Repercussion of Moyamoya syndrome and sickle cell anemia in a pediatric patient in the interior of Northeastern Brazil: a case report

Abstract

Case Presentation: A 10-year-old female patient with sickle anemia has suffered her first stroke at the age of 5, initially with left lower hemiplegia and aphasia lasting 5 days. Three months after, there was a second event, which resulted in more severe and disabling neurological sequelae. CT angiography was performed, revealing the ischemic insult. Due to the high risk of recurrent cerebrovascular events, the patient underwent a surgical cerebral revascularization procedure, aiming to reduce further ischemic episodes and improve long-term neurological outcomes and quality of life. Despite the surgical intervention, she became bedridden and developed recurrent epileptic seizures, in addition to motor and cognitive sequels. In recent years, she has noticed an increase in muscle spasticity, loss of head support and a more frequent epileptic seizure. Arterial MRI and Angio-MRI showed areas of cortical-subcortical signal alteration with hemorrhagic petechiae and atrophic effect, as well as areas of laminar cortical necrosis. Furthermore, vascular alterations were identified in the basal ganglia regions of both cerebral hemispheres, including occlusion of major arteries-most -notably the internal carotid arteries- and the development of prominent collateral circulation, findings consistent with Moyamoya syndrome. Discussion: Moyamoya Syndrome is a rare, but clinically significant cause of pediatric stroke, particularly when associated with systemic conditions such as sickle cell anemia. The clinical characteristic of this condition is the neoformation of thin, inefficient blood vessels, leading to hypoperfusion, with a high risk of recurrent thromboembolic and intraparenchymal hemorrhagic events. The clinical manifestations are heterogeneous. In pediatric patients, transient ischemic attacks often occur during hyperventilation caused by crying or episodes of fever and dehydration. Cerebral hemorrhagic events are more common in the adult population, as is cognitive dysfunction due to the greater susceptibility of white matter involvement. Sickle cell anemia is the main risk factor for stroke in the pediatric population, through multiple mechanisms, like chronic hemolysis, endothelial dysfunction and increased blood viscosity. Final Comments: This case offers a report on moyamoya syndrome, a rare and complex condition, in a pediatric patient. Sharing it is essential to increase understanding of this condition, its symptoms and prognosis. It will also arouse scientific interest for future research.