The role of SPECT and MRI for pre and postoperative evaluation of childhood moyamoya disease: Case report and review of literature

Moyamoya disease is a vascular disease of unknown aetiology characterized by chronic progressive stenosis leading to occlusion of the supraclinoid internal carotid arteries and the proximal anterior and middle cerebral arteries along with abundant collateral vessel formation. Clinically the disease manifests with features of cerebral ischaemia including recurrent TIA's, headache, seizures or motor deficits. Characteristic angiognaphic features on MR angiography and conventional angiography confirm diagnosis. However, as the presence of complete arterial occlusion on angiography does not reliably predict haemodynamic impairment, single photon emission computed tomography (SPECT) is indicated for quantitative assessment of regional cerebral blood flow. SPECT is thus employed to detect regional perfusion instability prior to treatment and to determine the extent of improvement of functional perfusion after treatment. Affected patients with recurrent or progressive cerebral ischemic episodes and haemodynamic deficits SPECT findings require surgical management aimed at improving blood supply to the hypoperfused ischaemic cortical regions. The most commonly suggested revascularization procedure for children is encephaloduroarteriosynangiosis (EDAS). We describe an illustrative case report of 7-year-old boy who presented with sudden-onset of left sided hemiparesis. Findings on CT, MRI and SPECT were consistent with a diagnosis of moyamoya disease with acute cerebral infarction. The boy underwent encephaloduroarteriosynangiosis twice with good outcome. Motor power in his left extremities improved from grade 1 to 3 without cognitive deficit. Postoperative MRI confirmed vascular patency while SPECT showed satisfactory cerebral perfusion consistent with his clinical outcome. We thus conclude that MRI and SPECT are invaluable tools in pre and postoperative evaluation of patients with moyamoya disease.