New and increased seizure frequency in HgSS with history of prior stroke. MRI: There is extensive encephalomalacia in the left frontal and parietal lobes. However, there is no evidence of acute infarct. The ventricles and basal cisterns are unchanged in size and configuration, with ex vacuo dilatation of the left lateral ventricle. There is no midline shift or herniation. The orbits, paranasal sinuses, and scalp soft tissues are grossly unremarkable. There is diffuse low T1 and T2 signal in the bone marrow.MRA: There is severe steno-occlusive disease of the left supraclinoid internal carotid artery. The proximal left anterior and middle cerebral arteries appear to be diffusely narrowed as well. There is a paucity of cortical vessels overlying the areas of left cerebral hemisphere encephalomalacia. There also appears to be narrowing of the supraclinoid right internal carotid artery and minimal collateral vessel formation in the region. The vertebral, basilar, and posterior cerebral arteries are intact. There is no evidence of cerebral aneurysms.
1. Chronic left middle cerebral artery territory infarction related to sickle cell disease, without evidence of acute infarction.2. Severe steno-occlusive disease of the left supraclinoid internal carotid artery. The proximal left anterior and middle cerebral arteries, and right supraclinoid internal carotid artery also appear to be narrowed.3. The bone marrow signal alterations are likely related to sickle cell disease