Background and Purpose- The differentiation between cerebral amyloid angiopathy (CAA) and hypertensive small vessel disease in primary intracerebral hemorrhage is mainly based on hemorrhagic neuroimaging markers in the supratentorial regions, and the cause for cerebellar microbleeds remains unknown. Our aim was to investigate whether superficial cerebellar microbleeds are more likely to be related to CAA rather than hypertensive small vessel disease. Methods- Two hundred seventy-five consecutive patients with intracerebral hemorrhage were retrospectively reviewed from a prospectively maintained hospital-based stroke registry. Eighty-five (33.1%) patients had cerebellar microbleeds and were categorized into superficial (gray matter, vermis), deep (white matter, deep nucleus, cerebellar peduncle), or mixed type based on the location of cerebellar hemorrhagic lesions. Amyloid imaging was obtained using 11C-Pittsburgh Compound B-positron emission tomography in a subgroup of patients. The associations between cerebellar microbleed locations and the type of small vessel disease (CAA versus hypertensive small vessel disease) based on distribution of supratentorial hemorrhagic lesions as well as other magnetic resonance imaging and positron emission tomography markers were analyzed. Results- The presence of cerebellar microbleed was independently associated with supratentorial microbleed and lacunar infarcts (both P<0.01). Strictly superficial cerebellar microbleeds were significantly related to CAA-intracerebral hemorrhage, cortical superficial siderosis and high-grade enlarged perivascular space in centrum semiovale (all P<0.05); deep or mixed cerebellar microbleeds were related to hypertension and deep microbleed (all P<0.05). In multivariable models, superficial cerebellar microbleeds were independently associated with CAA-intracerebral hemorrhage (P=0.03). Of 33 patients assessed by amyloid positron emission tomography, cerebral and cerebellar amyloid load (standardized uptake value ratio) was higher in patients with superficial cerebellar microbleeds compared with deep/mixed cerebellar microbleeds (cerebrum standardized uptake value ratio [reference: cerebellum] 1.33±0.24 versus 1.05±0.09, P<0.001; cerebellum standardized uptake value ratio [reference: pons] 0.58±0.08 versus 0.51±0.09, P=0.03). Conclusions- Patients with strictly superficial cerebellar microbleeds are associated with a clinicoradiological diagnosis of CAA as well as increased cerebral and cerebellar amyloid deposition on Pittsburgh Compound B-positron emission tomography, suggesting underlying CAA pathology.

中文翻译：

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浅表小脑微出血和脑淀粉样血管病：磁共振成像/正电子发射断层扫描研究。

背景和目的——原发性脑出血中脑淀粉样血管病 (CAA) 和高血压性小血管病的鉴别主要基于幕上区域的出血性神经影像学标志物，小脑微出血的原因尚不清楚。我们的目的是调查浅表小脑微出血是否更可能与 CAA 有关，而不是与高血压小血管病有关。方法- 对 275 名连续的脑出血患者进行了回顾性分析，这些患者来自前瞻性维护的基于医院的卒中登记。85 名 (33.1%) 患者有小脑微出血，分为浅表（灰质、蚓部）、深部（白质、深核、小脑脚）、或混合型根据小脑出血性病变的位置。在一组患者中使用 11C-匹兹堡化合物 B 正电子发射断层扫描获得淀粉样蛋白成像。基于幕上出血性病变的分布以及其他磁共振成像和正电子发射断层扫描标记，分析了小脑微出血位置与小血管疾病类型（CAA 与高血压小血管疾病）之间的关联。结果——小脑微出血的存在与幕上微出血和腔隙性梗死独立相关（均 P < 0.01）。严格浅表小脑微出血与CAA-脑出血、皮质浅铁质沉积和半卵圆中心高度扩大的血管周围间隙显着相关（均P<0.05）；深部或混合性小脑微出血与高血压和深部微出血有关（均P<0.05）。在多变量模型中，浅表小脑微出血与 CAA 脑出血独立相关 (P=0.03)。在通过淀粉样蛋白正电子发射断层扫描评估的 33 名患者中，浅表小脑微出血患者的大脑和小脑淀粉样蛋白负荷（标准化摄取值比）高于深部/混合性小脑微出血患者（大脑标准化摄取值比 [参考：小脑] 1.33±0.24对比 1.05±0.09，P<0.001；小脑标准化摄取值比率 [参考：脑桥] 0.58±0.08 对比 0.51±0.09，P=0.03）。