The Stroke Helpline get lots of queries from stroke survivors who want to return to driving, but aren't sure of the correct procedure they should follow.
You may find the following link useful in understanding the Standards for drivers who have had a stroke or transient ischaemic attack (TIA) - https://www.gov.uk/government/publications/inf1883-car-or-motorcycle-drivers-who-have-had-a-stroke-or-transient-ischaemic-attack-tia
It looks like they have moved the document. I will update the above link.
You can find the updated publication on this page: https://www.gov.uk/government/publications/inf1883-car-or-motorcycle-drivers-who-have-had-a-stroke-or-transient-ischaemic-attack-tia
When you click the link, you can scroll down, and under documents, click 'INF188/3' to read the document.