Have your wife done anything for treatment?
Not necessary as we've switched to using the TGV train (!) - it is almost as fast between Perpignan and London, first class isn't much more expensive than a LOCO flight, when baggage and extra charges are taken into account.
Incidently the TGV double-decker train (Reseau) is pressurized and neither of us has experienced any sinus reaction/problems entering tunnels or passing another train at cruise (300k plus per train).