adductor muscle spasms, leg tingling

My husband is(or was) a fit 51 yr old. He started getting muscle spasms in his adductor muscles after riding his horse. This then progressed to muscle spasms after walking up stairs, riding in the car, sitting on a plane or just walking to far
Now he gets numbness in his feet running up to his groin. He has had neg. MRI of pelvis,l-spine and lower extremity.
Has had nerve conduction study, which was neg. Is taking Baclofen and Trihexyphenidyl and when really bad Roboxin. Has had to go to the E.D for IV valium to relieve spasms. Meds make little difference . All blood work is normal. Went to local clinic and to U of Rochchester. They are calling it Dystonia. Thanks a lot, we already know he has muscle spasms of unknown origin !! Now has numbness in feet that comes and goes, sometimes spreading up to groin (use to only include ankles) Any information on where to go would be wonderful.