Increased Arterial Stiffness in Moyamoya Disease Presenting with Hypertension and Stroke: A Novel Finding in a Very Rare Condition in Singapore

We present a rare case of a 42 year old lady who presented initially with hypertensive emergency and episodes of transient ischemic attacks who was later diagnosed to have Moyamoya disease (MMD). She continued to have hypertension after left external carotid-internal carotid bypass. We followed her case for evaluation of hypertension. She was found to have increased arterial stiffness on SphygmoCor. The prevalence of hypertension MMD is high, but most notably associated with renal artery stenosis (RAS). Case studies of hypertension in patients with MMD without RAS are rare. We did a literature search on the histopathology and genes involved in MMD. RNF213 and ACTA2 gene mutations are identified to be related to MMD. Interestingly, ACTA2 gene mutation carriers are seen to have a variety of vascular diseases. We postulate that the genes involved in causing intimal thickening and media attenuation of the intracranial vasculature seen in MMD exerts systemic implications. We think this could possibly present with increased arterial stiffness and hypertension. In summary, we would like to highlight increased arterial stiffness as a cause of hypertension in patients with MMD. We postulate that the underlying histopathological changes affecting Moyamoya vessels might also affect systemic blood vessels presenting as increased arterial stiffness.