The aim of the study was to determine the location and number of CMB in patients with cerebrovascular and neurodegenerative diseases (Alzheimer’s disease and dementia with Lewy bodies) and to study the contribution CMB and accompanying vascular changes of the brain on the cognitive impairment. We observed 48 patients (mean age 73,3 years, 29 (60 %) male) by means MR tomograph and neuropsychological methods. The total number of patients with CMB were 40 % (19 patients). The total number of CMB – 220, of which 161 cortical localization. Of the 23 patients with AD, 10 (44 %) patients had occipital cortical CMB (65 %) and parietal (19 %) localization. Most CMB 202 (92 %) was observed in patients with leukoencephalopathy Fazekas 3 point (high) when they were accompanied by severe atrophy of the hippocampus. Thus, vascular process is universal and additional negative factor inducing different clinical forms of dementia.
Abbreviations
CMB – cerebral microbleeds
MRI – magnetic resonance imaging
CAA – cerebral amyloid angiopathy
AD – Alzheimer’s disease
Introduction. Cerebral microbleeds (CMB) are defined as small round hypointense spots on T2* – weighted gradient-recalled echo (GRE) magnetic resonance imaging (MRI) and are believed to represent hemosiderin deposits that can remain in macrophages for years following a microhemorrhage. CMB can be detected in cerebral microangiopathy of different origins: cerebral amyloid angiopathy and hypertensive arteriopathy.
Cerebral amyloid angiopathy (CAA) – a disease of leptomeningeal and cortical arteries of the brain, characterized by the deposition of amyloid in the vessel walls of small arteries and capillaries (media and adventitia). The amyloid changes the architecture of the vascular wall up to the formation of a «vessel in vessel» and microaneurysms, in addition to the vessel wall is marked fibrinoid necrosis, hyaline degeneration of the vessels with the lumen obliteration. Amyloid deposits are distributed irregularly. The cortical arteries are affected mainly, especially in the occipital lobes. CAA can be an independent disease, but is often combined with Alzheimer’s disease (AD).
Based on various sites CMBs in neurodegenerative and cerebrovascular diseases we can view CMB for differential diagnostic value. Thus, cortical CMB were observed in cerebral amyloid angiopathy and deep CMB were observed in hypertensive microangiopathy.
MRI plays a central role in the diagnosis of CMB. MRI T2-weighted sequences*-gradient echo (GRE) is an opportunity to find the «old» and «fresh» CMB, observed in this mode as gipointensivnyh spots, and can not be seen using other imaging techniques.
The aim of the study was to determine the location and number of CMB in patients with cerebrovascular and neurodegenerative diseases (Alzheimer’s disease and dementia with Lewy bodies) and to study the contribution CMB and accompanying vascular changes of the brain on the cognitive impairment.
Materials and methods. We observed 48 patients (mean age 73,3 years, 29 (60 %) male) with cerebrovascular and neurodegenerative diseases with cognitive impairment on the basis of clinical hospital named S.P. Botkin, Moscow. MRI was performed on a MR tomograph with a magnetic field of 1,5 Tesla «Signa Excite» company GE (USA, 2006), the thickness of the slice gwas 5 mm. To assess the associated changes were used visual Fazekas scale (Fazekas, 1998) and Sheltens (Scheltens). CMB were analyzed with mapping microbleeds anatomical rating scale (MARS) (Gregoire SM, 2009) and rating scale brain microbleeds (BOMBS). Neuropsychological testing included Montreal Cognitive Assessment scale (MoCA), Addenbrooke’s Cognitive Examination (ACE-R), Clock Drawing Test, fluency test, visual memory test (SCT).
Results. The total number of patients with CMB were 40 % (19 patients). The total number of CMB – 220, of which 161 cortical localization. Of the 23 patients with AD, 10 (44 %) patients had occipital cortical CMB (65 %) and parietal (19 %) localization. Patients with cerebrovascular disease had deep (subcortical) CMB only in cases of severe vascular leukoencephalopathy 2-3 points (7 cases, 64 %). Most CMB 202 (92 %) was observed in patients with leukoencephalopathy Fazekas 3 point (high) when they were accompanied by severe atrophy of the hippocampus. Patients with CMB had significantly lower scores of memory (by 2,1 points), attention (2,9), and visual-spatial functions (3,9) of neuropsychological profile than patients without CMB (Fisher’s exact test P < 0,01).
a
b
Example of 72-year-old patient with symptomatic Alzheimer’s disease and cerebrovascular disease with multiple cortical (a) and deep (a, b) CMBs (axial images 1,5 T MRI T2*-weighted images GE)
Conclusions. Based on the obtained results it can be concluded that the vascular process is universal and additional negative factor inducing different clinical forms of dementia. Cognitive decline in patients with cerebrovascular disease and cerebral amyloid angiopathy associated with numerous CMB with 1,5 Tesla MRI, but the multiple CMB is an independent predictor of cognitive decline.
The work was submitted to International Scientific Conference «Fundamental and applied research in medicine», France (Paris), 14-21, October, 2012, came to the editorial office on 30.10.2012.