Sorry to hear about Bryce. One of my shelties was like that when he was 7/8 months old, like you, I rushed him to the Vet when it happened but they cannot find anything wrong after the x-ray and blood test. It happened periodically but unpredictable, so I had my little video camera handy at all time and I managed to video one of the episode. I sent the video to one of my friends that was studied vet at that time, she shared the video with her lecturer and other vets, their conclusion was if my vet found nothing wrong with the muscle and joint, then it is more likely related to the brain. I then talked to my vet to ask for a referral to get his brain scan. Unfortunately it was a bad news, he had a small tumour in his brain that trigger the problem. His episode happened every 3/4 months and sometimes was 6/8 weeks. His first episode was at 7/8 months old. His last one was 18 months ago and he is four now.

Hopefully your neurologist would give you an answer.

Thinking of you and Bryce.

Lian