1st I am not a doctor, just someone with MS. Actually this does not sound like MS. Sounds more like diabetes, anemia, or seizures (just a guess). MS does not cause sudden collapsing and lower blood pressure. Waiting for the Nuero may be a wait in vain. Go see your/her GP now.
Jon
I agree with JonM. Please get her to a GP ASAP. This does not sound like MS. Does your fiancee have any history of health problems? I would not wait for the neuro appt. She needs help now.
Of course you can still go to the neuro, but she needs to be seen by a different type of physician too.
Elaine
My friend has this collapsing problem and was tested for everything including eplipepsi. She has pins and needles, problems walking, aching muscles, eye problems and any other problems.
She has low blood pressure and collapse and forms of fits. She has now been diagnosed with FIBROMYALGIA. Honestly. All her MRIs etc were normal. She is now slowly feeling better. They did tilt test and all kinds of things with her. She would freak out her sons, as she would just space out.
Its a thought its quite a complex disease.http://www.nfra.net/LowBlood.htm
http://www.fibromyalgia-symptoms.org/symptoms/eye_sight.html
I hope they find out what is wrong with her soon.
See here quite clearly that lockjaw is a fibromyaligia symptom.
http://www.craniorehab.com/patient/arthritis-fibromyalgia-scleroderma.html
............................Fibromyalgia in the jaw joint can cause trismus, i.e. stiffness, limiting of movement or lockjaw.