relationship between CMHs and neuroimaging and clinical markers of disease.

They found that 3% of non-carriers and 8% of carriers showed CMHs mainly in the lobe regions.

Carriers with CMHs are older, have higher diastolic blood pressure and Hachinski ischemia scores, and have more clinical, cognitive, and dyskinesias than carriers without CMHs.

APOE ε4 status has nothing to do with the prevalence or incidence of CMHs.
Old and new CMHs predicted faster changes in clinical dementia scores.
Over time, the presence of 2 or more CMHs is associated with a significant risk of the development of additional CMHs (an increase of 8.
95±10.
04 per year).

This study highlights factors related to the development of CMHs in DIAD individuals.
CMHs are part of the underlying disease process of DIAD and are significantly associated with dementia .
This highlights the participants in drug-exposed treatment trials who are at risk of ARIA-H as a complication, and it is challenging to separate the natural incidence of CMHs from drug-related CMHs.

Original Source: neurology.