Bilateral Numbness - So confused
 

My son was vomiting last Monday, thought typical stomach bug. He had complaints of some dizziness as well. That afternoon he said he lost feeling in his legs, we plucked some hairs he didn't flinch, thought it was strange, but was hoping for the best. Took him to ER Tuesday morning after numbness didn't subside. He explained it as a cold hard feeling, and like his feet were in wet shoes and heavy. He could walk perfectly fine though. Still vomiting until Tuesday night, had an MRI on spine Wednesday, came back normal. By this time feeling is returning to his legs and vomiting has stopped. Doctor's ran all kinds of bloodwork that came back normal, and since he fully recovered we were sent home. No recent vaccinations for over 6 years, no flu shot, no headaches, no blurry vision. Any ideas?! I've heard so many issues going around, but not one can I find has a child completely recovered on their own without any kind of treatment. While I'm thankful he's fine, it still worries me that there's no reason or explanation. Any insight is greatly appreciated. I do have a neuro apt next week to get a second opinion.