**2. Diagnosis of acute ischemic stroke**

## **2.1 Last known normal time (LKNT)**

The ECASS III trial has established that thrombolysis efficacy was significant up to 4.5 hours post stroke [12]. The precise onset of stroke allows a clear decision on whether to provide thrombolysis. However, 1 in 7 strokes are a wake-up stroke, and oftentimes patients and their families were vague about the time onset [13]. A key piece of information in the history of present illnesses is the LKN, which establishes the maximal duration from onset to presentation for those without a precisely known onset.


**Table 1.** *Differential diagnosis to stroke.*
