Recurrent convexity subarachnoid hemorrhage mimicking transient ischemic attack in cerebral amyloid angiopathy: A case report

Cerebral amyloid angiopathy is an important cause of spontaneous convexity subarachnoid hemorrhage in elderly patients and may present with transient focal neurological episodes that closely mimic transient ischemic attack. We report a 73-year-old man who presented with recurrent, stereotyped episodes of dysarthria and abnormal sensation in the left hand, initially suspected to represent transient ischemic attack. The symptoms developed during sleep, were presumed to have occurred almost simultaneously, lasted approximately 10 to 15 minutes, and resolved completely. Brain magnetic resonance imaging performed on the day of symptom onset revealed acute convexity subarachnoid hemorrhage in the right cerebral convexity, with cortical superficial siderosis and cerebral microbleeds on susceptibility-weighted imaging. Diffusion-weighted imaging showed no acute ischemic lesion, and magnetic resonance angiography revealed no responsible vascular abnormality. The patient fulfilled the Boston criteria version 2.0 for probable cerebral amyloid angiopathy. His symptoms were attributed to transient cortical dysfunction related to acute convexity subarachnoid hemorrhage rather than cerebral ischemia. Antithrombotic therapy was not initiated because of the hemorrhagic risk associated with cerebral amyloid angiopathy and the absence of a high-risk embolic source. Levetiracetam was administered during hospitalization because focal seizure could not be excluded, but it was discontinued after discharge. During more than 1 year of follow-up, he remained stable without recurrent neurological symptoms or hemorrhagic events. This case highlights the importance of recognizing cerebral amyloid angiopathy-related convexity subarachnoid hemorrhage as a transient ischemic attack mimic.