The proposed project is a multicentre prospective observational clinical research focused on refining multimodal computer tomography (CT) diagnostics in stroke mimics. The main aim is to accurately identify SM in order to minimize the risk of receiving inappropriate treatment and possible development of complications, which can have a negative impact on the patient´s health. The project includes an analysis of pharmacoeconomic parameters. It will examine saved costs in the case of non-administration of unindicated treatment and it will compare the number of adverse events related to the administration of unindicated treatment in patients diagnosed with SM.

The project has been designed as a prospective multicentre observational clinical research with applied outcomes leading to an improved provision of healthcare and healthcare costs. All patients older than 18 years admitted with suspected stroke will be included in the project.

The project will be implemented in 2 hospitals in the Czech Republic, namely the University Hospital in Ostrava and the Hospital in České Budějovice. The analyses will be performed at the University of Ostrava.

The primary objective of the project is to refine hospital diagnostics through the use of multimodal brain imaging (non-contrast CT (NCCT), CT angiography (CTA), and CT perfusion (CTP)) at hospital admission. The expected difference is at least 10% more patients with SM in the group diagnosed by the multimodal CT examination when compared to the group diagnosed with NCCT or NCCT/CTA. The primary objective is to demonstrate the specificity and sensitivity of multimodal brain imaging (NCCT, CTA, and CTP) when compared to the use of NCCT or NCCT/CTA in the acute diagnostics of SM in patients with a sudden focal neurological deficit (minimum 1 point on the National Institutes of Health Stroke Scale - NIHSS) within 24 hours from the onset of symptoms.

In addition to the importance of CTP in the diagnosis of stroke mimics, we will also analyze the significance of other clinical data.

The secondary objective is to compare the economic indicators and costs that will be saved by not providing inadequate treatment to patients with SM.

Inclusion Criteria:

- an acute focal neurological deficit (minimum 1 point on the National Institutes of Health Stroke Scale - NIHSS) within 24 hours from the onset of symptoms

Exclusion Criteria:

• the last period of normality is unknown prior to multimodal CT examination
• the last period of normality is >24 hours prior to multimodal CT examination
• the diagnostic evaluation is incomplete
• a final neurologic diagnosis cannot be determined

All consecutive adult patients >18 years of age with an acute focal neurological deficit (minimum 1 point on the National Institutes of Health Stroke Scale - NIHSS) within 24 hours from the onset of symptoms will be enrolled to the study.

There is no plan to make individual participant data available to other researchers.