Wake-Up Stroke versus Stroke with Known Onset Time: Clinical and Multimodality CT Imaging Characteristics.

Area of Science:

• Neurology
• Radiology
• Emergency Medicine

Background:

• Current acute ischemic stroke treatment guidelines rely on symptom onset time, which is unknown for wake-up stroke (WUS) patients.
• Investigating WUS patient characteristics is crucial for optimizing treatment strategies.
• This study compares clinical and imaging data of WUS patients with those of stroke patients with known onset times.

Purpose of the Study:

• To evaluate clinical and multimodality CT imaging characteristics of wake-up stroke (WUS) patients on admission.
• To compare these characteristics with those of stroke patients with a known onset time.
• To determine the utility of CT imaging in identifying WUS patients eligible for acute stroke treatment.

Main Methods:

• Prospective cohort study including patients with WUS and known stroke onset times.
• Comparison of WUS patients (last seen well > 4.5h and ≤4.5h) with controls (onset time ≤4.5h).
• Analysis of clinical data (NIHSS, age, gender, AF history) and CT imaging (NCCT ASPECTS, CT-perfusion, occlusions, collaterals) using Mann-Whitney U and Fisher's exact tests.

Main Results:

• WUS occurred in 10.7% of patients; no significant differences were found between WUS groups based on time last seen well.
• WUS patients >4.5h had lower NCCT ASPECTS than controls, but 85.2% had ASPECTS >7 and 75% had favorable ASPECTS with good collaterals.
• No significant differences in clinical or imaging characteristics were observed for WUS patients with proximal occlusions (last seen well >6h or ≤6h) compared to controls (onset ≤6h).

Conclusions:

• Clinical and imaging characteristics of WUS patients are largely similar to those with known onset times within treatment windows.
• CT imaging, particularly ASPECTS and collateral assessment, can help identify WUS patients who may benefit from acute stroke interventions.
• This approach can aid in selecting appropriate WUS patients for treatment while excluding those with severe ischemia and poor collateral status.