I have a dog who has seizures - they are much like what you describe. Noise is major trigger for her. In fact, thunderstorms are the worst. I give her Phenobarb once daily and more when there are storms.
Toto was ok with thunderstorms when he shared space with his brother Max . Max died last March , and ever since he goes nutso when we get a thunderstorm or when the local kids set off fireworks .