Hi Liz (@pec2884), to piggyback off of Colleen's comments, The American Speech-Language-Hearing Association (ASHA) may be a resource for locating a speech therapist or finding out more about swallowing problems. Likewise, maybe The Multiple System Atrophy Coalition might be able to point you in the direction of more information as well?
http://www.asha.org/public/speech/swallowing/Swallowing-Disorders-in-Adults/
https://www.multiplesystematrophy.org/