Advanced CT for diagnosis of seizure-related stroke mimics

BACKGROUND AND PURPOSE: It is assumed that up to 30 % of clinically diagnosed acute ischaemic strokes (AIS) are actually stroke mimics (SM). Our aim was to evaluate the usefulness of advanced CT including CT angiography (CTA) and CT perfusion (CTP) findings when distinguishing AIS from seizure-related SM.

METHODS: Over a 22-month period data were gathered of patients who presented to our stroke centre with AIS-like symptoms and were examined immediately with an advanced CT, analysed and evaluated by two experienced neuroradiologists who preferred SM rather than AIS. All these patients additionally received electroencephalography and follow-up imaging. CTA was the important feature to exclude vessel occlusion or haemodynamic relevant stenosis. Perfusion patterns were retrospectively analysed qualitatively.

RESULTS: The most common perfusion abnormality was cortical hyperperfusion (22/37 [59.5 %] patients) followed by a hypoperfusion pattern with a cortical-subcortical involvement (15/37 [40.5 %] patients) without evidence of vessel occlusion or stenosis. Seizure-related hyper- and hypoperfusion patterns typically crossed the normal anatomical vascular territories boundaries.

CONCLUSION: Beyond its use in core and penumbra estimation, advanced CT provides important information to emergency physicians in the difficult clinical diagnosis when differentiating between AIS and seizure-related symptoms with an important impact on therapeutic decision-making.

KEY POINTS: • Advanced CT helps to differentiate between ischaemic strokes and stroke mimics. • Seizure-related perfusion patterns are distinct from ischaemia hypoperfusion. • Advanced CT could improve rapid adequate treatment for AIS and seizure events.