Be open, I have an OML on my Class 1 from a 'severe' head injury in 2005. I didn't suffer epilepsy or any loss of consciousness but due to a small subdural brain haemorrhage my condition was classed as severe and required an OML. The neuro consultants now estimate my risk of developing PTE (Post Traumatic Epilepsy) to be less <0.3%
pr annum. Unfortunately I need it to be <0.1% to be free of the OML. That will (statistically) come with time...
My OML has been a massive pain in the arse. I have paid thousands in consultant reports and medical imaging. Sometimes I wonder if things would have been different if I had been careful with the truth during my Class 1 medicals. I'm glad I was honest though, you can never take back lies like that and they would haunt you your entire career.