Background and purpose: Diagnosis of transient ischemic attack can be difficult because many mimics exist. We report the clinical and neuroimaging features of a distinct hemorrhagic transient ischemic attack mimic.
Methods: Case series.
Results: We describe 4 elderly patients presenting with a cluster of stereotyped somatosensory migraine auras, initially referred for "crescendo transient ischemic attacks". Neuroimaging in each patient revealed an unexpected finding of spontaneous focal subarachnoid hemorrhage conforming to a cortical sulcus in the contralateral hemisphere. We postulate that the episodic aura symptoms corresponded to recurrent cortical spreading depression triggered by the presence of subarachnoid blood, and speculate that such episodes could be a presenting feature of cerebral amyloid angiopathy in the absence of typical cerebral microbleeds or history of cognitive impairment.
Conclusions: Focal subarachnoid hemorrhage can present clinically with transient repetitive migraine auras. Awareness of this entity is important because misdiagnosis as cerebral ischemic events could lead to incorrect treatment. We recommend that elderly patients presenting with a cluster of new unexplained migraine auras should be investigated ideally with MRI to detect focal subarachnoid hemorrhage.