Developmental Neurosciences Section and Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom; Departments of Child Health, Obstetrics and Gynaecology and Radiology, University Hospital Southampton, United Kingdom; Clinical and Experimental Sciences, University of Southampton, United Kingdom.
1st Department of Pediatrics, "Hippokratio' General Hospital, Aristotle University, Thessaloniki, Greece.
Eur J Paediatr Neurol. 2018 Nov;22(6):989-1005. doi: 10.1016/j.ejpn.2018.08.008. Epub 2018 Sep 11.
Fetal stroke is an important cause of cerebral palsy but is difficult to diagnose unless imaging is undertaken in pregnancies at risk because of known maternal or fetal disorders. Fetal ultrasound or magnetic resonance imaging may show haemorrhage or ischaemic lesions including multicystic encephalomalacia and focal porencephaly. Serial imaging has shown the development of malformations including schizencephaly and polymicrogyra after ischaemic and haemorrhagic stroke. Recognised causes of haemorrhagic fetal stroke include alloimmune and autoimmune thrombocytopaenia, maternal and fetal clotting disorders and trauma but these are relatively rare. It is likely that a significant proportion of periventricular and intraventricular haemorrhages are of venous origin. Recent evidence highlights the importance of arterial endothelial dysfunction, rather than thrombocytopaenia, in the intraparenchymal haemorrhage of alloimmune thrombocytopaenia. In the context of placental anastomoses, monochorionic diamniotic twins are at risk of twin twin transfusion syndrome (TTTS), or partial forms including Twin Oligohydramnios Polyhydramnios Sequence (TOPS), differences in estimated weight (selective Intrauterine growth Retardation; sIUGR), or in fetal haemoglobin (Twin Anaemia Polycythaemia Sequence; TAPS). There is a very wide range of ischaemic and haemorrhagic injury in a focal as well as a global distribution. Acute twin twin transfusion may account for intraventricular haemorrhage in recipients and periventricular leukomalacia in donors but there are additional risk factors for focal embolism and cerebrovascular disease. The recipient has circulatory overload, with effects on systemic and pulmonary circulations which probably lead to systemic and pulmonary hypertension and even right ventricular outflow tract obstruction as well as the polycythaemia which is a risk factor for thrombosis and vasculopathy. The donor is hypovolaemic and has a reticulocytosis in response to the anaemia while maternal hypertension and diabetes may influence stroke risk. Understanding of the mechanisms, including the role of vasculopathy, in well studied conditions such as alloimmune thrombocytopaenia and monochorionic diamniotic twinning may lead to reduction of the burden of antenatally sustained cerebral palsy.
胎儿中风是脑瘫的一个重要原因，但除非在有已知的母亲或胎儿疾病风险的妊娠中进行影像学检查，否则很难诊断。胎儿超声或磁共振成像可能显示出血或缺血性病变，包括多腔脑软化和局灶性脑穿通畸形。连续影像学检查显示，在缺血性和出血性中风后，畸形包括脑裂畸形和多微脑回的发育。已知引起胎儿出血性中风的原因包括同种免疫和自身免疫性血小板减少症、母亲和胎儿凝血障碍以及创伤，但这些情况相对较少见。很可能相当一部分的脑室周围和脑室内出血是静脉来源的。最近的证据强调了动脉内皮功能障碍的重要性，而不是血小板减少症，在同种免疫性血小板减少症的脑实质内出血中。在胎盘吻合的情况下，单绒毛膜双羊膜双胞胎有发生双胎输血综合征（TTTS）或部分形式的风险，包括双胞胎羊水过少过多序列（TOPS）、估计体重差异（选择性宫内生长受限；sIUGR）或胎儿血红蛋白差异（双胎贫血多血症序列；TAPS）。在局灶性和全身性分布中，缺血性和出血性损伤的范围很广。急性双胎输血可能导致接受者的脑室内出血和供者的脑室周围脑白质软化，但还有其他局部栓塞和脑血管疾病的危险因素。接受者循环超负荷，对全身和肺循环有影响，可能导致全身和肺动脉高压，甚至右心室流出道阻塞，以及引起血栓形成和血管病变的高红细胞血症。供者因贫血而出现低血容量和网织红细胞增多，而母亲的高血压和糖尿病可能会影响中风的风险。对机制的理解，包括同种免疫性血小板减少症和单绒毛膜双羊膜双胞胎等研究充分的情况下的血管病变的作用，可能会降低产前持续脑瘫的负担。
