Non-aneurysmal subarachnoid hemorrhage as presentation of moyamoya disease in an adult.

Background: The presentation of moyamoya disease (MMD) as an aneurysmal subarachnoid hemorrhage (SAH) is relatively frequent and in the absence of aneurysms is extremely rare.

Case Description: A 53-year-old male patient suddenly developed severe headache associated with dysarthria and an altered state of consciousness. At the time of admission, he was found drowsy with global aphasia, stiff neck, right hemiparesis and right Babinski's sign.