 Hello everyone. I'm Dr. Shantin Banerjee. I'm a third year radiology resident of Neelratam-Sarkar Medical College in Hospital Kolkata. Today, I'm going to talk about Moyamoya syndrome, secondary to sickle cell anemia, a case report. Introduction. Sickle cell disease may be complicated by Moyamoya syndrome and intracranial angiopathy, defined by stenoclusion of terminal portion of internal carotid arteries and development of collateral vessels called Moyamoya vessels. Ischemic stroke is the most frequent cerebrovascular consequence of this angiopathy, but haemorrhagic event can also occur. Moyamoya syndrome can even be found in sickle cell trait patients, but has a rare neurological complication, but it is found more in sickle cell disease patients. Conventional angiography can perform to diagnose and evaluate the Moyamoya angiopathy, but brain magnetic resonance angiography or MRA appears as a non-invasive alternate method. Now, we come to the clinical history of our patient, a 20-year-old male patient presented to the Neuromedicine OPD of our hospital with complaints of multiple episodes of GTCS. He was a known case of seizure disorder for the last four years with recent poor compliance with his prescribed antiepileptic medications. There was no associated fever, vomiting, photophobia, neck stiffness or vision problems. There was no significant family history other than hypertension. He had no history of any previous surgical intervention. The laboratory findings were as follows. The hemoglobin was 7.2 gram per dl, hematocrit, 24%. Total ecocide count was 9,200 per cubic millimeter. Britlite count, 2,16,000 per cubic millimeter. Mean corpuscular volume was 105 fL. Ceramel-DH was 478 iU per liter. The peripheral smear showed findings suggestive of sickle cell anemia, and hence hemoglobin electrophoresis was suggested. The hemoglobin electrophoresis showed 92% HBS, 6% HBF and 2% HBA2. Now we come to the imaging findings for patients. The AP and lateral radiograph of the skull shows diffusely thickened calvaria with expanded diploid spaces. The periventricular and deep white matter hyper-intensities are noted on the T2 flare sequences. Multiple flow voids were noted in bilateral thalamine and lentiform nuclei. Thin linear serpentine flow voids were noted in the basal systems. On MR angiographic sequence, multiple thalamostriate and leptomanangeal collaterals are noted. Bilateral distal ICA shows stenosis. The posterior cerebral arteries appear prominent. The MIP MR angiography images shows multiple tortuous Moyamoya-like collaterals between anterior and posterior circulations. Bilateral distal ICA shows stenosis. The imaging picture gives us a diagnosis of Moyamoya disease and the blood picture gives us sickle cell disease. Thus we come to the final diagnosis of Moyamoya syndrome secondary to sickle cell disease in our patient. Now coming to the discussion, Moyamoya syndrome also termed as the Moyamoya pattern or phenomenon is due to numerous conditions that can cause arterial occlusion of the circle of willis with resulting collaterals and appearances reminiscent of Moyamoya disease. The Moyamoya-like vascular collaterals can be seen in the following conditions. The idiopathic Moyamoya disease, vessel wall abnormalities such as atherosclerosis, radiation induced vasculopathy, fibromuscular dysplasia, Marfan syndrome, Ehlers-Danlos syndrome, fecomatosis like neurofibromatosis 1 and tuberosclerosis, connective tissue disorders like SLE and APLA, blood discretions like sickle cell disease, polycythemia rubravera and others such as Trisomy 21 and Graves disease. Sickle cell disease is an autosomal recessive hemoglobin disorder. It's a qualitative hemoglobinopathy resulting from a structural change in the sequence of amino acids on the beta-globin chain of hemoglobin molecule due to a point mutation. It is characterized by hemoglobin polymerization, erythrocyte stiffening and subsequent vaso-occlusion. Children with sickle cell disease present with a wide variety of neurological syndromes including ischemic and hemorrhagic stroke, transient ischemic attacks, soft neurological signs, seizures, headache, coma, visual loss, altered mental status, cognitive difficulties and covert or silent infarction. Sickle cell disease is the most common worldwide cause of childhood stroke. Damage to the endothelium of small vessels with progressive fibrosis, narrowing and eventually occlusion at the end result of SCD vasolopathy. A Moyamoya-like pattern with supra-clinoid ICS stenosis may develop, especially with severe sickle cell disease. The phenomena subsequently referred to as the Moyamoya disease was first described in 1957 by Takiyuchi and Shimizu. The name is Japanese and is descriptive of the angiographic appearance of the collateral vessels being reminiscent of a puff of cigarette smoke and was coined by Suzuki and Takaku in 1969. Moyamoya disease is an idiopathic progressive arteriopathy characterized by stenosis of the distal supra-clinoid ICS and formation of an abnormal vascular network at the base of the brain. Multiple enlarged telangiectatic, lenticulostriate, thalamocorporating, leptomaninjil, doodle and pylartaries develop as compensatory circulation. Moyamoya disease is most prevalent in Japan and Korea where its estimated incidence is 0.35 to 0.54 per 100,000 people. Moyamoya disease has two peak ages of presentation, two-third of all cases occur in children. Between one-fourth and one-third of all cases are seen in adults with a peak age of 50 years. Moyamoya-like collateral vessels, however, can also develop with any slowly progressive arteriopathy which affects the major intracranial arteries. In Moyamoya syndrome, stenoclosive changes in the main cerebral arteries and decrease in cerebral perfusion pressure results in neurovascularization and formation of fine network of collaterals. The collaterals show evidence of stress related to increased flow, including combination of fragmented elastic lamina, thinned media in the vessel wall and the presence of micronurizums. These findings help to explain why some patients present with hemorrhage. The vessels also often collapse due to lumen thrombosis causing ischemic symptoms. Cerebral angiography is a gold standard of diagnosing Moyamoya disease and its progression. When combined with catheter angiography, MR angiography was still found to be robust and when combined with MRI, the sensitivity and specificity were found to be 92% and 100% respectively. MRA being non-invasive and without the use of IV contrast agents, which persons with sickle cell disease are more susceptible have subsequently become a first-line diagnostic tool for diagnosis of Moyamoya. Now we come to the treatment. Drugs such as antiplatelet agents including aspirin are usually given to prevent clots but surgery is usually recommended. The surgical approaches to treatment include direct anestomosis, indirect procedures and combined therapies. In adults, external chided artery to middle cerebral artery anestomosis, that is ECAMC anestomosis can be performed as vessels are larger. One of the surgical options is the superficial temporal artery to middle cerebral artery bypass or the STAMC bypass. Indirect procedures include synangiosis involving placement of a vascularized tissue in the brain cortex in order to promote neo-angiogenesis. This type of procedure uses duramatter such as in edas, muscle tissue such as in edams or cranial periosteum. An alternative is to create multiple burrows to allow formation of local collateral. The indirect re-vascularization techniques are usually preferred in pediatric patients as their vessels are too small to allow for direct anestomosts. While symptoms may seem to improve almost immediately after the indirect edas, edams and multiple burrhole surgeries it will take probably 6 to 12 months before new vessels can develop to give a sufficient blood supply. With the direct STAMC surgery increased blood supply is immediate. Coming to the conclusion of our paper children and young adults with sickle cell disease who develop Moyamoya syndrome are at a significant risk of recurrent strokes, seizures and poor neurologic outcomes. In our setting, screening for Moyamoya is not done regularly in patients diagnosed with sickle cell disease. Indeed, there are no protocols established worldwide for screening for this entity. Therefore, it stands to reason that the prevalence of Moyamoya syndrome in populations of sickle cell patients is not known. It is thus possible that a significant proportion of sickle cell disease patients have Moyamoya syndrome at the time of their first stroke or seizure. This case also serves to remind us of the utility of the combined MRI and MRA in the diagnosis of Moyamoya syndrome. These are the references which I have used in this paper of mine. Thank you.