Feasibility Study of the CT Clock Tool for Estimating Onset Time of Ischaemic Stroke
Our proposed CT Clock Tool method for estimating the time of stroke onset (and thus clarifying individual patient eligibility for effective treatment) is significantly simpler to use in the acute setting than the advanced methods currently available (CT perfusion or MRI).
Interruption of blood supply to the brain from a blocked blood vessel causes ischaemic stroke. This leads to symptoms relating to the areas of brain affected. For example, people with stroke may suddenly have trouble moving their arms, legs or face, they may find it hard to speak or they may lose consciousness. There are treatments available to open up the blocked blood vessel:
- Thrombolysis involves injecting a medicine to break down the blood clot causing the blockage.
- Thrombectomy means pulling the blood clot out through a tiny tube placed within the blood vessel
Both treatments can help restore blood supply to the brain and reverse the symptoms caused by stroke. To offer these treatments we usually need to know when a patient’s stroke began. However, for around 20% of people with stroke the time of onset is unknown. They may wake up with symptoms, be confused or be found collapsed.
So that treatment can be available to more people, we have developed a method to estimate when an ischaemic stroke began, the CT Clock Tool. Our method involves taking measurements from the brain imaging that most patients with stroke routinely get when they arrive at hospital (CT or CAT scanning). In other words, we do not need any extra tests to use the method; we just make better use of what we already have.