Numbness/nerves not working following nausea/motion sickness

My 16 yo son is 4 years post diagnosis of GBS. I posted a few times in his first year of recovery but now find myself back in this forum searching for more answers. Chad had a non typical course of Guillain Barre (if there is any such thing as typical with GBS) and an “incomplete” recovery – meaning that he had axonal damage which resulted in significant permanent nerve damage in his lower legs, severe muscle atrophy below his knee and foot drop. To walk “normally” he requires AFO’s. He also has a tremor in his hands which worsens with fine motor movement…BUT he is walking, doing great in school and is an outstanding trap and skeet shooter 🙂 The question I have for others on this forum is if anyone has experienced a loss of nerve function – basically temporary paralysis in their hands and legs following a bout of motion sickness induced nausea? This has happened to Chad at least twice in the past 6 months. First following an evening at our county fair, the last ride of the night caused him to feel nauseous. When he tried to move his legs to get off of the ride he found they would not respond (described basically as “dead fish”) He somehow was able to get to his older sister and she helped him to the car. The next morning it had resolved. Then yesterday he was on a school trip riding the bus and became nauseated again (probably from the movement of the bus) Almost immeadiately his hands cramped into claws and were not able to move and his quads went “numb” with no movement. He had to remain on the bus until the symptoms subsided and it was very difficult to walk when he was able to get off. He has experience the hand cramping/lack of movement at school on several occasions but wasn’t feeling ill at that time. It does seem that these things have all started within the last 6 months. He is not followed by nuerology any longer through our Childrens hospital but we do have an appointment scheduled with a University of Washington neurologist in July to discuss this. Has anyone else had similar symptoms?