I recently looked into this for my father-in-law, who has had a heart attack. The DVLA and gov.uk sites give some very clear guidance. However, as expected, the situation is a lot less clear with the insurance companies. The ones I checked state that you only have to inform them if you are required to inform the DVLA of the condition. Unfortunately, it can also be considered as "relevant information" and could, therefore, be a problem if there was a claim. My conclusion was that it is best to advise the insurance company, stating that it is not a condition which needs to be notified to DVLA.
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