What Causes A Sudden Blackout Followed By Difficulty In Standing Or Walking?

I had an event that was stroke like. I passed out for maybe 1 to 5 minutes at most ( Dont remember passing out or what I was doing exactly ) When i came to i was off and didnt have any cordination.I feel as though I was thinking pretty good but i was not able to walk or stand for longer than a second or 2. This lasted for approx. 2 to 2.5 hours and then just went away like nothing happened. I seen a Neurologist and sent me for (MRI on brain ) ( sleep deprivation test ) think it was called and echo ,sleep deprived ? ( I had a dopler test done for arteries in my neck , I had a heart moniter test done where I had to wear it for 24 hours. Had echo , ekg ,blood tests and all my tests come back negative for anything wrong or that would cause that? I have COPD in maybe the moderate to a little worse than moderate stage. Acid reflux, High blood pressure. I take adderall for ADHD and lamotrigine. I was not taking Adderall for a few days when this happened. I also have numbness in my left leg ( Thigh area and along the side of my thigh ) and weakness that seems to be getting worse as time goes on. If I am on my feet for extended time , I get a painful burning sensation in the thigh as well. I was given Gabapentin for that 400MG.I was not taking that when event happened either. I was taking- ( lisinopril 20-12.5 ) ( Lamotrigine 100 mg. 2 times a day ) ( Omeprazole DR20mg once daily ) (Symbicort 80/4.5 , 2 puffs daily ) ( Spiriva handihaler 18MCG CP-handihaler. once daily ) Just a note: In the past 4 years I have had small episodes of getting light headed a bit and on maybe around 6 to 8 of those times , I have passed out and fell down, but came right back around like nothing happened. Usually happened when I was Coughing or a day or 2 after drinking alot. I was a heavy , Problem drinker for many years and dont drink anymore. This passing out thing use to happen maybe once a month ,but in past 2 years it only happened once and then of course , this major one I just had. It might be worth noting, I have not drank in 2 years ,so it seems that the quick passing out episodes for the most part,almost dont happen since I gave up the booze. My Neurologist says not problem with Brain , No prob. With Seizures that he can tell, Neck or the arteries they check in doppler are all ok ??? I am at a loss and am always worried about another falling out and worried it will be the last one. Oh, also, I am 53 years. Well, I really hope you can help me out with this mystery and I can take action to get the problem fixed. Thanks and hope to hear back soon! Randy.