The significant effects of cerebral microbleeds on cognitive dysfunction: An updated meta-analysis
September
The significant effects of cerebral microbleeds on cognitive dysfunction: An updated meta- analysis
Xuanting Li☯ 0 1 2
Junliang Yuan☯ 0 1 2
Lei Yang 0 1 2
Wei Qin 0 1 2
Shuna Yang 0 1 2
Yue Li 0 1 2
Huimin Fan 0 1 2
Wenli Hu 0 1 2
0 Natural Science Foundation of China (81271309, 81301016) and Beijing Municipal Administration of Hospitals' Youth Programme , QML20150303
1 Editor: Stephen D Ginsberg, Nathan S Kline Institute , UNITED STATES
2 Department of Neurology, Beijing Chaoyang Hospital, Capital Medical University , Beijing , China
A meta-analysis of 25 studies with 9343 participants total was conducted. Patients with
CMBs had higher incidence of cognitive impairment (OR:3.5410; 95% confidence interval
[CI] [2.2979, 5.4567], p<0.05) and lower scores of cognitive functions (SMD: -0.2700
[-0.4267, -0.1133], p<0.05 in Mini-Mental State Examination [MMSE] group and -0.4869
[-0.8902, -0.0818], p<0.05 in Montreal Cognitive Assessment [MoCA] group). Our results
also indicated that patients with CMBs had obvious decline in cognitive functions, for
instance, orientation (SMD: -0.9565 [-1.7260, -0.1869], p<0.05), attention and calculation
(SMD: -1.1518 [-1.9553, -0.3484], p<0.05) and delayed recall (SMD: -0.5527 [-1.1043,
-0.0011], p = 0.05).
Conclusions
Our data suggested that CMBs might be an important risk factor for cognitive dysfunction, especially in the domains of orientation, attention and calculation and delayed recall
Accumulated data suggests that cerebral microbleeds (CMBs) play an important role in the decline of cognitive function, but the results remain inconsistent. In the current study, we aimed to investigate the association between CMBs and cognitive function, as well as the various effects of CMBs on different domains of cognition.
We searched through the databases of PubMed, Embase, Cochrane Library, and Science
Direct. After a consistency test, the publication bias was evaluated and a sensitivity analysis
was performed with combined odds ratios (OR) and standardized mean difference (SMD) of
CMBs.
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OPEN ACCESS
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Competing interests: The authors have declared
that no competing interests exist.
Objective
Methods
Results
functions. Prospective cohort studies with further investigations will be needed in larger
samples.
Introduction
According to the World Alzheimer Report (2015), the increasing prevalence of dementia will
be one of the biggest global public health and social care challenges today and in the future. [
1
]
Cerebral small vessel disease (CSVD) is an important clinical and pathological condition
causing 20% of strokes worldwide, and one of the most common causes of vascular cognitive
impairment (VCI) and mixed dementia. [
2
] Cerebral microbleeds (CMBs), detected by T2
weighted gradient-recalled echo (GRE) or susceptibility-weighted imaging (SWI), have been
recognized as an important manifestation and diagnostic marker of CSVD. Although CMBs
have traditionally been considered as a part of clinical silence, a growing body of evidence has
indicated that CMBs play a crucial role in the pathophysiology of VCI.
A population-based Rotterdam Scan Study shows that the incidence of CMBs was approxi
mately 10% and CMBs rarely disappeared. [
3
] Studies from Asia also suggests that the presence
of multiple CMBs, particularly multiple lobar CMBs, was associated with higher global
neuropsychiatric burden on the Mini-Mental State Examination (MMSE) and Montreal Cognitive
Assessment (MoCA). Such associations were more significant with CMBs located in deep
areas and the increasing number of CMBs. [4±6] The Rotterdam Scan Study also suggested
that presence of numerous microbleeds, especially in a strictly lobar location, was associated
with worse performance on neuropsychological tests of information processing speed and
motor speed. [
7
] According to a recent longitudinal study, participants with 3 CMBs had a
substantial decline of global cognitive function, memory, and processing speed. [
8
] Over
CMBs burden has a prognostic significance of cognitive impairment, however, there are also
some controversies need to be clarified. For instance, one study from Netherland showed that
CMBs were not associated with cognitive performances. [9] Another Dutch study also suggested that CMBs may have less featured influence on specific types of dementia such as frontotemporal lobar degeneration, progressive supranuclear palsy, and corticobasal degeneration. [10]
To date, there are two studies that performed meta-analysis to exam the relationship
between CMBs and cognition. In 2013, a systematic review including 7 studies demonstrated
that the presence of CMBs was significantly associated with cognitive impairment. [
11
] One
year later, another meta-analysis also came to the similar conclusion that (...truncated)