CT perfusion in the acute setting: a useful tool in the differential diagnosis of aphasic syndromes

Acute-onset aphasia is a common condition in ischemic stroke but it can also occur in other conditions defined as stroke mimics (SM). CT perfusion (CTP) is a radiological tool employed during the "stroke code" but its role in differentiating patients with stroke from those with SM is still under investigation. We aimed to evaluate the role of CTP in the differential diagnosis between stroke-related aphasia and SM-related aphasia in the acute setting.

In this retrospective observational study conducted at Trieste University Hospital, we compared demographic, clinical, and imaging data of patients with stroke-related aphasia and patients with SM-related aphasia, differentiating the two groups according to the presence or absence of an ischemic lesion at the follow-up CT/MRI. Ischemic pattern was defined as regions of perfusion asymmetries following cerebral arteries' supply territories with MTT prolongation, decreased CBV, decreased CBF or summary map showing penumbra/core, while non-ischemic pattern was defined as regions of perfusion asymmetries not classifiable as ischemic pattern as stated above or as the absence of CTP asymmetries.

Out of 140 patients analyzed, 116 (83%) received a final diagnosis of stroke-related aphasia, while 24 were diagnosed with SM-related aphasia (17%). MTT was the most useful CTP map in identifying an ischemic pattern in patients with stroke-related aphasia (detection rate 95.69%).

CTP is an appropriate radiological tool for making an accurate etiological diagnosis in the context of aphasic syndromes. MTT map was found to be the most accurate in identifying an ischemic pattern.