Moyamoya syndrome in sickle cell disease Free

Introduction:

Sickle cell crisis is a common cause of admission for patients with sickle cell disease (SCD) but, in rare instances, other conditions such as Moyamoya syndrome can mimic it. Moyamoya syndrome is a rare chronic, progressive cerebrovascular disease, affecting <1 in 100,000 in the US. It is distinguished by stenosis or occlusion of the terminal internal carotid arteries and their proximal branches and development of fragile collateral vessels at the base of the brain. Moyamoya disease, an idiopathic form, is most prevalent in East Asian populations (Japan and Korea), but when associated with congenital or acquired disorders (SCD, neurofibromatosis type I, Down syndrome, prior cranial irradiation, autoimmune disorders, etc.) is referred to as Moyamoya syndrome. The cause is multi-factorial, and a genetic predisposition and secondary insult lead to intimal thickening, internal elastic lamina disruption, and smooth muscle cell proliferation, causing progressive luminal narrowing and fragile collateral development. Incidence in Western countries is rising as associated disease prevalence increases, for example, SCD. Treatment is supportive, and prevention of stroke and other complications is the goal with antiplatelet (aspirin or clopidogrel) medications, treatment of associated conditions, and surgical revascularization as definitive therapy.

In the case we present, clinical acumen separated the two conditions, and early diagnosis of Moyamoya syndrome averted an unnecessary exchange transfusion and potential morbidity.

Case Presentation:

A 30-year-old African American female with a history of sickle cell disease, stroke with residual left leg paresthesia, on Plavix presented to the hospital with sudden-onset left leg pain. Her vitals were stable, with a mildly elevated temperature, and laboratory studies were significant for leukocytosis, anemia, elevated reticulocytes, and mild electrolyte derangements. Imaging of the lower extremities did not show evidence of deep venous thrombosis, and no acute intra-abdominal pathology was seen on CT scan of Abdomen and Pelvis. The radiology report from the brain MRI noted absent flow void in the left internal carotid artery. Based on these findings, the patient was initially thought to have sickle cell crisis and to be in of need exchange transfusion.Hematology was consulted for Sickle Cell crisis, and to see if patient would benefit from exchange transfusion. Of note, The patient was supposed to get exchange transfusion as out patient, instead, she got worse and came to the emergency department. Hematology resident and attending, took a detailed history which clarified that she started with having weakness and twitching in her leg, which led her to have pain in the leg. She was very clear that the pain was not like other pain crises that she had had before. With careful history taking and reviewing of the MRI results, it was concluded that she was not in sickle cell crisis, but was manifesting symptoms of Moyamoya Syndrome. She was referred to Neurology for further w/u, and no exchange transfusion was arranged.

Conclusion:

Prompt diagnosis and neurology referral avoided an unnecessary exchange transfusion and lessened the patient's possible morbidity and unnecessary cost to the healthcare system. This case reinforces the need to consider rare differential diagnoses for presentations that can commonly be seen in conditions such as SCD.