cSAH is a common imaging finding in patients with traumatic brain injury (TBI). However, the management of cSAH can become challenging in cases without any history of informed trauma, especially when they present with Transient Focal Neurological Episodes (TFNEs). Although Cerebral Amyloid Angiopathy (CAA) related TFNEs has been described in literature, it is not well regarded in the patients with sporadic cSAH finding.

A 67-year-old, right-handed, woman with no significant medical history, presented with recurrent, transient right-sided hemiparesis and hemianesthesia spreading from the right side of face to right upper and lower extremities. Non-contrast CT head showed a left cerebral cSAH. CT angiogram of the head and neck did not show any evidence of aneurysms, vascular malformations or RCVS. UDS came back negative. EEG showed left frontoparietal focal slowing with no epileptiform discharges or seizures. Empiric treatment with levetiracetam was started with partial improvement of symptoms. Furthermore, six vessel angiogram showed a small incidental aneurysm in the left MCA bifurcation, deemed not the cause of the cSAH.  MRI brain without contrast showed several foci of hemosiderin deposition and superficial cortical siderosis, cSAH, and lobar cerebral microbleeds in frontal, temporal, and parietal lobes. She met the Modified Boston criteria for probable CAA and the diagnosis of TFNEs related to CAA with cSAH was made.