Better get your dog checked for SM &/or PSOM. Bentley started doing stuff like that and, in fact, had been exhibiting other random symptoms ever since he was very young. Our vet finally agreed with me that he was suspect for SM and had us take him to a university vet school for a MRI. It showed rather minor SM but the PSOM (Glue Ear, as it's sometimes called) is worse. He has been on Gabapentin and sometimes Prednisone since Feb/Mar and gets along fairly well with it. When he's having an "episode" he will act frightened, look around as if he sees something nobody else sees, and go in another room and cower in a corner or under a table.
Sorry if this scares you but on medication he does pretty well and seems happy. I know he sure makes us happy!