Hi @Daniela
Welcome but sorry you have had a reason to join us
There’s a lot in the Welcome Post that some of us put together to cover the most commonly useful subject areas and I think there are a number of themes within it that you will find start you on the road to better understanding
At the risk of repeating some of what it says… Every brain injury is unpredictable in its consequences. He could very easily be having neurological symptoms for years to come. Fatigue is the communist one but there are others and a good proportion of which Only evolve some months after the stroke.
After the stroke that hospitalised me - I apparently had many previous ones that were not correctly diagnosed ( no FAST/no CT) - when I got light-headedness while the GP and consultant weren’t sure they eventually blamed it on the blood pressure meds - I think they were just putting a label on something they didn’t really understand so lightheadedness could be disruption to the vestibular system with a neurological or a physiological cause - just because we’ve had a stroke doesn’t mean every change in our health following it is a tributable to it 
But it is the first suspicion forevermore by the medical staff
But you’re right to ask about emergent side effects and overdoing it could trigger fatigue which could manifest with dizziness other things would be extreme tiredness, when I am getting fatigued my speech deteriorates - There are many things that can interact and or temporarily degrade.
I’m not sure why you think another CT scan would be linked to stopping aspirin? Scans spot if there is damage - of which a CT isn’t particularly refined. Aspirin guards against blood clots. Are you suggesting that he might have had silent strokes since his hospital event? It is possible
I assume he’s been on 75 mg a day? This is because of its blood thinning properties. Is he also on clopidogrel? Or maybe warfarin? When I’ve felt a bit funny and been to the consultant they were suggested I take 75 mg for 30 days in addition to my clopidogrel It’s just belt n braces the absence of ability to say anything concrete (my case)
You should be very proud and supportive of him if he’s managed to return to work so quickly & has coped with it ok. That is not the norm 
!!
You might like to do the poll on FAST
Keep sharing asking and importantly celebrating the victories
Caio
Simon